bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Ib/II trial of lenvatinib plus pembrolizumab in urothelial cancer.
Authors: Vogelzang Nicholas J. , Encarnacion Carlos A. , Cohn Allen Lee , DiSimone Christopher , Rasco Drew W. , Richards Donald A. , Taylor Matthew H. , Dutcus Corina E. , Stepan Daniel E. , Shumaker Robert Charles , Guo Matthew , Schmidt Emmett V. , Mier James Walter
Published: July 2019

11

Background: Pembrolizumab (PEM), an anti-PD-1 antibody, is approved for advanced urothelial cancer in the second-line setting (objective response rate [ORR] 21%) and in the first-line setting for patients (pts) ineligible for cisplatin with combined positive score ≥10 or ineligible for platinum-based chemotherapy (ORR 29%). Tyrosine kinase inhibitors such as lenvatinib (LEN; a multikinase inhibitor of VEGFR 1-3, FGFR 1-3, PDGFRα, RET and KIT) have demonstrated activity in urothelial cancer and may reverse the immunosuppressive environment that leads to immuno-oncology (IO) failure. We present a phase 1b/2 trial of LEN + PEM in advanced urothelial cancer. Methods: In this multicenter, open-label study, pts with confirmed metastatic urothelial cancer and ECOG PS of 0 or 1 received oral LEN 20 mg/day + PEM (200 mg Q3W, IV). Pts were not preselected for PD-L1 status. The phase 2 primary end point was investigator-assessed ORR at week 24 (ORRwk24) per immune-related RECIST (irRECIST). Secondary end points included ORR, duration of response (DOR), and progression-free survival (PFS). Results: At data cutoff (March 1, 2018), 20 pts were enrolled: 9 (45%) PD-L1(+), 5 (25%) PD-L1(-); 6 (30%) not tested. 4 Pts (20%) were treatment-naïve; 11 (55%) and 5 (25%) pts had had 1 and 2 lines of prior anticancer therapies, respectively. No pt had received prior IO. ORRwk24 was 25% (95% CI: 8.7–49.1). 18 (90%) pts had ≥1 treatment-related adverse event (TRAE). Grade 3 and 4 TRAEs occurred in 5 (25%) and 5 (25%) pts, respectively. There was 1 fatal TRAE (gastrointestinal hemorrhage). The most common any-grade TRAEs were proteinuria (45%), diarrhea (40%), fatigue (30%), hypertension (30%), and hypothyroidism (30%). Conclusions: LEN + PEM demonstrated activity in this study of pts with advanced urothelial cancer, which included pts receiving later-line treatment, and deserves further investigation. Clinical trial information: NCT02501096. [Table: see text]
Responses to immune checkpoint therapy in pulmonary sarcomatoid carcinoma: A retrospective review.
Authors: Sukrithan Vineeth , Sandler Jason , Gucalp Rasim A. , Gralla Richard J. , Halmos Balazs
Published: July 2019

115

Background: Advanced Pulmonary Sarcomatoid Carcinoma (PSC) is associated with poor response to chemotherapy and a median survival of 4-6 months. PSC have a high frequency of PD-L1 positivity and high tumor mutational burden, which are markers of benefit with immune checkpoint inhibitors (ICPI). The parameters of response and survival for PSC treated in the era of immune checkpoint inhibition are unknown. Methods: A review of all cases of advanced PSC diagnosed at two institutions in Bronx, NY between 6/2015-6/2018 was performed. Responses were assessed by serial imaging obtained during routine care and graded by RECIST criteria v 1.1. Results: Five cases of advanced Stage IV PSC are reported. The median age was 57 years and all had received ICPI. All cases were smokers with a median of 30 pack-years and TPS > 75%. Three patients received Pembrolizumab as front-line therapy. Responses were seen in four out of five patients, including one complete response. The fifth patient had prolonged disease stability. After a median follow-up of 13 months, none of the patients had progressed. One patient died of infectious complications after 23 months with no evidence of progression. Four patients continue to be alive with ongoing OS ranging between 14-33 months. Conclusions: ICPI therapy has robust activity in advanced PSC and offers an effective line of therapy in this treatment-refractory aggressive malignancy. [Table: see text]
Development and correlative analysis of a TML assay in specimens with reference MSI and somatic variant results.
Authors: Mellert Hestia S. , Jackson Leisa , Pestano Gary Anthony
Published: July 2019

124

Background: Treatment of late-stage non-small cell lung cancer has been greatly impacted by the advances in immunotherapy. Molecular biomarkers such as tumor mutation load (TML or TMB) and micro-satellite instability (MSI) may identify patients with NSCLC that are more likely to respond to immune checkpoint inhibitors. In this report, we describe the development of and NGS-based assay for the robust detection of TML and somatic variants simultaneously using a targeted assay that covers 1.7 Mb of the genome. Methods: Initial feasibility included reference control cell-lines, HCC1143 and NIST8398, as well as FFPE (formalin-fixed, paraffin-embedded) samples from lung and colorectal tumors. In development, eight FFPE specimens from patients with late stage cancer and a reference MSI status were evaluated. FFPE slides were extracted using the MagMax FFPE DNA/RNA Ultra kit, and nucleic acid quality was assessed using qPCR. Extracted DNA was processed through the Oncomine TML Assay with a minimum input of 30 ng of DNA per specimen. Automated library and template preparation were performed followed by sequencing on the Ion GeneStudio S5 Plus system using replicate 540 chips. Eight samples with barcoded adapters were multiplexed per chip. Tumor mutation analysis and variant calling was performed using the Oncomine TML v2.0 workflow. Results: The time from FFPE extraction to result was 96 hours, and all samples passed QC metrics. TML scores ranged from 14.4-36.04 mutations/Mb for all samples with MSI-high reference results. A very high level of inter-chip concordance was also observed (R2=0.990). Additionally, the variant caller function within the TML workflow was used to detect BRAF V600E mutations with 100% concordance to reference testing results. Conclusions: The accurate quantification of somatic mutations paired with fast turn-around time and robust automated workflow is ideal for assessing the tumor mutation load as well as hotspot mutations from limited (FFPE) samples.
Liquid biopsy using plasma proteomic profiling to reveal predictors of immunotherapy response.
Authors: Mehta Arnav , Kasumova Gyulnara , Rucevic Marijana , Sallman-Almen Markus , Hultin Rosenberg Lina , Kim Michelle S. , Lieb David , Bai Xue , Frederick Dennie T. , Sullivan Ryan J. , Flaherty Keith , Hacohen Nir , Boland Genevieve Marie
Published: July 2019

