EDGAR 10-K Filing

Company CIK: 1680367
Filing Year: 2022
Filename: 1680367_10-K_2022_0001680367-22-000005.json

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ITEM 1. BUSINESS
Item 1. Business
Overview
We are an innovative clinical-stage biotechnology company pioneering the development of dual-sided fusion proteins as an entirely new class of biologic medicine. We have created a novel approach to immune modulation by designing biologics with structural characteristics that are not achievable by existing therapeutic modalities, including monoclonal or bispecific antibodies. Compounds derived from our proprietary Agonist Redirected Checkpoint, or ARC, platform simultaneously inhibit checkpoint molecules and activate costimulatory molecules within a single therapeutic.
Our lead product candidate, SL-172154, is designed to simultaneously inhibit the CD47/SIRPα macrophage checkpoint interaction and activate the CD40 costimulatory receptor to induce an antitumor immune response. Coupling CD40 activation with CD47 inhibition differentiates SL-172154 from all other clinical-stage CD47/SIRPα inhibitors in development, and in our published preclinical studies, SL-172154 resulted in superior antitumor immunity as compared to certain CD47/SIRPα inhibitors. We are pursuing a broad clinical development strategy in both hematologic and solid tumors, with multiple ongoing clinical trials. SL-172154 is in an ongoing Phase 1 clinical trial for the treatment of patients with ovarian cancer. In addition to our clinical trials in solid tumors, we are also evaluating SL-172154 in an ongoing Phase 1 clinical trial for the treatment of patients with certain hematologic malignancies, including acute myeloid leukemia, or AML, and higher-risk myelodysplastic syndromes, or HR-MDS. We believe our clinical development plan will provide both first-in-class and best-in-class development opportunities for SL-172154.
Our second product candidate, SL-279252, is designed to simultaneously inhibit the PD-1/PD-L1 interaction and activate the OX40 costimulatory receptor and is in an ongoing Phase 1 clinical trial in patients with advanced solid tumors.
In November 2021, at the 36th annual meeting of the Society for Immunotherapy of Cancer, or the SITC Meeting, we announced initial clinical data from our ongoing Phase 1 clinical trials for SL-172154 in ovarian cancer and for SL-279252 in advanced solid tumors and lymphoma. We believe that these data generated in human cancer patients have demonstrated that the unique protein engineering and physical properties of the ARC platform have led to a differentiated profile in terms of safety and on-target immune activation as compared to monoclonal or bispecific antibodies.
In addition to our clinical-stage ARC product candidates, we possess a deep pipeline of preclinical immuno-oncology candidates. As an example, SL-9258, an ARC in preclinical development, is designed to inhibit the TIGIT/PVR checkpoint interaction while simultaneously activating HVEM and LTβ costimulatory receptors.
Furthermore, our expertise in dual-sided fusion proteins has led to the development of a second novel platform technology. We call this our gamma delta T cell engager, or GADLEN, platform.
We plan to nominate a third clinical product candidate from our preclinical pipeline in 2022. Longer-term, we are pursuing additional disease areas, including autoimmune diseases, where our dual-sided fusion protein platforms may provide advantages over current treatment modalities.
Our Pipeline
Our lead product candidate, SL-172154, is designed to simultaneously inhibit the CD47/SIRPα macrophage checkpoint interaction and activate the CD40 costimulatory receptor to induce an antitumor immune response. Coupling the costimulatory effect of CD40 activation with CD47 inhibition differentiates SL-172154 from other CD47/SIRPα inhibitors in clinical development. In clinical studies, we believe that SL-172154 has further differentiated from other CD47/SIRPα inhibitors both in terms of safety and tolerability, and has demonstrated evidence of potent CD40 activation in human cancer patients.
We are conducting a Phase 1 clinical trial evaluating SL-172154 in patients with platinum-resistant ovarian cancer. In November 2021, at the SITC Meeting, we announced initial data from 15 patients in the first four dose-escalation cohorts from the monotherapy dose-escalation portion of this trial. These data demonstrated that SL-172154 was well tolerated through 3 mg/kg, with no treatment-related grade 3 or greater adverse events. Near-complete target occupancy on leukocytes was observed for both CD47 and CD40 at 3 mg/kg. We also observed pharmacodynamic activity, including dose-dependent margination of CD40 expressing leukocytes from the peripheral blood and dose-dependent increases in cytokines, such as IL-12, that are associated with antitumor immunity. Monotherapy dose escalation is ongoing. We plan to initiate combination clinical trials in parallel due to the observation of monotherapy immunologic activity across the current dose range. We plan to initiate a Phase 1B clinical trial evaluating SL-172154 in combination with liposomal doxorubicin in patients with platinum-resistant ovarian
cancer in 2022. We expect to announce additional data from the ongoing Phase 1A monotherapy dose-escalation trial and initial data from the Phase 1B combination trial in the first half of 2023.
We have conducted a Phase 1 clinical trial in patients with cutaneous squamous cell carcinoma, or CSCC, or head and neck squamous cell carcinoma, or HNSCC, to evaluate the intratumoral administration of SL-172154. We expect to announce data from this trial in the first half of 2022.
In addition to evaluating SL-172154 in solid tumors, we have expanded our evaluation of SL-172154 to include hematologic malignancies. We are conducting a Phase 1A/B clinical trial in patients with AML and HR-MDS, wherein patients will be enrolled into either a monotherapy Phase 1A or combination Phase 1B cohort in a staggered parallel design. In AML, we intend to study SL-172154 in combination with azacitidine and venetoclax. In HR-MDS and TP53 mutant AML, we intend to study SL-172154 in combination with azacitidine. We expect to announce initial data from this Phase 1A/B trial in the first half of 2023.
We also intend to continue to assess other drug combination opportunities for SL-172154 in ovarian cancer and other solid tumors, as well as hematologic malignancies.
Our second product candidate, SL-279252, is designed to simultaneously inhibit the PD-1/PD-L1 interaction and activate the OX40 receptor. We are evaluating SL-279252 in a Phase 1 clinical trial in patients with advanced solid tumors. In November 2021, at the SITC Meeting, we announced initial data from 43 patients from the first ten dose levels of this clinical trial. These data demonstrated initial monotherapy antitumor activity in patients who previously failed checkpoint inhibitors, at doses of 1 mg/kg or greater. Data through 6 mg/kg demonstrated that SL-279252 was well tolerated, and we observed pharmacodynamic activity, including dose-dependent margination of OX40+ lymphocytes from the peripheral blood. We are currently dosing at 12 mg/kg and plan to continue dose escalation to 24 mg/kg. We expect to announce additional data from this clinical trial in the second half of 2022.
We are leveraging our proprietary ARC and GADLEN platforms to discover and develop dual-sided, bi-functional fusion protein product candidates. We own, or have exclusively licensed, the intellectual property rights to our product candidates.
The following table highlights our clinical-stage product candidates:
In addition to our clinical-stage ARC product candidates, we possess a deep pipeline of preclinical immuno-oncology candidates. As an example, SL-9258 is designed to inhibit the interaction between TIGIT and its known ligands, including PVR, PVRL2, PVRL3, and NECTIN-4, while simultaneously activating HVEM and LTβ receptors with two preformed LIGHT trimers. With the addition of HVEM and LTβ receptor activation, we believe this compound is a highly differentiated TIGIT inhibitor. Utilizing a proprietary animal model of PD-1 acquired resistance, SL-9258 demonstrated differentiation from antibody-mediated TIGIT blockade in its ability to overcome checkpoint inhibitor acquired resistance.
The following table highlights the preclinical programs from which we may select our next clinical candidates:
Our ARC Platform
Our proprietary ARC platform has the potential to create therapeutics that can dramatically change the way we treat cancer and other diseases. We developed the ARC platform to address the need for a single therapeutic that consolidates multiple immune functions. Compounds developed from our ARC platform simultaneously block immune checkpoint receptors and activate costimulatory molecules in the tumor necrosis factor, or TNF, superfamily.
The functional domains of ARC compounds are derived from native human proteins, rather than antibody binding domains. This enables the rapid generation of new constructs, given that the starting template for distinct ARC compounds is the human genome. Therefore, an ARC compound can be taken from the conception stage to a manufactured purified protein in approximately six weeks, whereas it can take approximately six months to reach the same stage for an antibody therapeutic candidate. This rapid reduction in discovery processing time, has allowed us to generate more than 400 unique, dual-sided fusion proteins.
Structure of an ARC Compound
Our proprietary ARC platform is designed to overcome the limitations of existing bivalent antibodies. ARC compounds consolidate checkpoint blockade and immune costimulation within a single therapeutic. Additionally, ARC compounds possess a structure that matches the native structure of the target receptors and colocalizes both mechanisms of activity within the immune synapse to promote a coordinated immune response. We designed the ARC platform as a modular scaffold wherein three principal components are fused together, comprising a human Type 1 extracellular domain protein, an optimized, proprietary Fc domain, and a human Type 2 extracellular domain protein. As shown in Figure 1 below, one end of the ARC compound consists of a checkpoint receptor domain and the opposite end consists of a TNF ligand domain, connected by an optimized, proprietary scaffold such as an Fc domain. We designed ARC compounds to self-assemble into a hexameric structure, as shown in Figure 1 below, comprising six distinct checkpoint receptor domains and six distinct TNF ligand domains, which importantly form two trimerized costimulatory ligand domains.
Figure 1-Structural Properties of ARC Compounds
The unique dual-sided structure of our ARC compounds allows us to simultaneously and effectively target a wide array of pathways for the creation of a deep and differentiated product pipeline. We utilize our understanding of disease pathology and immune dysfunction to identify pairings of optimal domains. Initially, our efforts are concentrated on three broad target families: immune checkpoints, TNF superfamily costimulatory receptors, and cytokines.
We believe that the following features represent the key advantages offered by compounds developed with the ARC platform:
•Matching native structure of TNF receptors
•Target specificity, high affinity, and high avidity
•Replacing tumor immune evasion with potent immune stimulation
•Versatility
•Speed from concept to compound to clinic
•Accelerated lead selection process
We believe these collective advantages create the potential for the capital-efficient identification and pursuit of differentiated product candidates.
While many TNF receptor agonist antibodies have been developed and tested in human clinical trials, most have been discontinued prior to pivotal studies due to toxicity. As shown in Panel A of Figure 2 below, activation of TNF receptors, such as CD40, and downstream signaling requires the assembly of three receptor molecules, or trimerization. As shown in Panel B of Figure 2 below, there is a structural mismatch between bivalent antibody therapeutics and trimeric TNF receptors. Traditional bivalent antibodies can only bind to two TNF receptors and are thus unable to individually trimerize a TNF receptor, leading to weak signaling of TNF pathways. For TNF receptor agonist antibodies to trimerize a TNF receptor, multiple antibodies must be cross-linked through Fc receptors located on accessory cells. This mechanism becomes less effective at increasing antibody doses due to saturation of TNF receptors and Fc receptors independently of each other. Consequently, there is no free Fc receptor available to cross-link the TNF receptor bound antibody. This effect manifests in clinical trials as an atypical dose-response relationship, known as a “bell-shaped” dose-response curve, wherein any signs of immune activation initially increase with dose but then subsequently decrease at higher doses. As shown in Panel C of Figure 2, ARCs are designed to self-assemble into two sets of TNF trimers, which induces trimerization of TNF receptor targets and drives a costimulatory signal.
Figure 2-Antibody Therapies Lead to Inefficient TNF Pathway Activation
Versatility of the Platform
The modularity of our dual-sided fusion protein platforms, including our ARC platform, facilitates a vast repertoire of potential dual-sided fusion proteins that can be synthesized and developed. In the human genome, there are more than 1,400 Type 1 membrane proteins, which are characterized by an extracellular amino terminal domain, and more than 450 Type 2 membrane proteins, which are characterized by an extracellular carboxy terminal domain. ARC compounds are assembled from any combination of Type 1 and Type 2 membrane proteins and, therefore, have significant diversity, with more than 630,000 possible combinations. Within this vast set of possible combinations, we have chosen to focus initially on three classes of targets that have already shown significant clinical relevance for the treatment of cancer comprising immune checkpoints, the TNF superfamily, and cytokines. We utilize our understanding of disease pathology and immune dysfunction to identify pairings of optimal targets within a single therapeutic.
Our Strategy
Our goal is to become the world leader in the discovery, development, and commercialization of dual-sided, bi-functional fusion proteins for the treatment of cancer and autoimmune diseases. We plan to achieve this by utilizing our proprietary ARC and GADLEN platforms to create novel therapeutics to treat patients who lack effective treatment options. Key elements of our strategy include:
•Rapidly advancing our clinical-stage ARC product candidates, SL-172154 and SL-279252, through clinical development and marketing approval
•Leveraging our ARC and GADLEN platforms to rapidly advance additional product candidates into clinical development
•Continuing to augment our fusion protein manufacturing capabilities
•Collaborating with leading biopharmaceutical companies
•Building on our culture of R&D excellence and continuing to out-innovate ourselves
•Deepening our intellectual property portfolio to continue to protect our platform technologies and product candidates
Our ARC Product Candidates
SL-172154: A Dual CD47/SIRPα Blocking and CD40-Activating ARC Compound
Clinical Data to Date
In November 2021, at the SITC Meeting, we presented data from the dose-escalation portion of our ongoing Phase 1A trial of SL-172154 as monotherapy in heavily pretreated platinum-resistant ovarian cancer patients. As of a September 15, 2021 data cutoff, we had enrolled a total of 15 patients across four dose levels ranging from 0.1 mg/kg to 3 mg/kg. Dose escalation was conducted according to the Modified Toxicity Probability Interval-2 trial design. Patients received SL-172154 on either a weekly schedule or, after doses on day one, day eight, and day 15, a bi-weekly schedule. The patients treated as of September 15, 2021 were heavily pretreated with a median of five prior lines of systemic therapies.
SL-172154 has been generally well tolerated. Specifically, we did not observe dose-limiting hemolytic anemia, thrombocytopenia or other cytopenias (toxicities which have limited the development of some CD47 inhibitors) through the 3 mg/kg dose level. We believe that SL-172154 may have a differentiated safety profile, which may be due to the lack of an Fc gamma receptor binding Fc domain.
We have observed high levels of target occupancy of SL-172154 on both CD47 and CD40 through 3 mg/kg. As shown in Figure 3, we observed preferential binding of SL-172154 to CD47+ leukocytes compared to red blood cells. Binding to leukocytes approached near-full CD47 target occupancy at doses of 1 mg/kg or greater.
Figure 3-CD47 Targets Occupancy of SL-172154 on White Blood Cells and Red Blood Cells
We have also observed unique pharmacodynamic effects consistent with on-target CD40 activation. Immediately post-infusion of SL-172154, a rapid, dose-dependent margination of CD40+ B cells and monocytes from the circulation was observed, as shown in Panel A and Panel B of Figure 4. We also observed an increase in B cell activation markers CD86 and CD95 following each infusion of SL-172154, as shown in Panel C of Figure 4. Additionally, increases in on-target cytokines such as IL-12, CCL2, CCL3, CCL4 and CCL22 have been observed following each infusion of SL-172154. No evidence of a bell-shaped dose response curve was observed through 3 mg/kg, a dose at which high levels of CD40 target occupancy were observed.
Figure 4-CD40 Activation of SL-172154 with Dose-Dependent Margination and Activation B Cells
In paired biopsies collected from our ongoing clinical trials, we have observed increases in CD68+ macrophages as well as both CD40 and MHC Class II activation markers in the tumor microenvironment, consistent with induction of an innate immune response. Additionally, we have seen an increase in PD-L1 expression by the combined positive score, suggesting that the increase in tumor-infiltrating CD8+ T cells induced a local interferon response. We have also observed increases in Ki67+ CD8 T cells and the Granzyme B+ CD8 T cells. These findings are consistent with the postulated mechanism of action of SL-172154: simultaneous CD47 inhibition and CD40 activation bridging an innate to adaptive immune response.
As of October 7, 2021, 14 of the 15 patients treated with SL-172154 in platinum-resistant ovarian cancer had a post-baseline scan at eight weeks and were evaluable for efficacy. Four patients had stable disease as best response including one patient with stable disease of 16 weeks or greater at 0.3 mg/kg and nine had progressive disease. We are continuing monotherapy dose escalation at the next dose level of 10 mg/kg.
Clinical Development Strategy
We believe that SL-172154 is a highly differentiated CD47 inhibitor with potential for both best-in-class and first-in-class development opportunities. We are conducting Phase 1 clinical trials evaluating the administration of SL-172154 in both solid tumors and hematologic malignancies. As a class, CD47 inhibitors are being developed in combination with other agents that potentiate phagocytosis and initiate an immune response, such as chemotherapy, ADCP-competent antibodies, antibody drug conjugates, and others.
Ovarian Cancer
Ovarian cancer expresses the highest levels of CD47 of any solid tumor and is a tumor type with a significant infiltration of macrophages, which express CD40. We believe this makes ovarian cancer particularly well-suited to the investigation of SL-172154. We are conducting a Phase 1 clinical trial of SL-172154 administered intravenously in patients with advanced ovarian, fallopian tube, and primary peritoneal cancers, collectively referred to as ovarian cancer. Patients that are eligible for this trial have relapsed after standard-of-care therapies and are ineligible for further platinum-based therapies. The primary objective of this trial is to assess the safety and tolerability of SL-172154. The secondary objectives include evaluation of the pharmacokinetic and pharmacodynamic profiles and the antitumor activity of SL-172154.
In the ongoing Phase 1A monotherapy dose-escalation trial, three or more patients will be enrolled through each of the dose levels until a maximum tolerated dose or maximum administered dose is defined. In parallel, we plan to evaluate SL-172154 in a Phase 1B combination dose-escalation and dose-expansion trial in platinum-resistant ovarian cancer in combination with liposomal doxorubicin. Liposomal doxorubicin is a standard-of-care chemotherapy for this patient population. According to the literature and our internally generated data, liposomal doxorubicin upregulates calreticulin, an endogenous “eat me” signal, on the surface of tumor cells. We believe that liposomal doxorubicin is an attractive combination partner due to the observed upregulation of calreticulin, which led to potentiation of SL-172154-mediated ovarian cancer cell phagocytosis in in vitro studies. Furthermore, because the overall response rate of this patient population to liposomal doxorubicin is approximately 10%, there is significant opportunity for improved response rates in combination with SL-172154, wherein we believe the contribution of SL-172154 will be discernible. We are evaluating additional combination opportunities in ovarian cancer.
We expect to announce additional data from the ongoing Phase 1A monotherapy dose-escalation trial and initial data from the Phase 1B combination trial in the first half of 2023.
Cutaneous Squamous Cell Carcinoma and Head and Neck Squamous Cell Carcinoma
We conducted a Phase 1 trial of SL-172154 administered intratumorally in patients with locally advanced or metastatic CSCC and HNSCC not amenable to further treatment with surgery, radiation, or standard systemic therapies. The primary objective of this trial was to assess the safety and tolerability of SL-172154. The secondary objectives included evaluation of the pharmacokinetic and pharmacodynamic profiles and the antitumor activity of SL-172154.
Based on the totality of the safety and biomarker data collected to date in our ongoing Phase 1A clinical trial in ovarian cancer patients, we have decided to focus development of SL-172154 as an intravenously administered product candidate. Thus, as of February 24 2022, we ceased enrollment and are in the process of closing this trial. In addition, we experienced enrollment and operational challenges associated with intratumoral administration trials (which have been exacerbated by the COVID-19 pandemic), further supporting the decision to pursue a registrational strategy via intravenous administration. Overall, SL-172514 was well tolerated in this trial; we did not observe dose-limiting toxicities and did not reach a maximum tolerated dose. We expect to announce data from this trial in the first half of 2022. We may continue further development in HNSCC and/or CSCC in an intravenous administration trial of SL-172154 following selection of a recommended Phase 2 dose in our ovarian cancer trial.
Acute Myeloid Leukemia and Higher-Risk Myelodysplastic Syndrome
We are conducting a Phase 1A/B clinical trial for SL-172154 in patients with AML and HR-MDS. This ongoing Phase 1 clinical trial will evaluate the safety, tolerability, pharmacokinetics, antitumor activity, and pharmacodynamic effects of SL-172154, as both monotherapy and in combination. In AML, we plan to evaluate SL-172154 in combination with both azacitidine and venetoclax. In both HR-MDS and TP53 mutant AML, we plan to evaluate SL-172154 in combination with azacitidine.
We have initiated the monotherapy Phase 1A dose escalation portion of this trial. We plan to conduct the Phase 1B dose escalation portion of this trial of SL-172154 in combination with azacitidine in a parallel staggered manner. Monotherapy dose-escalation and initial dose-escalation combination cohorts are anticipated to be in a heavily pretreated, predominantly refractory patient population. Once a recommended dose and schedule have been determined in combination with azacitidine, we plan to enroll patients in expansion cohorts in combination with azacitidine, with or without venetoclax, depending on the indication. As a class, CD47 inhibitors have demonstrated clinical activity in both AML and HR-MDS. We see an opportunity for
SL-172154 to continue to differentiate from other compounds in the field due to the combined effects of CD47 blockade and CD40 costimulation. Specifically, we believe that our preclinical and initial clinical data from our ongoing Phase 1A clinical trial in ovarian cancer indicate that SL-172154 may differentiate from other CD47/SIRPα inhibitors in one or more of the following ways:
•Improved overall response rate due to CD40-mediated activation of both innate and adaptive immunity
•Improved response durability due to enhanced CD40-mediated activation of adaptive immunity
•Differentiated safety profile due to the absence of dose-limiting anemia or thrombocytopenia
We expect to announce initial combination data from this trial in the first half of 2023.
To date, we have experienced delays in our clinical trials of SL-172154 because of the ongoing COVID-19 pandemic. In particular, we have experienced: delays with certain third-party vendors supporting this trial, including third-party manufacturers; difficulty procuring sufficient quantities of raw materials required for our manufacturing processes; delays as a result of some patients choosing to forego one or more doses in our clinical trials; and staffing shortages at many clinical trial sites. We expect to continue to experience some or all of these delays in the future.
Preclinical Experience
Our lead product candidate, SL-172154, simultaneously inhibits CD47 and activates the CD40 receptor. The pairing of a CD40 agonist domain to a CD47 inhibitory domain was selected based on prior publications which demonstrated that tumor rejection in the setting of CD47 inhibition was dependent upon a T cell mediated adaptive immune response. Agents which only block the interaction between CD47 and SIRPα do not directly activate T cell mediated adaptive immunity, but instead function to enable macrophage mediated phagocytosis of tumor cells. Antigen presenting cells, including macrophages, express CD40. Stimulation of CD40 on antigen presenting cells is known to improve the efficiency of antigen presentation and activation of T cell mediated adaptive immunity, including antitumor immunity.
To date, we have conducted extensive preclinical studies of SL-172154 that have demonstrated the following:
•Specific binding to CD47 and CD40 with high picomolar affinity
•A significant increase in macrophage-mediated phagocytosis of tumor cells
•Durable receptor occupancy to CD47 expressing cells
•Dose-dependent CD40-mediated pharmacodynamic activity
•The activation of antigen presenting cells by a CD40-induced type I interferon response
•Dose-dependent increases in multiple anti-cancer cytokines in both non-human primates and by human lymphocytes
•Dose-dependent activation of a CD8+ T cell response, which was responsible for tumor cell killing
•Superior tumor rejection as compared to CD47 inhibitory antibodies, CD40 agonist antibodies, or the combination thereof, in mouse tumor models
Taken together, we believe these data demonstrate the potential ability of SL-172154 to activate and bridge the adaptive and innate immune responses.
We performed standard in vitro tumor cell phagocytosis assays to demonstrate whether SL-172154 enhanced macrophage-mediated phagocytosis of various tumor cell lines, both alone and in combination with tumor-targeted ADCP-competent antibodies. As shown in Figure 5 below, consistent with the mechanism of action of CD47 blocking agents, SL-172154 significantly enhanced the ability of macrophages to phagocytose tumor cells in the presence of tumor-targeted ADCP-competent antibodies. Additionally, SL-172154 potentiated macrophage-mediated phagocytosis of tumor cells that expressed calreticulin, a well-established “eat me” signal expressed on the surface of cells marked for phagocytosis.
Figure 5-Tumor Phagocytosis Activity of SIRPα-Fc-CD40L with or without ADCP-competent Antibodies
Human monocyte derived macrophages were co-cultured with HCC1954, A431, HCC827, or Caov-3 cells in the presence of an IgG negative control, SL-172154, an ADCP-competent tumor-targeted antibody, including Trastuzumab or Cetuximab, or the combination of SL-172154 and the ADCP-competent tumor-targeted antibody. After two hours, the proportion of tumor cells phagocytosed by human macrophages was determined and reported as the phagocytosis index.
We conducted dose-range finding and repeat dose toxicity studies in nonhuman primates, or NHP, to evaluate the safety and pharmacologic effects of SL-172154. In these studies, SL-172154 was administered as five once-weekly doses across a dose range of 0.1 mg/kg to 40 mg/kg, followed by a recovery period. Data from these studies indicated that SL-172154 induced a potent immune response in NHP. Figure 6 below shows dose-dependent saturation of CD47+ red blood cells, which was durable for greater than seven days. In addition, SL-172154 bound CD40-expressing B cells in the peripheral blood and stimulated a dose-dependent migration of lymphocytes from the peripheral blood within 24 hours of treatment. We believe these data are supportive of either a once weekly or every other week dosing schedule. Histology samples demonstrated that the post-dose decreases in peripheral blood lymphocytes were accompanied by accumulation of proliferating lymphocytes in lymph nodes, spleen and bone marrow. Whereas other CD47-targeted agents are administered at super-saturating doses, which we believe is intended to establish a concentration gradient that facilitates passive diffusion into tissues, we believe these data suggest that SL-172154 may be actively transported into tissues via CD40 binding, which may lead to a unique dosing profile in humans. Administration of SL-172154 was also associated with dose-dependent post-treatment increases in multiple serum cytokines, such as CCL2. Overall, SL-172154 was well tolerated; however, at the higher dose levels, we observed toxicities that were consistent with cytokine release syndrome in the setting of an anti-drug antibody response, which is expected in NHP because SL-172154 is a human protein construct. No evidence of anemia was observed.
Figure 6-CD47 Receptor Occupancy following SL-172154 Infusion
Cynomolgus monkeys were treated on Day 1 and 8 with 0.1 mg/kg, 1 mg/kg, 10 mg/kg, and 40 mg/kg of SL-172154 or a vehicle control. Receptor occupancy was evaluated at the indicated time points by flow cytometry. SL-172154 occupancy on red blood cell CD47 is plotted as the proportion of total CD47 expression minus the proportion of CD47 detected using an antibody that is prevented from binding when CD47 is occupied by SL-172154.
SL-279252: A Dual PD-1 Blocking and OX40-Activating ARC Compound
Our second product candidate, SL-279252, is a dual-sided, bi-functional fusion protein that both inhibits the PD-/PD-L1 interaction and activates the OX40 costimulatory receptor. We are evaluating SL-279252 in an ongoing Phase 1 dose-escalation clinical trial in patients with advanced solid tumors.
Clinical Data Observed to Date
In November 2021, at the SITC Meeting, we presented data from the dose-escalation portion of our ongoing Phase 1 clinical trial as monotherapy in late-stage solid tumor cancer patients. As of June 11, 2021 we had enrolled a total of 43 patients from the first ten dose levels, ranging from 0.0001 mg/kg to 6 mg/kg. Dose escalation was conducted according to the keyboard design. Patients received SL-279252 on either a weekly or bi-weekly basis with a 28-day cycle. The patients treated as of June 11, 2021, were heavily pretreated with a median of three prior lines of systemic therapies and 58% were checkpoint inhibitor experienced.
As of our latest safety data cutoff date of January 19, 2022, SL-279252 has been observed to be well tolerated and has demonstrated monotherapy antitumor activity in some PD-1 inhibitor experienced patients during dose escalation at doses of 1 mg/kg and higher. Dose escalation is continuing in a primarily PD-1/L1 inhibitor experienced patient population. Treatment-related adverse events, including immune-related events, have been reported in some patients. To date, we have observed no Grade 4 or Grade 5 adverse events, and we have not observed any dose-limiting toxicities. A maximum tolerated dose has not been reached.
As of June 11, 2021, preliminary pharmacodynamic activity has been evaluated in patients treated across a dose range of 0.0001 mg/kg to 6 mg/kg. Increases in the number of proliferating CD8+ central memory and effector memory T cells were observed in the peripheral blood of some patients at higher peak SL-279252 concentrations corresponding to doses of 1.0 mg/kg or greater. Post-dose receptor occupancy on OX40+ lymphocytes was observed in a dose-dependent fashion, and the total number of OX40+ cells in the blood declined rapidly post-infusion of SL-279252. We believe the post-infusion decreases in OX40+ lymphocytes provides evidence of on-target activation. In NHP, similar post-infusion decreases in lymphocytes were associated with migration of lymphocytes into tissues.
As of June 11, 2021, preliminary pharmacokinetic activity has been evaluated across a dose range of 0.0001 to 6 mg/kg. A linear increase in SL-279252 Cmax and AUC was observed up to 3.0 mg/kg, while a greater than proportional increase in AUC was observed at 6.0 mg/kg, suggesting potential target saturation at 6 mg/kg. Within subject exposure was similar on Days 1, 15 and 29, indicating no accumulation or time-dependent changes in pharmacokinetics on either schedule. The preliminary half-life is approximately 23 hours.
As of October 20, 2021, the best response to therapy has been one confirmed partial response, or PR, in a patient with ocular melanoma who remained on treatment for greater than one year. This patient was heavily pretreated, with four prior systemic regimens and had progressed on prior PD-1 and CTLA-4 checkpoint inhibitor therapies. In addition, stable disease, or SD, was seen in an additional 12 patients. In five of these patients, SD was sustained for greater than 24 weeks. One unconfirmed PR was observed in a patient with mucosal melanoma of the vulvar who had also progressed on prior PD-1 and CTLA-4 checkpoint inhibitor therapies.
Clinical Development Strategy
We are currently dosing at 12 mg/kg and plan to continue dose escalation to 24 mg/kg in our Phase 1 trial of SL-279252 in patients with advanced solid tumors and we are primarily selecting for patients with PD-L1 expressing tumors. The primary objective of the Phase 1 trial is to assess the safety and tolerability of SL-279252. The secondary objectives include evaluation of the pharmacokinetic and pharmacodynamic profiles as well as the antitumor activity of SL-279252. We are evaluating antitumor response according to immune Response Evaluation Criteria in Solid Tumors or Response Evaluation Criteria in Lymphoma 2017. These are standard, widely-accepted criteria to evaluate tumor response in oncology clinical trials. We expect to provide additional data from the dose-escalation portion of this Phase 1 trial in the second half of 2022.
Given the way that the PD-1 inhibitor landscape has evolved, the development path for SL-279252 is first in PD-1 relapsed and refractory patients.
To date, we have experienced delays in our clinical trial of SL-279252 because of the ongoing COVID-19 pandemic. In particular, we have experienced: delays with certain third-party vendors supporting this trial, including third-party manufacturers; difficulty procuring sufficient quantities of raw materials required for our manufacturing processes; delays as a result of some patients choosing to forego one or more doses in our clinical trials; and staffing shortages at many clinical trial sites. We expect to continue to experience some or all of these delays in the future.
Our GADLEN Platform
Our expertise in engineering dual-sided, bi-functional fusion proteins has enabled the development of our GADLEN platform to leverage gamma delta T cells for the treatment of cancer.
The therapeutic utilization of gamma delta T cells represents a novel approach for the treatment of cancer. This approach may be particularly beneficial in targeting tumors that are not addressable by alpha beta T cells. Additionally, as immunotherapies that stimulate alpha beta T cell-dependent immune response are increasingly utilized across cancer treatment paradigms, we expect the proportion of patients who will become refractory to alpha beta T cell-mediated therapies will also increase over time, creating an opportunity for therapeutics which harness the antitumor activity of gamma delta T cells.
A majority of T cells in the human body bear an alpha beta T cell receptor, which recognizes tumor antigens presented on major histocompatibility complex, or MHC, molecules. Some cancer cells reduce the expression of MHC molecules or tumor antigens, rendering those cancer cells invisible to most alpha beta T cells. The predominant gamma delta T cell population in the peripheral blood expresses the V gamma 9 / V delta 2 T cell receptor and is activated by a heterodimer consisting of butyrophilin 2A1 and butyrophilin 3A1. Thus, therapeutics which are designed to display a heterodimer of butyrophilin 2A1 and 3A1 may provide a means of modulating gamma delta T cells in vivo. We have leveraged our expertise in engineering dual sided bi-functional fusion proteins to develop a suite of heterodimerized butyrophilin proteins connected to antigen-targeted single chain antibody fragments.
