bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B129: A bispecific antibody inhibits FGFR3 dimerization and is highly effective in FGFR3-driven tumor models
Authors: Yang Yan , Avvaru Naga Suhasini , Jiang Zaoli , Liu Nina , Rosconi Michael , Zhang Bojie , Li Yinyin , Ullman Erica , Lin John Chia-Yang , Shen Yang , Daly Christopher
Published: December 2023

Background: The receptor tyrosine kinase (RTK) FGFR3 is frequently mutated in bladder cancer (~15-20% in muscle invasive bladder cancer, MIBC) and is a validated therapeutic target. Oncogenic alterations in FGFR3 include point mutations in the extracellular domain (S249C, R248C, G372C, Y375C) and gene fusions that place an oligomerization domain from a fusion partner at the FGFR3 C-terminus (e.g., FGFR3-TACC3). Although pan-FGFR tyrosine kinase inhibitors (TKI) have demonstrated clinical efficacy, toxicity and acquired resistance limit the benefit of these agents. While antibody-based therapy can offer superior selectivity compared to TKIs, conventional ligand-blocking antibodies are usually ineffective inhibitors of constitutively active RTKs. Further, the existence of multiple oncogenic variants of FGFR3 presents an additional challenge for antibody-mediated blockade.

Results: We generated a tetravalent bispecific FGFR3xFGFR3 antibody that potently inhibits both FGFR3 point mutants and fusions with better efficacy than the conventional antibodies that we produced and a clinical-stage comparator antibody. Mechanistically, our bispecific antibody binds FGFR3 through two different epitopes located in immunoglobulin-like domains D1 and D2/3 respectively. It potently blocks the dimerization of FGFR3 S249C, the most common oncogenic variant, inhibiting receptor phosphorylation and downstream signaling. Additionally, our bispecific antibody inhibits the function of FGFR3 gatekeeper mutations (V557M/L) that are resistant to TKIs. In FGFR3-driven tumor models, our antibody is highly effective, providing efficacy similar to that of the FDA-approved TKI erdafitinib.

Conclusion: We have characterized the properties of a tetravalent bispecific FGFR3xFGFR3 antibody that shows strong anti-tumor activity in models driven by FGFR3 S249C as well as by FGFR3-TACC3 fusion, outperforming a conventional antibody that was previously in clinical development. The activity of the bispecific antibody is superior to the mixture of the two parental antibodies and results from strong inhibition of FGFR3 dimerization. Our bispecific antibody provides a novel approach to achieve selective and potent inhibition of multiple oncogenic variants of FGFR3 in bladder cancer, including FGFR3 variants that are resistant to FGFR TKIs.

Citation Format: Yan Yang, Naga Suhasini Avvaru, Zaoli Jiang, Nina Liu, Michael Rosconi, Bojie Zhang, Yinyin Li, Erica Ullman, John Chia-Yang Lin, Yang Shen, Christopher Daly. A bispecific antibody inhibits FGFR3 dimerization and is highly effective in FGFR3-driven tumor models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B129.
Abstract B133: Anti-tumor efficacy of GMF-1A3-MMAE, an antibody drug conjugate targeting cell surface cleaved Amphiregulin in endocrine-resistant breast cancer
Authors: Lofgren Kristopher A , Kenny Paraic A
Published: December 2023

The Epidermal Growth Factor Receptor ligand, Amphiregulin, is a key proliferative effector of estrogen receptor signaling in breast cancer and also plays a role in other malignancies. Amphiregulin is a single-pass transmembrane protein proteolytically processed by TACE/ADAM17 to release the soluble EGFR ligand, leaving a residual transmembrane stalk that is subsequently internalized. Here, we describe the development of an antibody drug conjugate, GMF-1A3-MMAE, targeting an AREG neo-epitope revealed following ADAM17-mediated cleavage. The antibody does not interact with uncleaved Amphiregulin, providing a novel means of targeting cells with high rates of Amphiregulin shedding. Using fluorescent dye conjugation, we demonstrated that the antibody is internalized by cancer cells in a manner dependent on the presence of cell surface cleaved Amphiregulin. Antibodies conjugated with monomethyl auristatin E (MMAE) were cytotoxic in vitro and induced rapid regression of established breast tumor xenografts in immunocompromised mice. We further demonstrate that these antibodies recognize the Amphiregulin neo-epitope in formalin fixed paraffin embedded tumor tissue, suggesting their utility as a companion diagnostic for patient selection. A pan-cancer tissue microarray analysis indicates that the target is commonly detected at high levels (> 50% of cases) in breast, prostate, liver and lung cancer. In normal tissue microarrays, cleaved Amphiregulin was generally detected at moderate levels in several tissues with only 7 of 93 tissue cores having levels comparable to the high levels commonly found in tumors. These data suggest therapeutic opportunities for GMF-1A3-based ADCs in multiple malignancies, however the broad off-tumor detection of cleaved Amphiregulin suggest linker/payload optimization may be necessary for an adequate therapeutic window.