130

Background: The response of metastatic melanoma to anti-PD1 is heterogeneous. We performed proteomic profiling of patient plasma samples to build a predictor of immunotherapy response and uncover biological insights underlying primary resistance. Methods: 58 metastatic melanoma patients receiving anti-PD1 (Pembrolizumab or Nivolumab) at MGH comprised the initial cohort, and 150 additional patients comprised a validation cohort. Plasma samples were collected (MGH IRB #11-181) at baseline and several on-treatment time-points. Samples were analyzed for 1102 proteins by a multiplex proximity extension assay (Olink Proteomics). A subset of patients had single-cell RNA-seq (Smart-Seq2 protocol) performed on tumor tissue. Group differences and treatment effects were evaluated using linear mixed models with maximum likelihood estimation for model parameters, and Benjamini and Hochberg multiple hypothesis correction. Results: 70 significantly differentially expressed (DE) proteins were identified across the treatment period, including markers of immune activation (PD1, CXCL9, CXCL10, CD25, IL-17a, among others). 38 significantly DE proteins were identified with on-treatment time points between anti-PD1 responders (R) and non-responders (NR), including several implicated in primary or acquired resistance (IL8, MIA, ERBB2, among others). Importantly, we demonstrate the relationship of these serum biomarkers to overall and progression-free survival, and employed statistical learning approaches to build classifiers of treatment response, leveraging early and late on-treatment time points. Analysis of single-cell RNA-seq data (Sade-Feldman et al, Cell, 2018) of tumor tissue from a subset of these patients revealed that gene expression of most proteins predictive of response were enriched among tumor myeloid cells, with the remainder of proteins being reflective of exhausted T cell states. Conclusions: Whole plasma proteomic profiling of anti-PD1 treated patients revealed DE proteins between R and NR that may enable a liquid biopsy to predict anti-PD1 response. These results unveil a putative role of myeloid cells within the tumor microenvironment in anti-PD1 response or primary resistance.
Biomarkers to predict immune-related adverse events with checkpoint inhibitors.
Authors: Head Lia , Gorden Nicholas , Van Gulick Robert , Amato Carol M. , Frazer-Abel Ashley , Robinson William , Holers V. Michael , Messersmith Wells A. , Davis S. Lindsey
Published: July 2019

131

Background: Immune-related adverse events (IRAE) occur commonly with immune checkpoint inhibitor therapy for the treatment of cancer, although the specific event and severity can vary widely. Little is known regarding factors that may predict which patients will develop an IRAE. The goal of this study is to identify blood biomarkers predictive of IRAE associated with immune checkpoint inhibitor therapy. Methods: Blood samples collected from patients with melanoma prior to receiving therapy with immune checkpoint inhibitors were obtained from the University of Colorado Skin Cancer Biorepository. Testing for a panel of autoantibodies and cytokines (ANA, CCP 3.1, IL-1 beta, IL-2, IL-6, IL-10, IL-12, IP-10, MCP-1, TNF alpha, IFN alpha 2, IFN gamma) in serum samples from patients who had at least one documented IRAE was performed by Exsera BioLabs. Descriptive statistics were used to evaluate biomarker levels in relation to type, grade, and number of adverse events. Results: Pre-treatment samples from 45 patients were evaluated. Median age was 55; 26 were male and 19 were female. The most common IRAEs were colitis (n = 22), thyroid dysfunction (n = 21), and dermatitis (n = 20). Most IRAEs were grade 2 in severity, and the majority of patients (n = 36) experienced more than 1 IRAE. TNF alpha was elevated in 60% of patient samples, while IFN alpha 2 was elevated in 44%. Borderline ANA was detected in 27% of samples and ANA was positive in 11%. No samples had elevation of IL-2. Between 9% and 18% of samples had elevation of the other immune markers tested (IFN gamma, IL-1 beta, IL-6, IL-10, IL-12, and CCP 3.1). Elevation of TNF alpha and IFN alpha 2 were associated with higher grades of IRAEs. No associations between immune markers and the number or type of adverse events in an individual patient were noted. Results from 15 patients who did not have a documented IRAE on immune checkpoint inhibitor therapy are currently pending to confirm these findings are unique to patients developing IRAE. Conclusions: This preliminary data suggests that baseline elevations of TNF alpha and IFN alpha 2 may predict development of IRAEs with immune checkpoint inhibitor therapy. Results from samples from patients who did not develop an IRAE on therapy will be reported at the meeting.
Th17 responses to autologous dendritic cell vaccine.
Authors: Nistor Gabriel I. , Poole Aleksandra J. , Hsieh Candace , Keirstead Hans S. , Dillman Robert O.
Published: July 2019