GADLEN compounds are comprised of two distinct fusion protein chains, and an engineered Fc linker domain that facilitates heterodimerization between the two chains. As shown in the left panel of Figure 7 below, the assembled GADLEN compound contains the extracellular domains of heterodimerized butyrophilin proteins on one side and is linked to tumor antigen specific single chain antibody fragments on the opposite side. The gamma delta T cell receptors recognize and are activated by specific butyrophilin protein heterodimers. Thus, the GADLEN construct is designed to facilitate targeting of specific gamma delta T cells to tumor cells expressing a defined antigen, as shown in the right panel of Figure 7 below.
Figure 7-GADLEN Platform Overview
To demonstrate the feasibility of the GADLEN approach, a murine GADLEN construct was developed incorporating a butyrophilin 1, or BTNL1, and butyrophilin 6, or BTNL 6, heterodimer and an scFv domain targeting the CD19 antigen. In both mice and humans, gamma delta T cells represent approximately 2% to 5% of the total T cell population, as shown in Figure 10 in a murine model. We treated mice on Days 0, 3, and 6 with the murine GADLEN, mBTNL1/6-Fc-CD19scFv. We observed dose-dependent expansion of the endogenous gamma delta T cell compartment to approximately 12% of all T cells 24 hours after the second treatment. Concurrent with expansion, mBTNL1/6-Fc-CD19scFv also caused activation of murine gamma delta T cells, as demonstrated by upregulation of the CD69 activation marker, shown in Figure 10. Murine B cells express CD19, and therefore were a potential target of gamma delta T cells following treatment with mBTNL1/6-Fc-CD19scFv. Accordingly, we observed depletion of the endogenous B cell compartment concurrent with gamma delta T cell expansion and activation following treatment with mBTNL1/6-Fc-CD19scFv, as shown in Figure 8. Importantly, when mice with established CD19+ tumors were treated with mBTNL1/6-Fc-CD19scFv, dose-dependent reduction in tumor growth and rejection was observed. We believe these studies indicate that GADLEN compounds enable therapeutic modulation of gamma delta T cells in vivo, and that GADLEN compounds may be designed to activate tissue-restricted populations of endogenous gamma delta T cells to target specific tumor antigens in both solid and liquid tumors.
Figure 8-Dose Dependent Gamma T Cell Expansion, Activation, and Killing Activity Following Administration of the GADLEN Compound mBTNL1/6-Fc-CD19scFv
To characterize the types of gamma delta T cell subsets that reside within different tumor types, we performed single cell RNA sequencing of patient tumor tissues, including multiple colorectal, melanoma, and non-small cell lung cancer patient tumors to identify the prevalent gamma delta T cell subsets in each tumor type. As a result of this analysis, we have advanced a number of preclinical GADLEN candidates comprised of butyrophilin heterodimers and tumor antigen specific targeting domains for a number of antigens with therapeutic relevance for both hematologic and solid tumors. Our preclinical findings with these GADLEN compounds have also revealed that gamma delta T cells, like alpha beta T cells, require costimulation through either costimulatory or natural cytoxicity receptors (NCR) for efficient T cell receptor activation. The data generated to date suggest these signals can be provided by the tumor cells that express costimulatory ligands and stress ligands that enable efficient activation of gamma delta T cell receptors via GADLEN compounds.
In alignment with our strategy to leverage our expertise to build and expand novel platforms beyond our ARC platform, where dual-sided fusion proteins may provide advantages over existing therapeutic antibodies, we continue to invest in and advance our GADLEN platform.
Collaboration and License Agreements
Collaboration Agreement with Takeda
On August 8, 2017, we entered into a Collaboration Agreement with Millennium Pharmaceuticals, Inc., or Takeda, a wholly owned subsidiary of Takeda Pharmaceutical Company, Ltd., or the Collaboration Agreement. The Collaboration Agreement was subsequently amended in April 2018, October 2018 and March 2020. The Collaboration Agreement was
mutually terminated pursuant to the termination agreement, or the Termination Agreement, dated November 8, 2021. Under the terms of the Termination Agreement, we are not required to satisfy any remaining performance obligations, we will not make any payments to or receive any future milestone or royalty payments from Takeda, and all options to license and rights of first negotiation held by Takeda under the Collaboration Agreement were terminated. The remaining deferred revenue was recognized as revenue in the fourth quarter of 2021.
Heat License Agreement
In June 2016, we entered into an Exclusive License Agreement, or the Heat License Agreement, with Heat Biologics Inc., or Heat. The Heat License Agreement was subsequently amended in November 2016, December 2016, and March 2017. Pursuant to the Heat License Agreement, Heat granted to us (1) a worldwide, sublicensable exclusive license to research, develop, manufacture, and commercialize products under three provisional patent applications, including all patents issuing from such applications, or the Fusion Protein Patent Rights, and (2) a worldwide, sublicensable nonexclusive license to research, develop, manufacture, and commercialize certain know-how owned and controlled by Heat related to the Fusion Protein Patent Rights.
Under the Heat License Agreement, Heat was required to conduct certain research and development services under a mutually-agreed upon research and development plan and Heat was eligible to receive financial support from us for these efforts. Effective March 2017, Heat completed all research and development services under the Heat License Agreement and assigned to us three patent applications and all data derived from the research and development activities, referred to collectively as the Research Services Inventions. Pursuant to the terms of the Heat License Agreement, we are obligated to use commercially reasonable efforts to diligently research and develop at least one product covered by the Fusion Protein Patent Rights, including the obligation to file an Investigational New Drug, or IND, application for such product. Our development efforts to date, including the development of SL-279252 and certain other ARC compounds, satisfy these obligations. In addition, we are to provide annual reports to Heat on or before the anniversary of the effective date of the Heat License Agreement to inform Heat of our progress.
Unless sooner terminated or extended, the term of the Heat License Agreement continues until the later of (1) 20 years following the effective date, and (2) the expiration of the last-to-expire royalty term. Either party may terminate the agreement due to a material breach by the other party (subject to a 90-day cure period) or if the other party files for bankruptcy. In the event we terminate the Heat License Agreement due to a material breach by Heat, Heat must assign to us all right, title, and interest in the patent rights licensed under the Heat License Agreement.
In addition to an upfront payment of $50,000, which we made in 2016, the Heat License Agreement requires us to make further payments to Heat in the future of up to $20.6 million in the aggregate for the achievement of specified development, regulatory, and commercial sale milestones for certain licensed products. We are also required to pay Heat a percentage of certain upfront fees or other non-royalty payments that are not tied to milestone events which we receive in connection with certain sublicenses of the Fusion Protein Patent Rights. We are also required to pay Heat a royalty on all worldwide net sales by us, our affiliates, and sublicenses of certain licensed products in the low single digits. Royalties are payable, on a product-by-product and country-by-country basis, commencing on the first commercial sale of such product and continuing until the last-to-expire valid patent claim to the licensed patent rights that cover such product in that country.
Manufacturing and Supply
By working with third-party vendors to conduct activities in compliance with current Good Manufacturing Practices, or cGMP, we have invested significant resources to identify and scale up a suitable manufacturing process for ARC compounds, including SL-172154 and SL-279252. Currently, ARC compounds are produced by mammalian cell lines commonly used in the manufacture of monoclonal antibodies, including Chinese hamster ovary, or CHO, cells. Both SL-172154 and SL-279252 have achieved cell culture titer greater than two grams per liter, and another ARC compound has achieved titers exceeding seven grams per liter. Purification of ARC compounds initially utilizes affinity chromatography directed to the Fc domain for capture, and subsequent chromatography steps are designed to remove process-related impurities including CHO derived DNA and proteins.
To date, we have manufactured bulk drug substance, or BDS, for our product candidates utilizing the services of one third-party contract manufacturer, KBI Biopharma, Inc., or KBI, with whom we maintain a master service agreement, pursuant to which we may manufacture BDS through KBI on a per project basis. We may terminate the master services agreement at any time for convenience in accordance with the terms of the agreement. Either KBI or we may also terminate the master services agreement with respect to an uncured breach by the other party in accordance with the terms of the agreement. These agreements include confidentiality and intellectual property provisions to protect our proprietary rights related to our product candidates.
Given the complexity of manufacturing our dual-sided, bi-functional fusion proteins, our increased need for manufacturing driven by multiple clinical trial programs, and the challenges faced by biologics manufacturing facilities during
the COVID-19 pandemic, we are actively working to make arrangements to procure redundant supply, including engaging with additional third-party manufacturers to identify suitable additional suppliers and building out a facility to support internal process development activities and cGMP manufacturing. We have recently entered into a master service agreement with Abzena Plc, pursuant to which we may manufacture BDS on a per project basis.
We expect to continue to devote significant resources to process development and optimization of the manufacture of our product candidates. To our knowledge, no other company has successfully scaled up commercial manufacturing of dual-sided, bi-functional fusion proteins. Due to the novelty of our product candidates, we may face challenges in developing large-scale manufacturing processes. Moreover, the nature of biologic medicines could create challenges for the stability of the drug substance. While these and other challenges may result in timeline delays and higher costs, we believe that we will have sufficient BDS to support our current clinical trial programs.
All of our product candidates are manufactured from a master cell bank of that protein’s production cell line. We have or intend to have one master cell bank for each product candidate that was or will be produced and tested in accordance with cGMP and applicable regulations. Each master cell bank is or will be stored in two independent locations, and we intend to produce working cell banks for each product candidate later in product development. It is possible that we could lose multiple cell banks from multiple locations and have our manufacturing severely impacted by the need to replace the cell banks. However, we believe we have adequate backup should any particular cell bank be lost in a catastrophic event.
Competition
The pharmaceutical and biotechnology industries are characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. While we believe that our technology, development experience and scientific knowledge provide us with competitive advantages, we face potential competition from many different sources, including large pharmaceutical and biotechnology companies, academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection and establish collaborative arrangements for the research, development, manufacturing, and commercialization of cancer therapies. Any product candidates that we successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future.
We compete in the segments of the pharmaceutical, biotechnology, and other related markets that develop cancer therapies. There are many other companies that have commercialized or are developing cancer therapies, including large pharmaceutical and biotechnology companies, such as AstraZeneca/MedImmune, Bristol Myers Squibb, Merck, Novartis, Pfizer, Roche/Genentech and Gilead.
We face significant competition from pharmaceutical and biotechnology companies that target specific tumor-associated antigens using immune cells or other cytotoxic modalities. These generally include immune cell redirecting therapeutics (e.g., T cell engagers), adoptive cellular therapies (e.g., CAR-Ts), antibody drug conjugates, targeted radiopharmaceuticals, targeted immunotoxin, and targeted cancer vaccines.
With respect to our lead product candidate, SL-172154, we are aware of other competing clinical-stage therapeutics that target the CD47 pathway or the CD40 pathway, which include, but are not limited to magrolimab, ALX148, TTI-621, TTI-622, DSP107, and APX005M.
With respect to our second lead product candidate, SL-279252, we are aware of other competing clinical-stage therapeutics, that target the PD-1 pathway or the OX40 pathway, which include, but are not limited to PF-04518600, BMS-986178, INBRX-106, pembrolizumab, nivolumab, avelumab, and atezolizumab.
Many of the companies against which we are competing or against which we may compete in the future have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved drugs than we do. Mergers and acquisitions in the pharmaceutical, biotechnology, and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites and manufacturing capacity and enrolling subjects for our clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.
We could see a reduction or elimination of our commercial opportunity if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we or our collaborators may develop. Our competitors also may obtain FDA or foreign regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we or our collaborators are able to enter the market. The key competitive factors affecting the success of all our product candidates, if approved, are likely to be their efficacy, safety, convenience, price, the effectiveness of
companion diagnostics, if required, the level of biosimilar or generic competition, and the availability of reimbursement from government and other third-party payors.
Intellectual Property
We strive to protect and enhance our proprietary technology, inventions, and improvements that we consider commercially important to the development of our business, including by seeking, maintaining, and defending U.S. and foreign patent rights, including patents covering our platform technologies, product candidates, and methods of using the same, whether developed internally or licensed from third parties. We also rely on trade secrets, know-how, and continuing technological innovation to develop, strengthen and maintain our proprietary position in our field. Additionally, we intend to rely on regulatory protection afforded through data exclusivity and market exclusivity, among others, as well as patent term extensions, where available.
Our future commercial success depends, in part, on our ability to obtain and maintain patent and other proprietary protection for commercially important technology, inventions, and know-how related to our business, including our platform technologies and product candidates, defend and enforce our intellectual property rights, in particular our patents rights, preserve the confidentiality of our trade secrets, and operate without infringing, misappropriating, or violating the valid and enforceable patents and proprietary rights of third parties. Our ability to stop third parties from making, using, selling, offering to sell, or importing our products may depend on the extent to which we have rights under valid and enforceable patents or trade secrets that cover these activities.
The patent positions of biotechnology companies like ours are generally uncertain and can involve complex legal, scientific, and factual issues. We cannot predict whether the patent applications we are currently pursuing, or those we will file or license from others, will grant us patents in any particular jurisdiction or whether the claims of any granted patents will provide sufficient proprietary protection from competitors.
In addition, the coverage claimed in a patent application may be significantly reduced before a patent is granted, and its scope can be reinterpreted and even challenged after issuance. As a result, we cannot guarantee that any of our products will be protected or remain protectable by enforceable patents. Moreover, any patents that we hold may be challenged, circumvented, or invalidated by third parties. In addition, because of the extensive time required for clinical development and regulatory review of a product candidate we may develop, it is possible that, before any of our product candidates can be commercialized, any related patent may expire or remain in force for only a short period following commercialization, thereby limiting the protection such patent would afford the respective product and any competitive advantage such patent may provide. See “Risk Factors-Risks Related to Our Intellectual Property and Information Technology” for a more comprehensive description of risks related to our intellectual property.
For any individual patent, the term depends on the applicable law in the country in which the patent is granted. In most countries where we have filed patent applications or in-licensed patents and patent applications, patents have a term of 20 years from the application filing date or earliest claimed nonprovisional priority date. In the United States, the patent term is 20 years from the application filing date or earliest claimed nonprovisional priority date, but may be shortened if a patent is terminally disclaimed over another patent that expires earlier. The term of a U.S. patent may also be lengthened by a Patent Term Adjustment in order to address administrative delays by the U.S. Patent and Trademark Office in granting a patent.
In the United States, the term of a patent that covers an FDA-approved drug or biologic may be eligible for Patent Term Extension in order to restore the period of a patent term lost during the premarket FDA regulatory review process. The Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Act, permits a Patent Term Extension of up to five years beyond the natural expiration of the patent (but the total patent term, including the extension period, must not exceed 14 years following FDA approval). The term extension period granted on a patent covering a product is typically one-half the time between the effective date of a clinical investigation involving human beings is begun and the submission date of an application, plus the time between the submission date of an application and the ultimate approval date. Only one patent applicable to an approved product is eligible for the extension, and only those claims covering the approved product, a method for using it, or a method for manufacturing it may be extended. The application for the extension must be submitted prior to the expiration of the patent. The United States Patent and Trademark Office reviews and approves the application for any Patent Term Extension in consultation with the FDA. In the future, we may decide to apply for restoration of patent term for one of our currently owned or licensed patents to extend its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant biologics license application.
Intellectual property related to our most advanced programs is summarized below. We generally file patent applications directed to our key technologies and programs in an effort to secure our intellectual property positions. As of February 1, 2022, we own or exclusively license (i) more than 15 patents and more than 15 pending non-provisional patent applications in the United States and (ii) 3 patents and more than 120 pending patent applications in jurisdictions outside of the United States. We also own additional pending provisional patent applications in the United States and pending international patent applications
filed under the Patent Cooperation Treaty, or PCT. Patent prosecution is a lengthy process, during which the scope of the claims initially submitted for examination by the U.S. Patent and Trademark Office and other patent offices may be significantly revised before issuance, if granted at all.
SL-172154 Product Candidate
As of February 1, 2022, we own or exclusively license (i) 2 patents and 5 pending non-provisional patent applications in the United States and (ii) 3 patents and more than 35 pending patent applications in jurisdictions outside of the United States (including, among others, Australia, Canada, China, Europe, and Japan) that relate to SL-172154.
These patents and applications originate from several different patent families. Patents granted in a family generally directed to compositions and methods of treating cancer are expected to expire in the United States in 2036, without taking potential patent term extension or patent term adjustment into account. Patents granted in other families, generally directed to methods of treating cancer with various combination agents, are expected to expire in the United States in 2038 and 2039, depending on the family and without taking potential term extension or patent term adjustment into account. The terms of individual patents granted in jurisdictions outside of the United States depends on the legal term for patents in those jurisdictions.
SL-279252 Product Candidate
As of February 1, 2022, we own or exclusively license (i) 2 patents and 1 pending non-provisional patent application in the United States (ii) 3 patents and more than 35 pending patent applications in jurisdictions outside of the United States (including, among others, Australia, Canada, China, Europe, and Japan) that relate to SL-279252.
These patents and applications originate from two different patent families. Patents granted in a family generally directed to compositions and methods of treating cancer are expected to expire in the United States in 2036, without taking potential patent term extension or patent term adjustment into account. Patents granted in another family, generally directed to methods of treating cancer with various combination agents, are expected to expire in the United States in 2039, without taking potential patent term extension or patent term adjustment into account. The terms of individual patents granted in jurisdictions outside of the United States depends on the legal term for patents in those jurisdictions.
ARC Platform
As of February 1, 2022, we own or exclusively license (i) more than 15 patents and 15 pending non-provisional patent applications in the United States and (ii) 3 patents and more than 100 pending patent applications in jurisdictions outside of the United States (including, among others, Australia, Canada, China, Europe, and Japan) that relate to the ARC platform. As of February 1, 2022, these include patents and/or patent applications related to SL-172154 and SL-279252 (described above) and other ARC compounds combining TIM3, PD-1, SIRPα, TIGIT, CSF1R, VSIG8, or FLT3L with OX40, CD40L, 4-1BBL, or LIGHT.
These patents and applications originate from several different patent families. Patents granted in families generally directed to compositions and methods of treating cancer are expected to expire in the United States in 2036, 2038, 2039, and 2040, depending on the family and without taking potential patent term extension or patent term adjustment into account. Patents granted in other families, generally directed to methods of treating cancer with various combination agents, are expected to expire in the United States in 2038, 2039, and 2040, depending on the family and without taking potential patent term extension or patent term adjustment into account. The terms of individual patents granted in jurisdictions outside of the United States depends on the legal term for patents in those jurisdictions.
GADLEN Platform
As of February 1, 2022, we (i) own 2 patents and 1 pending non-provisional patent application in the United States and (ii) more than 10 pending patent applications in jurisdictions outside of the United States (including, among others, Australia, Canada, China, Europe, and Japan) that relate to the GADLEN platform.
These patents and applications originate from a family generally directed to compositions and methods of treating cancer. Patents granted in this family are expected to expire in the United States in 2040, without taking potential patent term extension or adjustment into account.
Trademark Protection
As of February 1, 2022, we own a registered trademark and an allowed application for “ARC” and an allowed application for “GADLEN” with the U.S. Patent and Trademark Office. We plan to register trademarks in connection with our biological products.
Licensed Intellectual Property from Heat Biologics, Inc.
In June 2016, we entered into an exclusive license agreement with Heat, pursuant to which we received an exclusive (as to the patent rights), non-transferable, sublicensable, worldwide, royalty-bearing, non-field restricted license to certain patent rights and know-how, including rights related to the ARC platform. We paid Heat an initial license fee of $50,000, and we are obligated to pay Heat fees upon receipt of certain sublicensing income, achievement of certain milestones, and royalties upon sales of commercial products. The Heat license provides us rights in the patent family including PCT/US16/54598. As of February 1, 2022, that family includes (i) 10 patents and 3 pending non-provisional patent applications in the United States, and (ii) 2 patents and more than 25 pending applications in jurisdictions outside of the United States (including, among others, Australia, Canada, China, Europe, and Japan). We control prosecution, maintenance, and enforcement of this family of patents and patent applications.
Government Regulation
The FDA and other regulatory authorities at federal, state and local levels, as well as in foreign countries, extensively regulate, among other things, the research, development, testing, manufacture, quality control, import, export, safety, effectiveness, labeling, packaging, storage, distribution, record keeping, approval, advertising, promotion, marketing, post-approval monitoring and post-approval reporting of biologics such as those we are developing. We, along with third-party contractors, will be required to navigate the various preclinical, clinical and commercial approval requirements of the governing regulatory agencies of the countries in which we wish to conduct studies or seek approval or licensure of our product candidates.
U.S. Biologics Regulation
In the United States, biological products are subject to regulation under the Federal Food, Drug, and Cosmetic Act, or FDCA, and the Public Health Service Act, or PHSA, and other federal, state, local, and foreign statutes and regulations. The process required by the FDA before biologic product candidates may be marketed in the United States generally involves the following:
•completion of preclinical laboratory tests and animal studies performed in accordance with the FDA’s current Good Laboratory Practices, or GLP, regulation;
•submission to the FDA of an IND, which must become effective before clinical trials may begin and must be updated annually or when significant changes are made;
•approval by an independent IRB or ethics committee at each clinical site before the trial is commenced;
•manufacture of the proposed biologic candidate in accordance with cGMPs;
•performance of adequate and well-controlled human clinical trials in accordance with good clinical practice, or GCP, requirements to establish the safety, purity and potency of the proposed biologic product candidate for its intended purpose;
•preparation of and submission to the FDA of a BLA after completion of all pivotal clinical trials;
•satisfactory completion of an FDA Advisory Committee review, if applicable;
•a determination by the FDA within 60 days of its receipt of a BLA to file the application for review;
•satisfactory completion of an FDA pre-approval inspection of the manufacturing facility or facilities at which the proposed product is produced to assess compliance with cGMPs, and to assure that the facilities, methods and controls are adequate to preserve the biological product’s continued safety, purity and potency, and of selected clinical investigation sites to assess compliance with GCPs; and
•FDA review and approval of a BLA to permit commercial marketing of the product for particular indications for use in the United States.
Preclinical and Clinical Development
Prior to beginning the first clinical trial with a product candidate, we must submit an IND to the FDA. An IND is a request for authorization from the FDA to administer an investigational new drug product to humans. The central focus of an IND submission is on the general investigational plan and the protocol or protocols for preclinical studies and clinical trials. The IND also includes results of animal and in vitro studies assessing the toxicology, pharmacokinetics, pharmacology and pharmacodynamic characteristics of the product, chemistry, manufacturing and controls information, and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day
period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before the clinical trial can begin. Submission of an IND therefore may or may not result in FDA authorization to begin a clinical trial.
In addition to the IND submission process, supervision of human gene transfer trials includes evaluation and assessment by an institutional biosafety committee, or IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment and such review may result in some delay before initiation of a clinical trial.
Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCPs, which include the requirement that all research subjects provide their informed consent for their participation in any clinical study. Clinical trials are conducted under protocols detailing, among other things, the objectives of the study, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. A separate submission to the existing IND must be made for each successive clinical trial conducted during product development and for any subsequent protocol amendments. Furthermore, an independent IRB for each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and its informed consent form before the clinical trial begins at that site, and must monitor the study until completed. Regulatory authorities, the IRB or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk or that the trial is unlikely to meet its stated objectives. Some studies also include oversight by an independent group of qualified experts organized by the clinical study sponsor, known as a data safety monitoring board, which provides authorization for whether or not a study may move forward at designated check points based on access to certain data from the study and may halt the clinical trial if it determines that there is an unacceptable safety risk for subjects or other grounds, such as no demonstration of efficacy. There are also requirements governing the reporting of ongoing preclinical studies and clinical trials and clinical study results to public registries.
For purposes of BLA approval, human clinical trials are typically conducted in three sequential phases that may overlap.
•Phase 1. The investigational product is initially introduced into healthy human subjects or patients with the target disease or condition. These studies are designed to test the safety, dosage tolerance, absorption, metabolism and distribution of the investigational product in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on effectiveness.
•Phase 2. The investigational product is administered to a limited patient population with a specified disease or condition to evaluate the preliminary efficacy, optimal dosages and dosing schedule and to identify possible adverse side effects and safety risks. Multiple Phase 2 clinical trials may be conducted to obtain information prior to beginning larger and more expensive Phase 3 clinical trials.
•Phase 3. The investigational product is administered to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for product approval.
In some cases, the FDA may require, or companies may voluntarily pursue, additional clinical trials after a product is approved to gain more information about the product. These so-called Phase 4 studies may be made a condition to approval of the BLA. Concurrent with clinical trials, companies may complete additional animal studies and develop additional information about the biological characteristics of the product candidate, and must finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, must develop methods for testing the identity, strength, quality and purity of the final product, or for biologics, the safety, purity and potency. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.
BLA Submission and Review
Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, nonclinical studies and clinical trials are submitted to the FDA as part of a BLA requesting approval to market the product for one or more indications. The BLA must include all relevant data available from pertinent preclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls, and proposed labeling, among other things. Data can come from company-sponsored clinical studies intended to test the safety and effectiveness of the product, or from a number of alternative sources, including studies initiated and sponsored by investigators. The submission of a BLA requires payment of a substantial application user fee to the FDA, unless a waiver or exemption applies.
In addition, under the Pediatric Research Equity Act, or PREA, a BLA or supplement to a BLA must contain data to assess the safety and effectiveness of the biological product candidate for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The Food and Drug Administration Safety and Innovation Act requires that a sponsor who is planning to submit a marketing application for a biological product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration submit an initial pediatric study plan, or PSP, within sixty days after an end-of-Phase 2 meeting or as may be agreed between the sponsor and FDA. Unless otherwise required by regulation, PREA does not apply to any biological product for an indication for which orphan designation has been granted.
Within 60 days following submission of the application, the FDA reviews a BLA submitted to determine if it is substantially complete before the agency accepts it for filing. The FDA may refuse to file any BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the BLA must be resubmitted with the additional information. Once a BLA has been accepted for filing, the FDA’s goal is to review standard applications within ten months after the filing date, or, if the application qualifies for priority review, six months after the FDA accepts the application for filing. In both standard and priority reviews, the review process may also be extended by FDA requests for additional information or clarification. The FDA reviews a BLA to determine, among other things, whether a product is safe, pure and potent and the facility in which it is manufactured, processed, packed or held meets standards designed to assure the product’s continued safety, purity and potency. The FDA may convene an advisory committee to provide clinical insight on application review questions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.
Before approving a BLA, the FDA will typically inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure compliance with GCPs. If the FDA determines that the application, manufacturing process or manufacturing facilities are not acceptable, it will outline the deficiencies in the submission and often will request additional testing or information. Notwithstanding the submission of any requested additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval.