Citation Format: Kristopher A Lofgren, Paraic A Kenny. Anti-tumor efficacy of GMF-1A3-MMAE, an antibody drug conjugate targeting cell surface cleaved Amphiregulin in endocrine-resistant breast cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B133.
Abstract B140: Elucidating the novel mechanism of action of VVD-065, an allosteric molecular glue for the KEAP1-CUL3 E3-ligase complex that promotes NRF2 degradation in NRF2-activated cancers
Authors: Snead Aaron , Bernard Steffen , Hee Kenneth , Tran Eileen , Jacinto Sarah , Roy Nil , Wyseure Tine , Pollock Jonathan , Simon Gabe , Kinsella Todd , Weinstein David , Patricelli Matt
Published: December 2023

Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that plays a crucial role in various NRF2-dependent cancers. The protein levels of NRF2 are tightly controlled by a specific E3 ligase complex composed of Kelch-like ECH Associated Protein 1 (KEAP1), Cullin 3 (CUL3), and RING-box protein 1 (RBX1). Under normal conditions, KEAP1 acts as an oxidative sensor and facilitates the ubiquitination and subsequent degradation of NRF2. However, during oxidative or electrophilic stress, KEAP1 can be inactivated through covalent modification of sensor cysteine residues, allowing NRF2 levels to increase and regulate NRF2-dependent genes. In this study, we have elucidated a novel mechanism-of-action for a first-in-class NRF2 inhibitor, VVD-065. Through biochemical and biophysical investigations, we have discovered that VVD-065 functions by covalently interacting with KEAP1 at a sensor cysteine residue, but surprisingly this interaction results in an enhanced affinity between KEAP1 and CUL3, and an increased capacity for Keap1 mediated NRF2 degradation. High-resolution co-crystal structures have revealed that binding of VVD-065 allosterically induces a conformational change that mimics the conformation of KEAP1 when in complex with CUL3. By targeting the KEAP1-CUL3 interaction and promoting the degradation of NRF2, VVD-065 offers a means to modulate NRF2 levels in NRF2-dependent cancers. The unprecedented mechanism of action exhibited by VVD-065 has been confirmed through in vitro and in vivo studies, paving the way for the development of a clinically relevant Keap1 activator.

Citation Format: Aaron Snead, Steffen Bernard, Kenneth Hee, Eileen Tran, Sarah Jacinto, Nil Roy, Tine Wyseure, Jonathan Pollock, Gabe Simon, Todd Kinsella, David Weinstein, Matt Patricelli. Elucidating the novel mechanism of action of VVD-065, an allosteric molecular glue for the KEAP1-CUL3 E3-ligase complex that promotes NRF2 degradation in NRF2-activated cancers [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B140.
Abstract B163: Discovery and characterization of OKI-219, an orally bioavailable H1047R-mutant-selective inhibitor of PI3Kα
Authors: Taylor Molly A , Zhao Qian , Mareska David , Hoh Maria , Izrayelit Yevgeniy , Litwiler Kevin , Boys Mark L , Woessner Rich , Walker Duncan , Diamond Jennifer , Winkler James D
Published: December 2023

Mutations in PI3Kα lead to constitutive activation of the PI3K/AKT/mTOR pathway and are found in approximately 13% of human cancers, with the PI3KαH1047R mutation being the most common. Targeting PI3Kα in cancer is a therapeutically proven strategy, with the currently approved drug alpelisib showing clinical efficacy alone or in combination with other therapies. However, treatment with non-mutant selective PI3Kα inhibitors, such as alpelisib, is associated with significant toxicities such as hyperglycemia due to on-target inhibition of the wild-type enzyme, which often leads to dose modification or discontinuation. Therefore, there is a significant need to develop new PI3Kα-targeted therapies that can avoid or minimize on-target toxicity and improve the safety and clinical benefit for patients.  OKI-219 is a PI3KαH1047R mutant-selective inhibitor, with ~100-fold cellular selectivity for the H1047R mutation over wild-type and biochemical selectivity across a 412 kinase panel, with no other kinases showing >30% inhibition at 1 µM.  In vitro, OKI-219 drives decreased phosphorylated AKT (pAKT) and decreased proliferation selectively in PI3KαH1047R mutant cell lines across several tumor types.  In vivo, as a monotherapy, OKI-219 demonstrates dose-dependent antitumor activity in multiple human CDX and PDX tumor xenograft models, with regression rates up to 100% in PI3KαH1047R heterozygous (T47D) and homozygous (SUM185PE) CDX models, at doses that show no sign of the metabolic dysfunction (increased glucose or insulin) that is associated with wild-type protein inhibition. The in vivo antitumor activity correlates with pathway inhibition, measured by decreased pAKT in tumors.  In addition to the monotherapy efficacy observed, OKI-219 in combination with the selective estrogen receptor degrader (SERD) fulvestrant showed significant combination benefit leading to tumor regressions in the H1047R-mutated ER+HER2- breast cancer model xxT47D, at doses where no regressions were observed with single agent treatment. These data support the hypothesis that OKI-219 will offer improved efficacy and a wider therapeutic window compared to non-mutant selective PI3Kα inhibitors. This hypothesis will be tested, as OKI-219 is moving into clinical investigation.