132

Background: Dendritic cells (DC) loaded with autologous tumor antigens in vitro, can induce a Th17 phenotype preceding a Th1 type response. We examined this in patients with metastatic melanoma who had been treated in a randomized trial with either DC loaded with autologous tumor antigens (ATA) from self-renewing tumor cells (DCV) or irradiated tumor cells (TCV). Methods: Blood samples were obtained at baseline, one week before three weekly vaccinations (week-0), and at week-4, (one week after the third vaccination). They were analyzed for growth factors, tumor markers and biomarkers using a quantitative, multiplex ELISA. Monocytes, lymphocytes, loaded and unloaded DC were analyzed for cytokine production and intercellular responses using mixed lymphocyte co-cultures (MLC). Results: When compared to baseline or the TCV arm, DCV-treated patients showed reductions in tumor markers, inflammation and angiogenesis in parallel with Th17 pathway activation, IL12 p70 heterodimer expression was detected in monocytes and DC only after antigen loading. The IL12 p40 fraction was present after differentiation and was enhanced after antigen loading. Similarly, the p19 component of IL23 was expressed before DC loading and later enhanced. MLC showed induction of Th17, Th1 and CD8 subpopulations. In the presence of antigen-loaded DCs, the FOXp3 cells were reduced in number, an effect that was canceled by neutralizing the IL12p40 subunit or by the adding tumor cells alone in the MLC. Conclusions: DC produced ex vivo can activate multiple cytotoxic pathways depending on IL12 subunits. Expression of IL23p19 and the shared IL12p40 fraction are responsible for Th1 priming (IL12 incomplete) and Th17 induction (IL23 complete), determinants of the reactive phenotype of naïve DCs. IL12 p70 heterodimer expression after DC loading enables a targeted Th1 type response while neutralizing the IL12 subunit p40, enhances Foxp3 positive T-regs. DC vaccines produced ex vivo could induce a Th1/Th17 cytotoxic response against tumors. In the absence of antigens, however, The Th17 phenotype can become tolerizing in the microenvironment. The findings are important for applications in settings in which tumor infiltration with Th17 correlates with survival, such as in advanced ovarian cancer. Clinical trial information: NCT00436930.
Prognostic models for advanced melanoma patients treated with anti-PD-1 monotherapy.
Authors: Bai Xue , Kim Michelle S. , Kasumova Gyulnara G. , Cohen Justine Vanessa , Lawrence Donald P. , Freedman Christine , Fadden Riley , Rubin Krista M. , Sharova Tatyana , Flaherty Keith , Sullivan Ryan J. , Boland Genevieve Marie
Published: July 2019

133

Background: Anti-PD-1 monotherapy has dramatically improved the outcomes of patients with advanced melanoma, yet the majority of patients develop therapeutic resistance. A prognostic model is needed to optimally select patients who are most and least likely to benefit. Methods: We performed a retrospective analysis of 141 advanced melanoma patients treated with anti-PD-1 monotherapy at Massachusetts General Hospital from Sept 2009 to Dec 2017. Demographic and clinical characteristics, baseline and early-on-treatment (median 3 weeks after anti-PD-1 monotherapy initiation) routine laboratory variables, and prognostic data were collected and correlated in both univariate and multivariate analyses. Results: Median progression free survival (PFS) and overall survival (OS) were 7.6 months (95% CI 2.3-12.9) and 57.3 months (95% CI 33.3-81.3), respectively. In multivariate analyses, significant independent prognostic variables ( P < 0.05) in favor of longer PFS included cutaneous subtype, low baseline lactic acid dehydrogenase (LDH); low early-on-treatment derived neutrophil-to-lymphocyte ratio (dNLR); high early-on-treatment albumin, basophil, and red blood cell counts (RBCs); those in favor of longer OS included BRAF V600 mutation; low baseline LDH and neutrophil-to-lymphocyte ratio (NLR); low early-on-treatment LDH; high early-on-treatment total protein, basophil, and lymphocyte counts. Prognostic scoring models (total scale: 0-6) were established based on these independent prognostic factors as dichotomous variables, for both PFS (HR 0.555, 95% CI 0.481-0.641, P<0.001) and OS (HR 0.411, 95% CI 0.326-0.519, P<0.001), respectively. For patients with PFS scores of ≤ 2, 3, 4, 5, and 6, rates without progression at 6 months were 0%, 9.4%, 31.0%, 67.3%, and 80.0%, respectively. For patients with OS scores of ≤ 2, 3, 4, 5, and 6, survival rates at 12 months were 25.0%, 68.4%, 79.3%, 97.1%, and 100% ; at 24 months were, 0%, 45.6%, 69.1%, 82.6%, and 100%, respectively. Conclusions: A scoring system based on clinical characteristics and easily accessible routinely tested biomarkers may be used to help predict outcomes of anti-PD-1 monotherapy treated advanced melanoma patients.
Real-world time to next treatment (TTNT) for first-line (1L) targeted and immuno-oncology therapies for BRAF-mutated metastatic melanoma (MM) by lactate dehydrogenase (LDH) level.
Authors: Luke Jason J. , Ghate Sameer R. , Kish Jonathan , Lee Choo Hyung , Ndife Briana , McAllister Lindsay , Mehta Sonam , Nakasato Antonio Reis , Feinberg Bruce A.
Published: July 2019