After the FDA evaluates a BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response letter. An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A Complete Response letter will describe all of the deficiencies that the FDA has identified in the BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the Complete Response letter without first conducting required inspections, testing submitted product lots and/or reviewing proposed labeling. In issuing the Complete Response letter, the FDA may recommend actions that the applicant might take to place the BLA in condition for approval, including requests for additional information or clarification. The FDA may delay or refuse approval of a BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.
If regulatory approval of a product is granted, such approval will be granted for particular indications and may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA may approve the BLA with a Risk Evaluation and Mitigation Strategy, or REMS, to ensure the benefits of the product outweigh its risks. A REMS is a safety strategy to manage a known or potential serious risk associated with a product and to enable patients to have continued access to such medicines by managing their safe use, and could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. Once approved, the FDA may withdraw the product approval if compliance with pre- and post-marketing requirements is not maintained or if problems occur after the product reaches the marketplace. The FDA may require one or more Phase 4 post-market studies and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing studies.
Expedited Development and Review Programs
The FDA offers a number of expedited development and review programs for qualifying product candidates. The fast track program is intended to expedite or facilitate the process for reviewing new products that meet certain criteria. Specifically, new products are eligible for fast track designation if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a fast track product has opportunities for more frequent interactions with the review team during product development and, once a BLA is submitted,
the product may be eligible for priority review. A fast track product may also be eligible for rolling review, where the FDA may consider for review sections of the BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the BLA, the FDA agrees to accept sections of the BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the BLA.
A product intended to treat a serious or life-threatening disease or condition may also be eligible for breakthrough therapy designation to expedite its development and review. A product can receive breakthrough therapy designation if preliminary clinical evidence indicates that the product, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product, including involvement of senior managers.
Any marketing application for a biologic submitted to the FDA for approval, including a product with a fast track designation and/or breakthrough therapy designation, may be eligible for other types of FDA programs intended to expedite the FDA review and approval process, such as priority review and accelerated approval. A product is eligible for priority review if it has the potential to provide a significant improvement in the treatment, diagnosis or prevention of a serious disease or condition. For original BLAs, priority review designation means the FDA’s goal is to take action on the marketing application within six months of the 60-day filing date (as compared to ten months under standard review).
Additionally, products studied for their safety and effectiveness in treating serious or life-threatening diseases or conditions may receive accelerated approval upon a determination that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA will generally require the sponsor to perform adequate and well-controlled post-marketing clinical studies to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. Products receiving accelerated approval may be subject to expedited withdrawal procedures if the sponsor fails to conduct the required post-marketing studies or if such studies fail to verify the predicted clinical benefit. In addition, the FDA currently requires as a condition for accelerated approval pre-approval of promotional materials, which could adversely impact the timing of the commercial launch of the product.
In 2017, the FDA established a new regenerative medicine advanced therapy, or RMAT, designation as part of its implementation of the 21st Century Cures Act. The RMAT designation program is intended to fulfill the 21st Century Cures Act requirement that the FDA facilitate an efficient development program for, and expedite review of, any drug that meets the following criteria: (i) the drug qualifies as a RMAT, which is defined as a cell therapy, therapeutic tissue engineering product, human cell and tissue product, or any combination product using such therapies or products, with limited exceptions; (ii) the drug is intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition; and (iii) preliminary clinical evidence indicates that the drug has the potential to address unmet medical needs for such a disease or condition. RMAT designation provides all the benefits of breakthrough therapy designation, including more frequent meetings with the FDA to discuss the development plan for the product candidate and eligibility for rolling review and priority review. Products granted RMAT designation may also be eligible for accelerated approval on the basis of a surrogate or intermediate endpoint reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of sites, including through expansion to additional sites. Once approved, when appropriate, the FDA can permit fulfillment of post-approval requirements under accelerated approval through: the submission of clinical evidence, preclinical studies, clinical trials, patient registries or other sources of real world evidence such as electronic health records; the collection of larger confirmatory datasets; or post-approval monitoring of all patients treated with the therapy prior to approval.
Fast track designation, breakthrough therapy designation, priority review and RMAT designation do not change the standards for approval but may expedite the development or approval process. Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened. In May 2018, the Right to Try Act established a new regulatory pathway to increase access to unapproved, investigational treatments for patients diagnosed with life-threatening diseases or conditions who have exhausted approved treatment options and who are unable to participate in a clinical trial.
Orphan Drug Designation
Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biologic intended to treat a rare disease or condition, which is a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States for which there is no reasonable expectation that the cost of developing and making available in the United States a drug or biologic for this type of disease or condition will be recovered from sales in the United States for that drug or biologic. Orphan drug designation must be requested before submitting a BLA. After the FDA grants
orphan drug designation, the generic identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. The orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review or approval process.
If a product that has orphan drug designation subsequently receives the first FDA approval for the disease for which it has such designation, the product is entitled to orphan drug exclusive approval (or exclusivity), which means that the FDA may not approve any other applications, including a full BLA, to market the same biologic for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity or if the FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan drug to meet the needs of patients with the disease or condition for which the drug was designated. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same disease or condition, or the same drug or biologic for a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the BLA application fee.
A designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which it received orphan designation. In addition, exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantities of the product to meet the needs of patients with the rare disease or condition.
Post-Approval Requirements
Any products manufactured or distributed by us pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. There also are continuing user fee requirements, under which the FDA assesses an annual program fee for each product identified in an approved BLA. Biologic manufacturers and their subcontractors are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMPs, which impose certain procedural and documentation requirements upon us and our third-party manufacturers. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMPs and impose reporting requirements upon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMPs and other aspects of regulatory compliance.
The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical studies to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. Other potential consequences include, among other things:
•restrictions on the marketing or manufacturing of a product, complete withdrawal of the product from the market or product recalls;
•fines, warning letters or holds on post-approval clinical studies;
•refusal of the FDA to approve pending applications or supplements to approved applications, or suspension or revocation of existing product approvals;
•product seizure or detention, or refusal of the FDA to permit the import or export of products;
•consent decrees, corporate integrity agreements, debarment or exclusion from federal healthcare programs;
•mandated modification of promotional materials and labeling and the issuance of corrective information;
•the issuance of safety alerts, Dear Healthcare Provider letters, press releases and other communications containing warnings or other safety information about the product; or
•injunctions or the imposition of civil or criminal penalties.
The FDA closely regulates the marketing, labeling, advertising and promotion of biologics. A company can make only those claims relating to safety and efficacy, purity and potency that are approved by the FDA and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other things, adverse publicity,
warning letters, corrective advertising and potential civil and criminal penalties. Physicians may prescribe legally available products for uses that are not described in the product’s labeling and that differ from those tested by us and approved by the FDA. Such off-label uses are common across medical specialties. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products.
Regulation of Diagnostic Tests
Our drug candidates may require use of a diagnostic to identify appropriate patient populations for our product candidates. These diagnostics, often referred to as companion diagnostics, are medical devices, often in vitro devices, which provide information that is essential for the safe and effective use of a corresponding drug. In the United States, the FDCA and its implementing regulations, and other federal and state statutes and regulations govern, among other things, medical device design and development, preclinical and clinical testing, premarket clearance or approval, registration and listing, manufacturing, labeling, storage, advertising and promotion, sales and distribution, export and import, and post-market surveillance. Unless an exemption applies, diagnostic tests require marketing clearance or approval from the FDA prior to commercial distribution. The two primary types of FDA marketing authorization applicable to a medical device are premarket notification, also called 510(k) clearance, and premarket approval, or PMA approval. We expect that any companion diagnostic developed for our drug candidates will utilize the PMA pathway.
PMA applications must be supported by valid scientific evidence, which typically requires extensive data, including technical, preclinical, clinical and manufacturing data, to demonstrate to the FDA’s satisfaction the safety and effectiveness of the device. For diagnostic tests, a PMA application typically includes data regarding analytical and clinical validation studies. As part of its review of the PMA, the FDA will conduct a pre-approval inspection of the manufacturing facility or facilities to ensure compliance with the Quality System Regulation, or QSR, which requires manufacturers to follow design, testing, control, documentation and other quality assurance procedures. FDA review of an initial PMA may require several years to complete. If the FDA evaluations of both the PMA application and the manufacturing facilities are favorable, the FDA will either issue an approval letter or an approvable letter, which usually contains a number of conditions that must be met in order to secure the final approval of the PMA. If the FDA’s evaluation of the PMA or manufacturing facilities is not favorable, the FDA will deny approval of the PMA or issue a not approvable letter. A not approvable letter will outline the deficiencies in the application and, where practical, will identify what is necessary to make the PMA approvable. The FDA may also determine that additional clinical trials are necessary, in which case the PMA approval may be delayed for several months or years while the trials are conducted and then the data submitted in an amendment to the PMA. Once granted, PMA approval may be withdrawn by the FDA if compliance with post approval requirements, conditions of approval or other regulatory standards is not maintained or problems are identified following initial marketing.
On August 6, 2014, the FDA issued a final guidance document addressing the development and approval process for “In Vitro Companion Diagnostic Devices.” According to the guidance, for novel drugs such as our drug candidates, a companion diagnostic device and its corresponding drug should be approved or cleared contemporaneously by the FDA for the use indicated in the therapeutic product labeling. The guidance also explains that a companion diagnostic device used to make treatment decisions in clinical trials of a drug generally will be considered an investigational device, unless it is employed for an intended use for which the device is already approved or cleared. If used to make critical treatment decisions, such as patient selection, the diagnostic device generally will be considered a significant risk device under the FDA’s Investigational Device Exemption, or IDE, regulations. Thus, the sponsor of the diagnostic device will be required to comply with the IDE regulations. According to the guidance, if a diagnostic device and a drug are to be studied together to support their respective approvals, both products can be studied in the same investigational study, if the study meets both the requirements of the IDE regulations and the IND regulations. The guidance provides that depending on the details of the study plan and subjects, a sponsor may seek to submit an IND alone, or both an IND and an IDE.
Biosimilars and Reference Product Exclusivity
The ACA includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or BPCIA, which created an abbreviated approval pathway for biological products that are highly similar, or “biosimilar,” to or interchangeable with an FDA-approved reference biological product. The FDA has issued several guidance documents outlining an approach to review and approval of biosimilars.
Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, is generally shown through analytical studies, animal studies, and a clinical study or studies. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product in any given patient and, for products that are administered multiple times to an individual, the biologic and the reference biologic may be alternated or switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic. A product shown to be biosimilar or interchangeable with an FDA-approved reference
biological product may rely in part on the FDA’s previous determination of safety and effectiveness for the reference product for approval, which can potentially reduce the cost and time required to obtain approval to market the product. Complexities associated with the larger, and often more complex, structures of biological products, as well as the processes by which such products are manufactured, pose significant hurdles to implementation of the abbreviated approval pathway that are still being worked out by the FDA. In September 2021, the FDA issued two guidance documents intended to inform prospective applicants and facilitate the development of proposed biosimilars and interchangeable biosimilars, as well as to describe the FDA’s interpretation of certain statutory requirements added by the BPCIA.
Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity and potency of its product. The BPCIA also created certain exclusivity periods for biosimilars approved as interchangeable products. At this juncture, it is unclear whether products deemed “interchangeable” by the FDA will, in fact, be readily substituted by pharmacies, which are governed by state pharmacy law.
A biological product can also obtain pediatric market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existing exclusivity periods and patent terms. This six-month exclusivity, which runs from the end of other exclusivity protection or patent term, may be granted based on the voluntary completion of a pediatric study in accordance with an FDA-issued “Written Request” for such a study.
The BPCIA is complex and continues to be interpreted and implemented by the FDA. In July 2018, the FDA announced an action plan to encourage the development and efficient review of biosimilars, including the establishment of a new office within the agency that will focus on therapeutic biologics and biosimilars. On December 20, 2020, Congress amended the PHSA as part of the COVID-19 relief bill to further simplify the biosimilar review process by making it optional to show that conditions of use proposed in labeling have been previously approved for the reference product, which used to be a requirement of the application. In addition, government proposals have sought to reduce the 12-year reference product exclusivity period. As of March 2020, certain products previously approved as drugs under the FDCA, such as insulin and human growth hormone, are now deemed to be biologics under the PHSA, which means they may face competition through the biosimilars pathway and are not be eligible for the twelve-year period of exclusivity granted to new BLAs. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation. As a result, the ultimate impact, implementation, and impact of the BPCIA is subject to significant uncertainty.
Other Healthcare Laws and Compliance Requirements
Pharmaceutical companies are subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states and foreign jurisdictions in which they conduct their business. Such laws include, without limitation: the federal Anti-Kickback Statute, or AKS; the federal False Claims Act, or FCA; HIPAA and similar foreign, federal and state fraud, abuse and transparency laws.
The AKS prohibits, among other things, persons and entities from knowingly and willfully soliciting, receiving, offering or paying remuneration, to induce, or in return for, either the referral of an individual, or the purchase or recommendation of an item or service for which payment may be made under any federal healthcare program. The term remuneration has been interpreted broadly to include anything of value. The AKS has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand, and prescribers and purchasers on the other. The government often takes the position that to violate the AKS, only one purpose of the remuneration need be to induce referrals, even if there are other legitimate purposes for the remuneration. There are a number of statutory exceptions and regulatory safe harbors protecting some common activities from AKS prosecution, but they are drawn narrowly and practices that involve remuneration, such as consulting agreements, that may be alleged to be intended to induce prescribing, purchasing or recommending may be subject to scrutiny if they do not qualify for an exception or safe harbor. Our practices may not in all cases meet all of the criteria for protection under a statutory exception or regulatory safe harbor. Failure to meet all of the requirements of a particular applicable statutory exception or regulatory safe harbor does not make the conduct per se illegal under the AKS. Instead, the legality of the arrangement will be evaluated on a case-by-case basis based on a cumulative review of all of its facts and circumstances. A person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.
Civil and criminal false claims laws, including the FCA, and civil monetary penalty laws, which can be enforced through civil whistleblower or qui tam actions, prohibit, among other things, individuals or entities from knowingly presenting, or causing to be presented, claims for payment of federal government funds, including in federal healthcare programs, that are false or fraudulent. Pharmaceutical and other healthcare companies have been prosecuted under these laws for engaging in a variety of different types of conduct that caused the submission of false claims to federal healthcare programs. Under the AKS,
for example, a claim resulting from a violation of the AKS is deemed to be a false or fraudulent claim for purposes of the FCA. The FCA imposes mandatory treble damages and per-violation civil penalties up to approximately $23,000.
HIPAA created additional federal criminal statutes that prohibit, among other things, executing a scheme to defraud any healthcare benefit program, including private third-party payors, and making false statements relating to healthcare matters. A person or entity does not need to have actual knowledge of the healthcare fraud statute implemented under HIPAA or specific intent to violate the statute in order to have committed a violation.
The FDCA addresses, among other things, the design, production, labeling, promotion, manufacturing, and testing of drugs, biologics and medical devices, and prohibits such acts as the introduction into interstate commerce of adulterated or misbranded drugs or devices. The PHSA also prohibits the introduction into interstate commerce of unlicensed or mislabeled biological products.
The U.S. federal Physician Payments Sunshine Act requires certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program, with specific exceptions, to annually report to CMS information related to payments or other transfers of value made to physicians and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members. Beginning in 2022, such reporting obligations will be expanded to include payments and other transfers of value provided in 2021 to certain other healthcare professionals, including physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists, and certified nurse-midwives.
We are also subject to additional similar U.S. state and foreign law equivalents of each of the above federal laws, which, in some cases, differ from each other in significant ways, and may not have the same effect, thus complicating compliance efforts. If our operations are found to be in violation of any of such laws or any other governmental regulations that apply, we may be subject to penalties, including, without limitation, civil, criminal and administrative penalties, damages, fines, exclusion from government-funded healthcare programs, such as Medicare and Medicaid or similar programs in other countries or jurisdictions, integrity oversight and reporting obligations to resolve allegations of non-compliance, disgorgement, individual imprisonment, contractual damages, reputational harm, diminished profits and the curtailment or restructuring of our operations.
Data Privacy and Security
Numerous state, federal, and foreign laws govern the collection, dissemination, use, access to, confidentiality, and security of personal information, including health-related information. In the United States, numerous federal and state laws and regulations, including state data breach notification laws, state health information privacy laws, and federal and state consumer protection laws and regulations, govern the collection, use, disclosure, and protection of health-related and other personal information could apply to our operations or the operations of our partners. For example, HIPAA, as amended by HITECH, and their respective implementing regulations imposes privacy, security, and breach notification obligations on certain health care providers, health plans, and health care clearinghouses, known as covered entities, as well as their business associates that perform certain services that involve using, disclosing, creating, receiving, maintaining, or transmitting individually identifiable health information for or on behalf of such covered entities. Entities that are found to be in violation of HIPAA may be subject to significant civil, criminal, and administrative fines and penalties and/or additional reporting and oversight obligations if required to enter into a resolution agreement and corrective action plan with HHS to settle allegations of HIPAA non-compliance. Further, entities that knowingly obtain, use, or disclose individually identifiable health information maintained by a HIPAA covered entity in a manner that is not authorized or permitted by HIPAA may be subject to criminal penalties.
Even when HIPAA does not apply, according to the FTC, violating consumers’ privacy rights or failing to take appropriate steps to keep consumers’ personal information secure may constitute unfair acts or practices in or affecting commerce in violation of Section 5(a) of the Federal Trade Commission Act.
In addition, state laws govern the privacy and security of personal information, including health-related information, in certain circumstances. Failure to comply with these laws, where applicable, can result in the imposition of significant civil and/or criminal penalties and private litigation. For example, the CCPA, which went into effect on January 1, 2020, creates new data privacy obligations for covered companies and provides new privacy rights to California residents.
Coverage and Reimbursement
Significant uncertainty exists as to the coverage and reimbursement status of any pharmaceutical or biological product for which we obtain regulatory approval. Sales of any product, if approved, depend, in part, on the extent to which such product will be covered by third-party payors, such as federal, state, and foreign government healthcare programs, commercial insurance and managed healthcare organizations, and the level of reimbursement, if any, for such product by third-party payors. Decisions regarding whether to cover any of our product candidates, if approved, the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. Further, no uniform policy for coverage and reimbursement
exists in the United States, and coverage and reimbursement can differ significantly from payor to payor. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement rates, but also have their own methods and approval process apart from Medicare determinations. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our product candidates to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.
For products administered under the supervision of a physician, obtaining coverage and adequate reimbursement may be particularly difficult because of the higher prices often associated with such drugs. Additionally, separate reimbursement for the product itself or the treatment or procedure in which the product is used may not be available, which may impact physician utilization. In addition, companion diagnostic tests require coverage and reimbursement separate and apart from the coverage and reimbursement for their companion pharmaceutical or biological products. Similar challenges to obtaining coverage and reimbursement, applicable to pharmaceutical or biological products, will apply to companion diagnostics.
In addition, the U.S. government, state legislatures and foreign governments have continued implementing cost-containment programs, including price controls, restrictions on coverage and reimbursement and requirements for substitution of generic products. Third-party payors are increasingly challenging the prices charged for medical products and services, examining the medical necessity and reviewing the cost effectiveness of pharmaceutical or biological products, medical devices and medical services, in addition to questioning safety and efficacy. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product that receives approval. Decreases in third-party reimbursement for any product or a decision by a third-party not to cover a product could reduce physician usage and patient demand for the product.
Healthcare Reform
The United States and some foreign jurisdictions are considering or have enacted a number of reform proposals to change the healthcare system. There is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by federal and state legislative initiatives, including those designed to limit the pricing, coverage, and reimbursement of pharmaceutical and biopharmaceutical products, especially under government-funded health care programs, and increased governmental control of drug pricing.
The Affordable Care Act, or the ACA, which was enacted in March 2010, substantially changed the way healthcare is financed by both governmental and private insurers in the United States, and significantly affected the pharmaceutical industry. The ACA contains a number of provisions of particular import to the pharmaceutical and biotechnology industries, including, but not limited to, those governing enrollment in federal healthcare programs, a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected, and annual fees based on pharmaceutical companies’ share of sales to federal health care programs. Since its enactment, there have been judicial and Congressional challenges to certain aspects of the ACA, and we expect there will be additional challenges and amendments to the ACA in the future. For example, the Tax Act was enacted, which, among other things, removes penalties for not complying with the ACA’s requirement to carry health insurance, known as the “individual mandate,” effective January 1, 2019. Since the enactment of the Tax Act, there have been additional amendments to certain provisions of the ACA. In December 2019, the U.S. District Court for the Fifth Circuit upheld a ruling by a Texas U.S. District Court Judge that the ACA is unconstitutional in its entirety because the “individual mandate” was repealed by Congress as part of the Tax Act. The Supreme Court heard the case but overturned the decision on the basis that the plaintiffs lacked standing and did not address the constitutionality. The Supreme Court’s decision left open the opportunity for additional challenges to the ACA.
Other legislative changes have been proposed and adopted since the ACA was enacted, including automatic aggregate reductions of Medicare payments to providers of 2% per fiscal year as part of the federal budget sequestration under the Budget Control Act of 2011. These reductions went into effect in April 2013 and, due to subsequent legislative amendments, will remain in effect through 2030 with the exception of a temporary suspension from May 1, 2020 through December 31, 2020, unless additional action is taken by Congress. In addition, the Bipartisan Budget Act of 2018, among other things, amended the Medicare Act (as amended by the ACA) to increase the point-of-sale discounts that manufacturers must agree to offer under the Medicare Part D coverage discount program from 50% to 70% off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs being covered under Medicare Part D.
Moreover, there has recently been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted federal and state measures designed to, among other things, reduce the cost of prescription drugs, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement
methodologies for drug products. For example, in May 2019, CMS adopted a final rule allowing Medicare Advantage Plans the option to use step therapy for Part B drugs, permitting Medicare Part D plans to apply certain utilization controls to new starts of five of the six protected class drugs, and requiring the Explanation of Benefits for Part D beneficiaries to disclose drug price increases and lower cost therapeutic alternatives, which went into effect on January 1, 2021. In October 2020, the FDA issued guidance describing procedures for manufacturers to facilitate the importation of FDA-approved biologics manufactured abroad and originally intended for sale in a foreign country into the United States.
Although the Biden administration has stayed the effective dates of some last-minute drug price regulations issued by the Trump administration, Congress and the Biden administration have each indicated that they will continue to seek new legislative and/or administrative measures to control drug costs. At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.
Other Government Regulation Outside of the United States
In addition to regulations in the United States, we are subject to a variety of regulations in other jurisdictions governing, among other things, research and development, clinical trials, testing, manufacturing, safety, efficacy, quality control, labeling, packaging, storage, record keeping, distribution, reporting, export and import, advertising, marketing and other promotional practices involving biological products as well as authorization, approval as well as post-approval monitoring and reporting of our products. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries.
Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application much like the IND prior to the commencement of human clinical trials.
The requirements and process governing the conduct of clinical trials, including requirements to conduct additional clinical trials, product licensing, safety reporting, post-authorization requirements, marketing and promotion, interactions with healthcare professionals, pricing and reimbursement may vary widely from country to country. No action can be taken to market any product in a country until an appropriate approval application has been approved by the regulatory authorities in that country. The current approval process varies from country to country, and the time spent in gaining approval varies from that required for FDA approval. In certain countries, the sales price of a product must also be approved. The pricing review period often begins after market approval is granted. Even if a product is approved by a regulatory authority, satisfactory prices may not be approved for such product, which would make launch of such products commercially unfeasible in such countries.
Regulation in the European Union
European Data Laws
The collection and use of personal health data and other personal information in the European Union is governed by the provisions of the European General Data Protection Regulation (EU) 2016/679, or the GDPR, which came into force in May 2018, and related implementing laws in individual EU Member States. Under the GDPR, personal data can only be transferred to countries outside the EU Member States and the three additional European Economic Area, or EEA, countries (Norway, Iceland and Liechtenstein) that have adopted a national law implementing the GDPR if such cross-border transfers comply with specific conditions.
The GDPR imposes a number of strict obligations and restrictions on the ability to collect, analyze and transfer personal data of individuals within the EU and in the EEA, including health data from clinical trials and adverse event reporting. The GDPR also includes requirements relating to (i) the consent of the individuals to whom the personal data relates, (ii) the information provided to such individuals prior to processing their personal data, (iii) data processing obligations to the national data protection authorities and (iv) the security and confidentiality of the personal data. EU Member States may also impose additional requirements. The GDPR increased responsibility and liability in relation to personal data that we process.
Failure to comply with the requirements of the GDPR and the related national data protection laws of the EU Member States may result in significant monetary fines for noncompliance (up to €20 million or 4% of the annual global revenues of the noncompliant company, whichever is greater); other administrative penalties and a number of criminal offenses (punishable by uncapped fines) for organizations and, in certain cases, their directors and officers; and civil liability claims from individuals whose personal data was processed. Data protection authorities from the different EU Member States may still implement certain variations, enforce the GDPR and national data protection laws differently, and introduce additional national regulations and guidelines, which adds to the complexity of processing personal data in the EU. Guidance developed at both the EU level
and at the national level in individual EU Member States concerning implementation and compliance practices are regularly updated or otherwise revised.