Citation Format: Molly A Taylor, Qian Zhao, David Mareska, Maria Hoh, Yevgeniy Izrayelit, Kevin Litwiler, Mark L Boys, Rich Woessner, Duncan Walker, Jennifer Diamond, James D Winkler. Discovery and characterization of OKI-219, an orally bioavailable H1047R-mutant-selective inhibitor of PI3Kα [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B163.
Abstract B175: In-vitro multicellular 3D-Spheroid model demonstrates the synergistic effect of 2-domain soluble FMS-like Tyrosine Kinase-1 (2d-sFlt-1) for breast cancer targeted therapies
Authors: Mutahar Adel Zaid I.
Published: December 2023

Using a conventional 2D-culture model, the anti-cancer drug failure rate was approximately 95%. Thus, incorporating in-vitro 3D models that better mimic in-vivo conditions became a central focus of drug discovery and regenerative medicine. Drug screening on triple-negative breast cancer (TNBC) with paclitaxel, doxorubicin alone or in combination with 2d-sFlt-1 revealed 28, 17, and 8-fold increase in the cytotoxicity effect using 2D-culture compared to 3D-spheroids. Tumor spheroids treated with 2d-sFlt-1 in combination with paclitaxel revealed a 13.5-fold higher response than paclitaxel alone. The targeted therapy was validated by a significant decrease in the formation of blood vessels either in tube formation or 3D-angiogenesis assays in endothelial-tumor cells co-cultured spheroids. The cytotoxicity effect of paclitaxel on 3D-tumor spheroids was enhanced with 2d-sFlt-1 (58% of dead cells) compared to (33% of dead cells) in paclitaxel alone. Furthermore, the antiproliferative effect of paclitaxel was significantly enhanced by combinatorial treatment with 2d-sFlt-1 (p<0.0001) compared to bevacizumab (p<0.05). Immunohistochemistry of 3D-tumor spheroids revealed inhibition in the expression of Ki-67 in combinatorial treatment. The increase in the migration rate of TNBC was significantly inhibited by combinatorial treatment as evidenced in 2D and 3D-invasion assays.  Further, immunofluorescence of 3D-spheroids showed downregulation of EMT markers (E. Cadherin, vimentin, cortactin, and paxillin) in response to combinatorial treatment compared to paclitaxel alone. Moreover, inhibition of FAK expression upon 2d-sFlt-1 treatment was exhibited either in endothelial cells, MDA-MB231, or co-cultured spheroids. Expression of vascular endothelial growth factor (VEGF) was also decreased in combinatorial treatment as evidenced by ELISA. qPCR of 3D-spheroids revealed the downregulation of EMT genes (N-cadherin, SNAIL, and TWIST) and upregulation of E-cadherin in combinatorial treatment. These findings demonstrate the antiangiogenic and anti-metastatic properties of 2d-sFlt-1 on TNBC. We conclude that multicellular 3D spheroids for bioengineering tumor models are promising in vitro animal-free models for cancer therapies and regenerative medicine.

Citation Format: Adel Zaid I. Mutahar. In-vitro multicellular 3D-Spheroid model demonstrates the synergistic effect of 2-domain soluble FMS-like Tyrosine Kinase-1 (2d-sFlt-1) for breast cancer targeted therapies [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B175.
Abstract C003: A quantitative mass spectrometry workflow for highly multiplexed measurement of immunomodulatory proteins to support immunotherapy clinical trials
Authors: Ousji Ons , Jang Anne , Genovesi Luca , Dupuis Nicholas , Geib Timon , Pottiez Gwenael , Schirm Michael
Published: December 2023

Background: Since the approval of the first immune checkpoint-directed immunotherapies, it has been well-known that the efficacy of these therapies has been limited to a subset of cancer patients. As the number of new potential immunotherapy targets has grown, including novel combination therapy strategies, improved immune-related biomarker measurement has played a key role in understanding novel mechanisms of action and response to drugs. To support these efforts, we have developed an analytically validated assay for the multiplexed quantitation of up to 113 immunomodulatory proteins in various matrices (e.g., human plasma, PBMC, cells, or tissue) based on anti-peptide immunoaffinity capture followed by LC-MRM mass spectrometry analysis.

Methods: Remnant samples from commercial biobanks were acquired in a variety of solid tumor indications. Briefly, matrices were denatured, reduced, alkylated, and digested using trypsin. Immunoaffinity capture of the peptide targets consisted of overnight incubation of the digested sample with anti-peptide antibodies coupled to protein G magnetic beads, followed by automated washing and elution of the peptides from the antibodies using the KingFisher platform.  The peptides were analyzed in a multiplexed method by LC-MRM mass spectrometry. Endogenous levels for each target were measured relative to a stable isotopically labeled peptide standard.

Results: In panel experiments, we found that the targets can be quantified precisely and accurately over 3 orders of magnitude with an intra-/inter-assay precision and accuracy of less than 20%. In total, 107 peptide targets were detected endogenously in cell lines. We expand on these data with analysis of solid tumor FFPE specimens where the results will be compared to immunohistochemical staining for selected targets.

Conclusions: This study shows how multiplex immunoaffinity methods can complement classical methods of tissue-based protein expression for simultaneous and quantitative interpretation of protein levels.