141

Background: Dabrafenib plus trametinib (D+T), ipilimumab plus nivolumab (I+N), and both nivolumab and pembrolizumab (“PD-1 mono”) are approved for the 1L treatment of MM. This study reports real world 1L TTNT for patients receiving these therapies by LDH status. Methods: This was a retrospective, observational study. MM patients initiating 1L treatment with D+T, I+N, or PD-1 monotherapy from Jan-2014 through Jun-2017 were identified from community oncology practices in the U.S. Patients treating oncologist abstracted patient date into case report forms. LDH at initiation of treatment was classified by the provider as normal or abnormal ( > 1x and < 2x ULN or ≥ 2x ULN) according to the reference laboratory. TTNT was calculated from 1L initiation to initiation of second-line (2L). Cox proportional hazard models estimated the risk of initiating 2L (proxy for progression) between groups adjusted for age, gender, brain/liver metastases (mets), number of mets and ECOG-PS. Results: Data for 332 patients were submitted by 53 providers including 51.6% who initiated 2L. Abnormal LDH: D+T = 60.3%, ipi/nivo = 53.0%, PD-1 mono = 35.4%. No differences in the frequency of patients with stage IV M1c, brain mets, ECOG, or discontinuation due to toxicity (8.4% of all patients) were noted between cohorts. TTNT was significantly longer in both normal and abnormal LDH cohorts for D+T (14.1 and 11.6 mo.) vs. ipi/nivo (10.1 and 10.2 mo.) but not PD-1 mono (13.3 and 10.6). Adjusted for confounding variables in the abnormal LDH cohort the hazard ratio (HR) for risk of 2L initiation was significantly higher (2.08, p < 0.01) for ipi/nivo vs. D+T but not significant different among normal LDH patients (HR = 1.89, p = 0.054). No significant difference in the risk of 2L initiation between D+T and ipi/nivo were noted in either the normal or abnormal cohorts. Conclusions: For normal and abnormal LDH cohorts 1L TTNT was longer for patients receiving D+T vs. ipi/nivo (but not vs. PD-1 mono). Using the multivariate model we observed the risk of 2L initiation, a proxy for progression, was higher for ipi/nivo treated vs. D+T adjusted for clinical factors for abnormal LDH patients.
Use of TMB and PD-L1 to predict outcomes of checkpoint inhibitor treatment.
Authors: Robbins Paul B. , Krieger Tina , Pearson Isobel , Bell Judith , Doherty Jim P.
Published: July 2019

150

Background: Medical practice is moving toward a more tailored, patient-centric one with precision medicine (biomarker)-guided therapies. Studies have evaluated ways of applying precision medicine to cancer therapies, and the use of several biomarkers has shown promise. The potential value of tumor mutational burden (TMB) and/or programmed death-ligand 1 (PD-L1) biomarkers to enhance the prediction of which patients are most likely to respond to checkpoint inhibitors has been explored in many studies. The objective of this literature review was to identify and summarize these studies. Methods: Literature searches were performed using electronic medical databases (MEDLINE, Embase, and BIOSIS) and internet searches of specified sites. Bibliographies of key systematic literature reviews and meta-analyses were reviewed for studies of interest. Due to the volume of literature for various cancer types, studies with a sample size of <50 patients were excluded. Results: The review identified 27 trials in non-small cell lung cancer (NSCLC), 39 trials in melanoma, 10 trials in urothelial cancer, and 5 trials in renal cell cancer indications. Studies also were identified in other cancer types (eg, colorectal, breast, and gastric cancer and Merkel cell carcinoma [MCC]). TMB as a predictor of outcomes was evaluated in 12 trials, including 6 in NSCLC. A TMB of ≥10 mutations per megabase was shown to be an effective biomarker in the CheckMate 227 study. PD-L1 was found to predict response in melanoma and all types of NSCLC other than squamous (Checkmate-017). However, prediction of response was not a prespecified analysis in some PD-L1 studies; other studies had small sample sizes and wide CIs. A clear predictive trend for PD-L1 was not identified in renal, breast, or gastric cancer or MCC. Conclusions: On the basis of the data in this review, assessment of TMB and PD-L1 biomarker expression may enhance the prediction of response to checkpoint inhibition in some tumors, such as NSCLC and melanoma. In this rapidly growing area of research, further exploratory biomarkers are being investigated, such as tumor-infiltrating lymphocytes and KRAS and BRAF mutations, that may provide insight on the potential efficacy of a treatment in a given patient.
RRx-001 is a phase III aerospace-derived small molecule that immunonormalizes the tumor microenvironment.
Authors: Cabrales Pedro
Published: July 2019

156

Background: Tumor associated macrophages (TAMs) with M2-like phenotypes produce angiogenic factors and cytokines which lead to vascular immaturity. M2 cytokines also impair immune cell activity. CD47 and SIRP⍺ are innate immune checkpoints which inhibit macrophage phagocytosis and enhance M2 polarization. Disruption of the CD47/SIRP⍺ axis polarize TAMs away from an M2-like phenotype to normalize tumor vessels and stimulate antitumor immunity. Normalized vessels facilitate delivery of drugs and immune cells and also sensitizes tumors to therapy and promotes M1-like TAM phenotype. RRx-001 modulates TAM infiltration and phenotype via CD47/SIRP⍺ downregulation, which normalizes both the tumor vasculature, and the immune cell milieu. Methods: The effect of RRx-001 on intratumoral blood flow was evaluated both preclinically and clinically with dynamic contrast MRI. An in vitro phagocytotic assay was used to determine whether RRx-001 promoted engulfment of A549 tumor cells by macrophages. Transcriptional mRNA profiling in murine tumor associated macrophages (TAMs) was performed to analyze the cytokine profile of TAMs in the presence or absence of RRx-001. Athymic mice with intracranial GBM43 were administered RRx-001 (10 mg/kg) followed 4 hours later by 0.4 mg of irinotecan by tail vein on days 12, 18, 24 and 30 after implantation of tumor cells. Mice were euthanized 24 hours after last irinotecan administration, with brains immediately resected and tumor tissue dissected prior to snap-freezing by immersion in liquid nitrogen. Results: RRx-001 was shown to induce: vascular normalization with increased intratumoral perfusion, dual downregulation of CD47 and SIRP⍺, increased phagocytosis, improved delivery of chemotherapy and increased T cell infiltration. Conclusions: RRx-001 leads to vascular normalization and enhanced delivery of chemotherapy and immune cell infiltration. The increase in tumor perfusion diminishes hypoxia and also serves to polarize TAMs away from an M2-like state. These results also suggest and are borne out by clinical biopsies that the effect of RRx-001 depends on the number of TAMs present in the tumor microenvironment with higher numbers leading to better activity.
Phase I study of the safety and activity of formulated IL-12 plasmid administered intraperitoneally in combination with neoadjuvant chemotherapy in patients with newly diagnosed advanced-stage ovarian cancer.
Authors: Thaker Premal H. , Bradley William Hampton , Leath Charles A. , Gunderson Camille Catherine , Borys Nicholas , Musso Lauren , Anwer Khursheed , Alvarez Ronald David
Published: July 2019