Moreover, there is a growing trend towards required public disclosure of clinical trial data in the EU, which adds to the complexity of obligations relating to processing health data from clinical trials. Such public disclosure obligations are provided in the new EU Clinical Trials Regulation, European Medical Agency, or the EMA, disclosure initiatives and voluntary commitments by industry. Failure to comply with these obligations could lead to government enforcement actions and significant penalties against us, harm to our reputation, and adversely impact our business and operating results. The uncertainty regarding the interplay between different regulatory frameworks, such as the EU Clinical Trials Regulation and the GDPR, further adds to the complexity that we face with regard to data protection regulation.
With regard to the transfer of data from the EU to the United Kingdom, or UK, personal data may now freely flow from the EU to the UK since the UK is deemed to have an adequate data protection level. Such adequacy decisions include a ‘sunset clause’ which entails that the decisions will automatically expire four years after their entry into force (June 2025). Following the UK's withdrawal from the EU and the EEA, companies also have to comply with the UK’s data protection laws (including the GDPR as incorporated into UK national law). Penalties under this regime are up to the greater of £17.5 million or 4% of global turnover.
Drug and Biologic Development Process
The conduct of clinical trials is currently governed by the EU Clinical Trials Directive 2001/20/EC, or Clinical Trials Directive, and will be replaced by the EU Clinical Trials Regulation (EU) No. 536/2014, or Clinical Trials Regulation, once the latter comes into effect. The Clinical Trials Regulation introduces a complete overhaul of the existing regulation of clinical trials for medicinal products in the EU. It entered into force on January 31, 2022.
Under the current regime, which will expire after a transition period of three years (as outlined below in more detail), before a clinical trial can be initiated, it must be approved in each EU Member State where there is a site at which the trial is to be conducted. The approval must be obtained from two separate entities: the National Competent Authority, or NCA, and one or more Ethics Committees. The NCA of the EU Member States in which the clinical trial will be conducted must authorize the conduct of the trial, and the independent Ethics Committee must grant a positive opinion in relation to the conduct of the clinical trial in the relevant EU Member State before the commencement of the trial. Any substantial changes to the trial protocol or other information submitted with the clinical trial applications must be submitted to or approved by the relevant NCA and Ethics Committees. Under the current regime all suspected unexpected serious adverse reactions to the investigated drug that occur during the clinical trial must be reported to the NCA and to the Ethics Committees of the EU Member State where they occur.
A more unified procedure will apply under the new Clinical Trials Regulation. A sponsor will be able to submit a single application for approval of a clinical trial through a centralized EU clinical trials portal. One national regulatory authority (the reporting EU Member State proposed by the applicant) will take the lead in validating and evaluating the application consult and coordinate with the other concerned Member States. If an application is rejected, it may be amended and resubmitted through the EU clinical trials portal. If an approval is issued, the sponsor may start the clinical trial in all concerned Member States. However, a concerned EU Member State may in limited circumstances declare an “opt-out” from an approval and prevent the clinical trial form being conducted in such Member State. The Clinical Trials Regulation also aims to streamline and simplify the rules on safety reporting, and introduces enhanced transparency requirements such as mandatory submission of a summary of the clinical trial results to the EU Database. After several postponements of the effective date of the Clinical Trials Regulation, or CTR, due to technical difficulties with the underlying IT systems, the “go live” date of these systems and, accordingly, the coming into force of the regulation, occurred on January 31, 2022. The CTR foresees a three-year transition period. Member States will work in CTIS immediately after the system has gone live. For one year, until January 31, 2023, clinical trial sponsors can still choose whether to submit an initial clinical trial application in line with the current system (Clinical Trials Directive) or via CTIS. After January 31, 2023, submission of initial clinical trial applications via CTIS becomes mandatory and by January 31, 2025, all ongoing trials approved under the current Clinical Trials Directive will be governed by the new Clinical Trials Regulation and have to be transitioned to CTIS.
Under both the current regime and the new Clinical Trials Regulation, national laws, regulations, and the applicable Good Clinical Practice and Good Laboratory Practice standards must also be respected during the conduct of the trials, including the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use, or ICH, guidelines on Good Clinical Practice, or GCP, and the ethical principles that have their origin in the Declaration of Helsinki.
During the development of a medicinal product, the EMA and national regulators within the EU provide the opportunity for dialogue and guidance on the development program. At the EMA level, this is usually done in the form of scientific advice, which is given by the Committee for Medicinal Products for Human Use, or CHMP, on the recommendation of the Scientific Advice Working Party, or SAWP. A fee is incurred with each scientific advice procedure, but is significantly reduced for
designated orphan medicines. Advice from the EMA is typically provided based on questions concerning, for example, quality (chemistry, manufacturing and controls testing), nonclinical testing and clinical studies, and pharmacovigilance plans and risk-management programs. Advice is not legally binding with regard to any future marketing authorization application of the product concerned.
Drug Marketing Authorization
In the European Union, medicinal products, including advanced therapy medicinal products, or ATMPs, are subject to extensive pre- and post-market regulation by regulatory authorities at both the European Union and national levels. ATMPs comprise gene therapy products, somatic cell therapy products and tissue engineered products, which are genes, cells or tissues that have undergone substantial manipulation and that are administered to human beings in order to cure, diagnose or prevent diseases or regenerate, repair or replace a human tissue. We anticipate that our gene therapy development products will be regulated as ATMPs in the European Union under the EU Regulation (EC) No 1394/2007 on advanced therapy medicinal products, or ATMP Regulation. Pursuant to the ATMP Regulation, the Committee on Advanced Therapies, or CAT, is responsible in conjunction with the CHMP for the evaluation of ATMPs. The CHMP and CAT are also responsible for providing guidelines on ATMPs. These guidelines provide additional guidance on the factors that the EMA will consider in relation to the development and evaluation of ATMPs and include, among other things, the preclinical studies required to characterize ATMPs; the manufacturing and control information that should be submitted in a marketing authorization application; and post-approval measures required to monitor patients and evaluate the long term efficacy and potential adverse reactions of ATMPs. Although such guidelines are not legally binding, compliance with them is often necessary to gain and maintain approval for product candidates.
In the EEA, after completion of all required clinical testing, medicinal products may only be placed on the market after a related Marketing Authorization, or MA, has been granted. MAs can be obtained through, amongst others, a centralized procedure, which is compulsory for certain medicinal products such as ATMPs. The centralized procedure provides for the grant of a single MA by the European Commission, or EC, that is valid for all 27 EU Member States and, after respective national implementing decisions, in the three additional EEA Member States (Iceland, Norway, and Liechtenstein). The centralized procedure is compulsory for certain medicinal products, including medicinal products derived from biotechnological processes, orphan medicinal products, ATMPs and products with a new active substance indicated for the treatment of AIDS, cancer, neurodegenerative disorders, diabetes, auto-immune and viral diseases. It is optional for medicinal products containing a new active substance not yet authorized in the EEA before May 20, 2004, that constitute significant therapeutic, scientific or technical innovations, or for which the grant of a MA through the centralized procedure would be in the interest of public health at EU level. The timeframe for the evaluation of an application under the centralized procedure is 210 days, excluding clock stops. Typically, the overall process takes a year or more unless the application is eligible for an accelerated assessment. Applications may be eligible for accelerated assessment if the CHMP decides the product is of major interest for public health and therapeutic innovation. On request, the CHMP can reduce the time frame to 150 days if the applicant provides sufficient justification for an accelerated assessment. The CHMP will provide a positive opinion regarding the application only if it meets certain quality, safety and efficacy requirements. However, the EC has final authority for granting the MA within 67 days after receipt of the CHMP opinion.
The decentralized marketing authorization procedure permits companies to file identical applications for a marketing authorization to the competent authorities in several EU Member States simultaneously for a pharmaceutical product that has not yet been authorized in any EU Member State. This procedure is available for pharmaceutical products not falling within the mandatory scope of the centralized procedure. The competent authority of a single EU Member State, the reference member state, is appointed to review the application and provide an assessment report. The competent authorities of the other EU Member States, the concerned member states, are subsequently required to grant a marketing authorization for their territories on the basis of this assessment. The only exception to this is where the competent authority of an EU Member State considers that there are concerns of potential serious risk to public health related to authorization of the product. In these circumstances the matter is submitted to the Heads of Medicines Agencies, or CMDh, for review.
All new marketing authorization applications must include a Risk Management Plan, or RMP, describing the risk management system that the company will put in place and documenting measures to prevent or minimize the risks associated with the product. The regulatory authorities may also impose specific obligations as a condition of the MA. RMPs and Periodic Safety Update Reports, or PSURs, are routinely available to third parties requesting access, subject to limited redactions.
Additionally, the holder of a marketing authorization for an ATMP must put in place and maintain a system to ensure that each individual product and its starting and raw materials, including all substances coming into contact with the cells or tissues it may contain, can be traced through the sourcing, manufacturing, packaging, storage, transport and delivery to the relevant healthcare institution where the product is used.
MAs have an initial duration of five years. The authorization may subsequently be renewed for an unlimited period on the basis of a reevaluation of the risk-benefit balance unless the EC or the national competent authority grants only a five-year
renewal on justified grounds relating to pharmacovigilance. Applications for renewal must be made to the EMA at least nine months before the five-year period expires.
Data and Market Exclusivity
As in the United States, it may be possible to obtain a period of market and/or data exclusivity in the EU that would have the effect of postponing the entry into the marketplace of a competitor’s generic, hybrid or biosimilar product (even if the pharmaceutical product has already received a marketing authorization) and prohibiting another applicant from relying on the marketing authorization holder’s pharmacological, toxicological and clinical data in support of another marketing authorization for the purposes of submitting an application, obtaining MA or placing the product on the market. New chemical entities, or NCE, approved in the EU qualify for eight years of data exclusivity and 10 years of marketing exclusivity.
An additional non-cumulative one-year period of marketing exclusivity is possible if during the data exclusivity period (the first eight years of the 10-year marketing exclusivity period), the MA holder obtains an authorization for one or more new therapeutic indications that are deemed to bring a significant clinical benefit compared to existing therapies.
The data exclusivity period begins on the date of the product’s first marketing authorization in the EU. After eight years, a generic product application may be submitted and generic companies may rely on the marketing authorization holder’s data. However, a generic product cannot launch until two years later (or a total of 10 years after the first marketing authorization in the EU of the innovator product), or three years later (or a total of 11 years after the first marketing authorization in the EU of the innovator product) if the marketing authorization holder obtains marketing authorization for a new indication with significant clinical benefit within the eight-year data exclusivity period. Additionally, another noncumulative one-year period of data exclusivity can be added to the eight years of data exclusivity where an application is made for a new indication for a well-established substance, provided that significant preclinical or clinical studies were carried out in relation to the new indication. Another year of data exclusivity may be added to the eight years, where a change of classification of a pharmaceutical product has been authorized on the basis of significant pre-trial tests or clinical trials (when examining an application by another applicant for or holder of market authorization for a change of classification of the same substance the competent authority will not refer to the results of those tests or trials for one year after the initial change was authorized).
Products may not be granted data exclusivity since there is no guarantee that a product will be considered by the European Union’s regulatory authorities to include a NCE. Even if a compound is considered to be a NCE and the MA applicant is able to gain the prescribed period of data exclusivity, another company nevertheless could also market another version of the medicinal product if such company can complete a full marketing authorization application with their own complete database of pharmaceutical tests, preclinical studies and clinical trials and obtain MA of its product.
Orphan Designation and Exclusivity
The criteria for designating an orphan medicinal product in the European Union are similar in principle to those in the United States. The EMA grants orphan drug designation if the medicinal product is intended for the diagnosis, prevention or treatment of (i) a life-threatening or chronically debilitating condition affecting no more than five in 10,000 persons in the European Union (prevalence criterion). In addition, Orphan Drug Designation can be granted if, for economic reasons, the medicinal product would be unlikely to be developed without incentives and if there is no other satisfactory method approved in the European Union of diagnosing, preventing, or treating the condition, or if such a method exists, the proposed medicinal product is a significant benefit to patients affected by the condition. An application for orphan drug designation (which is not a marketing authorization, as not all orphan-designated medicines reach the authorization application stage) must be submitted first before an application for marketing authorization of the medicinal product is submitted. The applicant will receive a fee reduction for the marketing authorization application if the orphan drug designation has been granted, but not if the designation is still pending at the time the marketing authorization is submitted, and sponsors must submit an annual report to EMA summarizing the status of development of the medicine. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. Designated orphan medicines are eligible for conditional marketing authorization.
The EMA’s Committee for Orphan Medicinal Products reassesses the orphan drug designation of a product in parallel with the review for a marketing authorization; for a product to benefit from market exclusivity it must maintain its orphan drug designation at the time of marketing authorization review by the EMA and approval by the EC. Additionally, any marketing authorization granted for an orphan medicinal product must only cover the therapeutic indication(s) that are covered by the orphan drug designation. Upon the grant of a marketing authorization, orphan drug designation provides up to ten years of market exclusivity in the orphan indication.
During the 10-year period of market exclusivity, with a limited number of exceptions, the regulatory authorities of the EU Member States and the EMA may not accept applications for marketing authorization, accept an application to extend an existing marketing authorization or grant marketing authorization for other similar medicinal products for the same therapeutic indication. A similar medicinal product is defined as a medicinal product containing a similar active substance or substances as
contained in a currently authorized orphan medicinal product, and which is intended for the same therapeutic indication. An orphan medicinal product can also obtain an additional two years of market exclusivity for an orphan-designated condition when the results of specific studies are reflected in the Summary of Product Characteristics, or SmPC, addressing the pediatric population and completed in accordance with a fully compliant PIP. No extension to any supplementary protection certificate can be granted on the basis of pediatric studies for orphan indications.
The 10-year market exclusivity may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, i.e. the condition prevalence or financial returns criteria under Article 3 of Regulation (EC) No. 141/2000 on orphan medicinal products. When the period of orphan market exclusivity for an indication ends, the orphan drug designation for that indication expires as well. Orphan exclusivity runs in parallel with normal rules on data exclusivity and market protection. Additionally, a marketing authorization may be granted to a similar medicinal product (orphan or not) for the same or overlapping indication subject to certain requirements.
Pediatric Development
In the European Union, companies developing a new medicinal product are obligated to study their product in children and must therefore submit a PIP together with a request for agreement to the EMA. The EMA issues a decision on the PIP based on an opinion of the EMA’s Pediatric Committee, or PDCO. Companies must conduct pediatric clinical trials in compliance with the PIP approved by the EMA, unless a deferral (e.g. until enough information to demonstrate its effectiveness and safety in adults is available) or waiver (e.g., because the relevant disease or condition occurs only in adults) has been granted by the EMA. The marketing authorization application for the product must include the results of all pediatric clinical trials performed and details of all information collected in compliance with the approved PIP, unless a waiver or a deferral has been granted, in which case the pediatric clinical trials may be completed at a later date. Products that are granted a marketing authorization on the basis of the pediatric clinical trials conducted in accordance with the approved PIP are eligible for a six month extension of the protection under a supplementary protection certificate (if any is in effect at the time of approval) or, in the case of orphan medicinal products, a two year extension of the orphan market exclusivity. This pediatric reward is subject to specific conditions and is not automatically available when data in compliance with the approved PIP are developed and submitted. An approved PIP is also required when a marketing-authorization holder wants to add a new indication, pharmaceutical form or route of administration for a medicine that is already authorized and covered by intellectual property rights.
PRIME Designation
In March 2016, the EMA launched an initiative to facilitate development of product candidates in indications, often rare, for which few or no therapies currently exist. The PRIority MEdicines, or PRIME, scheme is intended to encourage drug development in areas of unmet medical need and provides accelerated assessment of products representing substantial innovation reviewed under the centralized procedure. Products from small- and medium-sized enterprises may qualify for earlier entry into the PRIME scheme than larger companies on the basis of compelling non-clinical data and tolerability data from initial clinical trials. Many benefits accrue to sponsors of product candidates with PRIME designation, including but not limited to, early and proactive regulatory dialogue with the EMA, frequent discussions on clinical trial designs and other development program elements, and potentially accelerated marketing authorization application assessment once a dossier has been submitted. Importantly, once a candidate medicine has been selected for the PRIME scheme, a dedicated contact point and rapporteur from the CHMP or from CAT are appointed facilitating increased understanding of the product at EMA’s Committee level. A kick-off meeting with the CHMP/CAT rapporteur initiates these relationships and includes a team of multidisciplinary experts to provide guidance on the overall development plan and regulatory strategy. PRIME eligibility does not change the standards for product approval, and there is no assurance that any such designation or eligibility will result in expedited review or approval.
Post-Approval Regulation
Similar to the United States, both MA holders and manufacturers of medicinal products are subject to comprehensive regulatory oversight by the EMA, the EC and/or the competent regulatory authorities of the EU Member States. This oversight applies both before and after grant of manufacturing licenses and marketing authorizations. It includes control of compliance with EU good manufacturing practices rules, manufacturing authorizations, pharmacovigilance rules and requirements governing advertising, promotion, sale, and distribution, recordkeeping, importing and exporting of medicinal products.
Failure by us or by any of our third-party partners, including suppliers, manufacturers and distributors to comply with EU laws and the related national laws of individual EU Member States governing the conduct of clinical trials, manufacturing approval, marketing authorization of medicinal products and marketing of such products, both before and after grant of marketing authorization, statutory health insurance, bribery and anti-corruption or other applicable regulatory requirements may result in administrative, civil or criminal penalties. These penalties could include delays or refusal to authorize the conduct of clinical trials or to grant marketing authorization, product withdrawals and recalls, product seizures, suspension, withdrawal or
variation of the marketing authorization, total or partial suspension of production, distribution, manufacturing or clinical trials, operating restrictions, injunctions, suspension of licenses, fines and criminal penalties.
The holder of a marketing authorization for a medicinal product must also comply with EU pharmacovigilance legislation and its related regulations and guidelines, which entail many requirements for conducting pharmacovigilance, or the assessment and monitoring of the safety of medicinal products.
These pharmacovigilance rules can impose on holders of MAs the obligation to conduct a labor intensive collection of data regarding the risks and benefits of marketed medicinal products and to engage in ongoing assessments of those risks and benefits, including the possible requirement to conduct additional clinical studies or post-authorization safety studies to obtain further information on a medicine’s safety, or to measure the effectiveness of risk-management measures, which may be time consuming and expensive and could impact our profitability. MA holders must establish and maintain a pharmacovigilance system and appoint an individual qualified person for pharmacovigilance, who is responsible for oversight of that system. Key obligations include expedited reporting of suspected serious adverse reactions and submission of PSURs in relation to medicinal products for which they hold MAs. The EMA reviews PSURs for medicinal products authorized through the centralized procedure. If the EMA has concerns that the risk benefit profile of a product has varied, it can adopt an opinion advising that the existing MA for the product be suspended, withdrawn or varied. The agency can advise that the MA holder be obliged to conduct post-authorization Phase IV safety studies. If the EC agrees with the opinion, it can adopt a decision varying the existing MA. Failure by the marketing authorization holder to fulfill the obligations for which the EC’s decision provides can undermine the ongoing validity of the MA.
More generally, non-compliance with pharmacovigilance obligations can lead to the variation, suspension or withdrawal of the MA for the product or imposition of financial penalties or other enforcement measures.
The manufacturing process for pharmaceutical products in the European Union is highly regulated and regulators may shut down manufacturing facilities that they believe do not comply with regulations. Manufacturing requires a manufacturing authorization, and the manufacturing authorization holder must comply with various requirements set out in the applicable EU laws, regulations and guidance, including Directive 2001/83/EC, Directive 2003/94/EC, Regulation (EC) No 726/2004 and the European Commission Guidelines for Good Manufacturing Practice, or GMP. These requirements include compliance with EU GMP standards when manufacturing pharmaceutical products and active pharmaceutical ingredients, including the manufacture of active pharmaceutical ingredients outside of the European Union with the intention to import the active pharmaceutical ingredients into the European Union. Similarly, the distribution of pharmaceutical products into and within the European Union is subject to compliance with the applicable EU laws, regulations and guidelines, including the requirement to hold appropriate authorizations for distribution granted by the competent authorities of the EU Member States. The manufacturer or importer must have a qualified person who is responsible for certifying that each batch of product has been manufactured in accordance with GMP, before releasing the product for commercial distribution in the European Union or for use in a clinical trial. Manufacturing facilities are subject to periodic inspections by the competent authorities for compliance with GMP.
Sales and Marketing Regulations
The advertising and promotion of our products is also subject to EU laws concerning promotion of medicinal products, interactions with physicians, misleading and comparative advertising and unfair commercial practices. In addition, other national legislation of individual EU Member States may apply to the advertising and promotion of medicinal products and may differ from one country to another. These laws require that promotional materials and advertising in relation to medicinal products comply with the product’s SmPC as approved by the competent regulatory authorities. The SmPC is the document that provides information to physicians concerning the safe and effective use of the medicinal product. It forms an intrinsic and integral part of the marketing authorization granted for the medicinal product. Promotion of a medicinal product that does not comply with the SmPC is considered to constitute off-label promotion. All advertising and promotional activities for the product must be consistent with the approved SmPC and therefore all off-label promotion is prohibited. Direct-to-consumer advertising of prescription-only medicines is also prohibited in the European Union. Violations of the rules governing the promotion of medicinal products in the European Union could be penalized by administrative measures, fines and imprisonment. These laws may further limit or restrict the advertising and promotion of our products to the general public and may also impose limitations on its promotional activities with healthcare professionals.
Anti-Corruption Legislation
In the EU, interactions between pharmaceutical companies and physicians are also governed by strict laws, regulations, industry self-regulation codes of conduct and physicians’ codes of professional conduct both at EU level and in the individual EU Member States. The provision of benefits or advantages to physicians to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is prohibited in the European Union. The provision of benefits or advantages to physicians is also governed by the national anti-bribery laws of the EU Member States. Violation of these laws could result in substantial fines and imprisonment.
Payments made to physicians in certain EU Member States also must be publicly disclosed. Moreover, agreements with physicians must often be the subject of prior notification and approval by the physician’s employer, his/her regulatory professional organization, and/or the competent authorities of the individual EU Member States. These requirements are provided in the national laws, industry codes, or professional codes of conduct, applicable in the individual EU Member States. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.
Other Markets
The UK formally left the EU on January 31, 2020 and the transition period, during which EU laws continued to apply to the UK, expired on December 31, 2020. This means EU laws now only apply to the UK in respect of Northern Ireland as laid out in the Protocol on Ireland and Northern Ireland. Following the end of the transition period, the EU and the UK concluded the TCA, which applied provisionally from January 1, 2021 and entered into force on May 1, 2021.
The TCA includes provisions affecting the life sciences sector (including on customs and tariffs) but areas for further discussion between the EU and the UK remain. Some specific provisions concerning pharmaceuticals are in place, including the mutual recognition of Good Manufacturing Practice, or GMP, and issued GMP documents. The TCA does not, however, contain wholesale mutual recognition of UK and EU pharmaceutical regulations and product standards.
Since January 1, 2021, the EU laws which have been transposed into UK law through secondary legislation continue to be applicable in the UK as “retained EU law.” As there is no general power to amend these regulations, the UK government has enacted the Medicines and Medical Devices Act 2021. The purpose of the act is to enable the existing regulatory frameworks in relation to human medicines, clinical trials of human medicines, veterinary medicines and medical devices to be updated. The powers under the act may only be exercised in relation to specified matters and must safeguard public health.
Specified provisions of the Medicines and Medical Devices Act 2021 entered into force on February 11, 2021. The remaining provisions came into effect within two months of February 11, 2021 or will otherwise come into effect as stipulated in subsequent statutory instruments. The Medicines and Medical Devices Act 2021 supplements the UK Medical Devices Regulations 2002, or the UK Regulations, which are based on the EU Medical Devices Directive as amended to reflect the UK’s post-Brexit regulatory regime. Notably, the UK Regulations do not include any of the revisions that have been made by the EU Medical Devices Regulation (EU) 2017/745, which, since May 26, 2021, now applies in all EU Member States.
The UK’s Medicines and Healthcare products Regulatory Agency, or MHRA, conducted a comprehensive consultation between September and November 2021 on proposals to develop a new UK regime for medical devices in the UK. The proposals include more closely aligning definitions for medical devices and in vitro medical devices with internationally recognized definitions and changing the classification of medical devices according to levels or risk. The proposals are intended to improve patient and public safety and increase the appeal of the UK market. The new regime is planned to come into force on July 1, 2023, which will align with the date from which the UK is due to stop accepting CE marked medical devices and require UK Conformity Assessed marking. It is envisaged that, in Northern Ireland, the amended regime could run in parallel with any existing or future EU rules in accordance with the Protocol on Ireland and Northern Ireland.
For other countries outside of the European Union, such as countries in Eastern Europe, Latin America or Asia, the requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. In all cases, again, the clinical trials must be conducted in accordance with GCP and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki.
If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension of clinical trials, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.
Human Capital Management
Shattuck Employees
As of December 31, 2021, Shattuck employed 85 full-time employees at two locations in the United States, including Austin, TX and Durham, NC. During 2021, we expanded our capabilities across the two sites by hiring 37 new employees. These employees were hired to support our clinical development, preclinical research and development, and efforts associated with operating as a public company.
We expect to continue to hire additional employees in 2022 and beyond with a focus on increasing expertise and bandwidth in preclinical and clinical research and development and in-house process development and manufacturing, as well as expanding our in-house general and administrative functions. The Company continually evaluates business needs and opportunities, with a hiring philosophy that balances in-house expertise with outsourced services. Currently, we outsource clinical trial work to clinical research organizations and drug manufacturing to contract manufacturers.
Drug development is a complex endeavor which requires deep expertise and experience across a broad array of disciplines. Pharmaceutical companies compete for a limited number of highly qualified applicants to fill specialized positions. To attract these applicants to the Company, Shattuck offers a total rewards package consisting of a base salary and cash target bonus targeting the 25th to 75th percentile of market based on geography, a comprehensive benefit package and equity compensation for full-time employees. Bonus opportunity and equity compensation increase as a percentage of total compensation based on level of responsibility.
We believe our management team has the experience necessary to effectively execute our strategy and advance our product and technology leadership. A large majority of Shattuck’s employees have obtained advanced degrees in their professions. Shattuck supports our employees’ further development with individualized development plans, mentoring, coaching, group training and conference attendance.
Research and Development
Research and development expenses for the years ended December 31, 2021 and 2020 were $56.6 million and $37.5 million, respectively.
Corporate Information
We were incorporated in Delaware in May 2016. Our corporate offices are located at 500 W. 5th Street, Suite 1200, Austin, Texas 78701 and 21 Alexandria Way, Suite 200, Durham, North Carolina 27709 and our telephone number is (512) 900-4690. Our website address is www.shattucklabs.com. Information contained on or accessible through our website is not a part of this Annual Report on Form 10-K, and the inclusion of our website address in this Annual Report on Form 10-K is for convenience only and the information on the referenced website does not constitute a part of nor is incorporated by reference into this report.
Our reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, including our annual reports on Form 10-K, our quarterly reports on Form 10-Q and our current reports on Form 8-K, and amendments to those reports, are accessible through our website, free of charge, as soon as reasonably practicable after these reports are filed electronically with, or otherwise furnished to, the SEC. These SEC reports can be accessed through the “Investors” section of our website.