Citation Format: Ons Ousji, Anne Jang, Luca Genovesi, Nicholas Dupuis, Timon Geib, Gwenael Pottiez, Michael Schirm. A quantitative mass spectrometry workflow for highly multiplexed measurement of immunomodulatory proteins to support immunotherapy clinical trials [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C003.
Abstract C014: Pan-cancer analysis portrays NVL as a diagnostic and prognostic biomarker
Authors: Datta Mousumi , Nayak Dr. Aditi
Published: December 2023

NVL (also known as NVL2), an AAA+ ATPase, has recently been linked with various cancers. By systematic bioinformatics analyses, here we predict the prospect of NVL as a cancer biomarker. Our pan-cancer analyses reveal that NVL is overexpressed in cancers [GEPIA and UALCAN (TCGA) databases] and the top five cancers with elevated expression (more than twofold) of NVL are Breast Invasive Carcinoma, Testicular Germ Cell Tumors, Cholangiocarcinoma, Diffuse large B cell lymphoma, and Thymoma. NVL is also highly expressed in all stages of most cancers. Additionally, this high expression was found to be correlated to the poor survival of cancer patients (Kaplan-Meier Plotter and OncoDB databases). Since, genetic alteration is one of the major cause of cancer, we investigated mutation and copy number amplification status (cBioPortal and COSMIC databases) of NVL across the cancers. Many potential mutation sites were predicted (cBioPortal and COSMIC databases) and most strikingly, four mutation sites at the ATPase domain of NVL. This signifies that these are the mutations that might have role in carcinogenesis. The copy number amplification study also revealed the high amplification percentage of NVL across different cancers. We further focused on the functional characteristics of the protein NVL across cancers. The protein-protein interaction analyses found the proteins like SKIV2L2, WDR12, WDR74, UTP18, NAT10, TERT, DKC1, GTPBP4, BOP1, TEP1 directly interact with NVL. The top canonical pathways of NVL also indicate that NVL has crucial functions in cancer cell proliferation (DAVID). We, therefore, surmise that NVL could be considered as a potential diagnostic and prognostic marker for multiple cancers and a very promising biomarker and target for cancer.

Citation Format: Mousumi Datta, Dr. Aditi Nayak. Pan-cancer analysis portrays NVL as a diagnostic and prognostic biomarker [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C014.
Abstract C016: Evaluating clinical biomarkers of FHD-286, a potent and selective inhibitor of BRG1/BRM, in metastatic uveal melanoma
Authors: Wan Jessica , Horrigan Kim , Elliott GiNell , Johannessen Liv , Collins Mike , Lazar Alexander J. , Corrigan Dillon , Patriquin Caitlin , Agresta Sam , Piel Jessica , Hentemann Martin
Published: December 2023

The BRG/Brahma-associated factors (BAF) family of chromatin remodeling complexes (also referred to as the mSWI/SNF complex) regulates chromatin accessibility and gene expression through its ATP-dependent remodeling activity. FHD-286, a first-in-class compound that potently and selectively inhibits the ATPase components of the BAF complex, BRG1 and BRM, was evaluated in a Phase I dose escalation in subjects with metastatic uveal melanoma (mUM) (FHD-286-001). The pharmacodynamics of FHD-286 were assessed to demonstrate proof-of-mechanism and understand the downstream molecular and clinical impact of BRG1/BRM inhibition. In addition, circulating tumor DNA (ctDNA) was evaluated as an early predictor of overall survival benefit. Seventy-three subjects were on a daily dosing regimen ranging from 2.5 to 10 mg or an intermittent regimen of 1-week on/1-week-off ranging from 10 to 22.5 mg. Tumor biopsies were collected at screening and either Cycle 3, or end of treatment. Biomarker changes in the tumor were observed by histological assessment, by IHC/IF biomarker assays, and RNA sequencing. Observations were suggestive of a differentiation effect by FHD-286 on the tumor cells, including a decrease in stemness genes and an increase in mature melanocytic markers. Evidence of necrosis and a trend of decreasing tumor cell density were also seen. In addition, ctDNA was measured in serial plasma samples using a targeted NGS panel. A reduction in ctDNA was shown in approximately 50% of subjects, which correlated with an increased overall survival benefit. Lastly, serial blood samples collected in Paxgene RNA tubes were analyzed by RNA sequencing. A robust dose-dependent gene signature was identified as a peripheral readout of target engagement at steady-state in both dosing regimens and across dose cohorts.  In summary, we observed changes in the tumor cells at the biopsy site and ctDNA that suggest FHD-286 has a biological impact on uveal melanoma that may lead to clinical benefit. Given the limitations and challenges to obtain tumor biopsies from every subject and at a frequent rate, the identified PD gene signature in the blood is a valuable tool to measure target engagement in this study, and other potential solid tumor indications. 

Citation Format: Jessica Wan, Kim Horrigan, GiNell Elliott, Liv Johannessen, Mike Collins, Alexander J. Lazar, Dillon Corrigan, Caitlin Patriquin, Sam Agresta, Jessica Piel, Martin Hentemann. Evaluating clinical biomarkers of FHD-286, a potent and selective inhibitor of BRG1/BRM, in metastatic uveal melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C016.
Abstract C024: Trial in progress: Phase 1 study of BAL0891 as monotherapy and in combination with chemotherapy in patients with advanced solid tumors
Authors: Kummar Shivaani , Barve Minal , Feldman Eric , Ma Seunghyun , Merchan Jaime , Im Seock-Ah , Rha Sun Young
Published: December 2023

Background: BAL0891 is a first-in-class small-molecule mitotic checkpoint inhibitor (MCI) that targets threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1) to disrupt spindle assembly checkpoint (SAC) regulation and induce tumor cell death. It has a more potent anti-tumor activity as compared to TTK-specific inhibitors due to its combined prolonged effect on TTK and transient effect on PLK1. In preclinical studies, BAL0891 demonstrated potent anti-tumor activity as a monotherapy and in combination with paclitaxel and carboplatin. In the first-in-human microdose study of TTK-CS-001 in healthy subjects, key BAL0891 pharmacokinetic (PK) parameters were investigated (i.e., clearance, half-life, exposure), and no safety signals were detected.