2

Background: This study evaluated weekly intraperitoneal (IP) GEN-1, an IL-12 plasmid formulated with polyethyleneglycol-polyethyleneimine-cholesterol lipopolymer, with intravenous (IV) weekly taxane (T) and carboplatinum (C) every 3 weeks in epithelial ovarian, fallopian tube or primary peritoneal cancer (EOC) patients undergoing neoadjuvant therapy (NAC). The primary objective was to evaluate the tolerability and safety of GEN-1 with NAC. Secondary objectives included objective clinical response and pathological response at interval debulking surgery (IDS). Methods: Newly diagnosed EOC patients with no prior therapies were eligible. The trial utilized a 3+3 design with dose escalation in ~30% increments at GEN-1 IP dose levels of 36 mg/m2, 47 mg/m2, 61 mg/m2, and 79 mg/m2 weekly for 8 treatments with concurrent IV T/C. Dose-limiting toxicity (DLT) was based on the first 4 doses of GEN-1 administered. Results: 18 patients were enrolled into the study and 12 of those patients received all 8 treatments with no DLTs. 14 patients underwent IDS. Most common related toxicities were Gr 1 nausea, abdominal pain and fatigue. One patient experienced Gr 2 fevers associated with GEN-1 but responded to acetaminophen and fluids. Conclusions: Adding GEN-1 to T/C is safe and appears to be active in EOC patients receiving NAC. Dose limiting toxicity was not reached and further dose escalation and safety and activity is being evaluated in an ongoing phase I/II study. Clinical trial information: NCT02480374. [Table: see text]
Phase Ib: Preliminary clinical activity and immune activation for NKTR-262 [TLR 7/8 agonist] plus NKTR-214 [CD122-biased agonist] in patients (pts) with locally advanced or metastatic solid tumors (REVEAL Phase Ib/II Trial).
Authors: Diab Adi , Marcondes Mario , Kotzin Brian , Tagliaferri Mary Ann , Hoch Ute , Li Yunfeng , Cattaruzza Fiore , Zalevsky Jonathan , Brohl Andrew Scott , Brugarolas James , Bilen Mehmet Asim , Gupta Shilpa , Domingo Musibay Evidio , Conley Anthony Paul , Borazanci Erkut Hasan , D'Angelo Sandra P. , Curti Brendan D.
Published: July 2019

26

Background: NKTR-262 is a novel intratumoral prodrug designed to promote tumor antigen release, an immune stimulatory environment, and antigen presentation. NKTR-214 increases CD8+ T cells and NK cells in the tumor microenvironment. The combination of NKTR-262 with NKTR-214 accesses innate and adaptive immunity to provide an abscopal response and systemic tumor immunity. The Phase 1b/2 REVEAL trial is enrolling. Methods: In a 3+3 Phase 1 design, pts who are relapsed/refractory to ≥1 CPI receive escalating doses of intratumoral (IT) NKTR-262 followed by combined q3w treatment of IT NKTR-262 and fixed-dose intravenous (IV) NKTR-214 (0.006 mg/kg). Phase 1 will evaluate PK, safety, efficacy, and determine recommended Phase 2 dose. Scans are conducted every 9 wks (± 1 wk). Peripheral blood (PB) and tumor tissue are collected to measure biomarkers of immune activation. In Phase 2 expansion, NKTR-262 + NKTR-214 ± IV nivolumab (360 mg) will be assessed in specific tumor cohorts of IO-naïve and experienced pts. Results: As of 06 Nov 2018, 11 pts had received at least one cycle of NKTR-262 + NKTR-214 therapy. 7/11 pts were efficacy evaluable with at least one on-treatment scan (4 MEL, 2 SARC, 1 CRC). 2/4 R/R melanoma pts had uPRs with 100% (scan 2) and 40% (scan 1) reductions in target lesions per RECIST 1.1, respectively. Both patients remain on treatment. Two SARC pts had stable disease at scan 1. No pts experienced G3 or higher TRAEs or immune-related adverse events (AEs). Most common G1-2 AEs were transient flu-like symptoms. Gene expression analysis of tumor and PB show dose-dependent induction (4 to 16-fold) of TLR target genes. Consistent with the mechanism of action for NKTR-214, PB flow cytometry shows an average 13-fold increase from baseline in Ki67+ CD8+T cells in 6 pts. Conclusions: NKTR-262 + NKTR-214 engage the immune activation cascade from local tumor antigen production to anti-tumor T cell response. Initial dose levels of NKTR-262 with fixed-dose NKTR-214 were well-tolerated with early evidence of clinical activity. These data support continued evaluation of the combination +/- nivolumab. Clinical trial information: NCT03435640.
Upregulation of programmed death ligand 1 (PD-L1) on circulating epithelial tumor cells (CETCs) as consequence of adjuvant radiation therapy in primary breast cancer patients.
Authors: Pizon Monika , Schott Dorothea , Pachmann Ulrich A. , Pachmann Katharina , Maeurer Matthias
Published: July 2019