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ITEM 1A. RISK FACTORS
Item 1A. Risk Factors
Investing in shares of our common stock involves a high degree of risk. You should carefully consider the following risks and uncertainties, together with all of the other information contained in this Annual Report on Form 10-K before making an investment decision. The occurrence of any of the following risks could materially and adversely affect our business, financial condition, reputation, or results of operations. In such case, the trading price of shares of our common stock could decline, and you may lose all or part of your investment. It is not possible to predict or identify all such risks; our operations could also be affected by factors, events or uncertainties that are not presently known to us or that we currently do not consider to present significant risks to our operations. Therefore, you should not consider the following risks to be a complete statement of all the potential risks or uncertainties that we face.
Summary of Key Risk Factors
•We are an early clinical-stage biotechnology company and have incurred significant losses since our inception, and we expect to incur losses for the foreseeable future. We have no products approved for commercial sale and may never achieve or maintain profitability.
•Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.
•We will require additional funding in order to complete development of our product candidates and commercialize our products, if approved. Additional funding may not be available on acceptable terms, or at all. If we are unable to raise capital when needed, we could be forced to delay, reduce, or eliminate our product development programs, our efforts to access manufacturing capacity and our commercialization efforts.
•Raising additional capital may cause dilution to our existing stockholders, restrict our operations, or require us to relinquish rights to our technologies or product candidates.
•Public health crises such as pandemics or other events could materially and adversely affect our business operations, workforce, product development activities, research and development activities, preclinical and clinical trials, and financial condition.
•Our ARC and GADLEN platforms are based on novel technologies that are unproven and may not result in approvable or marketable products, which exposes us to unforeseen risks and makes it difficult for us to predict the time and cost of product development and potential for regulatory approval. We may not be successful in our efforts to use and expand our technology platforms to develop and commercialize our product candidates, or may experience significant delays in doing so.
•Our clinical trials may fail to demonstrate substantial evidence of the safety and efficacy of our product candidates or any future product candidates, which would prevent or delay or limit the scope of regulatory approval and commercialization.
•Interim, topline or preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data becomes available and are subject to audit and verification procedures that could result in material changes in the final data.
•Clinical drug development is a lengthy and expensive process with uncertain outcomes. If clinical trials of our product candidates are prolonged or delayed, we or any collaborators may be unable to obtain required regulatory approvals, and therefore be unable to commercialize our product candidates on a timely basis or at all.
•Our product candidates may have serious adverse, undesirable, or unacceptable side effects or other properties that may delay or prevent marketing approval.
•If we experience delays or difficulties enrolling patients in our clinical trials, our research and development efforts and business, financial condition, and results of operations could be materially and adversely affected.
•The development and commercialization of biopharmaceutical products is subject to extensive regulation, and the regulatory approval processes of the FDA and comparable foreign authorities are lengthy, time-consuming, and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for our product candidates on a timely basis if at all, our business will be substantially harmed. We operate in highly competitive and rapidly changing industries, which may result in others discovering, developing or commercializing competing products before or more successfully than we do.
•We rely on third parties to manufacture biological materials and our product candidates. The manufacture of our product candidates is complex.
•We rely on patents and other intellectual property rights to protect our technology, including product candidates from our ARC and GADLEN platforms, methods used to manufacture those product candidates, formulations thereof, and the methods for treating patients using those product candidates.
Risks Related to Our Business
We are an early clinical-stage biotechnology company and have incurred significant losses since our inception, and we expect to incur losses for the foreseeable future. We have no products approved for commercial sale and may never achieve or maintain profitability.
Biotechnology product development is a highly speculative undertaking and involves a substantial degree of risk. We have incurred significant operating losses since inception. For the years ended December 31, 2021 and 2020, we reported a net loss of $45.0 million and $36.6 million, respectively. As of December 31, 2021, we had an accumulated deficit of $117.1 million. We expect to continue to incur significant operating losses for the foreseeable future. To become and remain profitable, we must succeed in developing and eventually commercializing products that generate significant revenue. We may never succeed in these activities and, even if we do, we may never generate revenue that is sufficient to achieve profitability.
Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.
Since our inception in 2016, we have devoted a significant portion of our resources to developing our product candidates, our other research and development efforts, building our intellectual property portfolio, raising capital, and providing general and administrative support for these operations. While we are conducting Phase 1 clinical trials for SL-172154 and SL-279252, we have not completed a clinical trial for any product candidate. We have not yet demonstrated our ability to successfully complete product development activities, complete clinical trials (including Phase 3 or other pivotal clinical trials), obtain regulatory approvals, manufacture a commercial-scale product or arrange for a third-party to do so on our behalf, or conduct sales and marketing activities necessary for successful product commercialization. Additionally, we expect our financial condition and operating results to continue to fluctuate significantly from period to period due to a variety of factors, many of which are beyond our control. Consequently, any predictions you may make about our future success or viability may not be as accurate as they could be if we had a longer operating history.
We will require additional funding in order to complete development of our product candidates and commercialize our products, if approved. Additional funding may not be available on acceptable terms, or at all. If we are unable to raise capital when needed, we could be forced to delay, reduce, or eliminate our product development programs and other operations.
Based on our current business plans, we estimate that our existing cash and cash equivalents and short-term investments will enable us to fund our operating expenses into the second half of 2024. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect, requiring us to seek additional funds sooner than planned, through public or private equity or debt financings or other sources, such as strategic collaborations. In addition, we may seek additional capital due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. Attempting to secure additional financing may divert our management from our day-to-day activities, which may materially and adversely affect the development of our product candidates. Our ability to raise additional funds will depend on financial, economic, and market conditions and other factors, over which we may have no or limited control. Additional funds may not be available when we need them, on terms that are acceptable to us or at all.
Raising additional capital may cause dilution to our existing stockholders, restrict our operations, or require us to relinquish rights to our technologies or product candidates.
If we raise additional capital through the sale of equity or convertible debt securities, the ownership interests of existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our existing stockholders’ rights as holders of our common stock. In addition, the possibility of such issuance may cause the market price of our common stock to decline. Debt financing, if available, may result in increased fixed payment obligations and involve agreements that include covenants limiting or restricting our ability to take certain actions, which could materially and adversely impact our ability to conduct our business.
Public health crises such as pandemics or other events could materially and adversely affect our business operations, workforce, product development activities, research and development activities, preclinical and clinical trials, and financial condition.
We expect that our program timelines may continue to be negatively affected by the COVID-19 pandemic, which could materially and adversely affect our business, financial condition, and results of operations. We have experienced delays in our clinical trials of SL-172154 and SL-279252 as a result of the ongoing pandemic, including delays with certain third-party
vendors supporting these trials. In addition, we have experienced and may in the future experience additional disruptions, including:
•delays or difficulties in initiating or expanding clinical trials, including delays or difficulties with clinical site initiation and recruiting clinical site investigators and clinical site staff;
•delays or difficulties in manufacturing sufficient quantities of materials of our product candidates for preclinical studies and clinical trials, including difficulty reserving manufacturing capacity with our third-party vendors and obtaining sufficient quantities of raw materials required for our manufacturing processes;
•increased rates of patients either declining to enroll in our clinical trials, missing treatments, or withdrawing from our clinical trials following enrollment as a result of contracting COVID-19 or other health conditions or being forced to quarantine;
•interruption of key clinical trial activities; and
•interruption or delays in the operations of the FDA and comparable foreign regulatory agencies.
Further, due to public health guidance measures, we may need to implement policies that could negatively impact productivity, or disrupt, delay, or otherwise materially and adversely impact our business. For example, we have in the past and may again in the future implement work-from-home requirements, and if our personnel are required to work from home, some of our research activities that require our personnel to be in our laboratories may be delayed. The COVID-19 pandemic may also result in the loss of some of our employees and key personnel, either temporarily or permanently, which could negatively impact our operations.
The COVID-19 pandemic continues to evolve rapidly. The ultimate impact of the COVID-19 pandemic or a similar public health emergency is highly uncertain and subject to change. We do not yet know the full extent of potential delays or impacts on our business, our research, our clinical trials, healthcare systems, or the global economy as a whole. Specifically, biologics manufacturing resources are being diverted to assist with COVID-19 vaccine production, which may result in delays in the manufacture of our product candidates. In addition, hospitals, healthcare workers, and other medical care resources are being diverted to treat COVID-19 patients and administer COVID-19 vaccines, which may result in further delays to the progress of our clinical trials. We do not yet know the full impact that the COVID-19 pandemic may have on our business. Any one or a combination of these events could have a material and adverse effect on our results of operations and financial condition.
Our ARC and GADLEN platforms are based on novel technologies that are unproven and may not result in approvable or marketable products, which exposes us to unforeseen risks and makes it difficult for us to predict the time and cost of product development and potential for regulatory approval. We may not be successful in our efforts to use and expand our technology platforms to develop and commercialize our current and future product candidates, or may experience significant delays in doing so.
A key element of our strategy is to use and expand our proprietary ARC and GADLEN platforms to build a pipeline of product candidates and progress these product candidates through preclinical and clinical development. Although our research and development efforts to date have resulted in a pipeline of product candidates directed at various cancers and other indications, we have not received regulatory approval for any of our product candidates. The scientific research that forms the basis of our efforts to develop product candidates with our proprietary platforms is still ongoing. Further, the scientific evidence to support the feasibility of developing therapeutic treatments based on our platforms is both preliminary and limited. Given the novelty of our technologies, we intend to work closely with the FDA and other regulatory authorities to perform the requisite scientific analyses and evaluation of our methods to obtain regulatory approval for our product candidates. We cannot be certain that our approach will lead to the development of approvable or marketable products, alone or in combination with other therapies. To our knowledge, our dual-sided fusion protein product candidates have not previously been tested in humans and may have properties that negatively impact safety or efficacy, such as greater immunogenicity when compared to existing therapeutics. Moreover, our product candidates may have unexpected biological interactions when administered in vivo. For example, it may be necessary to either implement a loading dose strategy or delay enrollment of patients recently treated with anti-PD-1 antibodies to mitigate interactions between anti-PD-1 antibodies and SL-279252. Finally, the FDA or other regulatory agencies may lack experience in evaluating the safety and efficacy of our product candidates, which could result in a longer than expected regulatory review process, increase our expected development costs, and delay or prevent commercialization of our product candidates.
The successful development of our product candidates will depend on several factors, including the successful and timely completion of clinical trials and preclinical studies, successful patient enrollment in clinical trials, receipt of regulatory approvals and marketing authorizations, commercially viable manufacturing processes, and our ability to demonstrate the safety and efficacy of our product candidates.
Our ability to generate revenues, which we do not expect will occur for at least the next several years, if ever, will depend heavily on the successful development and eventual commercialization of our product candidates, which may never occur. We currently generate no revenue from sales of any products, and we may never be able to develop or commercialize a marketable product, which could result in significant harm to our financial position and materially and adversely affect our share price.
Our future growth and ability to compete depends on retaining our key personnel and recruiting additional qualified personnel. We expect to continue to expand our capabilities, and as a result, we may encounter difficulties in managing our growth, which could disrupt our operations.
Our success depends upon the continued contributions of our key management, scientific, and technical personnel, many of whom have been instrumental for us and have substantial experience with our product candidates and related technologies. Although we have employment agreements with certain of our key employees, including our Chief Executive Officer, these employment agreements provide for at-will employment, which means that any of our employees could leave our employment at any time, with or without notice.
We expect to experience continued growth in the number of our employees and the scope of our operations, particularly in the areas of drug development, clinical operations, business development, manufacturing, regulatory affairs, quality assurance, human resources, legal, accounting and finance and, ultimately, sales and marketing. The competition for qualified personnel in the biotechnology and pharmaceutical industries is intense, and our future success depends upon our ability to attract, retain, and motivate highly-skilled scientific, technical, and managerial employees. If our recruitment and retention efforts are unsuccessful in the future, it may be difficult for us to implement our business strategy, which could have a material adverse effect on our business.
To manage our anticipated future growth, we must continue to implement and improve our managerial, operational, and financial systems, and expand our facilities. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expansion of our operations systems and facilities. These activities may lead to significant costs and may divert our management and other resources. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.
In addition, we are a small company with limited resources, our business prospects are uncertain and our stock price is volatile. For some or all of the foregoing reasons, we may not be able to recruit all of the management, technical and other personnel that we require or we may be unable to retain all of our existing personnel. In such event, we may be required to limit our growth and expansion efforts and our business and financial results may suffer.
Risks Related to the Development and Clinical Testing of Our Product Candidates
Our clinical trials may fail to demonstrate substantial evidence of the safety and efficacy of our product candidates or any future product candidates, which would prevent or delay or limit the scope of regulatory approval and commercialization.
To obtain the requisite regulatory approvals to market and sell any product candidates, we must demonstrate through extensive preclinical studies and clinical trials that our investigational drug products are safe and effective for use in each targeted indication. Clinical testing is expensive and takes many years to complete, and its outcome is inherently uncertain. The process of obtaining regulatory approval is expensive, often taking many years following the commencement of clinical trials, and can vary substantially based upon the type, complexity, and novelty of the product candidates involved, as well as the target indications, patient population, and regulatory agency. As mentioned herein, our product candidates and technology platforms are novel and entail significant complexity.
Clinical trials that we conduct may not demonstrate the efficacy and safety that is necessary to obtain regulatory approval to market our product candidates. If the results of our ongoing or future clinical trials are inconclusive with respect to the efficacy of our product candidates, if we do not meet the clinical endpoints with statistical and clinically meaningful significance, or if there are safety concerns associated with our product candidates, we may be delayed in obtaining marketing approval, if at all. Additionally, any safety concerns observed in any one of our clinical trials could limit the prospects for regulatory approval of that product candidate or other product candidates in any indications.
Even if our clinical trials are successfully completed, clinical data are often susceptible to varying interpretations and analyses, and we cannot guarantee that the FDA or comparable foreign regulatory authorities will interpret the results as we do, and more trials could be required before we are able to submit our product candidates for approval. Moreover, results that are acceptable to support approval in one jurisdiction may be deemed inadequate to support regulatory approval in other jurisdictions. Even if regulatory approval is secured for a product candidate, the terms of such approval may limit the scope and use of the specific product candidate in a manner that does not meet our expectations, which limitations may reduce its commercial potential.
Interim, topline or preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data becomes available and are subject to audit and verification procedures that could result in material changes in the final data.
From time to time, we may publicly disclose interim, topline or preliminary data from our preclinical studies and clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular trial. The interim, topline or preliminary results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. As a result, interim, topline or preliminary data should be viewed with caution until the final data are available.
Interim, topline or preliminary data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Material differences between interim, topline or preliminary data and final data could significantly harm our business prospects. Further, disclosure of interim, topline or preliminary data by us or by our competitors could impact our ability to enroll our clinical trials and influence industry expectations, which could result in volatility in the price of our common stock and affect our ability to raise additional capital.
Clinical drug development is a lengthy and expensive process with uncertain outcomes. If clinical trials of our product candidates are prolonged or delayed, we or any collaborators may be unable to obtain required regulatory approvals, and therefore be unable to commercialize our product candidates on a timely basis or at all.
It is impossible to predict when or if any of our product candidates will prove effective and safe in humans or will receive regulatory approval. Before obtaining marketing approval from regulatory authorities for the sale of any drug candidate, we must complete preclinical studies and then conduct extensive clinical trials to demonstrate the safety and efficacy of our product candidates in humans. Our clinical trials may not be conducted as planned or completed on schedule, if at all, and a failure of one or more clinical trials can occur at any stage of testing. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. The design of a clinical trial can determine whether its results will support approval of a product candidate, and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their product candidates. In addition, the results of our preclinical animal studies, including our non-human primate studies, may not be predictive of the results of outcomes in subsequent clinical trials on human subjects. Product candidates in clinical trials may fail to show the desired pharmacological properties or safety and efficacy traits despite having progressed through preclinical studies.
Additionally, all of our trials, including our ongoing Phase 1 trial evaluating SL-279252 and Phase 1 trials evaluating SL-172154, are open-label trials in which both the patient and investigator know whether the patient is receiving the investigational product candidate or an existing approved therapy. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect, as patients in open-label clinical trials are aware when they are receiving treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. Therefore, it is possible that positive results observed in open-label trials will not be replicated in later placebo-controlled trials.
We could also encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such clinical trials are being conducted, by the Data Safety Monitoring Board, if any, for such clinical trial or by the FDA or other regulatory authorities. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical trial protocols, inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from the product candidates, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates, if the results of these trials are not positive or are only moderately positive or if there are safety concerns, our business and results of operations may be materially and adversely affected, and we may incur significant additional costs.
Our product candidates may have serious adverse, undesirable, or unacceptable side effects or other properties that may delay or prevent marketing approval.
Undesirable side effects that may be caused by our product candidates could cause us or regulatory authorities to interrupt, delay, or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other comparable foreign authorities. While we believe that the targeted nature of our dual-sided fusion proteins may carry a lower risk of overstimulating the immune system and causing a cytokine storm (a side effect associated with certain other antibody therapies), we do not have enough clinical data and experience with these molecules in humans to fully anticipate side effects. Accordingly, we may experience unexpected side effects and/or higher levels of known side effects in clinical trials, such as cytokine storms associated with certain immunotherapies or red blood cell lysis associated with some CD47 targeting therapies.
Results of our clinical trials could reveal a high and unacceptable severity and prevalence of these or other side effects. In such an event, our clinical trials could be suspended or terminated and the FDA or comparable foreign authorities could order us to cease further development or deny approval of our product candidates for any or all targeted indications. The drug-related side effects could affect patient recruitment or the ability of enrolled patients to complete the clinical trial or result in potential product liability claims. Any of these occurrences may harm our business and financial condition significantly.
Further, clinical trials by their nature utilize a sample of the potential patient population. With a limited number of patients and limited duration of exposure, rare and severe side effects of our product candidates may only be uncovered with a significantly larger number of patients exposed to the product candidate.
If we experience delays or difficulties enrolling patients in our clinical trials, our research and development efforts and business, financial condition, and results of operations could be materially and adversely affected.
Successful and timely completion of clinical trials will require that we enroll a sufficient number of patient candidates. Trials have been and may continue to be subject to delays for a variety of reasons, including as a result of patient enrollment taking longer than anticipated, fewer than expected patients who meet enrollment eligibility criteria, patient withdrawal, or adverse events.
Our clinical trials compete with other clinical trials that are in the same therapeutic areas as our product candidates and/or that seek to enroll the same specific patient populations as our clinical trials, which reduces the number and types of patients available to us. Moreover, enrolling patients in clinical trials for cancer therapies is challenging, as cancer patients will first receive the applicable standard of care. Many patients who respond positively to the standard of care therapy, such as PD-1 checkpoint inhibitors, (and thus do not enroll in clinical trials) are believed to have tumor types that may have responded well to our product candidates. This may limit the number of eligible patients able to enroll in our clinical trials and could extend development timelines or increase costs for these programs. Patients who fail to respond positively to the standard of care treatment will be eligible for clinical trials of unapproved drug candidates. However, these patients may have either compromised immune function from prior administration of chemotherapy or an enhanced immune response from the prior administration of checkpoint inhibitors. Either of these prior treatment regimens may render our therapies less effective in clinical trials. We have sought and may continue to seek to mitigate these effects in the future through modification of enrollment eligibility criteria, including patients with tumor types that are not typically responsive to anti-PD-1 antibodies, or pursuing combination regimens early in clinical development to enable access to anti-PD-1 naïve patients. Additionally, patients who have failed approved therapies will typically have more advanced cancer and a poorer long-term prognosis.
If we are unable to adequately enroll our clinical trial sites in the United States, Canada, and Europe, we may in the future use clinical trial sites in other parts of the world. It may be more difficult to control international clinical trials and the results may be less reliable. In addition, if the international clinical trial was conducted in a country with lower quality healthcare than in developed countries, the patients may experience side effects not experienced by patients in developed countries.
Delays in the completion of any clinical trial of our product candidates will increase our costs, slow down our product candidate development and approval process, and delay or potentially jeopardize our ability to commence product sales and generate revenue. In addition, some of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates.
Risks Related to Our Regulatory Environment
The development and commercialization of biopharmaceutical products is subject to extensive regulation, and the regulatory approval processes of the FDA and comparable foreign authorities are lengthy, time-consuming, and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for our product candidates on a timely basis, if at all, our business will be substantially harmed.
The clinical development, manufacturing, labeling, packaging, storage, recordkeeping, advertising, promotion, export, import, marketing, distribution, adverse event reporting, including the submission of safety and other post-marketing information and reports, and other possible activities relating to our product candidates are subject to extensive regulation. Obtaining approval of a BLA can be a lengthy, expensive, and uncertain process, and as a company we have no experience with the preparation of a BLA submission or any other application for marketing approval. This lengthy approval process may result in our failing to obtain regulatory approval to market any of our product candidates, which would significantly harm our business, results of operations, and prospects. See “Business-Government Regulation-BLA Submission and Review.”
Disruptions at the FDA and other government agencies could negatively affect the review of our regulatory submissions, which could negatively impact our business.
The ability of the FDA to review and approve regulatory submissions can be affected by a variety of factors, including disruptions caused by government shutdowns and public health crises. Such disruptions could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business.
Our research and development activities could be affected or delayed as a result of possible restrictions on animal testing.
Certain laws and regulations require us to test our product candidates on animals before initiating clinical trials involving humans. To the extent the activities of animal rights groups are successful, our research and development activities may be interrupted, delayed, or become more expensive.
Our business operations and current and future relationships with healthcare professionals, principal investigators, consultants, vendors, customers, and third-party payors are subject to applicable healthcare laws, which could expose us to penalties.
Our business operations and current and future arrangements with investigators, healthcare professionals, consultants, third-party payors, patient organizations and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations. These laws may constrain the business or financial arrangements and relationships through which we conduct our operations, including how we research, market, sell and distribute our product candidates, if approved. See “Business-Government Regulation-Other Healthcare Laws and Compliance Requirements.” for a more detailed description of the laws that may affect our ability to operate.
Ensuring that our internal operations and future business arrangements with third parties comply with applicable healthcare laws and regulations will involve substantial costs. If our operations are found to be in violation of any of these laws or any other governmental laws and regulations that may apply to us, we may be subject to significant penalties, including civil, criminal and administrative penalties, damages, fines, exclusion from government-funded healthcare programs, integrity oversight and reporting obligations to resolve allegations of non-compliance, disgorgement, individual imprisonment, contractual damages, reputational harm, diminished profits and the curtailment or restructuring of our operations. Further, defending against any such actions can be costly, time-consuming, may require significant personnel resources and may impair our business even if we are successful in defending against such claims. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired.
Our employees, independent contractors, principal investigators, CROs, consultants, commercial partners, suppliers, and vendors acting for us or on our behalf may engage in misconduct or other improper activities, including noncompliance with applicable laws and regulations.
We have adopted a code of conduct, but it is not always possible to identify and deter such misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations.
Risks Related to Commercialization of Our Product Candidates
We operate in highly competitive and rapidly changing industries, which may result in others discovering, developing or commercializing competing products before or more successfully than we do.
Our success is highly dependent on our ability to expeditiously discover, develop and obtain marketing approval for new and innovative products on a cost-effective basis and market them successfully. With the proliferation of new oncology drugs and immuno-therapies, we expect to face increasingly intense competition as new technologies become available. If we fail to stay at the forefront of technological innovation, we may be unable to compete effectively.
The market opportunities for our product candidates may be limited to those patients who are ineligible for or have failed prior treatments and may be small.
Cancer therapies are sometimes characterized by line of therapy (first, second, third, fourth, etc.), and the FDA often initially approves new therapies only for use in a particular line or lines of therapy. For example, we may initially seek approval of our product candidates as a third line therapy for patients who have failed other approved treatments. We may subsequently seek approval as a second and first line therapy. There is no guarantee that our product candidates, even if initially approved, would be subsequently approved as a second or first line therapy. Because the potentially addressable patient target population for our product candidates may be limited to patients who are ineligible for or have failed prior treatments, even if we obtain significant market share for our product candidates, we may never achieve profitability.
Our product candidates for which we intend to seek approval may face competition sooner than anticipated.
We believe that any of our product candidates approved as a biological product under a BLA should qualify for the 12-year period of exclusivity under the BPCIA. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider our product candidates to be reference products for competing products, potentially creating the opportunity for competition sooner than anticipated. See “Business-Government Regulation-Biosimilars and Reference Product Exclusivity.”
Risks Related to Our Dependence on Third Parties
We rely on third parties to manufacture our product candidates and other biological materials. The manufacture of our product candidates is complex. Our third-party manufacturers may encounter difficulties in production, which could delay or entirely halt their ability to supply our product candidates for clinical trials or, if approved, for commercial sale.
The process of manufacturing our product candidates is complex and requires significant expertise and capital investment, including the development of advanced manufacturing techniques and process controls that are in compliance with current Good Manufacturing Practices, or cGMP. We do not currently own or operate any GMP manufacturing facilities, nor do we have any in-house GMP manufacturing capabilities. We rely on third-party contract manufacturers to produce sufficient quantities of materials required for the manufacture, transport, and storage of our product candidates for preclinical testing and clinical trials, in compliance with applicable regulatory and quality standards. If we are unable to arrange for such third-party manufacturing sources, or fail to do so on commercially reasonable terms, we may not be able to successfully produce sufficient supply of product candidate or we may be delayed in doing so. Such failure or substantial delay could materially and adversely harm our business.
We currently rely on a single-source supplier for bulk drug substances, or BDS. The loss of our current supplier or its failure to supply us with BDS on a timely basis could cause our inability to develop and manufacture our product candidates, which could materially and adversely affect our business. We are working toward the successful manufacture of satisfactory, validated BDS with additional suppliers. The process for identifying additional BDS suppliers and successfully manufacturing BDS with those suppliers is lengthy and expensive, and there can be no assurance that any additional suppliers will be able to successfully produce satisfactory BDS. If we are not able to successfully manufacture BDS with additional suppliers, our existing supplier may need to increase manufacturing capacity to meet anticipated demand, which could involve significant challenges.
Because we rely on a third-party manufacturer to provide our BDS, there can be no assurance that our supply of BDS will not be limited or interrupted, have satisfactory quality or product characteristics, or continue to be available at acceptable prices. There can also be no assurance that our supplier will continue to meet regulatory requirements for cGMP manufacturing. As is common in our industry, we have experienced enrollment delays in our clinical trials as a result of delays in receipt of BDS. We have limited control over the process or timing of the acquisition or manufacture of materials by our supplier, and cannot ensure that it will deliver to us the BDS we order on time, or at all.
In the normal course of business, the process of manufacturing our product candidates has been negatively impacted by equipment failure, or improper installation or operation of equipment, vendor or operator error, inconsistency in yields, variability in product characteristics, and difficulties in scaling the production process. Even minor deviations from normal manufacturing processes, which we have experienced, results in reduced production yields and other supply disruptions. If microbial, viral, or other contaminations are discovered in our product candidates or in the manufacturing facilities in which our product candidates are made, this could lead to withdrawal of our products from the market, and such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination.
As part of our process development efforts, we also may make changes to our manufacturing processes at various points during development, for various reasons, such as controlling costs, achieving scale, decreasing processing time, increasing manufacturing success rate, or other reasons. We are investing in an in-house process development pilot plant to reduce our reliance on third parties for process development efforts. This undertaking is costly, and we have no guarantee that these efforts
will result in useful changes to our manufacturing processes. Any changes to our manufacturing processes carry the risk that they will not achieve their intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of our ongoing clinical trials or future clinical trials. In some circumstances, changes in the manufacturing process may require us to perform ex vivo comparability studies and to collect additional data from patients prior to undertaking more advanced clinical trials.
In addition, the FDA and other regulatory authorities require that our product candidates be manufactured according to cGMPs and similar foreign standards relating to methods, facilities, and controls used in the manufacturing, processing, packing, storage, and distribution of the product, which are intended to ensure that biological products are safe and that they consistently meet applicable requirements and specifications. We are dependent on third parties for all of these activities, and we have limited ability to prevent or control the risk that such activities will not be in compliance with cGMP. In addition, the storage and distribution of our product candidates for use in clinical trials is subject to extensive regulation by the FDA and other regulatory authorities. Any failure by our third-party manufacturers to comply with cGMP or failure to scale up manufacturing processes, including any failure to deliver sufficient quantities of product candidates in a timely manner, could lead to a delay in our clinical trials and development efforts, or a delay in or failure to obtain regulatory approval of any of our product candidates.
Pharmaceutical manufacturers are also subject to extensive oversight by the FDA and comparable regulatory authorities in other jurisdictions, which include periodic unannounced and announced inspections by the FDA to assess compliance with cGMP requirements. If an FDA inspection of a manufacturer’s facilities reveals conditions that the FDA determines not to comply with applicable regulatory requirements, the FDA may issue observations through a Notice of Inspectional Observations, commonly referred to as a “Form FDA 483” report. If observations in the Form FDA 483 report are not addressed in a timely manner and to the FDA’s satisfaction, the FDA may issue a Warning Letter or proceed directly to other forms of enforcement action. Any failure by one of our contract manufacturers to comply with cGMP or to provide adequate and timely corrective actions in response to deficiencies identified in a regulatory inspection could result in further enforcement action that could lead to a shortage of products and harm our business. The failure of a manufacturer to address any concerns raised by the FDA or foreign regulators could also lead to plant shutdown or the delay or withholding of product approval by the FDA in additional indications, or by foreign regulators in any indication. Moreover, if the FDA determines that our third-party manufacturers are not in compliance with FDA laws and regulations, including those governing cGMPs, the FDA may deny BLA approval until the deficiencies are corrected or we replace the manufacturer in our BLA with a manufacturer that is in compliance. Certain countries may impose additional requirements on the manufacturing of drug products or drug substances, and on manufacturers, as part of the regulatory approval process for products in such countries. The failure by our third-party manufacturers to satisfy such requirements could impact our ability to obtain or maintain approval of our products in such countries.