Trial design: This clinical trial is a multiple-cohort, open-label phase 1 study with 3 dose-escalation substudies, investigating intravenous (IV) BAL0891 as monotherapy, and in combination with carboplatin or paclitaxel, in patients with advanced solid tumors.

Primary objectives: 1) To evaluate safety/tolerability 2) To estimate the maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of BAL0891 monotherapy and in combination with carboplatin/paclitaxel.

Eligibility: Patients ages ≥18 years with advanced/metastatic solid tumors that are refractory to, or intolerant of existing therapy may participate in this study. Patients enrolled in dose level ≥4 of Substudy 1 and all patients in Substudies 2 and 3 must have measurable disease.

Substudy 1: Monotherapy BAL0891: IV doses of BAL0891 on Days 1 (D1) and 8 (D8) every 3 weeks (Q3W). A Bayesian logistic regression model (BLRM) will guide dose escalations, with 8 nominal DLs of 5/10/20/40/80/160/320/480 mg.

Substudy 2: Phase 1 BAL0891 D1, D8 + carboplatin AUC5-6 D1 Q3W.

Substudy 3: Phase 1 BAL0891 D1, D15 + paclitaxel 70-80 mg/m2 D1, D8, D15 Q4W. Substudies 2 and 3 may begin once the maximum tolerated dose (MTD) of BAL0891 monotherapy has been established or at the first signs of expected target toxicity and/or efficacy with monotherapy. Enrollment began in February 2023 and is ongoing in the United States and South Korea. Clinical trial information; NCT05768932

Citation Format: Shivaani Kummar, Minal Barve, Eric Feldman, Seunghyun Ma, Jaime Merchan, Seock-Ah Im, Sun Young Rha. Trial in progress: Phase 1 study of BAL0891 as monotherapy and in combination with chemotherapy in patients with advanced solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C024.
Abstract C029: Phase Ib/II open label, multi-arm, parallel cohort dose finding and expansion study of NUC-3373 in combination with pembrolizumab in patients with advanced solid tumors or docetaxel in patients with lung cancer (NuTide:303)
Authors: Wilson Richard H , Thistlethwaite Fiona , McKissock Fiona G , Oelmann Elisabeth , Bloss Jeffrey D , Spicer James F , Middleton Gary
Published: December 2023

Background: NUC-3373 is a phosphoramidate transformation of fluorodeoxyuridine monophosphate (FUDR-MP) designed to replace fluoropyrimidines, such as 5-FU, which exert their activity via inhibition of thymidylate synthase (TS) and disruption of DNA synthesis and repair. Intracellular cleavage of NUC-3373 releases the anti-cancer metabolite FUDR-MP, thereby potentially improving the therapeutic ratio of 5-FU whilst reducing the practical barriers associated with 5-FU administration. In addition to generating high intracellular levels of FUDR-MP and being a potent inhibitor of TS, pre-clinical data have shown that NUC-3373 can enhance the activity of immunotherapy agents by promoting the release of damage associated molecular patterns, activating a natural killer cell response and reducing inhibitory signals on T-cells.

Methods: NuTide:303 is a Phase Ib/II open label, multi-arm, parallel cohort dose finding and expansion study to assess the safety, PK and efficacy of NUC-3373 given in combination with leucovorin (LV) and either (i) pembrolizumab in patients (pts) with solid tumors  in Module 1 or (ii) docetaxel in pts with non-small cell lung cancer (NSCLC) or pleural mesothelioma in Module 2. Both modules consist of dose-validation (Phase Ib) and dose-expansion (Phase II). The Phase Ib part will determine the MTD, safety and tolerability along with preliminary efficacy of the combinations (in 6 - 20 pts).  In the Phase II part, an additional 20-40 pts will be added. In both modules, pts with measurable disease and ECOG PS 0-1 are eligible.  For Module 1, pts  diagnosed with any solid tumor who have progressed on ≤2 prior lines of therapy for advanced/metastatic disease (including 1 prior line of an immunotherapy-containing regimen), and for whom pembrolizumab treatment would be appropriate, are eligible. For Module 2, pts with advanced/metastatic NSCLC or pleural mesothelioma who have progressed on, or were unable to tolerate, ≤2 prior lines of chemotherapy-containing regimens for advanced/metastatic disease are eligible. Additional modules combining other agents with NUC-3373 + LV are being planned.   Clinical trial information: NCT05714553

Citation Format: Richard H Wilson, Fiona Thistlethwaite, Fiona G McKissock, Elisabeth Oelmann, Jeffrey D Bloss, James F Spicer, Gary Middleton. Phase Ib/II open label, multi-arm, parallel cohort dose finding and expansion study of NUC-3373 in combination with pembrolizumab in patients with advanced solid tumors or docetaxel in patients with lung cancer (NuTide:303) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C029.
Abstract C034: First in Human phase 1/2a trial of a macrocyclic ATR inhibitor (ATRN-119) in patients with advanced solid tumors
Authors: Simpkins Fiona , Schneider Reva , Mahipal Amit , LoRusso Patricia , Miller Crystal , Brown Eric , Carleton Mike , Gullbo Joachim , Mirza Nadeem Q
Published: December 2023