3

Background: Radiation therapy (RT) is an integral part of the treatment of breast carcinoma but unfortunately many patients experience local recurrence. During the inflammatory response that accompanies radiation tumor cells may develop multiple resistance mechanisms for example the up-regulation of PD-L1 on tumor cells which leads to immune evasion. Since CETCs arise from the tumor it is conceivable that under evolutionary pressure they might share some of the immune escape mechanism inherent to tumor cells. In this study we demonstrate that RT leads to a transitory adaptive up-regulation of PD-L1 expression on CETCs. Methods: CETCs and the expression of PD-L1 and Ki-67 were analyzed from 25 patients with primary non-metastatic breast cancer using the maintrac method. The fraction of PD-L1 and Ki-67 positive CETCs were assessed at baseline, 3 and 6 weeks after start of RT and 6 weeks after end of therapy. Additionally, copy number status of PD-L1 was determined using FISH. Results: Fractionated-dose RT leads to a significant increase in PD-L1 expression on CETCs with the highest expression level midterm of irradiation as compared to baseline (49% vs. 74%, p < 0.01). 6 weeks after end of RT the number of PD-L1 positive CETCs returned to baseline value. The up-regulation of PD-L1 was dose dependent. Patients who received higher total dose had significantly more PD-L1 positive CETCs as compared to patients treated with lower total dose midterm of RT (64% vs. 43, p < 0.05). Before start of therapy there was a correlation between the fraction of PD-L1 and Ki-67 positive CETCs (r = 0.6, p < 0.01). PD-L1 copy number gains were significantly associated with PD-L1 expression (r = 0.6, P < 0.05). Conclusions: RT leads to an up-regulation of PD-L1 expression on CETCs, which could be a possible mechanism of acquired radioresistance. Combining immunomodulatory agents with radiation might have the potential to overcome this resistance and could improve clinical outcome in breast cancer.
Phase I study of cemiplimab, a human monoclonal antibody to programmed death (PD)-1, in Japanese patients (pts) with advanced malignancies: Results from the dose exploration.
Authors: Kitano Shigehisa , Shimizu Toshio , Koyama Takafumi , Ebata Takahiro , Iwasa Satoru , Kondo Shunsuke , Shimomura Akihiko , Fujiwara Yutaka , Yamamoto Noboru , Paccaly Anne Josee , Baum Clifford , Li Siyu , Rietschel Petra , Sims Tasha Nicholle
Published: July 2019

33

Background: Cemiplimab (REGN2810), a high-affinity, highly potent, human monoclonal antibody to PD-1, has demonstrated a safety profile comparable with that of other anti-PD-1 antibodies and antitumor activity in various solid tumors including cutaneous squamous cell carcinoma and non-small-cell lung cancer (NSCLC) in pts outside of Japan. We present analysis of Part 1 of a two-part, multicenter, open-label, Phase 1 study of cemiplimab in Japanese pts with advanced malignancies. Methods: Part 1 dose exploration pts received either cemiplimab 250 mg (n=6) or 350 mg (n=7) Q3W IV for up to 108 weeks. Tumor measurements were performed every 9 weeks according to RECIST 1.1. Data cut-off date was July 13, 2018. Results: Thirteen pts were enrolled: median age, 62 years (range: 33–75); 8 F. Twelve (92.3%) and 7 (53.8%) pts had received prior cancer-related systemic therapy and radiotherapy, respectively. Median duration of cemiplimab exposure was 13.1 weeks (range: 3.0–54.6). At the data cut-off date Part 1 was fully enrolled and 9 pts (69.2%) had discontinued treatment, primarily due to disease progression (n=7, 53.8%). The most common treatment-emergent adverse events (TEAEs) of any grade were contact dermatitis, rash, and viral upper respiratory tract infection, each occurring in 3 pts (23.1%). The following grade ≥3 TEAEs occurred in 1 pt (7.7%): hypophosphatemia, hyponatremia, autoimmune colitis, and dehydration; the last two events occurred in the same pt. No dose-limiting toxicities were reported. Cemiplimab serum concentrations were as expected from the reported PK characteristics of cemiplimab. Objective response rate (ORR; complete response + partial response [PR]) and disease control rate (ORR + stable disease [SD]) were 23.1% (3 PR) and 53.8% (7/13; 4 SD), respectively. Conclusions: Cemiplimab exhibited substantial antitumor activity in Japanese pts with advanced malignancies. Cemiplimab 350 mg Q3W dosing regimen was selected for the expansion studies. The safety profile was comparable with those previously reported for cemiplimab and other anti-PD-1 agents. Part 2 is open and enrolling pts with NSCLC in Japan. Clinical trial information: NCT02760498.
Localizing radioimmunotherapy via nanochannel device for sustained intratumoral drug delivery for solid tumor treatment.
Authors: Ho Jeremy , Susnjar Antonia , Rhudy Jessica , Sizovs Antons , Lolli Graziano , Pino Ramiro , Chua Corrine Ying Xuan , Butler E. Brian , Demaria Sandra , Grattoni Alessandro
Published: July 2019