We rely, and expect to continue to rely, on third parties to conduct preclinical studies, nonclinical studies, and clinical trials. If these third parties do not successfully carry out their contractual duties, comply with applicable regulatory requirements, or meet expected deadlines, we may not be able to obtain regulatory approval for or commercialize our product candidates and our business could be materially and adversely affected.
We have relied, and plan to continue to rely, upon third parties, including independent clinical investigators and third-party CROs, to conduct certain preclinical studies, nonclinical studies, and clinical trials and to monitor, record, and manage data for our ongoing preclinical, nonclinical, and clinical programs. We rely on these parties for execution of certain preclinical studies and clinical trials, and control only certain aspects of their activities. As a result, we will have less direct control over the conduct, timing and completion of these preclinical studies, nonclinical studies and clinical trials and the management of data developed through these preclinical studies and clinical trials than would be the case if we were relying entirely upon our own staff. If we or any of these third parties fail to comply with applicable good laboratory practice, or GLP, or good clinical practice, or GCP, regulations, such data may be deemed unreliable and the FDA or comparable foreign regulatory authorities may require us to perform additional preclinical or nonclinical studies, or clinical trials before approving our marketing applications. Moreover, our business may be implicated if any of these third parties violates federal or state fraud and abuse or false claims laws and regulations or healthcare privacy and security laws.
The investigators and CROs are not our employees and we will not be able to control, other than by contract, the amount of resources, including time, that they devote to our product candidates and clinical trials. There is a limited number of third-party service providers that specialize in or have the expertise required to achieve our business objectives. If any of our relationships with these third parties terminate, we may not be able to enter into arrangements with alternative third parties or to do so in a timely manner or on commercially reasonable terms. If the third parties do not successfully carry out their contractual duties or obligations or meet expected deadlines, if they need to be replaced or if the quality or accuracy of the preclinical, nonclinical, or clinical data they obtain is compromised due to the failure to adhere to our preclinical or clinical protocols, regulatory requirements or for other reasons, our preclinical studies, nonclinical studies, or clinical trials may be extended,
delayed, or terminated and we may not be able to obtain regulatory approval for or successfully commercialize our product candidates.
We may not realize the benefits of any existing or future collaborative or licensing arrangement, and if we fail to enter into new strategic relationships our business, financial condition, commercialization prospects, and results of operations may be materially and adversely affected.
We have entered into, and may decide in the future to enter into, collaborations with pharmaceutical or biopharmaceutical companies for the development and potential commercialization of certain of our product candidates. We cannot be certain that, following a strategic transaction or license, we will achieve the results, revenue, or specific net income that justifies such transaction. We may not be able to control the amount and timing of resources that is required of us to complete our development obligations or that the collaboration partner devotes to the product development or marketing programs. We also may not be able to ensure that our collaboration partner adequately protects and does not misuse our intellectual property. We and our collaboration partner may disagree regarding the research plan or the development plan for product candidates on which we are collaborating and disputes could arise between the collaborators and us that result in the delay or termination of the research, development or commercialization of our product candidates or that result in costly litigation or arbitration that diverts management attention and resources. If our strategic collaborations do not result in the successful development and commercialization of product candidates or if one of our collaborators fails to act under the collaboration agreement or terminates its agreement with us, we may not receive any future research funding or milestone or royalty payments under the collaboration. In November 2021, we and Takeda mutually agreed to terminate, pursuant to a Termination Agreement, our collaboration agreement for SL-279252 and SL-115154, originally executed in 2017. Under the terms of the Termination Agreement, we are not required to satisfy any remaining performance obligations, we will not make any payments to or receive any future milestone or royalty payments from Takeda, and all options to license and rights of first negotiation held by Takeda under the Collaboration Agreement were terminated. In addition, if a collaboration is terminated, it may result in a need for additional capital to pursue further development or commercialization of the applicable product candidates. If we license products or businesses, we may not be able to realize the benefit of such transactions if we are unable to successfully integrate such products or business into our existing operations and company culture.
If we are unable to obtain sufficient raw and intermediate materials on a timely basis or if we experience other manufacturing or supply difficulties, our business may be materially and adversely affected.
We work closely with our suppliers to ensure the continuity of supply of raw and intermediate materials but cannot guarantee these efforts will always be successful. As has been commonly experienced during the COVID-19 pandemic, we have experienced raw and intermediate materials supply shortages, which has contributed to manufacturing delays and impacted the progress of our clinical trials. Further, while efforts are made to diversify our sources of raw and intermediate materials, in certain instances we acquire raw and intermediate materials from a sole supplier, and there can be no assurance that we will be able to quickly establish additional or replacement sources for some materials. A reduction or interruption in supply, and an inability to develop alternative sources for such supply, could adversely affect our ability to manufacture our product candidates in a timely or cost-effective manner and could delay completion of our clinical trials, product testing, and potential regulatory approval of our product candidates.
Risks Related to Intellectual Property and Information Technology
We rely on patents and other intellectual property rights to protect our technology, including product candidates from our ARC and GADLEN platforms, methods used to manufacture those product candidates, formulations thereof, and the methods for treating patients using those product candidates.
The prosecution, enforcement, defense, and maintenance of intellectual property rights is often challenging, costly, and uncertain. Contributors to these challenges and uncertainty include the early stage of our products and our intellectual property portfolio development; the unpredictability of what patent claim scope will ultimately be issued to protect our products and how the law will change or develop as to scope, length and enforcement of patent protection; the competitive and crowded immune-oncology space; complicated and unforgiving procedural, documentary and fee requirements of U.S. and foreign patent offices; lack of perfect visibility into what our competitors are doing and the patent claim scope they are obtaining; lack of perfect ability to determine what prior art may exist; and the expense and time consuming nature of patent portfolio development across relevant jurisdictions. For at least these reasons, the issuance, scope, validity, enforceability, and commercial value of our current or future patent rights are highly uncertain. We cannot be sure that patent coverage will issue, or will be maintained, to protect our products, in some or all relevant jurisdictions. We cannot be sure that we will not encounter freedom-to-operate challenges in the development and commercialization of our product candidates. We cannot be sure our trademarks and trade names are sufficient to build name recognition in our markets of interest. We cannot be sure our measures to protect our trade secrets will be sufficient. Failure to protect or enforce these rights adequately could harm our ability to develop and market our product candidates and could impair our business.
Others may challenge our patents or other intellectual property as invalid or unenforceable.
Our patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless and until a patent issues from such applications, and then only to the extent the issued claims cover the technology. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, our intellectual property may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours. Even if patents do successfully issue and even if such patents cover our product candidates and extend for a commercially relevant time, third parties may initiate invalidity, non-infringement, opposition, interference, re-examination, post-grant review, inter partes review, nullification, or derivation actions in court or before patent offices, or similar proceedings challenging the validity, inventorship, ownership, enforceability, or scope of such patents, which may result in the patent claims being narrowed, invalidated, or held unenforceable or circumvented. Such challenges and potential negative results could materially and adversely affect our business.
Furthermore, even where we have a valid and enforceable patent, we may not be able to exclude others from practicing our invention, such as where the other party can show that they used the invention in commerce before our filing date or the other party benefits from a compulsory license. Additionally, some countries, including China and India, have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties; and some countries limit the enforceability of patents against government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such patent. Additionally, our competitors or other third parties may be able to evade our patent rights by developing new fusion proteins, antibodies, biosimilar antibodies, or alternative technologies or products in a non-infringing manner. These risks may impact our ability to enjoy the protection we obtain, and may materially and adversely impact our business.
Our commercial success depends, in part, on our ability to develop, manufacture, market, and sell our product candidates without infringing or otherwise violating the intellectual property and other proprietary rights of third parties.
Others may accuse us of infringing their intellectual property. Contested proceedings are lengthy, time consuming, and costly, and we cannot guarantee that our operations and activities do not, or will not in the future, infringe existing or future patents. We also cannot guarantee that any of our patent searches or analyses, including the identification of relevant patents, the scope of patent claims or the expiration of relevant patents, are complete or thorough, nor can we be certain that we have identified each and every third-party patent and pending application in the United States and abroad that is relevant to our product candidates or necessary for the commercialization of our product candidates in any jurisdiction. Furthermore, we may be subject to third-party claims asserting that our employees, consultants, contractors, collaborators, or advisors have misappropriated or wrongfully used or disseminated their intellectual property, or claiming ownership of what we regard as our own intellectual property. These and related risks to defending against third-party claims may materially and adversely affect our business.
Our competitors in both the United States and abroad, many of which have substantially greater resources and have made substantial investments in patent portfolios and competing technologies, may have applied for or obtained or may in the future apply for and obtain, patents that will prevent, limit, or otherwise interfere with our ability to make, use, and sell our product candidates. We do not always conduct independent reviews of pending patent applications of and patents issued to third parties. As such, there may be applications of third parties now pending or recently revived patents of which we are unaware.
Our interpretation of the relevance or the scope of a patent or a pending application may be incorrect, which may negatively impact our ability to market our product candidates. We may incorrectly determine that our product candidates are not covered by a third-party patent or may incorrectly predict whether a third party’s pending application will issue with claims of relevant scope. Our determination of the expiration date of any patent in the United States or abroad that we consider relevant may be incorrect, which may negatively impact our ability to develop and market our product candidates. We cannot provide any assurances that third-party patents do not exist that might be enforced against our current technology, including our platform technologies, product candidates and their respective methods of use, manufacture, and formulations thereof, and could result in either an injunction prohibiting our manufacture or future sales, or, with respect to our future sales, an obligation on our part to pay royalties and/or other forms of compensation to third parties, which could be significant.
We rely in part on in-licensed patents and other intellectual property rights to develop and commercialize our product candidates. We may need to obtain additional licenses of third-party technology that may not be available to us or are available only on commercially unreasonable terms, and which may cause us to operate our business in a more costly or otherwise adverse manner that was not anticipated.
Our competitive position may suffer if patents issued to third parties or other third-party intellectual property rights cover our methods or product candidates or elements thereof, our manufacture or uses relevant to our development plans, our product candidates or other attributes of our product candidates, or our ARC or GADLEN platform. In such cases, we may not be in a
position to develop or commercialize product candidates unless we successfully pursue litigation to nullify or invalidate the third-party intellectual property right concerned, which can be expensive and time-consuming, or we may have to enter into a license agreement with the intellectual property right holder, which may not be available on commercially reasonable terms, if at all.
There is a substantial amount of intellectual property litigation in the biotechnology and pharmaceutical industries, and we may become party to, or threatened with, litigation or other adversarial proceedings regarding intellectual property rights with respect to our product candidates. Parties making claims against us may seek and obtain injunctive or other equitable relief, which could effectively block our ability to further develop and commercialize our product candidates. For example, we are aware of a patent that may impact our competitive position with respect to SL-172154. The patent lists claims that generally relate to methods of using fusion proteins to treat certain types of cancers. While we believe that the claims may not be valid and that they may be reasonably challenged for validity, there can be no assurance that any such challenge would be successful, in which case we may be required to obtain a license in order to commercialize our product candidate, if approved. The targets of our product candidates have also been the subject of research by many companies that have filed patent applications or have patents related to such targets and therapeutics methods related to those targets.
Disputes may arise with our licensors of patents and other intellectual property rights. We may yet need to obtain licenses from others for continued development and commercialization of our product candidates, and we may be unable to secure those licenses on commercially reasonable terms or at all. Should we be required to obtain licenses to any third-party technology, including any such patents required to manufacture, use, or sell our product candidates, the growth of our business will likely depend in part on our ability to acquire, in-license, maintain, or use these proprietary rights. The inability to obtain any third-party license required to develop or commercialize any of our product candidates could cause us to abandon any related efforts, which could seriously harm our business and operations.
In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. We also may be unable to license or acquire third-party intellectual property rights on terms that would allow us to make an appropriate return on our investment. Even if we are able to obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us. If we are unable to successfully obtain a license to third-party intellectual property rights necessary for the development of a product candidate or program, we may have to abandon development of that product candidate or program and our business and financial condition could suffer.
In addition, all licenses impose obligations upon us that must be met to maintain the license. If we are unable to meet these obligations, we may be required to pay damages and our licensors may be able to license their rights to other third parties, including our competitors, and our competitors could market competing products and technology. In addition, we and/or our licensors must cooperate in order to enforce such patents against third parties, and such cooperation may not be provided. We also may rely on our licensors to file and prosecute patent applications and maintain patents and otherwise protect the intellectual property rights we license from them and may have limited control over these activities or any other intellectual property rights that may be related to our in-licensed intellectual property rights.
In addition, our competitors may independently develop substantially equivalent trade secrets, proprietary information, or know-how and may even apply for patent protection in respect of the same. If successful in obtaining such patent protection, our competitors could limit our use of our trade secrets and/or confidential know-how. Under certain circumstances, and to make it more likely that we have our freedom to operate, we may also decide to publish some know-how to make it difficult for others to obtain patent rights covering such know-how, at the risk of potentially exposing our trade secrets to our competitors. Any of the foregoing could have a material adverse effect on our competitive position, business, financial conditions, results of operations and prospects.
We depend on intellectual property licensed from third parties and if we fail to comply with our obligations under any license, collaboration or other agreements, we may be required to pay damages and could lose intellectual property rights that are necessary for developing and protecting our product candidates or we could lose certain rights to grant sublicenses.
Our current licenses impose, and any future licenses we enter into are likely to impose, various development, commercialization, funding, milestone, royalty, diligence, sublicensing, insurance, patent prosecution and enforcement, and/or other obligations on us. If we breach any of these obligations, or use the intellectual property licensed to us in an unauthorized manner, we may be required to pay damages and the licensor may have the right to terminate the license, which could result in us being unable to develop, manufacture, and sell any future products that are covered by the licensed technology or enable a competitor to gain access to the licensed technology. Moreover, our licensors may own or control intellectual property that has not been licensed to us and, as a result, we may be subject to claims, regardless of their merit, that we are infringing or otherwise violating the licensor’s rights. In addition, while we cannot determine currently the amount of the royalty obligations we would be required to pay on sales of future products, if any, the amounts may be significant. The amount of our future royalty obligations will depend on the technology and intellectual property we use in products that we successfully develop and
commercialize, if any. Therefore, even if we successfully develop and commercialize products, we may be unable to achieve or maintain profitability.
We enjoy only limited geographical protection with respect to certain patents and may not be able to protect our intellectual property rights throughout the world.
Patents are of national or regional effect. While we will endeavor to try to protect our technologies, products and product candidates with intellectual property rights such as patents throughout the world, as appropriate, the process of obtaining patents is time-consuming, expensive, and sometimes unpredictable in other countries. We may not be able to file, prosecute, maintain, enforce, or license all necessary or desirable patent rights at a commercially reasonable cost or in a timely manner. In addition, we may not pursue or obtain patent protection in all markets. We have not, and will not, file for patent protection in all national and regional jurisdictions where such protection may be available. Filing, prosecuting, and defending patents on all of our research programs and product candidates in all countries throughout the world would be prohibitively expensive, and, therefore, the scope and strength of our intellectual property rights will vary from jurisdiction to jurisdiction.
We may become subject to claims challenging the inventorship or ownership of our patents and other intellectual property.
We generally enter into confidentiality and intellectual property assignment agreements with our employees, consultants, and contractors. These agreements generally provide that inventions conceived by the party in the course of rendering services to us will be our exclusive property. However, those agreements may not be honored and may not effectively assign intellectual property rights to us. Moreover, there may be some circumstances where we are unable to negotiate for such ownership rights. Disputes regarding ownership or inventorship of intellectual property can also arise in other contexts, such as collaborations and sponsored research. If we are subject to a dispute challenging our rights in or to patents or other intellectual property, such a dispute could be expensive and time consuming. If we were unsuccessful, we could lose valuable rights in intellectual property that we regard as our own.
Intellectual property rights do not necessarily address all potential threats to our competitive advantage.
The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations, and may not adequately protect our business, or permit us to maintain our competitive advantage. Moreover, if a third party has intellectual property rights that cover the practice of our technology, we may not be able to fully exercise or extract value from our intellectual property rights. The following examples are illustrative:
•others may be able to make product candidates similar to our product candidates but that are not covered by the claims of the patents that we own or have exclusively licensed;
•the patents of third parties may have a material and adverse effect on our business;
•we or any future strategic partners might not have been the first to conceive or reduce to practice the inventions covered by the issued patent or pending patent application that we own or have exclusively licensed;
•we or any future strategic partners might not have been the first to file patent applications covering certain of our inventions;
•others may independently develop similar or alternative technologies or duplicate any of our technologies without infringing, misappropriating, or otherwise violating our intellectual property rights;
•it is possible that our pending patent applications will not lead to issued patents;
•issued patents that we own or have exclusively licensed may not provide us with any competitive advantage, or may be held invalid or unenforceable, as a result of legal challenges by our competitors;
•we cannot predict the degree and range of protection any issued patents will afford us against competitors, whether or not others will obtain patents claiming aspects similar to those covered by our patents and patent applications, or whether we will need to initiate litigation or administrative proceedings which may be costly whether we win or lose;
•our competitors might conduct research and development activities in countries where we do not have patent rights and then use the information learned from such activities to develop competitive products for sale in our major commercial markets;
•third parties performing manufacturing or testing for us using our product candidates or technologies could use the intellectual property of others without obtaining a proper license; and
•we may not develop additional technologies that are patentable.
Should any of these events occur, they could significantly harm our business, results of operations, and prospects.
We rely on trade secret and proprietary know-how, which can be difficult to trace and enforce and, if we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.
Trade secrets and/or confidential know-how can be difficult to protect or maintain as confidential. To protect this type of information against disclosure or appropriation by competitors, we generally require our employees, consultants, contractors, collaborators, advisors, and other third parties to enter into confidentiality agreements with us. Despite these efforts, any of these parties may unintentionally or willfully breach the agreements and disclose our confidential information, and confidentiality agreements may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. Monitoring unauthorized uses and disclosures is difficult, and we do not know whether the steps we have taken to protect our proprietary technologies will be effective. Enforcing a claim that a third party obtained illegally and is using trade secrets and/or confidential know-how is also expensive, time-consuming, and unpredictable.
The enforceability of confidentiality agreements may vary from jurisdiction to jurisdiction. The laws of some foreign countries do not protect proprietary rights to the same extent or in the same manner as the laws of the United States. As a result, we may encounter significant problems in protecting and defending our intellectual property both in the United States and abroad. Furthermore, if a competitor lawfully obtained or independently developed any of our trade secrets, we would have no right to prevent such competitor from using that technology or information to compete with us, which could harm our competitive position. Additionally, if the steps taken to maintain our trade secrets are deemed inadequate, we may have insufficient recourse against third parties for misappropriating the trade secret. In addition, some courts inside and outside the United States are less willing or are unwilling to protect trade secrets or other proprietary information.
Any sort of contested proceeding related to intellectual property, offensive or defensive, may cause us to incur significant expenses and would be likely to divert significant resources from our core business, including distracting our technical and management personnel from their normal responsibilities, and may impact our reputation.
There could be public announcements of the results of hearings, motions or other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a material and adverse effect on the price of our common stock. Such litigation or proceedings could substantially increase our operating losses and reduce our resources available for development activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. Infringement or related suits against us by others could result in damages awards against us or injunction or other equitable relief precluding continued commercialization of our products. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace.
Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for noncompliance with these requirements.
Periodic maintenance and annuity fees on any issued patent are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patent. The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment, and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Noncompliance events that could result in abandonment or lapse of a patent or patent application include failure to respond to official actions within prescribed time limits, non-payment of fees, and failure to properly legalize and submit formal documents within prescribed time limits. If we fail to maintain the patents and patent applications covering our product candidates or if we otherwise allow our patents or patent applications to be abandoned or lapse, our competitors might be able to enter the market, which would have a material and adverse effect on our business.
Our information technology systems, or those used by our CROs or other contractors or consultants, may fail or suffer security breaches, which could materially and adversely affect our business.
In the ordinary course of our business, we collect, store, and transmit large amounts of confidential information in digital form. Despite the implementation of security measures, our information technology systems and data and those of our current or future CROs or other contractors and consultants are vulnerable to compromise or damage from computer hacking, malicious software, fraudulent activity, employee misconduct, human error, telecommunication and electrical failures, natural disasters, or other cybersecurity attacks or accidents. While we continue to make investments to improve the protection of data and information technology, there can be no assurance that our efforts will prevent service interruptions or security breaches. Although to our knowledge we have not experienced any material cybersecurity incident to date, if such an event were to occur, it could seriously harm our development programs and our business operations or subject us to litigation or regulatory actions
taken by governmental authorities. See Part I, Item 1. “Business-Government Regulation-Data Privacy and Security.” Further, a cybersecurity incident may disrupt our business or damage our reputation, which could have a material adverse effect on our business, prospects, operating results, share price, stockholder value, and financial condition. We could also incur substantial remediation costs, including the costs of investigating the incident, repairing or replacing damaged systems, restoring normal business operations, implementing increased cybersecurity protections, and paying increased insurance premiums.
Risks Related to Ownership of Our Common Stock
Our stock price may be volatile or may decline regardless of our operating performance, resulting in substantial losses for investors.
The market price of our common stock may be highly volatile and may fluctuate significantly as a result of a variety of factors, some of which are related in complex ways and many of which are beyond our control, including the factors described in this “Risk Factors” section and elsewhere in this Annual Report on Form 10-K.
In addition, the stock market in general, and The Nasdaq Stock Market, or Nasdaq, and biopharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. In particular, the trading prices for pharmaceutical, biopharmaceutical and biotechnology companies have been highly volatile as a result of the COVID-19 pandemic. In addition, broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance. Securities class action litigation is often been instituted against companies following periods of volatility in the market price of a company’s securities. We are the subject of putative securities class action cases against the Company and certain of our officers and directors, alleging that defendants made false or misleading statements. This type of litigation, and others like it, could result in substantial costs and a diversion of management’s attention and resources, which would harm our business, operating results, or financial condition. See the discussion of Legal Proceedings in Part I, Item 3 of this Form 10-K.
Our principal stockholders and management own a significant percentage of our stock and are able to exert significant control over matters subject to stockholder approval.
As of March 1, 2022, our executive officers, directors, holders of 5% or more of our capital stock and their respective affiliates beneficially owned approximately 41.6% of our outstanding voting stock. Therefore, these stockholders have the ability to influence us through this ownership position and may be able to determine all matters requiring stockholder approval. For example, these stockholders may be able to control elections of directors, amendments of our organizational documents, or approval of any merger, sale of assets, or other major corporate transaction. This may prevent or discourage unsolicited acquisition proposals or offers for our common stock that you may feel are in your best interest as one of our stockholders.
General Risk Factors
If securities or industry analysts either do not publish research about us or publish inaccurate or unfavorable research about us, our business or our market, or if they change their recommendations regarding our common stock adversely, the trading price or trading volume of our common stock could decline.
The trading market for our common stock depends in part upon research and reports that securities or industry analysts may publish about us, our business, our market, or our competitors. If any analyst who may cover us were to cease coverage of us or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause the trading price or trading volume of our common stock to decline.
The requirements of being a public company may strain our resources, result in more litigation, and divert management’s attention.
As a public company, we are subject to certain reporting requirements, listing requirements, and other applicable securities rules and regulations. Complying with these rules and regulations has increased and will continue to increase our legal and financial compliance costs, make some activities more difficult, time consuming or costly and increase demand on our systems and resources. As a result, management’s attention may be diverted from other business concerns, which could materially and adversely affect our business and operating results. We may also need to hire additional employees or engage outside consultants to comply with these requirements, which will increase our costs and expenses.
By disclosing information in this and in future filings required of a public company, our business and financial condition will become more visible, which has resulted in and may in future result in threatened or actual litigation, including by competitors and other third parties. If those claims are successful, our business could be seriously harmed. Even if the claims do not result in litigation or are resolved in our favor, the time and resources needed to resolve them could divert our management’s resources and seriously harm our business. See the discussion of Legal Proceedings in Part I, Item 3 of this Form 10-K.
Class-action litigation filed against us could harm our business, and insurance coverage may not be sufficient to cover all related costs and damages.
We face the threat of legal claims and regulatory matters involving various aspects of our business. Given the volatility of the trading price of our common stock, and the increase in shareholder litigation generally, we face a risk of lawsuits alleging violations of the securities laws. On January 31, 2022 and February 11, 2022, putative class action lawsuits were filed in the U.S. District Court for the Eastern District of New York against the Company and certain of our officers and directors, in each case alleging that defendants made false or misleading statements regarding our collaboration agreement with Takeda. The plaintiffs in both lawsuits seek a ruling that the case may proceed as a class action, and seeks unspecified damages, and attorneys’ fees, expert fees and costs. Similar class-action lawsuits may be filed in future. We and the individual defendants deny any allegations of wrongdoing and intend to vigorously defend against the claims asserted in these lawsuits. However, litigation is inherently uncertain, and adverse rulings may occur, including awards of monetary damages, that may have a material adverse impact on our business. These lawsuits may also divert management’s attention and resources, and may require us to incur substantial costs, some of which will not be covered by insurance. See the discussion of Legal Proceedings in Part I, Item 3 of this Form 10-K.
If we fail to maintain proper and effective internal controls over financial reporting our ability to produce accurate and timely financial statements could be impaired.
We are required to report upon the effectiveness of our internal control over financial reporting. To comply with the requirements of being a reporting company under the Securities Exchange Act of 1934, as amended, or the Exchange Act, we have implemented and will continue to implement additional financial and management controls, reporting systems and procedures and we have hired and will continue to hire additional accounting and finance staff. We cannot assure you that there will not be material weaknesses or significant deficiencies in our internal control over financial reporting in the future.
Our disclosure controls and procedures may not prevent or detect all errors or acts of fraud.
We are subject to the periodic reporting requirements of the Exchange Act. We have designed our disclosure controls and procedures to reasonably assure that information we must disclose in reports we file or submit under the Exchange Act is accumulated and communicated to management, and recorded, processed, summarized, and reported within the time periods specified in the rules and forms of the SEC. We believe that any disclosure controls and procedures or internal controls and procedures, no matter how well-conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. For example, our directors or executive officers could inadvertently fail to disclose a new relationship or arrangement causing us to fail to make a required related party transaction disclosure. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements due to error or fraud may occur and not be detected.
Provisions in our amended and restated certificate of incorporation and our amended and restated bylaws and Delaware law might discourage, delay or prevent a change in control of our company or changes in our management and, therefore, depress the market price of our common stock.
Our amended and restated certificate of incorporation and our amended and restated bylaws each contain provisions that could depress the market price of our common stock by acting to discourage, delay, or prevent a change in control of our company or changes in our management that the stockholders of our company may deem advantageous. As a Delaware corporation, we are subject to the anti-takeover provisions of Section 203 of the Delaware General Corporation Law, which prohibits a Delaware corporation from engaging in a business combination specified in the statute with an interested stockholder (as defined in the statute) for a period of three years after the date of the transaction in which the person first becomes an interested stockholder, unless the business combination is approved in advance by a majority of the independent directors or by the holders of at least two-thirds of the outstanding disinterested shares. The application of Section 203 of the Delaware General Corporation Law could also have the effect of delaying or preventing a change of control of our company.
Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for substantially all disputes between us and our stockholders, which could limit our stockholders’ ability to obtain a favorable judicial forum for disputes.
Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware (or another state court or the federal court located within the State of Delaware if the Court of Chancery does not have or declines to accept jurisdiction) is the exclusive forum for certain actions. It also provides that the federal district courts of the United States will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act but that the forum selection provision will not apply to claims brought to enforce a duty or liability created by the Exchange Act. These exclusive forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for
disputes, which may discourage lawsuits. There is uncertainty as to whether a court would enforce such provisions. If a court were to find these types of provisions to be inapplicable or unenforceable, and if a court were to find the exclusive forum provision in our amended and restated bylaws to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving the dispute in other jurisdictions, which could materially and adversely affect our business.
Our ability to use our net operating loss carryforwards and other tax attributes may be limited.
As of December 31, 2021, we had U.S. federal and state net operating loss, or NOL, carryforwards of $97.4 million and $0.2 million, respectively, which may be available to offset future taxable income. As of December 31, 2021, we also had gross federal tax credits of $7.6 million, which may be used to offset future tax liabilities. These NOLs and tax credit carryforwards will begin to expire in 2036. Use of our NOL carryforwards and tax credit carryforwards depends on many factors, including having current or future taxable income, which cannot be assured.