Background: ATRN-119 is an oral and highly selective nanomolar inhibitor of Ataxia Telangiectasia and Rad3- related (ATR) kinase, an enzyme that is activated by replication stress and DNA damage and prevents the collapse of DNA replication forks into double strand breaks. ATRN-119 is being studied in advanced solid tumors with dysregulated components of the DNA damage response (DDR) based on the hypothesis that these tumors will be more susceptible to ATR inhibition. Single agent ATRN-119 demonstrates increased cytotoxicity in vitro against a broad spectrum of human colon, breast, pancreatic, sarcoma, ovarian and prostate cancer cell lines that harbor genomic alterations of DDR genes. In vivo, ATRN-119 has demonstrated tumor growth inhibition in human castration-resistant prostate cancer and human colon cancer cell line-derived xenografts (CDX) mice models, and in BRCA mutant high grade serous ovarian cancer patient derived xenografts (PDXs).

Trial design: This is a first-in-human Phase 1/2a open-label study (NCT04905914) to evaluate safety, tolerability, pharmacokinetics (PK), and preliminary e!cacy of oral daily ATRN-119 in subjects with advanced solid tumors, conducted in 2 parts. Part 1 consists of a 3+3 dose escalation design at up to 6 dose levels to evaluate the tolerability, PK, dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of repeated daily doses of ATRN-119. Enrollment in Part 1 is ongoing. Subjects must be ≥12 years old with advanced solid tumor, have documented DDR mutations, or advanced Merkel cell carcinoma, must have failed at least one prior standard treatment, have ECOG performance status of 0 or 1, with a life expectancy > 3 months. Primary objective is safety/tolerability and secondary objective is efficacy. After determination of the MTD or maximum feasible dose (MFD) in Part 1, Part 2 will enroll up to 30 additional subjects. The trial is currently recruiting across 4 locations in the United States. Clinical trial identification: ClinicalTrials.gov Identifier: NCT04905914

Citation Format: Fiona Simpkins, Reva Schneider, Amit Mahipal, Patricia LoRusso, Crystal Miller, Eric Brown, Mike Carleton, Joachim Gullbo, Nadeem Q Mirza. First in Human phase 1/2a trial of a macrocyclic ATR inhibitor (ATRN-119) in patients with advanced solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C034.
Abstract C053: BACE1 cleaves EGFR to drive lung adenocarcinoma brain metastasis
Authors: Chafe Shawn C , Zhai Kui , Singh Sheila K
Published: December 2023

Brain metastasis occurs in up to 40% of patients with non-small cell lung cancer (NSCLC).  Considerable genomic heterogeneity exists between the primary lung tumour and respective brain metastasis; however, the identity of the genes capable of driving brain metastasis is incompletely understood.  Here, we carried out an in vivo genome-wide CRISPR activation (CRISPRa) screen to identify molecular drivers of brain metastasis from a NSCLC patient-derived xenograft model.  We discovered activation of the Alzheimer’s disease associated b-site amyloid precursor protein cleaving enzyme 1 (BACE1) led to a significant increase in brain metastasis.   Furthermore, BACE1 knockout or inhibition with Verubecestat treatment blocked NSCLC brain metastasis.  Mechanistically, we identified BACE1 cleaves an N-terminal fragment of EGFR to activate downstream signalling through MEK and ERK and drive this metastatic phenotype.  Together our data highlights the power of in vivo CRISPR screening to unveil novel molecular drivers and potential therapeutic targets of NSCLC brain metastasis.

Citation Format: Shawn C Chafe, Kui Zhai, Sheila K Singh. BACE1 cleaves EGFR to drive lung adenocarcinoma brain metastasis [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C053.
Abstract C071: HBI-2375, a selective inhibitor of MLL1-WDR5 interaction, possesses desirable preclinical characteristics in solid tumors in combination with checkpoint inhibitors and also in leukemias in the future clinical investigations
Authors: Shojaei Farbod , Fang Che , Ricono Jill M , Gillings Mireille
Published: December 2023

MLL1 (mixed lineage leukemia1) interaction with WDR5 (WD repeat domain 5) is critical for its histone methyl transferase (HMT) activity leading to transcriptional regulation of gene expression. MLL1 dysregulation such as its translocation at chromosome 11q23 results in generation of MLL1 fusion genes and leukemia development. Additionally, recent studies indicated a role for MLL1-WDR5 interaction in solid tumors progression via directly affecting cancer cells or by suppression of tumor immunity. Therefore, MLL1-WDR5 interaction is an important target in the discovery of anti-cancer drugs for both leukemia and solid tumors. HUYABIO recently identified HBI-2375 as a selective inhibitor of MLL1-WDR5 interaction. HBI-2375 showed potent inhibition of WDR5 (IC50=4.48 nM) and inhibited MV4-11 cellular proliferation (average IC50=3.15 µM) in CTG assays. In addition, HBI-2375 was stable in liver S9 and whole blood, with moderate to high plasma protein binding rates in multiple species, and acceptable hERG IC50 (17 µM). Furthermore, HBI-2375 displayed reasonable oral PK properties (Cmax, T1/2, AUC, and F%) in mouse and dog. In vivo, HBI-2375 has shown significant dose dependent anti-tumor activity in MV4-11 xenograft AML model along with reduction in methylation of H3K4 in the tumors harvested from the treated animals demonstrating the targeted disruption of HMT activity in cancer cells by HBI-2375. Furthermore HBI-2375 in combination with PD-1 mAb significantly inhibited tumor growth in MC38, colorectal tumor model, and in 3LL lung carcinoma syngeneic tumor models. Flow cytometry and IHC showed significant increase in the infiltration of CD8+ CTLs in the combination group further providing immune-driven mechanisms for greater efficacy of combination therapy. Gene expression analysis also identified genes that are involved in promoting immune system activity in the combination group. Therefore, HBI-2375 may represent a first-in-class MLL1-WDR5 inhibitor in the clinic.