37

Background: Immune related adverse events still occur in up to 91% of patients receiving immunotherapy. Intratumoral administration is a potential solution to limit these events by reducing systemic exposure while increasing local concentration. However, intratumoral injection is hindered by rapid clearance of drug from the tumor. Our group has developed an intratumoral nanochannel implant for sustained delivery of immunotherapy (NDES) as a solution. Recent clinical and preclinical studies have found success in the combination of radiotherapy and immunotherapy in improving both local and distant tumor response. We propose a combination of radiotherapy followed by sustained intratumoral delivery of immunotherapy as a treatment regimen to improve tumor response and reduce side effects. Methods: Mice were implanted with the 4T1 murine mammary carcinoma and separated into treatment and control groups. CD40 agonist antibody was delivered intratumorally via NDES. Radiotherapy was administered at 8 Gy for three consecutive days and implantation of the NDES occurred the day after the final fraction of radiation. The tumor growth curve was plotted and tumor, spleen, lymph nodes, lungs, and blood were collected at the study endpoint for further flow cytometry and histological analysis. Results: The combination of radiotherapy and sustained intratumoral CD40 antibody showed significantly decreased tumor growth rates over radiotherapy or sustained intratumoral immunotherapy alone. Both intratumoral and systemic T-cell activation was observed. Mice treated with sustained intratumoral CD40 antibody showed decreased toxicity when compared to those receiving comparable systemic dosage. Conclusions: Radiotherapy combined with local sustained intratumoral immunotherapy is a potential strategy for improving treatment of solid tumors which currently show suboptimal response to current immunotherapy regimens and for inducing a systemic response to distant metastases while minimizing adverse side effects. The sustained delivery profile of the NDES presents an opportunity for practical intratumoral administration and avoidance of repeated invasive procedures in patients.
Epigenetic biomarkers for noninvasive detection of colorectal cancer.
Authors: Roy Dhruvajyoti , Taggart David , Zheng Lianghong , Liu Dan , Li Gen , Li Mingzhen , Zhang Kang , Van Etten Richard A.
Published: July 2019

45

Background: Aberrant DNA hypermethylation is known to be a major mechanism for inactivation of cancer-associated genes, including tumor suppressor genes, in colorectal cancer (CRC) and in other human cancers. Cancer-specific DNA methylation patterns of cell-free DNA (cfDNA) isolated from blood samples is a non-invasive method to obtain representative epigenetic information from solid tumors. In the present study, we identified and validated colorectal cancer-specific methylation markers for diagnosis of the disease with high sensitivity and specificity. We also compared the relative amount of DNA methylation at these target sites in relation to colorectal cancer stage. Methods: For marker validation, a total of 154 samples drawn from 68 subjects diagnosed with colorectal cancer (Stage I to IV), 42 healthy donors, 14 subjects with benign colorectal diseases, and 30 subjects diagnosed with other cancer types (breast, liver and lung cancer: 10 cases each) were obtained for a randomized, blinded study. Cell-free DNA was then extracted from the samples, bisulfite converted, and DNA methylation was quantified by using the IvyGene Platform. Results: By quantifying DNA methylation at the target sites, colorectal cancer samples were differentiated from samples drawn from healthy subjects or subjects with benign disease with an overall sensitivity of 93% (95% CI: 86-99) and specificity of 100% (95% CI: 85-100). All stages (I to IV) of colorectal cancer were identified with sensitivities ranging from 67% to 100%. None of the 30 samples drawn from subjects diagnosed with breast, liver or lung cancers were incorrectly identified as a colorectal cancer by the assay, for a calculated analytical specificity of 100%. Conclusions: These results demonstrate the high diagnostic potential of cfDNA methylation markers isolated from blood for the detection of colorectal cancer. Taken together, these findings establish the utility of methylation biomarkers for the detection of colorectal cancers as early as Stage I. In addition, a quantitative analysis of cfDNA provides an opportunity for non-invasive detection and monitoring of disease.
A comparison of microsatellite instability analysis methods in colorectal cancer.
Authors: Lewis Samantha , Peterson Shaun , Oostdik Kathryn , Tomlinson Heather
Published: July 2019

46

Background: Use of biomarkers for patient treatment stratification is an increasingly important topic with the recent FDA approval of Pembrolizumab and Nivolumab for microsatellite instability (MSI) high/mismatch repair (MMR) deficient cancers. This ground-breaking approval allows physicians to make patient treatment decisions based on molecular biomarker status. Thus, performance of detection methods for these biomarkers is of great importance. The gold standard for MSI analysis in a research setting is PCR followed by fragment analysis to resolve DNA size. Recently, PCR followed by melt curve analysis has been presented as an alternative approach. In this set of experiments these two methods are compared using a subset of human colorectal cancer samples. Methods: A cohort of matched human colorectal cancer and adjacent normal FFPE samples were used for this comparison. Eight pairs were selected that contained subtle shifts, low tumor volume or heterozygosity at microsatellite loci. These samples were then tested for MSI by fragment or melt curve analysis. Samples were then classified as MSI-H, MSI-L or microsatellite stable (MSS) according to manufacturer specifications for melt curve analysis or by an interpretive software for fragment analysis. Results: 40 mononucleotide markers were examined for each method. Melt curve analysis was concordant with fragment analysis in 70% of markers tested (28/40). Of discordant markers, 92% (11/12) were identified as unstable with fragment analysis but were stable by melt curve analysis. Additionally, two of the samples identified as MSI-H by fragment analysis were called MSS or MSI-L using the melt curve analysis method. These preliminary results suggest there may be differences in sensitivity when using challenging samples with melt curve compared to the gold standard method, fragment analysis. Conclusions: The standard method for determining MSI status utilizes PCR and fragment analysis. Recently, melt curve analysis has been proposed as an alternative method. We present preliminary findings of decreased sensitivity with melt curve compared to fragment analysis. Additional studies with a larger, more diverse sample set will be required to define this relationship further.
Investigating the tumor-immune microenvironment in an autochthonous murine model of cholangiocarcinoma.
Authors: Han Booyeon Julia , Ruffolo Luis I. , Jackson Katherine M. , Belt Brian A. , Figueroa Nathania , Murphy Joseph D. , Linehan David , Prieto Peter A.
Published: July 2019