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ITEM 1B. UNRESOLVED STAFF COMMENTS
Item 1B. Unresolved Staff Comments
None.

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ITEM 2. PROPERTIES
Item 2. Properties
Our corporate headquarters are located in Austin, Texas where we currently occupy approximately 8,000 square feet of office space under a lease that expires on September 30, 2026. We use this facility for administrative purposes.
We currently lease approximately 32,200 square feet of office and laboratory space in Durham, North Carolina under a lease that expires on December 31, 2028. We use this facility for research and development purposes.
We believe these spaces to be sufficient to meet our needs for the foreseeable future and that any additional space we may require will be available on commercially reasonable terms.

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ITEM 3. LEGAL PROCEEDINGS
Item 3. Legal Proceedings
On January 31, 2022 and February 11, 2022, putative class action lawsuits were filed in the U.S. District Court for the Eastern District of New York against us and certain of our officers and directors. In each complaint, the plaintiff cites the volatility in our common stock and alleges that the defendants made or are responsible for false or misleading statements regarding our collaboration agreement with Takeda. The plaintiffs in both lawsuits seek a ruling that the case may proceed as a class action, and seek unspecified damages and attorneys’ fees, expert fees and costs. We and the individual defendants deny any allegations of wrongdoing and intend to vigorously defend against these lawsuits.

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ITEM 4. MINE SAFETY DISCLOSURE
Item 4. Mine Safety Disclosures
None.
Part II.

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ITEM 5. MARKET FOR REGISTRANT'S COMMON EQUITY
Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issue Purchases of Equity Securities
Our common stock is traded on The Nasdaq Global Select Market under the symbol “STTK”. At March 1, 2022, there were approximately 36 stockholders of record of our common stock and the closing price of our common stock was $5.01 per share. Since many of our shares of common stock are held by brokers and other institutions on behalf of stockholders, we are unable to estimate the total number of stockholders represented by these record holders.
Dividends
The Company has never paid dividends on its Common Stock and does not anticipate that it will do so in the foreseeable future.
Use of Proceeds from Initial Public Offering of Common Stock
There has been no material change in our intended use of proceeds from our IPO as described in our final prospectus filed with the SEC pursuant to Rule 424(b)(4) on October 13, 2020.

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ITEM 6. SELECTED FINANCIAL DATA
Item 6. Reserved

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ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations
You should read the following discussion and analysis of our financial condition and results of operations together with our audited financial statements and related notes appearing in this Annual Report on Form 10-K. This discussion and other parts of this Annual Report on Form 10-K contain forward-looking statements that involve risks and uncertainties, such as statements of our plans, objectives, expectations and intentions. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the section of this report entitled “Risk Factors.” You should carefully read the “Cautionary Note About Forward-Looking Statements” and “Risk Factors” sections of this Annual Report on Form 10-K to gain an understanding of the important factors that could cause actual results to differ materially from the results described below.
Overview
We are an innovative clinical-stage biotechnology company pioneering the development of dual-sided fusion proteins as an entirely new class of biologic medicine. We have created a novel approach to immune modulation by designing biologics with structural characteristics that are not achievable by existing therapeutic modalities, including monoclonal or bispecific antibodies. Compounds derived from our proprietary Agonist Redirected Checkpoint, or ARC, platform simultaneously inhibit checkpoint molecules and activate costimulatory molecules within a single therapeutic.
Our lead product candidate, SL-172154, is designed to simultaneously inhibit the CD47/SIRPα macrophage checkpoint interaction and activate the CD40 costimulatory receptor to induce an antitumor immune response. Coupling CD40 activation with CD47 inhibition differentiates SL-172154 from all other clinical-stage CD47/SIRPα inhibitors in development, and in our published preclinical studies, SL-172154 resulted in superior antitumor immunity as compared to certain CD47/SIRPα inhibitors. We are pursuing a broad clinical development strategy in both hematologic and solid tumors, with multiple ongoing clinical trials. SL-172154 is in an ongoing Phase 1 clinical trial for the treatment of patients with ovarian cancer. In addition to our clinical trials in solid tumors, we are also evaluating SL-172154 in an ongoing Phase 1 clinical trial for the treatment of patients with certain hematologic malignancies, including acute myeloid leukemia, or AML, and higher-risk myelodysplastic syndromes, or HR-MDS. We believe our clinical development plan will provide both first-in-class and best-in-class development opportunities for SL-172154.
Our second product candidate, SL-279252, is designed to simultaneously inhibit the PD-1/PD-L1 interaction and activate the OX40 costimulatory receptor and is in an ongoing Phase 1 clinical trial in patients with advanced solid tumors.
In November 2021, at the 36th annual meeting of the Society for Immunotherapy of Cancer, or the SITC Meeting, we announced initial clinical data from our ongoing Phase 1 clinical trials for SL-172154 in ovarian cancer and for SL-279252 in advanced solid tumors and lymphoma. We believe that these data generated in human cancer patients have demonstrated that the unique protein engineering and physical properties of the ARC platform have led to a differentiated profile in terms of safety and on-target immune activation as compared to monoclonal or bispecific antibodies.
In addition to our clinical-stage ARC product candidates, we possess a deep pipeline of preclinical immuno-oncology candidates. As an example, SL-9258, an ARC in preclinical development, is designed to inhibit the TIGIT/PVR checkpoint interaction while simultaneously activating HVEM and LTβ costimulatory receptors.
Furthermore, our expertise in dual-sided fusion proteins has led to the development of a second novel platform technology. We call this our gamma delta T cell engager, or GADLEN, platform.
We plan to nominate a third clinical product candidate from our preclinical pipeline in 2022. Longer-term, we are pursuing additional disease areas, including autoimmune diseases, where our dual-sided fusion protein platforms may provide advantages over current treatment modalities.
Overview of Operations
Since our inception in 2016, we have devoted substantially all of our resources to developing and perfecting our intellectual property rights, conducting research and development activities, including undertaking nonclinical studies of our product candidates, conducting clinical trials of our most advanced product candidates, manufacturing our product candidates, organizing and staffing our company, business planning, and raising capital. We do not have any products approved for sale, and we have not generated any revenue from product sales. We have funded our operations as of the filing date of this Annual Report on Form 10-K through the net proceeds from our initial public offering of approximately $213.5 million, the sale of redeemable convertible preferred stock for approximately $152.9 million, the issuance of convertible notes for approximately $10.5 million and payments received pursuant to our collaboration agreement with Takeda for approximately $82.0 million.
For the years ended December 31, 2021 and 2020, our net loss was $45.0 million and $36.6 million, respectively. We have not been profitable since inception, and as of December 31, 2021, we had an accumulated deficit of $117.1 million and $268.8 million in cash and cash equivalents and short-term investments. We expect to continue to incur significant expenses and increasing operating losses in the near term. We expect our expenses will increase substantially in connection with our ongoing activities, as we:
•continue to advance the nonclinical and clinical development of our clinical-stage product candidates, SL-172154 and SL-279252;
•initiate nonclinical studies and clinical trials for additional product candidates that we may identify in the future;
•manufacture sufficient quantities of bulk drug substance and drug product to support our ongoing and planned nonclinical studies and clinical trials;
•continue our process development efforts for our current and future product candidates;
•expand our operational, financial, and management systems;
•increase personnel and infrastructure to support our clinical development, research and manufacturing efforts;
•build out and expand our in-house process development and manufacturing capabilities;
•continue to develop, perfect, and defend our intellectual property portfolio; and
•incur additional legal, accounting, or other expenses in operating our business, including the additional costs associated with operating as a public company.
We do not expect to generate significant product revenue unless and until we successfully complete development and obtain regulatory and marketing approval of, and begin to sell, one or more of our product candidates, which we expect will take several years. We expect to spend a significant amount in development and marketing costs prior to such time. We may never succeed in achieving regulatory and marketing approval for our product candidates. We may obtain unexpected results from our nonclinical and clinical trials. We may elect to discontinue, delay, or modify nonclinical and clinical trials of our product candidates. A change in the outcome of any of these variables with respect to the development of a product candidate could mean a significant change in the costs and timing associated with the development of that product candidate. Accordingly, until such time as we can generate significant product revenue, if ever, we expect to continue to seek private or public equity and debt financing to meet our capital requirements. There can be no assurance that such funding may be available to us on acceptable terms, or at all, or that we will be able to commercialize our product candidates. In addition, we may not be profitable even if we commercialize any of our product candidates.
COVID-19 Pandemic
There is significant uncertainty as to the future effects of the ongoing COVID-19 pandemic, which may, among other things, materially impact our business, including our ongoing and planned clinical trials. We have experienced, and expect to continue to experience, delays in our SL-172154 and SL-279252 clinical trials as a result of the ongoing pandemic. Our manufacturing operations have been impacted by the ongoing pandemic, including delays with our third-party manufacturer and difficulties in obtaining raw materials needed to manufacture material for our clinical trials. Additionally, we have experienced, and expect to continue to experience, delays in enrolling patients, missed treatments for enrolled patients, and performance delays from certain third-party vendors supporting the SL-172154 and SL-279252 clinical trials, although the significance of any future delays is difficult to predict.
Further, due to public health guidance measures, we have in the past implemented, and may in the future implement, a work-from-home policy for our employees, excluding those necessary to maintain minimum basic operations, which may negatively impact productivity, or disrupt, delay, or otherwise adversely impact our business. For example, some of our research activities that require our personnel to be in our laboratories may be delayed. We may also experience delays or disruptions to our operations if and when our employees need to take time off work due to illness or other COVID-19-related impacts to our workforce.
Due to the impact of the COVID-19 pandemic and work-from-home policies and other operational limitations mandated by federal, state and local governments as a result of the pandemic, certain of our research and development activities, including the conduct of nonclinical studies, have been delayed and may be further delayed and other aspects of our business, such as the conduct of various corporate functions and the ability of our Board and management to provide oversight and guidance may be adversely impacted until such operational limitations are lifted. The COVID-19 pandemic or local outbreaks associated with the COVID-19 pandemic could result in difficulty manufacturing our product candidates, securing clinical trial site locations, contract research organizations, or CROs; and/or trial monitors and other critical vendors and consultants supporting our clinical trials. In addition, outbreaks or the perception of an outbreak near a clinical trial site location could impact our ability to enroll patients or to complete all scheduled physician visits for currently enrolled patients. These situations, or others associated with COVID-19 pandemic, could cause delays in our clinical trial plans and could increase expected costs, all of which could have a material adverse effect on our business and its financial condition. At the current time, we are unable to quantify the potential effects of the COVID-19 pandemic on our future operations.
Collaboration Agreement
On August 8, 2017, we entered into a Collaboration Agreement with Millennium Pharmaceuticals, Inc., or Takeda, a wholly owned subsidiary of Takeda Pharmaceutical Company, Ltd., or the Collaboration Agreement. The Collaboration Agreement was mutually terminated pursuant to the termination agreement, or the Termination Agreement, dated November 8, 2021. Under the terms of the Termination Agreement, we are not required to satisfy any remaining performance obligations, we will not make any payments to or receive any future milestone or royalty payments from Takeda, and all options to license and rights of first negotiation held by Takeda under the Collaboration Agreement were terminated. The remaining deferred revenue was recognized as revenue in the fourth quarter of 2021.
Components of our Results of Operation
Collaboration Revenue - Related Party
We have no products approved for commercial sale, and we have not generated any revenue from commercial product sales. Our total revenue to date has been generated solely from our Collaboration Agreement with Takeda, which was terminated in November 2021. We expect that any collaboration revenue we may generate from any future collaboration partners will fluctuate from period to period.
We have received cash of $3.6 million and $14.0 million for the years ended December 31, 2021 and 2020, respectively, from Takeda under the Collaboration Agreement. We have recognized total aggregate revenue of $82.0 million through December 31, 2021 under the Collaboration Agreement.
Operating Expense
Research and Development Expense
Our research and development expenses consist primarily of costs incurred in connection with the discovery and development of our product candidates. These expenses include:
•expenses incurred to conduct our clinical trials and nonclinical studies;
•costs of manufacturing clinical trial and nonclinical study materials, including the costs of raw materials required for manufacturing;
•process development activities to optimize manufacturing processes;
•employee-related expenses, including salaries, benefits, and stock-based compensation;
•fees paid to third parties who assist with research and development activities;
•expenses relating to regulatory activities, including filing fees paid to regulatory agencies;
•laboratory materials and supplies used to support our research activities; and
•allocated expenses for facility-related costs.
The following table summarizes our research and development expenses by product candidate:
Year ended December 31,
(in thousands) 2021 2020
SL-172154 $ 15,708 $ 6,478
SL-279252 10,804 16,362
Other pipeline candidates 14,031 6,210
Internal costs, including personnel related benefits, facilities, and depreciation 16,020 8,433
$ 56,563 $ 37,483
Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials, including increased demand for clinical trial material. We expect our research and development expenses to increase significantly over the next several years as we conduct additional nonclinical studies and clinical trials, including later-stage clinical trials, for our current and future product candidates and pursue regulatory approval of our product candidates.
The process of conducting the necessary nonclinical and clinical research to obtain regulatory approval is costly and time consuming. The actual probability of success for our product candidates may be affected by a variety of factors including:
•the safety and efficacy of our product candidates;
•early clinical data for our product candidates;
•investment in our clinical programs;
•competition;
•manufacturing capability; and
•commercial viability.
We may never succeed in achieving regulatory approval for any of our product candidates due to the uncertainties discussed above. We are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of our product candidates, if ever.
General and Administrative Expense
General and administrative expense consists primarily of personnel expenses, including salaries, benefits, and stock-based compensation expense, for employees and consultants in executive, finance, accounting, legal, information technology and human resource functions. General and administrative expense also includes corporate facility costs, including rent, utilities, depreciation, and maintenance, not otherwise included in research and development expense, as well as legal fees related to intellectual property and corporate matters and fees for accounting and tax services.
We expect that our general and administrative expense will increase in the future to support our growing research and development activities and as a result of the increased costs of operating as a public company. These increases will likely include increased costs related to the hiring of additional personnel and fees to outside consultants, lawyers, and accountants, among other expenses. Additionally, we anticipate increased costs associated with being a public company, including expenses related to services associated with maintaining compliance with the requirements of Nasdaq and the Securities and Exchange Commission, or SEC, insurance, and investor relations costs. If any of our current or future product candidates obtains regulatory approval, we expect that we would incur significantly increased expenses associated with building a sales and marketing team.
Interest Income
Interest income consists of interest earned on our cash, cash equivalents and short-term investments, which consists of amounts held in a money market fund and at various times in short-term government and corporate obligations.
Income Taxes
Since our inception, we have not recorded any income tax benefits for the net operating losses, or NOLs, we have incurred or for our research and development tax credits, as we believe, based upon the weight of available evidence, that it is
more likely than not that all of our NOLs and tax credits will not be realized. Our NOLs and tax credit carryforwards will begin to expire in 2036. We have recorded a full valuation allowance against our deferred tax assets at each balance sheet date.
Results of Operations
Comparison of the Years Ended December 31, 2021 and 2020
The following table sets forth our results of operations for the years ended December 31, 2021 and 2020.
Year Ended December 31, Change
(in thousands) 2021 2020 Dollar Percentage
Collaboration revenue - related party $ 30,017 $ 9,934 $ 20,083 202.2 %
Operating expenses:
Research and development 56,563 37,483 19,080 50.9 %
General and administrative 18,723 9,382 9,341 99.6 %
Loss from operations (45,269) (36,931) (8,338) 22.6 %
Other income (expense):
Interest income 625 549 76 13.8 %
Other (330) (221) (109) 49.3 %
Net loss $ (44,974) $ (36,603) $ (8,371) 22.9 %
Collaboration Revenue - Related Party
Collaboration revenue increased by $20.1 million, or 202.2%, to $30.0 million for the year ended December 31, 2021 from $9.9 million for the year ended December 31, 2020. The Collaboration Agreement with Takeda was mutually terminated pursuant to the Termination Agreement and all remaining deferred revenue under the Collaboration Agreement was recognized in the fourth quarter of 2021. The increase was primarily attributable to the recognition of the remainder of the deferred revenue associated with the Collaboration Agreement.
Research and Development Expense
Research and development expenses increased by $19.1 million, or 50.9%, to $56.6 million for the year ended December 31, 2021 from $37.5 million for the year ended December 31, 2020. The increase was primarily attributable to an increase of $6.4 million in personnel costs as a result of an increase in headcount to expand our manufacturing and clinical development capabilities, an increase of $5.8 million in manufacturing and clinical costs, an increase of $3.1 million in assay development and nonclinical pipeline costs and an increase of $2.0 million in laboratory and facilities related costs. The remaining $1.8 million increase primarily resulted from an increase in depreciation and outside service fees.
General and Administrative Expense
General and administrative expenses increased by $9.3 million, or 99.6%, to $18.7 million for the year ended December 31, 2021 from $9.4 million for the year ended December 31, 2020. The increase was primarily due to a $5.0 million increase in personnel-related costs driven by higher employee headcount needed to support our growing research and development activities, and a $3.3 million increase for costs associated with being a public company.
Interest Income
Interest income increased by $0.1 million to $0.6 million for the year ended December 31, 2021 from $0.5 million for the year ended December 31, 2020.
Liquidity and Capital Resources
Since our inception, our primary sources of liquidity have been generated by sales of our preferred stock and common stock, including our initial public offering, or IPO, and through our Collaboration Agreement with Takeda. As of December 31, 2021, we had an accumulated deficit of $117.1 million and $268.8 million of cash and cash equivalents and short-term investments.
Capital Resources and Funding Requirements
Our primary uses of cash and cash equivalents and short-term investments are to fund our operations, which consist primarily of research and development expenditures related to our programs, product development costs, research expenses, administrative support, capital expenditures related to bringing in-house certain process development and manufacturing
capabilities and working capital requirements. We anticipate incurring additional net losses and negative cash flows from operations in the near future until such time, if ever, that we can generate significant sales of our product candidates currently in development. Our future funding requirements will depend on many factors, including:
•the scope, timing, progress, and results of discovery, nonclinical development, laboratory testing, and clinical trials for our product candidates;
•the costs of process development and scale-up of a commercially ready manufacturing process to support registrational clinical trials;
•the costs of manufacturing our product candidates for clinical trials and in preparation for marketing approval and commercialization;
•the extent to which we enter into collaborations or other arrangements with additional third parties in order to further develop our product candidates;
•the costs of preparing, filing and prosecuting patent applications, maintaining, and enforcing our intellectual property rights and defending other intellectual property-related claims;
•the costs and fees associated with the discovery, acquisition, or in-license of additional product candidates or technologies;
•the costs of future commercialization activities, if any, including establishing sales, marketing, manufacturing, distribution, and storage capabilities, for any of our product candidates for which we receive marketing approval; and
•revenue, if any, received from commercial sales of our product candidates, should any of our product candidates receive marketing approval.
Until we obtain regulatory approval to market our product candidates, if ever, we cannot generate revenues from sales of our products. Even if we are able to sell our products, we may not generate a sufficient amount of product revenues to finance our cash requirements. Accordingly, it will be necessary for us to seek to raise additional capital through equity offerings and/or debt financings or from other potential sources of liquidity, which may include new collaborations, licensing or other commercial agreements for one or more of our development programs or patent portfolios. There can be no assurance that such funding may be available to us on acceptable terms, or at all. The issuance of equity securities may result in dilution to stockholders and the issuance of debt securities may have rights, preferences and privileges senior to those of our common stock and the terms of any such debt securities could impose significant restrictions on our operations. The failure to raise funds as and when needed could have a negative impact on our financial condition and ability to pursue our business strategies. Additionally, if additional funding is not secured when required, we may need to delay or curtail our operations until such funding is received, which would have a material and adverse impact on our business prospects and results of operations.
We believe that our cash and cash equivalents and short-term investments as of December 31, 2021 are sufficient to fund projected operations into the second half of 2024.
Cash Flows
The following table shows a summary of our cash flows for the periods indicated:
Year ended December 31,
(in thousands) 2021 2020
Net cash used in operating activities $ (57,116) $ (33,659)
Net cash used in investing activities (10,443) (146,322)
Net cash provided by financing activities 1,929 330,866
Net (decrease) increase in cash and cash equivalents $ (65,630) $ 150,885
Net Cash Used in Operating Activities
During the year ended December 31, 2021, net cash used in operating activities was $57.1 million and primarily reflected our net loss of $45.0 million, offset primarily by noncash charges of $6.8 million in stock-based compensation and depreciation, $3.0 million in net amortization of premium on short-term investments and a $22.0 million net change in our operating assets and liabilities. We expect our operating activities expenses to increase as we continue to conduct our clinical trials and nonclinical studies, incur costs of manufacturing clinical trial and nonclinical study materials and continue process development activities to optimize our manufacturing processes.
During the year ended December 31, 2020, net cash used in operating activities was $33.7 million and primarily reflected our net loss of $36.6 million, offset primarily by noncash charges of $1.9 million in stock-based compensation and depreciation and a $1.1 million net change in our operating assets and liabilities.
Net Cash Used in Investing Activities
During the year ended December 31, 2021, net cash used in investing activities was $10.4 million of which $204.1 million was used to purchase short-term investments, $201.6 million was received from the sale of short-term investments and $7.9 million was used to purchase property and equipment.
During the year ended December 31, 2020, net cash used in investing activities was $146.3 million of which $183.2 million was used to purchase short-term investments, $37.6 million was received from the sale of short-term investments and $0.7 million was used to purchase property and equipment.
Net Cash Provided by Financing Activities
During the year ended December 31, 2021, net cash provided by financing activities was $1.9 million and was from the exercise of stock options and ESPP purchases.
During the year ended December 31, 2020, net cash provided by financing activities was $330.9 million and was primarily from the sale of our Series B and B-1 redeemable convertible preferred stock and proceeds from our initial public offering.
Contractual Obligations and Other Commitments
The following table summarizes our contractual obligations and commitments at December 31, 2021:
(in thousands) Less than
1 year
1 to
3 years
3 to
5 years
More than
5 years
Total
Operating lease obligations
$ 1,058 $ 2,209 $ 2,245 $ 1,721 $ 7,233
Total $ 1,058 $ 2,209 $ 2,245 $ 1,721 $ 7,233
The commitment amounts in the table above are associated with contracts that are enforceable and legally binding and that specify all significant terms, including fixed or minimum services to be used, fixed, minimum, or variable price provisions, and the approximate timing of the actions under the contracts. Payments due upon cancellation consisting only of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation are not included in the preceding tables as the amount and timing of such payments are not known.
We have not included any potential contingent payments upon the achievement by us of specified regulatory and commercial events, as applicable, or patent prosecution or royalty payments we may be required to make under the Heat License Agreement (as defined below). We have excluded these potential payments in the preceding tables because the timing and likelihood of these contingent payments are not currently known and would be difficult to predict or estimate. Contractual obligations represent future cash commitments and liabilities under agreements with third parties, and exclude contingent liabilities for which we cannot reasonably predict future payment. Our contractual obligations result primarily from obligations for various contract manufacturing organizations, or CMO, and clinical research organizations, or CROs, which include potential payments we may be required to make under its agreements. The contracts also contain variable costs and milestones that are hard to predict. The timing of payments and actual amounts paid under CMO and CRO agreements may be different depending on the timing of receipt of goods or services or changes to agreed-upon terms or amounts for some obligations. Also, those agreements are cancellable upon written notice by us and, therefore, not long-term liabilities.
Heat License Agreement
In June 2016, we entered into an Exclusive License Agreement, or the Heat License Agreement, with Heat Biologics Inc., or Heat. The Heat License Agreement was subsequently amended in November 2016, December 2016, and March 2017. Pursuant to the Heat License Agreement, Heat granted to us a worldwide, sublicensable exclusive license to research, develop, manufacture, and commercialize products under three provisional patent applications, including all patents issuing from such applications, or the Fusion Protein Patent Rights and a worldwide, sublicensable nonexclusive license to research, develop, manufacture, and commercialize certain know-how owned and controlled by Heat related to the Fusion Protein Patent Rights.
Under the Heat License Agreement, Heat was required to conduct certain research and development services under a mutually-agreed upon research and development plan and Heat was eligible to receive financial support from us for these efforts. Effective March 2017, Heat completed all research and development services under the Heat License Agreement and assigned to us three patent applications and all data derived from the research and development activities, referred to collectively as the Research Services Inventions. Pursuant to the terms of the Heat License Agreement, we are obligated to use
commercially reasonable efforts to diligently research and develop at least one product covered by the Fusion Protein Patent Rights, including the obligation to file an IND application for such product. Our development efforts, including the development of SL-279252 and certain other ARC compounds, to date satisfy these obligations.
Unless sooner terminated or extended, the term of the Heat License Agreement continues until the later of 20 years following the effective date and the expiration of the last-to-expire royalty term. Either party may terminate the agreement due to a material breach by the other party (subject to a 90-day cure period) or if the other party files for bankruptcy. In the event we terminate the Heat License Agreement due to a material breach by Heat, Heat must assign to us all right, title, and interest in the patent rights licensed under the Heat License Agreement.
In addition to an upfront payment of $50,000, which we made in 2016, the Heat License Agreement requires us to make further payments to Heat in the future of up to $20.6 million in the aggregate, for the achievement of specified development, regulatory, and commercial sale milestones for certain licensed products. We are also required to pay Heat a percentage of certain upfront fees or other non-royalty payments not tied to milestone events that we receive in connection with certain sublicenses of the Fusion Protein Patent Rights. We will be required to pay Heat a royalty on all worldwide net sales by us, our affiliates, and sublicenses of certain licensed products in the low single digits. Royalties are payable, on a product-by-product and country-by-country basis, commencing on the first commercial sale of such product and continuing until the last-to-expire valid patent claim to the licensed patent rights that cover such product in that country.
Critical Accounting Policies
Our management’s discussion and analysis of our financial condition and results of operations are based on our financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, and expenses and the disclosure of contingent assets and liabilities in our financial statements. On an ongoing basis, we evaluate our estimates and judgments, including those related to revenue recognition, the accrual for research and development expenses, and the valuation of stock-based awards. We base our estimates on historical experience, known trends and events, and various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
While our significant accounting policies are described in more detail in Note 2 to our financial statements included elsewhere in this Annual Report on Form 10-K, we believe the following accounting policies are the most critical to the judgments and estimates used in the preparation of our financial statements.
Revenue Recognition
We have and may continue to enter into collaboration agreements with other companies. Arrangements with collaborators may include licenses to intellectual property, research and development services, manufacturing services for clinical and commercial supply, and participation on joint steering and patent committees. We evaluate the promised goods or services in the contract to determine which promises, or group of promises, represent performance obligations. In contemplation of whether a promised good or service meets the criteria required of a performance obligation, we consider the stage of development of the underlying intellectual property, the capabilities and expertise of the customer relative to the underlying intellectual property, and whether the promised goods or services are integral to or dependent on other promises in the contract. When accounting for an arrangement that contains multiple performance obligations, we develop judgmental assumptions, which may include market conditions, reimbursement rates for personnel costs, development timelines, and probabilities of regulatory success to determine the stand-alone selling price for each performance obligation identified in the contract.
When we conclude that a contract should be accounted for as a combined performance obligation and recognized over time, we then determine the period over which revenue should be recognized and the method by which to measure revenue. We generally recognize revenue using a cost-based input method.
We recognize collaboration revenue when our customer or collaborator obtains control of promised goods or services, in an amount that reflects the consideration that we expect to receive in exchange for those goods or services. To determine revenue recognition for such arrangements, we perform the following five steps:
i.identify the contract(s) with a customer;
ii.identify the performance obligations in the contract;
iii.determine the transaction price;
iv.allocate the transaction price to the performance obligations within the contract; and
v.recognize revenue when (or as) the entity satisfies a performance obligation.
We only apply the five-step model to contracts when we determine that it is probable we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer.
At contract inception, we assess the goods or services promised within the contract to determine whether each promised good or service is a performance obligation. The promised goods or services in the arrangement consist of a license to our intellectual property and research, development and manufacturing services. We may provide options to additional items in such arrangements, which are accounted for as separate contracts when the customer elects to exercise such options, unless the option provides a material right to the customer. Performance obligations are promises in a contract to transfer a distinct good or service to the customer that (i) the customer can benefit from on its own or together with other readily available resources, and (ii) are separately identifiable from other promises in the contract. Goods or services that are not individually distinct performance obligations are combined with other promised goods or services until such combined group of promises meet the requirements of a performance obligation.
We determine transaction price based on the amount of consideration we expect to receive for transferring the promised goods or services in the contract. Consideration may be fixed, variable, or a combination of both. At contract inception for arrangements that include variable consideration, we estimate the probability and extent of consideration we expect to receive under the contract utilizing either the most-likely amount method or expected amount method, whichever best estimates the amount expected to be received. We then consider any constraints on the variable consideration and include in the transaction price variable consideration to the extent it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved.
We then allocate the transaction price to each performance obligation based on the relative standalone selling price and recognize revenue as the amount of the transaction price that is allocated to the respective performance obligation when (or as) control is transferred to the customer and the performance obligation is satisfied. For performance obligations that consist of licenses and other promises, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress. We evaluate the measure of progress each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.
We record amounts as accounts receivable when the right to consideration is deemed unconditional. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded as deferred revenue.
Amounts received prior to satisfying the revenue recognition criteria are recognized as deferred revenue in our balance sheet. Deferred revenues expected to be recognized as revenue within the 12 months following the balance sheet date are classified as a current liability. Deferred revenues not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as noncurrent liabilities.
Research and Development Expense
Research and development expenses consist primarily of costs incurred in connection with the development of our product candidates. We expense research and development costs as incurred.
We accrue expenses for manufacturing, process development, nonclinical studies and clinical trial activities performed by vendors based upon estimates of the proportion of work completed. We determine the estimates by reviewing contracts, vendor agreements and purchase orders, and through discussions with our internal personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services. However, actual costs and timing of clinical trials are highly uncertain, subject to risks and may change depending upon a number of factors, including our clinical development plan.
We make estimates of our prepaid and accrued expenses as of each balance sheet date in our financial statements based on facts and circumstances known at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, we will adjust the accrual accordingly. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed.
Stock-Based Compensation
We measure compensation expense for all share-based awards based on the estimated fair value of the share-based awards on the grant date. We use the Black-Scholes option pricing model to value our stock option awards. We recognize
compensation expense on a straight-line basis over the requisite service period, which is generally the vesting period of the award.
The Black-Scholes option-pricing model requires the use of subjective assumptions that include the expected stock price volatility and, for options granted prior to our IPO, the fair value of the underlying common stock on the date of grant. See Note 9 to our audited financial statements included elsewhere in this Annual Report on Form 10-K for information concerning certain of the specific assumptions we used in applying the Black-Scholes option pricing model to determine the estimated fair value of our stock options granted during the year ended December 31, 2021.
Recent Accounting Pronouncements
See Note 2 to our financial statements found elsewhere in this Annual Report on Form 10-K for a description of recent accounting pronouncements applicable to our financial statements.
Emerging Growth Company and Smaller Reporting Company Status
We are an emerging growth company as defined in the JOBS Act. Under the JOBS Act, an emerging growth company can take advantage of the extended transition period for complying with new or revised accounting standards and delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to avail ourselves of this exemption from complying with new or revised accounting standards and, therefore, will not be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies. As a result, our financial statements may not be comparable to companies that comply with new or revised accounting pronouncements as of public company effective dates.
We have evaluated the benefits of relying on other exemptions and reduced reporting requirements under the JOBS Act. Subject to certain conditions, as an emerging growth company, we may rely on certain of these exemptions, including without limitation exemptions to the requirements for (1) providing an auditor’s attestation report on our system of internal controls over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act and (2) complying with any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation or a supplement to the auditor’s report providing additional information about the audit and the financial statements, known as the auditor discussion and analysis. We will remain an emerging growth company until the earlier of (a) the last day of the fiscal year (i) following the fifth anniversary of the completion of our initial public offering, (ii) in which we have total annual gross revenues of at least $1.07 billion or (iii) in which we are deemed to be a “large accelerated filer” under the rules of the SEC, which means the market value of our common stock that is held by non-affiliates exceeds $700.0 million as of the prior June 30th, or (b) the date on which we have issued more than $1.0 billion in non-convertible debt during the prior three-year period.
We are also a “smaller reporting company” as defined under the Exchange Act. We may continue to be a smaller reporting company if either (i) the market value of our stock held by non-affiliates is less than $250.0 million or (ii) our annual revenue is less than $100.0 million during the most recently completed fiscal year and the market value of our stock held by non-affiliates is less than $700.0 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.