Citation Format: Farbod Shojaei, Che Fang, Jill M Ricono, Mireille Gillings. HBI-2375, a selective inhibitor of MLL1-WDR5 interaction, possesses desirable preclinical characteristics in solid tumors in combination with checkpoint inhibitors and also in leukemias in the future clinical investigations [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C071.
Abstract C082: SCD1 is a potent therapeutic target in MYC-amplified group 3 medulloblastoma
Authors: Custers Stefan , Escudero Laura , Suk Yujin , McKenna Dillon , Gwynne William , Chaudhry Iqra , Chan Jeremy , Quaile Andrew , Moffat Jason , Venugopal Chitra , Montenegro-Burke Rafael , Singh Sheila
Published: December 2023

Medulloblastoma (MB) is the most common pediatric brain tumor comprising of four subgroups: WNT, SHH, Group 3 (Gp3) and Group 4 (G4). Improved Standard of care has led to a greatly improved patient survival. However, 30% of patients still succumb to the disease and survivors are plagued with lifelong neuro-cognitive and neuro-developmental disorders. MYC amplified G3MB is a highly aggressive subgroup with a high frequency of metastasis and recurrence, leading to a bleak prognosis. Molecular understanding of G3MB is lacking and improved treatment options are urgently needed. Recent studies suggest a role for reprogrammed lipid metabolism, especially at recurrence. Here, we utilized comparative profiling of the G3MB and neural stem cells (NSC) lipidome with liquid chromatography-mass spectrometry (LC-MS). We identified a class of lipids whose differential abundance in G3MB renders these tumor cells sensitive to chemical inhibition of their biosynthesis. Pharmacological and genetic inhibition of the rate limiting enzyme of the de novo lipid synthesis pathway, Stearoyl-CoA Desaturase-1 (SCD1), completely abolishes self-renewal and proliferation in vitro, while supplementing cell culturing media with Oleic Acid (OA) fully restores these effects. Genetic knockout of SCD1 in G3MB cells significantly prolongs survival and reduced tumor burden in vivo. Moreover, administration of CAY10566, a SCD1 specific small molecule inhibitor significantly prolongs survival in vivo as well. RNA-seq, lipidomic and metabolomic analyses of G3MB treated with CAY10566 or DMSO is being employed to unravel SCD1-mediated mechanisms. Together, these data suggest that enzymes regulating lipid metabolism in G3MB represent potential targets for therapeutic translation.

Citation Format: Stefan Custers, Laura Escudero, Yujin Suk, Dillon McKenna, William Gwynne, Iqra Chaudhry, Jeremy Chan, Andrew Quaile, Jason Moffat, Chitra Venugopal, Rafael Montenegro-Burke, Sheila Singh. SCD1 is a potent therapeutic target in MYC-amplified group 3 medulloblastoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C082.
Abstract C097: Cancer-selective metabolic vulnerabilities in MYC-amplified medulloblastoma
Authors: Singh Sheila , Gwynne William , Suk Yujin , Chan Jeremy , Qualie Andrew , Escudero Laura , Brown Kevin , Venugopal Chitra , Moffat Jason , Montenegro-Burke Rafael
Published: December 2023

Background: MYC-amplified group 3 (G3) medulloblastoma (MB) represents a clinically aggressive subgroup of MB that is defined by leptomeningeal metastases, disease recurrence and particularly poor survivorship in comparison to other MB subgroups. There is an urgent need for a more thorough molecular understanding of G3 MB to develop more effective therapeutic modalities that will improve the durability of remission. 

Methods: We mapped the functional G3 MB metabologenomic landscape via parallel genome-wide CRISPR-Cas9 screening and untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics. The tractability of potential therapeutic targets was assessed using patient-derived orthotopic preclinical models of G3 MB. Transcriptomics, functional genomics, and metabolomics were employed to discern a mechanism whereby inhibition of DHODH (dihydroorotate dehydrogenase), which is a mitochondrial-bound enzyme that facilitates de novo pyrimidine biosynthesis, selectively impairs G3 MB tumor cell fitness.