53

Background: Cholangiocarcinoma (CCA) is the most common liver malignancy within the biliary tree with increasing incidence and poor survival. Although surgical resection can be curative, prognosis remains abysmal with high rates of unresectability and recurrence, and new systemic therapies are needed. CCA tumors are characterized by an abundant inflammatory immune cell infiltrate, yet little is known about the immune dynamics underlying the disease. Here, we present a preclinical murine model of CCA for identifying potential targets susceptible to immune-based therapies. Methods: Mice with targeted activation of KrasG12D and loss of p53 (Kras-p53-/-) in the liver were exposed to 5-Diethoxycarbonyl-1.4-dihydrocollidine for 4 weeks to induce spontaneous CCA tumorigenesis. Immunohistochemistry staining was performed for mouse and human CCA. Immune compartments (bone marrow, spleen, peripheral blood, tumor draining and non-draining lymph nodes, and CCA tumor) of mice were processed for CyTOF analysis. In vitro assays of isolated myeloid leukocytes were performed to demonstrate function. Results: Tumor associated neutrophils (TANs) and tumor associated macrophages (TAMs) were present in high levels in human CCA tumors and the murine model. CyTOF analysis demonstrated mobilization of TANs, TAMs, and CCR2+ inflammatory monocytes into the tumor. The checkpoint marker PD-1 was upregulated on CD8+ and CD4+ T cells and associated with PD-L1+ TANs, TAMs, monocytes, and dendritic cells. The immunosuppressive tumor microenvironment was also characterized by TAMs expressing IL-10, TGFβ, and arginase 1; regulatory B cells expressing IL-10 and TGFβ; and Gata3+ TH2 cells. Isolated myeloid leukocytes suppressed T cell proliferation and induced invasive migration. Conclusions: Kras-p53-/- mice developed CCA tumors histologically similar to human disease: the data portray immunosuppressive cells in the tumor microenvironment, a possible obstacle for an effective anti-tumor response. Understanding the immune dynamics of immunosuppressive populations within the tumor microenvironment will be key to mount a potent therapeutic response for durable remission and improved survival.
Breaking immune tolerance for the treatment of pancreatic cancer: Phase I/II clinical experience.
Authors: Nam David , Hwang Larn , Trieu Vuong N.
Published: July 2019

54

Background: Escalating Intratumoral heterogeneity resulting in xenogenization which is countered by overexpression of TGF-β. Here we report on the use of OT-101/Chemo to break immune tolerance to cure pancreatic cancer (PC). OT-101 is an antisense against TGF-β2. Methods: Total of 37 pts 2nd line and beyond received OT-101 with option to go on subsequent Chemo (OT-101/Chemo) or Best Supportive Care (BSC) (OT-101/BSC). Stratification by treatment line, schedule, metastasis location, disease control (DC), and baseline CA19-9, was performed. Plasma levels of 31 cyto-/chemokine were measured in a subset of 12 pts. Results: mOS of the 18 pts receiving OT-101/Chemo was 9.4 mos vs. OT-101/BSC (2.8 mos, p=0.0004). No significance was observed on stratification. However, pts with only liver metastasis had a mOS of 9.5 mos while those with liver metastasis and others only had a mOS of 4.7 mos (p=0.0077). Among the former, 1006 has Complete Response beyond 77.3 mos and 1022 had Stable Disease with OS of 40.3 mos; and OS was higher with OT-101/Chemo – 12.4 mos versus 1.9 mos, p=0.0006. There were 16 of 37 pts with DC, with mOS of 9.7 mos vs. 3.0 mos (p<0.0001); and OS was higher with OT-101/Chemo – 11.8 mos vs. 5.0 mos, p=0.0021. Pts exhibited spike in IL-8 level which returned to basal level at treatment stop. R squares relating the IL-8 spike and OS were 0.8522 and 0.9895 and p values were 0.0011 and 0.0053 for OT-101/Chemo and OT-101/BSC, respectively. Preclinically, OT-101 enhanced PBMC activity in cell kill assay and in vivo xenograft. Conclusions: The MOA for OT-101/Chemotherapy is consistent with the reactivation of immunity during TGF-β suppression and subsequent boosting/expansion of immunity during Chemo. Contrary to traditional tumor vaccine- this is universally applicable to all patients.
Developing a new urine cell flow cytometry analysis of PD-L1 expression and DNA content for diagnosis of bladder cancer.
Authors: Alanee Shaheen Riadh , Deebajah Mustafa , Chen Pin-I , Wang Alice (Xiaoyang) , Patterson Bruce Kendrick
Published: July 2019

60

Background: Bladder cancer is the fifth most common cancer in the United States. PD-1/PD-L1, a pathway used by cancer cells to evade immune response, correlates with bladder cancer severity and has emerged as a target in bladder cancer treatment. Chromosomal instability is also a prominent feature associated with the development of bladder cancer. A method for unbiased analysis of PD-L1 expression and DNA content in cells from urine samples promises to be a new test for diagnosis of bladder cancer. Methods: To evaluate the PD-L1 expression and DNA content, we developed a 4-color flow assay. Cells in voided urine samples were pelleted, fixed in incellMAX (IncellDx Inc.) and stained with antibodies against pan-cytokeratin (CK), CD45, PD-L1 and a cell cycle dye. The stained samples were analyzed by a flow cytometer alongside stained control cells. Results: Fifty bladder cancer patient and 15 normal donor urine samples were collected and tested with this assay. We could distinguish epithelial cells (pan-CK+) and white blood cells (WBCs, CD45+) in urine samples and obtain PD-L1 expression and DNA content information simultaneously from these cell populations. The patient samples showed a significantly higher percentage of WBCs with substantial PD-L1 expression (P < 0.001). The percentage of PD-L1 positive epithelial cells was not distinguishable between normal donor and patient samples. However increased post G1 epithelial cells ( > 5%) were observed in a majority of bladder cancer patients, with around 25% of samples showing a DNA index above 1.05. Conclusions: We developed a flow cytometry-based method to investigate PD-L1 and DNA content simultaneously in cells from urine samples that could provide us with a new method to accurately identify bladder cancer patients through urine testing.