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ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
Item 7A. Quantitative and Qualitative Disclosures About Market Risk
We are a smaller reporting company, as defined by Rule 12b-2 under the Securities and Exchange Act of 1934 and in Item 10(f)(1) of Regulation S-K, and are not required to provide the information under this item.

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ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
Item 8. Audited Financial Statements
SHATTUCK LABS, INC.
Page
Report of Independent Registered Public Accounting Firm
Balance Sheets as of December 31, 2021 and 2020
Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2021 and 2020
Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders’ Equity (Deficit) for the Years Ended December 31, 2021 and 2020
Statements of Cash Flows for the Years Ended December 31, 2021 and 2020
Notes to Financial Statements
Report of Independent Registered Public Accounting Firm
To the Stockholders and Board of Directors
Shattuck Labs, Inc.:
Opinion on the Financial Statements
We have audited the accompanying balance sheets of Shattuck Labs, Inc. (the Company) as of December 31, 2021 and 2020, the related statements of operations and comprehensive loss, changes in redeemable convertible preferred stock and stockholders’ equity (deficit), and cash flows for the years then ended, and the related notes (collectively, the financial statements). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2021 and 2020, and the results of its operations and its cash flows for the years then ended, in conformity with U.S. generally accepted accounting principles.
Basis for Opinion
These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.
We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.
Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.
/s/ KPMG LLP
We have served as the Company’s auditor since 2018.
Austin, Texas
March 15, 2022
SHATTUCK LABS, INC.
BALANCE SHEETS
(In thousands, except share and per share amounts)
December 31,
2021 2020
Assets
Current assets:
Cash and cash equivalents $ 92,268 $ 157,898
Short-term investments 176,536 177,551
Prepaid expenses and other current assets 19,462 10,190
Total current assets 288,266 345,639
Property and equipment, net 9,938 3,000
Other assets 381 349
Total assets $ 298,585 $ 348,988
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable $ 10,012 $ 1,754
Accrued expenses 14,574 7,352
Deferred revenue - related party - 7,728
Total current liabilities 24,586 16,834
Deferred rent 2,213 987
Deferred revenue - related party, net of current portion - 21,306
Total liabilities 26,799 39,127
Commitments and contingencies (Note 6)
Stockholders’ equity:
Common stock; $0.0001 par value: 300,000,000 shares authorized, 42,338,898 shares issued and outstanding at December 31, 2021 and 41,779,183 shares issued and 41,767,431 shares outstanding at December 31, 2020
5 5
Additional paid-in capital 389,408 382,012
Accumulated other comprehensive loss (560) (63)
Accumulated deficit (117,067) (72,093)
Total stockholders’ equity 271,786 309,861
Total liabilities and stockholders’ equity $ 298,585 $ 348,988
See accompanying notes to financial statements
SHATTUCK LABS, INC.
STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
(In thousands, except share and per share amounts)
Year Ended December 31,
2021 2020
Collaboration revenue - related party $ 30,017 $ 9,934
Operating expenses:
Research and development 56,563 37,483
General and administrative 18,723 9,382
Expense from operations 75,286 46,865
Loss from operations (45,269) (36,931)
Other income (expense):
Interest income 625 549
Other (330) (221)
Total other income (expense) 295 328
Net loss $ (44,974) $ (36,603)
Unrealized loss on investments (497) (117)
Comprehensive loss $ (45,471) $ (36,720)
Net loss per share - basic and diluted $ (1.07) $ (2.36)
Weighted-average shares outstanding - basic and diluted 42,032,384 15,506,067
See accompanying notes to financial statements
SHATTUCK LABS, INC.
STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK
AND STOCKHOLDERS’ EQUITY (DEFICIT)
(In thousands, except share amounts)
Series A
Redeemable
Convertible
Preferred Stock
Series B
Redeemable
Convertible
Preferred Stock
Series B-1
Redeemable
Convertible
Preferred Stock
Common Stock Additional
Paid-In
Capital
Accumulated Other Comprehensive Income (Loss) Accumulated
Deficit
Total Stockholders’ Equity (Deficit)
Shares Amount Shares Amount Shares Amount Shares Amount
Balance at December 31, 2019 1,093,019 $ 49,064 - $ - - $ - 7,600,877 $ 1 $ 887 $ 54 $ (35,490) $ (34,548)
Sales of Series B Redeemable convertible preferred stock, net of issuance costs - - 550,571 34,427 - - - - - - - -
Sales of Series B-1 Redeemable convertible preferred stock, net of issuance costs - - - - 1,319,964 82,613 - - - - - -
Conversion of Series A redeemable convertible preferred stock (1,093,019) (49,064) - - - - 7,487,151 1 49,063 - - 49,064
Conversion of Series B redeemable convertible preferred stock - - (550,571) (34,427) - - 3,771,363 1 34,426 - - 34,427
Conversion of Series B-1 redeemable convertible preferred stock - - - - (1,319,964) (82,613) 9,041,739 1 82,612 - - 82,613
Issuance of common stock upon initial public offering, net of issuance cost - - - - - - 13,664,704 1 213,529 - - 213,530
Exercise of stock options - - - - - - 181,449 - 229 - - 229
Vesting of common stock previously subject to vesting requirements - - - - - - 20,148 - - - - -
Stock-based compensation expense - - - - - - - - 1,266 - - 1,266
Unrealized loss on investments - - - - - - - - - (117) - (117)
Net loss - - - - - - - - - - (36,603) (36,603)
Balance at December 31, 2020 - $ - - $ - - $ - 41,767,431 $ 5 $ 382,012 $ (63) $ (72,093) $ 309,861
Exercise of stock options and ESPP purchases - - - - - - 559,715 - 1,929 - - 1,929
Vesting of common stock previously subject to vesting requirements - - - - - - 11,752 - - - - -
Stock-based compensation expense - - - - - - - - 5,467 - - 5,467
Unrealized loss on investments - - - - - - - - - (497) - (497)
Net loss - - - - - - - - - - (44,974) (44,974)
Balance at December 31, 2021 - $ - - $ - - $ - 42,338,898 $ 5 $ 389,408 $ (560) $ (117,067) $ 271,786
See accompanying notes to financial statements
SHATTUCK LABS, INC.
STATEMENTS OF CASH FLOWS
(In thousands)
Year Ended December 31,
2021 2020
Cash flows from operating activities:
Net loss $ (44,974) $ (36,603)
Adjustments to reconcile net loss to net cash used in operations:
Stock-based compensation 5,467 1,266
Depreciation 1,380 618
Net amortization of premium on short-term investments 3,035 1
Changes in operating assets and liabilities:
Prepaid expenses and other current assets (9,272) (6,835)
Other assets (32) (326)
Accounts payable 7,866 (1,751)
Accrued expenses 6,924 3,313
Deferred revenue - related party (29,034) 6,569
Deferred rent 1,524 89
Net cash used in operating activities (57,116) (33,659)
Cash flows from investing activities:
Purchase of property and equipment (7,926) (727)
Sale and maturities of short-term investments 201,575 37,595
Purchases of short-term investments (204,092) (183,190)
Net cash used in investing activities (10,443) (146,322)
Cash flows from financing activities:
Proceeds from the exercises of stock options and ESPP purchases 1,929 229
Proceeds from the initial public offering - 232,301
Issuance costs of the initial public offering - (18,738)
Proceeds from sale of Series B-1 redeemable convertible preferred stock - 83,000
Issuance costs of Series B-1 redeemable convertible preferred stock - (387)
Proceeds from sale of Series B redeemable convertible preferred stock - 34,620
Issuance costs of Series B redeemable convertible preferred stock - (159)
Net cash provided by financing activities 1,929 330,866
Net increase (decrease) in cash and cash equivalents (65,630) 150,885
Cash and cash equivalents, beginning of period 157,898 7,013
Cash and cash equivalents, end of period $ 92,268 $ 157,898
Supplemental disclosures of non-cash financial activities:
Unrealized loss on short-term investments $ (497) $ (117)
Unpaid amounts related to purchase of property and equipment $ 392 $ 454
See accompanying notes to financial statements
SHATTUCK LABS, INC.
NOTES TO FINANCIAL STATEMENTS
1. Organization and Description of Business
Shattuck Labs, Inc. (the “Company”) was incorporated in 2016 in the State of Delaware and is a clinical-stage biopharmaceutical company developing dual-sided fusion proteins, including its ARC® and GADLEN™ platforms, as novel classes of biologic medicines capable of multifunctional activity with potential applications in oncology and inflammatory diseases. Using its proprietary technology, the Company is building a pipeline of therapeutics, initially focused on the treatment of solid tumors and hematologic malignancies. The Company has two clinical-stage product candidates, SL-172154 and SL-279252, and has several compounds in preclinical development.
Liquidity
The Company has incurred losses and negative cash flows from operations since inception and has an accumulated deficit of $117.1 million as of December 31, 2021. The Company anticipates incurring additional losses and negative cash flows from operations until such time, if ever, that it can generate significant sales of its product candidates currently in development, and is highly dependent on its ability to find additional sources of funding in the form of licensing of its technology, collaboration agreements, and/or public and private debt and equity financings. Adequate additional funding may not be available to the Company on acceptable terms, or at all. The failure to raise funds as and when needed could have a negative impact on the Company’s financial condition and ability to pursue its clinical operations, research and development and commercialization of its product candidates. Management believes that the Company’s cash and cash equivalents and short-term investments of $268.8 million as of December 31, 2021, are sufficient to fund projected operations of the Company for at least the next twelve months.
COVID-19 Pandemic
On March 10, 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. The virus and actions taken to mitigate its spread have had, and are expected to continue to have, a broad adverse impact on the economies and financial markets of many countries, including the geographical areas in which the Company operates and conducts its business and in which the Company’s partners operate and conduct their business. The Company is currently following the recommendations of local health authorities to minimize exposure risk for its team members and visitors. However, the scale and scope of this pandemic is unknown and the duration of the business disruption and related financial impact cannot be reasonably estimated at this time. While the Company has implemented specific business continuity plans to reduce the potential impact of COVID-19, there is no guarantee that the Company’s continuity plans will be successful.
The Company has already experienced disruptions to its business such as work-from-home orders for offices and similar disruptions have occurred for its partners. Specifically, the outbreak has caused disruptions in its ability to manufacture clinical trial materials, including the acquisition of raw materials needed for such manufacturing, enrollment and treatment of patients in clinical trials in process, and slowdowns and shutdowns of the laboratories and other service providers that are being relied upon in the development of the Company’s product candidates.
The extent to which the COVID-19 pandemic or any other health epidemic may impact the Company’s results will depend on future developments, which are highly uncertain and cannot be predicted, including new information that may emerge concerning the severity of COVID-19 and the actions to mitigate its impact, among others. Accordingly, the COVID-19 pandemic could have a material adverse effect on the Company’s business, results of operations and financial condition.
2. Basis of Presentation and Summary of Significant Accounting Policies
Basis of Presentation
The accompanying audited financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”).
Use of Estimates
The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses, and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates, if any, are recorded in the period in which they become known and actual results could differ from management’s estimates. A change in the Company’s estimates occurred in the second quarter of 2021, which impacted the Company’s revenue recognition and related balance sheet accounts.
Fair Value of Financial Instruments
Fair value is defined as the price that would be received upon the sale of an asset or paid upon the transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. Fair value measurements are classified and disclosed in one of the following categories:
•Level 1: Observable inputs such as quoted prices in active markets for identical assets the reporting entity has the ability to access as of the measurement date;
•Level 2: Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and
•Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
Fair value measurements are classified based on the lowest level of input that is significant to the measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of the assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values stated below takes into account the market for its financial assets and liabilities, the associated credit risk and other factors as required. The Company considers active markets as those in which transactions for the assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis.
Management believes that the carrying amounts of the Company’s financial instruments, including short-term investments and accounts payable, approximate fair value due to the short-term nature of those instruments.
Concentration of Risk
Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents and short-term investments. The Company maintains its cash and cash equivalents at two accredited financial institutions in amounts that exceed federally-insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company invests in only highly rated debt securities that management believes protects the Company from risk of default and impairment of value.
All of the Company’s revenue is derived from its collaboration agreement with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”), which was mutually terminated pursuant to the termination agreement, dated November 8, 2021.
The Company is highly dependent on one third-party contract manufacturing organization (“CMO”) to supply drug products for its research and development activities of its programs, including clinical trials and non-clinical studies. These programs could be adversely affected by a significant interruption in the supply of such drug products.
The Company is highly dependent on three contract research organizations (“CROs”) and a limited number of third-party service providers to manage and support its clinical trials. These programs could be adversely affected by a significant disruption in services provided by these CROs and third parties.
Cash and Cash Equivalents
The Company considers all demand deposits with financial institutions and all highly liquid investments with original maturities of 90 days or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents consisted of $14.6 million held in operating accounts and $77.7 million held in money market funds as of December 31, 2021 and $2.7 million held in operating accounts, $80.2 million held in money market funds and $75.0 million held in government obligations as of December 31, 2020.
Short-Term Investments
Short-term investments consist of highly-rated U.S. Treasury securities with maturities of more than three months but less than one year at the date of purchase. The Company classifies its short-term investments at the time of purchase as available-for-sale securities. Available-for-sale securities are carried at fair value. Credit impairments for available-for-sale debt securities are recorded through an allowance rather than a direct write-down of the security and are recorded through a charge to the statements of operations. Unrealized gains or losses not related to credit impairments are recorded in accumulated other comprehensive income, a component of stockholders’ equity, until realized. The Company reviews available-for-sale debt securities for impairments related to credit losses and other factors each quarter. As of December 31, 2021, there were no impairments related to credit losses of short-term investments.
Deferred Offering Costs
The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs will be recorded against gross proceeds.
Series A, Series B and Series B-1 Redeemable Convertible Preferred Stock
The Company records shares of redeemable convertible preferred stock at their respective fair values on the date of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ equity on the balance sheet because the shares contain liquidation features that are not solely within the Company’s control. Upon the completion of the Company’s initial public offering (“IPO”) in the fourth quarter of 2020, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into common stock.
Prepaid Expenses and Other Current Assets
Prepaid expenses and other current assets include prepaid expenses for general business purposes and services used in research projects, which are stated at cost and amortized on a straight-line basis over the related period of benefit. Supplies and materials that have multiple applications for alternative future use are expensed as they are consumed.
Property and Equipment
Property and equipment are stated at cost, net of accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of the asset. Expenditures for repairs and maintenance that do not extend the estimated useful life or improve an asset are expensed as incurred. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts, and any resulting gain or loss is included in the statement of operations and comprehensive loss.
Depreciation periods are as follows:
Office equipment 3 years
Furniture and fixtures 5 to 10 years
Lab equipment 5 years
Leasehold improvements Shorter of lease term or 15 years
Impairment of Long-Lived Assets
Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstance indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2021 and 2020.
Deferred Rent
The Company records rent expense on a straight-line basis over the term of the leases and, accordingly records the difference between cash payments and the recognition of rent expense as a deferred rent asset or liability. Incentives granted under the Company’s leases, including allowances to fund leasehold improvements, are deferred and recognized as adjustments to rent expense on a straight-line basis over the term of the leases.
Revenue Recognition
Collaboration revenue is recognized in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). Arrangements with collaborators may include licenses to intellectual property, research and development services, manufacturing services for clinical and commercial supply and participation on joint steering committees. The Company evaluates the promised goods or services in the contract to determine which promises, or group of promises, represent performance obligations. In contemplation of whether a promised good or service meets the criteria required of a performance obligation, the Company considers the stage of development of the underlying intellectual property, the capabilities and expertise of the customer relative to the underlying intellectual property and whether the promised goods or services are integral to or dependent on other promises in the contract. When accounting for an arrangement that contains multiple performance obligations, the Company must develop judgmental assumptions, which may include market conditions, reimbursement rates for personnel costs, development timelines and probabilities of regulatory success to determine the stand-alone selling price for each performance obligation identified in the contract.
Upon the amendment of an existing agreement, the Company evaluates whether the amendment represents a modification to an existing contract which would be recorded through a cumulative catch-up to revenue, or a separate contract. If it is determined that it is a separate contract, the Company will evaluate the necessary revenue recognition through the five-step process described below.
When the Company concludes that a contract should be accounted for as a combined performance obligation and recognized over time, the Company must then determine the period over which revenue should be recognized and the method by which to measure revenue. The Company generally recognizes revenue using a cost-based input method.
The Company recognizes collaboration revenue in an amount that reflects the consideration that the Company expects to receive in exchange for those goods or services when its customer or collaborator obtains control of promised goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the following five steps are performed:
i.identify the contract(s) with a customer;
ii.identify the performance obligations in the contract;
iii.determine the transaction price;
iv.allocate the transaction price to the performance obligations within the contract; and
v.recognize revenue when (or as) the entity satisfies a performance obligation.
The Company only applies the five-step model to contracts when it determines that it is probable it will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer.
At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract to determine whether each promised good or service is a performance obligation. The promised goods or services in the Company’s arrangements may consist of a license of, or options to license, the Company’s intellectual property and research, development and manufacturing services. The Company may provide options to additional items in such arrangements, which are accounted for as separate contracts when the customer elects to exercise such options, unless the option provides a material right to the customer. Performance obligations are promises in a contract to transfer a distinct good or service to the customer that (i) the customer can benefit from on its own or together with other readily available resources and (ii) are separately identifiable from other promises in the contract. Goods or services that are not individually distinct performance obligations are combined with other promised goods or services until such combined group of promises meet the requirements of a performance obligation.
The Company determines transaction price based on the amount of consideration the Company expects to receive for transferring the promised goods or services in the contract. Consideration may be fixed, variable or a combination of both. At contract inception for arrangements that include variable consideration, the Company estimates the probability and extent of consideration it expects to receive under the contract utilizing either the most-likely amount method or expected amount method, whichever best estimates the amount expected to be received. The Company then considers any constraints on the variable consideration and includes variable consideration in the transaction price to the extent it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved.
The Company then allocates the transaction price to each performance obligation based on the relative standalone selling price and recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) control is transferred to the customer and the performance obligation is satisfied. For performance obligations which consist of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.
The Company records amounts as accounts receivable when the right to consideration is deemed unconditional. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded as deferred revenue.
Amounts received prior to satisfying the revenue recognition criteria are recognized as deferred revenue in the Company’s accompanying balance sheet. Deferred revenues expected to be recognized as revenue within the 12 months following the balance sheet date are classified as a current liability. Deferred revenues not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as non-current liabilities.
The Company’s collaboration revenue arrangements may include the following:
Up-front License Fees: If a license is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from nonrefundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.
Milestone Payments: At the inception of an agreement that includes research and development milestone payments, the Company evaluates each milestone to determine when and how much of the milestone to include in the transaction price. The Company first estimates the amount of the milestone payment that the Company could receive using either the expected value or the most-likely amount approach. The Company primarily uses the most-likely amount approach as that approach is generally most predictive for milestone payments with a binary outcome. The Company then considers whether any portion of that estimated amount is subject to the variable consideration constraint (that is, whether it is probable that a significant reversal of cumulative revenue would not occur upon resolution of the uncertainty). The Company updates the estimate of variable consideration included in the transaction price at each reporting date which includes updating the assessment of the likely amount of consideration and the application of the constraint to reflect current facts and circumstances.
Royalties: For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).
To date, the Company has not granted a development and commercialization license nor recognized any revenue related to sales-based royalties or milestone payments based on the level of sales.
Research and Development Services: The Company will record costs associated with development and process optimization activities as research and development expenses in the statements of operations and comprehensive loss consistent with ASC 730, Research and Development. The Company considered the guidance in ASC 808, Collaborative Agreements and will recognize the payments received from these agreements as revenue when the related costs are incurred.
Research and Development Costs
Research and development costs are expensed as incurred, and include salaries, stock-based compensation and other personnel-related costs, equipment and supplies, depreciation, nonclinical studies, clinical trials and manufacturing development activities.
A substantial portion of the Company’s ongoing research and development activities are conducted by third-party service providers, including CROs and CMOs. The Company accrues for expenses resulting from obligations under agreements with CROs, CMOs and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through an evaluation of the progress or stage of completion of the services. In the event advance payments are made to a CRO, CMO or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals and prepaid assets accordingly. Inputs, such as the services performed, the number of patients enrolled or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. The Company makes significant judgements and estimates in determining the accrual and/or prepaid balance in each reporting period and changes in these estimates may result in material changes to the Company’s accruals that could materially affect the Company’s results of operations.
Stock-Based Compensation
The Company recognizes the grant-date fair value of stock-based awards issued to employees and nonemployee Board members as compensation expense on a straight-line basis over the vesting period of the award. The Company uses the Black-Scholes option pricing model to determine the grant-date fair value of stock options. The Company adjusts expense for forfeitures in the periods they occur.
Income Taxes
The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities will be recognized in the period that includes the enactment date. Additionally, any changes in income tax laws are immediately recognized in the year of enactment.
A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance.
The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense.
Net Loss Per Share
Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as redeemable convertible preferred stock, convertible notes, stock options and unvested shares of restricted stock, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive.
The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive:
December 31,
2021 2020
Stock options 2,448,676 2,742,022
Unvested restricted stock - 11,752
2,448,676 2,753,774
Other Comprehensive Income (Loss)
Other comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other comprehensive income (loss) is comprised of the net loss and unrealized gains and losses on short-term investments.
Recently Adopted Accounting Pronouncements
In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes. The ASU removes certain exceptions to the general principles in ASC 740, Income Taxes and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, including interim periods within that fiscal year, with early adoption permitted. The Company adopted this pronouncement effective January 1, 2021 and it did not have a material impact on the financial statements or related disclosures.
Recently Issued Accounting Pronouncements (not yet adopted)
In February 2016, the FASB issued ASU No. 2016-02, Leases which requires a lessee to record a right-of-use asset and a corresponding lease liability on the balance sheet for all leases with terms longer than 12 months. A modified retrospective
transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The FASB deferred the effective date of this ASU until the annual periods beginning after December 15, 2021. The Company expects that the most significant effects of adopting this standard will primarily relate to (a) the recognition of right of use assets and lease liabilities on the balance sheet in relation to its existing operating lease agreements in Austin, Texas and Durham, North Carolina; and (b) providing significant new disclosures about leasing activities. The Company is currently evaluating the expected impact that the standard could have on its financial statements and related disclosures.
3. Short-Term Investments
The following table represents the Company’s available for sale short-term investments by major security type (amounts in thousands):
December 31, 2021
Amortized
Cost
Gross Unrealized
Loss
Total
Fair Value
Short-term investments:
U.S. government securities $ 177,096 $ (560) $ 176,536
Total short-term investments $ 177,096 $ (560) $ 176,536
December 31, 2020
Amortized
Cost
Gross Unrealized
Loss
Total
Fair Value
Short-term investments:
U.S. government securities $ 177,614 $ (63) $ 177,551
Total short-term investments $ 177,614 $ (63) $ 177,551
The Company’s short-term investment instruments and cash and cash equivalents are classified using Level 1 inputs within the fair value hierarchy and are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. Debt securities have an average maturity of 0.43 years as of December 31, 2021.
4. Property and Equipment
Property and equipment consisted of the following (amounts in thousands):
December 31,
2021 2020
Lab equipment $ 5,823 $ 2,790
Leasehold improvements 3,709 1,073
Construction in progress 2,521 355
Furniture and fixtures 459 157
Office equipment 206 105
12,718 4,480
Accumulated depreciation and amortization (2,780) (1,480)
Property and equipment, net $ 9,938 $ 3,000
Depreciation and amortization expense for the years ended December 31, 2021 and 2020 was $1.4 million and $0.6 million, respectively.
5. Accrued Expenses
Accrued expenses consisted of the following (amounts in thousands):
December 31,
2021 2020
Research and development contract costs $ 10,253 $ 5,382
Compensation and related benefits 3,320 1,551
Other 1,001 419
Total accrued expenses $ 14,574 $ 7,352
6. Commitments and Contingencies
Operating Leases
As of December 31, 2021, future minimum payments, by year and in aggregate, under non-cancelable operating leases consist of the following (amounts in thousands):
2022 $ 1,058
2023 1,089
2024 1,120
2025 1,152
2026 1,093
Thereafter 1,721
Total minimum lease payments $ 7,233
The Company recognized rent expense of $0.7 million and $0.4 million for the years ended December 31, 2021 and 2020, respectively.
Heat License Agreement
In connection with a license agreement with Heat Biologics Inc. (“Heat”), the Company is required to make payments of up to $20.6 million in aggregate for the achievement of specified development, regulatory and commercial sales milestones for certain licensed products. The Company is required to pay Heat a percentage of upfront fees or other non-royalty payments not tied to milestone events that it receives in connection with certain sublicenses of the licensed patents. The Company is also required to pay Heat a royalty on all of its worldwide net sales, those of its affiliates and sublicenses of certain licensed patents in the low single digits. The Company has not recorded a liability for the payments aforementioned given the achievement of specified development, regulatory and commercial sales milestones for certain licensed products is not probable as of the balance sheet date.
Litigation
From time to time, the Company may become involved in various legal actions arising in the ordinary course of business. On January 31, 2022 and February 11, 2022, putative class action lawsuits were filed in the U.S. District Court for the Eastern District of New York against us and certain of the Company’s officers and directors. In each complaint, the plaintiff cites the volatility in the Company’s common stock and alleges that the defendants made or are responsible for false or misleading statements regarding the Company’s collaboration agreement with Takeda. The plaintiffs in both lawsuits seek a ruling that the case may proceed as a class action, and seeks unspecified damages and attorneys’ fees, expert fees and costs. The Company and the individual defendants deny any allegations of wrongdoing and intend to vigorously defend against these lawsuits.
Contractual Obligations
Contractual obligations represent future cash commitments and liabilities under agreements with third parties, and exclude contingent liabilities for which the Company cannot reasonably predict future payment. The Company’s contractual obligations result primarily from obligations for various CMOs and CROs, which include potential payments that may be required under its agreements. The contracts also contain variable costs and milestones that are hard to predict as they are based on such things as patients enrolled and clinical trial sites. The timing of payments and actual amounts paid under CMO and CRO agreements may be different depending on the timing of receipt of goods or services or changes to agreed-upon terms or amounts for some obligations. Such agreements are cancellable upon written notice by the Company and, therefore, are not long-term liabilities.
7. Preferred Stock
During the year ended December 31, 2020, the Company entered into various stock purchase agreements with new and existing investors pursuant to which the Company sold an aggregate 550,571 shares of Series B redeemable convertible
preferred stock and 1,319,964 shares of Series B-1 redeemable convertible preferred stock at $62.88051 per share for net proceeds of $117.0 million.
The Company’s Series A, Series B and Series B-1 redeemable convertible preferred stock converted into common stock upon the completion of the Company’s IPO in 2020 and the rights, preferences, and terms are no longer applicable.
8. Collaboration Agreement - Related Party
The Company recognized revenue for the allocated up-front payments using a cost-based input measure. In applying the cost-based input method of revenue recognition, the Company used actual costs incurred relative to budgeted costs expected to be incurred for the combined performance obligation. In August 2017, the Company entered into a Collaboration Agreement with Takeda related to the development of certain ARC molecules, as amended in April 2018, October 2018 and March 2020 (the “Collaboration Agreement”). The Collaboration Agreement was mutually terminated pursuant to a termination agreement dated November 8, 2021 (the “Termination Agreement”). Under the terms of the Termination Agreement, the Company is not required to satisfy any remaining performance obligations, the Company will not make any payments to or receive any future milestone or royalty payments from Takeda, and all options to license and rights of first negotiation held by Takeda under the Collaboration Agreement were terminated. The remaining deferred revenue was recognized as revenue in the fourth quarter of 2021. The Company received cash of $3.6 million and $14.0 million in the years ended December 31, 2021 and 2020, respectively, and recognized total revenue of $82.0 million through December 31, 2021 under the Collaboration Agreement.
9. Stock-Based Compensation
2020 Equity Incentive Plan
In September 2020, the Company adopted the 2020 Stock Incentive Plan (the “2020 Plan”) which, as of the adoption date, replaced the 2016 Stock Incentive Plan. Under the 2020 Plan, the share reserve automatically increases on January 1st of each year beginning in 2021 and ending with a final increase on January 1, 2030 in an amount equal to 4% of the Company’s outstanding common shares on December 31st of the preceding calendar year. The Board of Directors may provide that there will be no increase in the share reserve for any such year or that the increase in the share reserve may be smaller than would otherwise occur. As of December 31, 2021, there were 3,912,408 shares available for future grants under the 2020 Plan and on January 1, 2022, the share reserve automatically increased by 1,693,555 shares. The 2020 Plan permits the granting of options and restricted stock. The terms of the agreements under the 2020 Plan are determined by the Company’s Board of Directors. The Company’s awards vest based on the terms in the agreements and generally vest over four years and have a term of 10 years.
2020 Employee Stock Purchase Plan
The 2020 Employee Stock Purchase Plan (“2020 ESPP”) became effective in connection with the Company’s IPO. A total of 395,795 shares of common stock were reserved for issuance under the 2020 ESPP. Eligible employees may purchase shares of common stock under the 2020 ESPP at 85% of the lower of the fair market value of the Company’s common stock as of the first or the last day of each offering period. Employees are limited to contributing 15% of the employee’s eligible compensation and may not purchase more than $25,000 of stock during any calendar year or more than 600 shares during any one purchase period. The 2020 ESPP share reserve automatically increases on January 1st of each calendar year, for ten years, commencing on January 1, 2021, in an amount equal to 1% of the total number of shares of common stock outstanding on December 31st of the preceding calendar year. The Board may act prior to January 1st of a given year to provide that there will be no January 1st increase of the share reserve for such year or that the increase in the share reserve for such year will be a smaller number of shares of common stock than would otherwise occur pursuant to the preceding sentence. As of December 31, 2021 there were 393,689 shares available for future purchases and on January 1, 2022, the share reserve automatically increased by 423,388 shares. Under the 2020 ESPP, the Company issued 2,106 shares of common stock for aggregate cash proceeds of $0.1 million during the year ended December 31, 2021. There were no shares of common stock issued during the year ended December 31, 2020.
The Company recorded stock-based compensation expense in the following expense categories of its accompanying audited statements of operations and comprehensive loss (amounts in thousands):
Year Ended December 31,
2021 2020
Research and development $ 2,200 $ 531
General and administrative 3,267 735
Total stock-based compensation $ 5,467 $ 1,266
The following table summarizes option activity under the 2020 Plan and the 2016 Stock Incentive Plan:
Options Weighted
Average
Exercise Price
Weighted
Average
Remaining Life
(Years)
Balance at January 1, 2021 2,742,022 $ 7.95 8.82
Granted 325,671 23.60
Exercised (557,609) 3.40
Forfeited (61,408) 12.13
Balance at December 31, 2021 2,448,676 $ 10.96 8.08
Vested and expected to vest 2,418,923 $ 10.88 8.07
Exercisable at the end of the period 1,259,440 $ 6.44 7.55
Options granted during the years ended December 31, 2021 and 2020 had weighted-average grant-date fair values of $16.38 and $8.93 per share, respectively. As of December 31, 2021, the unrecognized compensation cost was $11.4 million and will be recognized over an estimated weighted-average amortization period of 2.48 years. The aggregate intrinsic value of options exercised as of December 31, 2021 and 2020 was $10.8 million and $49.7 million, respectively. The aggregate intrinsic value of options outstanding and exercisable as of December 31, 2021 was $5.9 million.
The fair value of each option is estimated on the date of grant using a Black-Scholes option pricing model which takes into account inputs such as the exercise price, the estimated fair value of the underlying common stock at grant date, expected term, expected stock price volatility, risk-free interest rate and dividend yield. The fair value of stock options was determined using the methods and assumptions discussed below.
•The expected term of employee stock options with service-based vesting is determined using the “simplified” method, whereby the expected life equals the arithmetic average of the vesting term and the original contractual term of the option due to the Company’s lack of sufficient historical data.
•The expected stock price volatility is based on historical volatilities of comparable public entities within the Company’s industry.
•The risk-free interest rate is based on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the expected term.
•The expected dividend yield is 0% because the Company has not historically paid, and does not expect, for the foreseeable future, to pay a dividend on its common stock.
•Prior to the Company’s IPO, its Board periodically estimated the fair value of the Company’s common stock considering, among other things, contemporaneous valuations of its common stock prepared by an unrelated third-party valuation firm. Subsequent to the Company’s IPO, options are issued with a strike price no less than the market price on date of grant.
The grant-date fair value of options granted under the Company’s 2020 Plan were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions:
Year Ended December 31,
2021 2020
Expected term - years 6.08 5.94
Expected volatility 81.4 % 75.3 %
Risk-free interest rate 1.1 % 0.5 %
Expected dividends - -
The restricted shares are considered the issuance of share-based payments as opposed to the sale of stock and as such, the Company has recognized compensation expense for these awards based on the fair value of the award on the date of grant.
The following table summarizes the activity relating to these shares:
Awards
Outstanding at December 31, 2020 11,752
Vested (11,752)
Outstanding at December 31, 2021 -
The grant-date fair value of shares issued under the Company’s 2020 ESPP were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions:
Year Ended December 31,
2021 2020
Expected term - years 0.50 0.00
Expected volatility 81.3 % - %
Risk-free interest rate 0.9 % - %
Expected dividends - -
10. Income Taxes
The Company recorded no federal provision for income taxes as of December 31, 2021 and 2020 due to reported net losses since inception. The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows for the years ended December 31, 2021 and 2020 (amounts in thousands):
Year Ended December 31,
2021 2020
Income tax benefit computed at federal statutory tax rate $ (9,445) $ (7,687)
Change in valuation allowance 13,045 8,717
Return to provision adjustments - (745)
General business credits (3,108) (1,114)
Other permanent differences - 119
Stock compensation (1,923) -
Section 162(m) limitation 809 -
Change in uncertain tax position 622 223
Other - 487
Income tax benefit $ - $ -
Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are as follows (amounts in thousands):
December 31,
2021 2020
Deferred tax asset:
Net operating loss carryforwards $ 20,460 $ 9,891
Accrued expenses and other 3,520 1,345
Stock compensation 779 182
Credit carryforwards 6,194 3,708
Deferred revenue - 2,631
Capital loss carryforwards 484 27
Gross deferred tax asset 31,437 17,784
Less valuation allowance (30,331) (17,285)
Net deferred tax asset 1,106 499
Deferred tax liability:
Depreciation and amortization (578) (121)
Prepaid expenses (528) (378)
Total deferred tax liability (1,106) (499)
Total net deferred tax asset $ - $ -
The Company has established a valuation allowance equal to the net deferred tax asset due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $13.0 million and $8.7 million during the years ended December 31, 2021 and 2020, respectively, primarily due to continuing loss from operations, general business credit carryforwards, and accrued expenses.
As of December 31, 2021 and 2020, the Company had gross U.S. net operating loss (“NOL”) carryforwards of $97.4 million and $47.1 million, respectively. Additionally, as of December 31, 2021 and 2020, the Company had capital loss carryforwards of $2.3 million and $0.1 million, respectively. As of December 31, 2021 and 2020, the Company had gross state NOL carryforwards of $0.2 million and $0.2 million, respectively. As of December 31, 2021 and 2020, the Company had gross U.S. tax credit carryforwards of $7.6 million and $4.5 million, respectively. The NOL, capital loss, and tax credit carryforwards will begin to expire in 2036, if not utilized. The NOL, capital loss, and credit carryforwards are subject to Internal Revenue Service adjustments until the statute closes on the year the net operating loss or credit carryforwards are utilized.
Section 382 of the Internal Revenue Code limits the utilization of U.S. NOLs following a change of control. After the 2019 financial statements were filed, the Company completed a Section 382 study from formation through October 14, 2020. Although an ownership change occurred during 2020, no deferred tax assets were impacted by the limitation.
A reconciliation of our liability for unrecognized tax benefits is as follows:
Year Ended December 31,
Balance, beginning of the year $ 783 $ 560
Increase for tax positions related to the current year 449 223
Increase for tax positions related to prior years 172 -
Balance, end of year $ 1,404 $ 783
All of the Company’s gross unrecognized tax benefits, if recognized, would affect its effective tax rate. The Company does not expect unrecognized tax benefits to decrease within the next twelve months due to the lapse of statute limitations. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of income tax expense. As of December 31, 2021, the Company has not accrued any interest or penalties related to unrecognized tax benefits.
The Company files income tax returns in the U.S. and state jurisdictions. The Company is subject to examination by taxing authorities in its significant jurisdictions for the 2018, 2019, and 2020 tax years. There are currently no federal or state income tax audits in progress.
11. Related Party
As of December 31, 2020, Takeda held an approximate 5.0% ownership interest in the Company’s outstanding shares. Considering the resignation of the Takeda director and percent ownership of the Company’s common stock as of December 31, 2020, the Company no longer considers Takeda a related party.
12. Subsequent Events
None.

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ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS
Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure
None.

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ITEM 9A. CONTROLS AND PROCEDURES
Item 9A. Controls and Procedures
Evaluation of Disclosure Controls and Procedures
Our management, with the participation of our principal executive officer and our principal financial officer, evaluated, as of the end of the period covered by this Annual Report on Form 10-K, the effectiveness of our disclosure controls and procedures. Based on this evaluation of our disclosure controls and procedures as of December 31, 2021, our principal executive officer and principal financial officer concluded that our disclosure controls and procedures as of such date are effective at the reasonable assurance level. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, or the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act are recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by us in the reports we file or submit under the Exchange Act is accumulated and communicated to our management, including our principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and our management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.
Management’s Annual Report on Internal Control Over Financial Reporting
Our management is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rules 13a-15(f) under the Exchange Act). Internal control over financial reporting is a process designed under the supervision and with the participation of our management, including our principal executive officer and our principal financial officer, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles in the United States.
As of December 31, 2021, our management assessed the effectiveness of our internal control over financial reporting using the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in Internal Control-Integrated Framework. Based on this assessment, our management concluded that our internal control over financial reporting was effective as of December 31, 2021.
Attestation Report of Registered Public Accounting Firm
This Annual Report on Form 10-K does not include an attestation report of our registered public accounting firm. For as long as we remain an “emerging growth company” as defined in Section 2(a) of the Securities Act of 1933, or the Securities Act, as modified by the Jumpstart Our Business Startups Act of 2012, we intend to take advantage of the exemption permitting us not to comply with the requirement that our independent registered public accounting firm provide an attestation on the effectiveness of our internal control over financial reporting.
Changes in Internal Control over Financial Reporting
There were no changes in our internal control over financial reporting during fourth quarter ended December 31, 2021 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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ITEM 9B. OTHER INFORMATION
Item 9B. Other Information
None.

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ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE
Item 10. Directors, Executive Officers and Corporate Governance
The information required by this item is incorporated herein by reference to our Proxy Statement with respect to our 2022 Annual Meeting of Stockholders to be filed with the SEC within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K, including under the heading “Directors, Executive Officers, and Corporate Governance.”
We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing
similar functions. A copy of the code is available on our website located at ir.shattucklabs.com, under “Governance.” We intend to disclose on our website any amendments to, or waivers from, the code of business conduct and ethics that are required to be disclosed pursuant to the disclosure requirements of Item 5.05 of Form 8-K within four business days following the date of the amendment or waiver.

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ITEM 11. EXECUTIVE COMPENSATION
Item 11. Executive Compensation
The information required by this item is incorporated herein by reference to our Proxy Statement with respect to our 2022 Annual Meeting of Stockholders to be filed with the SEC within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K, including under the headings “Executive Compensation” and “Directors, Executive Officers and Corporate Governance.”

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ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS
Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholders
The information required by this item is incorporated herein by reference to our Proxy Statement with respect to our 2022 Annual Meeting of Stockholders to be filed with the SEC within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K, including under the headings “Security Ownership of Certain Beneficial Owners and Management” and “Executive Compensation-Securities Authorized for Issuance Under Equity Compensation Plans.”

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ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
Item 13. Certain Relationships and Related Transactions, and Director Independence
The information required by this item is incorporated herein by reference to our Proxy Statement with respect to our 2022 Annual Meeting of Stockholders to be filed with the SEC within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K, including under the headings “Directors, Executive Officers and Corporate Governance” and “Certain Relationships and Related Party Transactions.”

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ITEM 14. PRINCIPAL ACCOUNTING FEES AND SERVICES
Item 14. Principal Accountant Fees and Services
The information required by this item is incorporated herein by reference to our Proxy Statement with respect to our 2022 Annual Meeting of Stockholders to be filed with the SEC within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K, including under the heading “Proposal 2: Ratification of Selection of Independent Registered Public Accounting Firm.” Our independent registered public accounting firm is KPMG LLP, Austin, TX PCAOB ID:185.
Part IV.

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ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES
Item 15. Exhibits and Financial Statement Schedules
The following documents are filed as part of this Annual Report on Form 10-K:
(a) Financial Statements.
See Index to Consolidated Financial Statements at Part II, Item 8 “Financial Statements - Audited Financial Statements.”
(b) Financial Statement Schedules.
No financial statement schedules are provided because the information called for is not required or is shown in the financial statements or the notes thereto.
(c) Exhibits.
The following exhibits are filed (or incorporated by reference herein) as part of this Annual Report on Form 10-K:
Exhibit
Number Description of Exhibit
3.1 Amended and Restated Certificate of Incorporation of Shattuck Labs, Inc. (incorporated by reference from Exhibit 3.1 to the Company’s Current Report on Form 8-K filed on October 14, 2020 (Commission File No. 001-39593)).
3.2 Amended and Restated Bylaws of Shattuck Labs, Inc. (incorporated by reference from Exhibit 3.2 to the Company’s Current Report on Form 8-K filed on October 14, 2020 (Commission File No. 001-39593)).
4.1 Form of common stock certificate of the Company (incorporated by reference from Exhibit 4.1 of the Company’s Amendment No. 2 to Registration Statement on Form S-1 filed on October 8, 2020 (Commission File No. 333-248918)).
4.2 Second Amended and Restated Investors’ Rights Agreement, dated as of June 12, 2020, by and among Shattuck Labs, Inc. and certain of its stockholders (incorporated by reference from Exhibit 4.2 of the Company’s Amendment No. 2 to Registration Statement on Form S-1 filed on October 8, 2020 (Commission File No. 333-248918)).
4.3 Description of Securities (incorporated by reference from Exhibit 4.3 of the Company’s Annual Report on Form 10-K filed on March 16, 2021).
10.1+ Form of Indemnification Agreement for directors and executive officers (incorporated by reference from Exhibit 10.1 of the Company’s Amendment No. 1 to Registration Statement on Form S-1 filed on October 5, 2020 (Commission File No. 333-248918)).
10.4+ Employment Agreement, dated December 5, 2019, by and between Shattuck Labs, Inc. and Taylor Schreiber (incorporated by reference from Exhibit 10.4 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.5+ Amendment No. 1 to Employment Agreement, dated March 27, 2020, by and between Shattuck Labs, Inc. and Taylor Schreiber (incorporated by reference from Exhibit 10.5 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.6+ Amendment No. 2 to Employment Agreement, dated March 12, 2021, by and between Shattuck Labs, Inc. and Taylor Schreiber (incorporated by reference from Exhibit 10.6 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.7+ Employment Agreement, dated December 5, 2019, by and between Shattuck Labs, Inc. and Arundathy Nirmalini Pandite (incorporated by reference from Exhibit 10.6 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.8+ Amendment No. 1 to Employment Agreement, dated March 12, 2021, by and between Shattuck Labs, Inc. and Arundathy Nirmalini Pandite (incorporated by reference from Exhibit 10.8 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.9+ Employment Agreement, dated December 5, 2019, by and between Shattuck Labs, Inc. and Erin Ator Thomson (incorporated by reference from Exhibit 10.7 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.10+ Amendment No. 1 to Employment Agreement, dated March 12, 2021, by and between Shattuck Labs, Inc. and Erin Ator Thomson (incorporated by reference from Exhibit 10.10 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.11+ Employment Agreement, dated December 5, 2019, by and between Shattuck Labs, Inc. and Andrew R. Neill (incorporated by reference from Exhibit 10.8 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.12+ Amendment No. 1 to Employment Agreement, dated March 12, 2021, by and between Shattuck Labs, Inc. and Andrew R. Neill (incorporated by reference from Exhibit 10.12 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.13+ Employment Agreement, dated December 9, 2019, by and between Shattuck Labs, Inc. and Casi DeYoung (incorporated by reference from Exhibit 10.13 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.14+ Amendment No. 1 to Employment Agreement, dated March 12, 2021, by and between Shattuck Labs, Inc. and Casi DeYoung (incorporated by reference from Exhibit 10.14 of Shattuck’s Annual Report on Form 10-K filed on March 16, 2021 (Commission File No. 001-39593))
10.15+ 2020 Equity Incentive Plan (incorporated by reference from Exhibit 10.9 of the Company’s Amendment No. 2 to Registration Statement on Form S-1 filed on October 8, 2020 (Commission File No. 333-248918)).
10.16+ 2020 Employee Stock Purchase Plan (incorporated by reference from Exhibit 10.10 of the Company’s Amendment No. 2 to Registration Statement on Form S-1 filed on October 8, 2020 (Commission File No. 333-248918)).
10.17+ Non-Employee Director Compensation Policy (incorporated by reference from Exhibit 10.11 of the Company’s Amendment No. 1 to Registration Statement on Form S-1 filed on October 5, 2020 (Commission File No. 333-248918)).
10.19† Exclusive License Agreement, dated June 3, 2016, by and between Shattuck Labs, Inc. and Heat Biologics, Inc., as amended (incorporated by reference from Exhibit 10.12 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.20 Lease Agreement, dated April 17, 2018, between Shattuck Labs, Inc. and Parmer RTP, LLC, as amended (incorporated by reference from Exhibit 10.13 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.21 Lease Agreement, dated January 8, 2021, between Shattuck Labs, Inc. and International Bank of Commerce, Laredo, Texas.
10.22† Master Services Agreement, dated March 31, 2017, between Shattuck Labs, Inc. and KBI Biopharma, Inc. (incorporated by reference from Exhibit 10.14 to the Company’s Registration Statement on Form S-1 filed on September 18, 2020 (Commission File No. 333-248918)).
10.23† Takeda Termination Agreement (incorporated by reference from Exhibit 10.1 of Shattuck’s Quarterly Report on Form 10-Q filed on November 9, 2022 (Commission File No. 001-39593))
23.1* Consent of Independent Registered Public Accounting Firm.
31.1* Certification of the principal executive officer pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934.
31.2* Certification of the principal financial officer pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934.
32.1# Certification of the principal executive officer and principal financial officer pursuant to 18 U.S.C. Section 1350 and Rule 13a-14(b) under the Securities Exchange Act of 1934.
101.INS* XBRL Instance Document
101.SCH* XBRL Taxonomy Extension Schema Document
101.CAL* XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF* XBRL Taxonomy Extension Definition
101.LAB* XBRL Taxonomy Extension Label Linkbase Document
101.PRE* XBRL Taxonomy Extension Presentation Linkbase Document
104 The cover page from the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021, formatted in Inline XBRL (included in Exhibit 101).
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* Filed herewith.
+ Indicates management contract or compensatory plan.
† Certain confidential portions of this exhibit were omitted by means of marking such portions with asterisks because the identified confidential portions (i) are not material and (ii) would be competitively harmful if publicly disclosed.
# The certifications on Exhibit 32 hereto are deemed not “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that Section. Such certifications will not be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act.