Results: Untargeted metabolomic profiling shows enrichment of de novo pyrimidine biosynthesis and depletion of salvage pyrimidine intermediates in G3 MB tumor cells in comparison to neural stem cells (NSC), which are the prospective cell-of-origin of MB. In agreement with reprogrammed nucleotide metabolism, DHODH was identified as a corresponding ‘druggable hit’ in the genetic screen. We demonstrate that genetic or pharmacological inhibition of DHODH selectively targets G3 MB brain tumor initiating cells (BTIC) while sparing normal NSC. We further show that MYC-amplified G3 MB tumors harbor subgroup-specific transcriptomic signatures that delineate enrichment of de novo pyrimidine biosynthesis, which sustains c-Myc activity via a metabolite-protein interaction.

Significance: Despite clear evidence favoring an altered metabolic landscape in MYC-driven cancers, there have been few reports into the role of metabolic reprogramming in MYC-amplified G3 MB. This metabolic vulnerability is hence not exclusive to MB and has recently been identified in other primary brain malignancies; current efforts are focused on establishing relevant biomarkers that will facilitate clinical translation.

Citation Format: Sheila Singh, William Gwynne, Yujin Suk, Jeremy Chan, Andrew Qualie, Laura Escudero, Kevin Brown, Chitra Venugopal, Jason Moffat, Rafael Montenegro-Burke. Cancer-selective metabolic vulnerabilities in MYC-amplified medulloblastoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C097.
Abstract C106: Identification of nucleic acid drug candidates against mesenchymal transition and its application to breast cancer and glioblastoma cells
Authors: Yoshikawa Kiyotsugu , Takahashi Rei
Published: December 2023

Cancer stem-like cells (CSLC) have a feature of epithelial-mesenchymal transition (EMT) responsible for tumor heterogeneity and therapeutic resistance. To identify molecular targets of CSLC, we underwent shRNA screening for epithelialization of MDA-MB-231 mesenchymal breast cancer cell line with novel EMT/MET dual reporter system and identified 2 shRNAs (shP1 and shH1) which reverse EMT in mesenchymal breast cancer as well as glioblastoma cells. While mesenchymal breast cancer cells undergo adipogenic differentiation upon PPAR gamma activation, shP1-induced epithelialization suppresses adipogenic differentiation. Of the two shRNAs, the shH1 strongly inhibited their growth, indicating shH1-specific sequence has a therapeutic potential for nucleic acid therapeutics.   Metabolome/transcriptome analyses of immortalized human mammary epithelial cells (HMLE) undergoing EMT in the presence of absence of H-Ras oncogene revealed global metabolic change upon EMT, including reduced glycolysis, increased shunting to pentose phosphate pathways, shift in TCA, and increased glutathione biosynthesis. Ras-mesenchymal CSLC cells overcame the effects of EMT on glycolysis and acquired hybrid metabolic state. In summary, we have revelaed metabolic plasticity of mesenchymal cancer cells and identified nucleic acid drug candidates against mesenchymal transition.

Citation Format: Kiyotsugu Yoshikawa, Rei Takahashi. Identification of nucleic acid drug candidates against mesenchymal transition and its application to breast cancer and glioblastoma cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C106.
Abstract C111: A novel human monoclonal antibody targeting active ADAM10 demonstrates anti-tumor effects in colorectal cancer
Authors: Mashati Pargol , Sun Dan , Reino Eduardo Garcia , Blandino Jessica A. , Mason Ben , Saha Nayanendu , Nikolov Dimitar B. , Premsrirut Prem
Published: December 2023

Colorectal cancer (CRC) is the third most diagnosed cancer in the USA and accounts for more than 600,000 deaths annually worldwide, primarily due to relapse with highly aggressive, chemo-resistant disease characterized by poorly differentiated cancer cells with stem cell-like properties. A common signature of these chemo-resistant tumors is dysregulation of Notch receptor signaling, as well as upregulation of its metalloprotease activator, ADAM10. Although small molecule inhibition of either Notch or ADAM10 has been shown to produce potent anti-tumor effects, these therapeutic strategies have failed in clinical trials primarily due to systemic toxicities, especially cytotoxic effects on the gastrointestinal tract and musculoskeletal system, highlighting the need for development of more targeted approaches. We have previously demonstrated that ADAM10 predominantly exists in an inhibited state in normal tissues but is activated in tumor cells through a conformational change in the extracellular domain, thus providing a potential target for tumor-specific modulation of ADAM10 activity. Here, we look to characterize a novel human monoclonal antibody agent (1H5) that selectively targets an exposed extracellular region of activated ADAM10 on tumor cells. We previously demonstrated that treatment with a murine version of the antibody (8C7), specific for the activated form of both mouse and human ADAM10, conferred a significant reduction in tumor burden against human CRC cell lines in cell culture and transplants in xenograft models, and relapse was prevented when 8C7 was combined with chemotherapy. Here, we demonstrate that the 1H5 monoclonal antibody effectively reduces cell viability in numerous colorectal cancer cell lines in vitro and induces marked tumor regression in established xenograft models through inhibition of Notch signaling. Through the use of additional genetic tools combined with in vitro and in vivo models, our preclinical study aims to fully evaluate 1H5 as novel therapeutic agent to treat aggressive colorectal cancer. We aim to propel this novel agent toward clinical-stage development.

Citation Format: Pargol Mashati, Dan Sun, Eduardo Garcia Reino, Jessica A. Blandino, Ben Mason, Nayanendu Saha, Dimitar B. Nikolov, Prem Premsrirut. A novel human monoclonal antibody targeting active ADAM10 demonstrates anti-tumor effects in colorectal cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C111.