Approved Therapy Research Articles

Abstract 6457: The real-world data of comprehensive genomic profiling tests with tissue specimens from lung cancer patients in Japan

Abstract Introduction: Molecularly targeted therapy improves prognosis of lung cancer patients with specific genomic alterations, and thus it is important to identify actionable genomic alterations leading to appropriate therapy. In Japan, comprehensive genomic profiling (CGP) tests have been covered by insurance since June 2019. 99.7% of the CGP data under insurance coverage have been registered with the nationwide database: Center for Cancer Genomics and Advanced Therapeutics (C-CAT). C-CAT data include CGP test results and clinical information such as companion diagnostic results for EGFR, ALK, ROS1, and BRAF as well as therapeutic history. The aim of this study is to evaluate the usefulness of CGP tests for identifying actionable genomic alterations in real-world lung cancer patients. Methods: Among the 3,240 lung cancer patients registered in the C-CAT database by September 2023, 2,076 non-small cell lung cancer cases were tested using tissue specimens and analyzed retrospectively. The analysis was based on the levels of evidence defined by C-CAT. Level A indicated approved drugs for the particular cancer type, while level C indicated approved drugs or presence of positive clinical trials regardless of cancer type. Level F indicated that the genomic alteration was an oncogenic marker. Results: The cases were divided into two groups: 335 cases with known genomic alterations with positive results from companion diagnostic tests or use of specific inhibitors and 1,741 cases without. Genomic alterations with level A, A to C, and A to F were identified in 430 cases (24.7%), 1174 cases (67.4%), and 1718 cases (98.7%) with unknown genomic alterations, respectively. Genomic alterations with level A included rearrangement of RET (43 of 1741 cases, 2.5%), ALK (14 cases, 0.8%), ROS1 (8 cases, 0.5%), and NTRK1 (2 cases, 0.1%), and mutations of EGFR (124 cases, 7.1%), MET (38 cases, 2.2%), ERBB2 (122 cases, 7.0%), KRAS G12C (66 cases, 3.8%), and BRAF V600E (15 cases, 0.9%). Genomic alterations with level C included mutations in KRAS (185 cases, 10.6%), PIK3CA (99 cases, 5.7%), BRAF (55 cases, 3.2%), and PTEN (32 cases, 1.8%) and amplifications in ERBB2 (147 cases, 8.4%) and MET (68 cases, 3.9%). Among cases with known genomic alterations, ALK and ROS1 fusion genes were not detected in 11 of 49 (22.4%) and 17 of 46 (37.0%), while EGFR and BRAF mutation was not detected in 11 of 218 (5.0%) and 3 of 4 cases (75.0%), respectively. The detection rate of fusion genes was lower than that of mutated genes (70.5% vs 93.7%, p<0.001). Conclusion: In non-small cell lung cancer patients with unknown driver genes, driver oncogenes with corresponding approved therapy were found in a quarter of the patients. CGP tests offer the possibility of increasing the opportunities of receiving new therapies. CGP tests may have a lower detection rate for fusion genes compared with other mutations. Citation Format: Koki Fujii, Momoko Morishita, Michiko Ueki, Hiroaki Ikushima, Hideaki Isago, Kousuke Watanabe, Katsutoshi Oda, Hidenori Kage. The real-world data of comprehensive genomic profiling tests with tissue specimens from lung cancer patients in Japan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6457.

Abstract 3910: The Atlas of Blood Cancer Genomes: A resource for therapeutic and biomarker development

Abstract Developing a novel cancer therapy is an expensive, time-consuming, high-risk endeavor that involves identifying a molecular target as well as target indications. This process could be accelerated by a comprehensive interrogation of driver variants and gene expression profiles across cancer types. The Atlas of Blood Cancer Genomes (ABCG) project was initiated to elucidate the molecular basis of all leukemias and lymphomas, building on advances in genomic technologies, our capabilities for data analysis, and economies of scale. The ABCG project includes collaborators from 25 institutions worldwide who contributed samples from 10,512 patients comprising every type of blood cancer in the World Health Organization classifications. All cases were de-identified and their associated pathology and clinical information entered into a purpose-built web-based system. All cases underwent pathology and clinical data review by experienced hematopathologists and oncologists. Samples were subjected to whole exome DNA and RNA sequencing. We examined three classes of therapeutic targets with selected examples of application: 1. Surface markers: Surface markers are targets of many approved and experimental therapies in blood cancers (CAR-T cells, monoclonal and bispecific antibodies). We found that CD22, which has been evaluated as a target in diffuse large B-cell lymphoma (DLBCL), is also highly expressed in follicular lymphoma, adult ALL, mantle cell lymphoma, and high-grade B cell lymphoma, all areas of clinical need. We can evaluate the expression of virtually any marker or combination of markers across all blood cancers while noting areas of greatest clinical need within and across diseases, providing the basis to reclassify diseases by therapeutic target. 2. Genetic targets: Our work assesses the entire spectrum of genetic alterations including mutations and fusions. We found targetable alterations including BCR-ABL1 fusions, EZH2 Y641, IDH2 R140Q and BRAF V600E mutations in multiple cancers, albeit at low frequency, pointing to potential new indications for existing drugs in subsets of rare diseases. 3. Complex targets (immune or expression signatures or combinations of gene variants): Past work defined DLBCL immune and other signatures associated with response to avadomide, a novel cereblon inhibitor. We found that these signatures are also highly expressed in large subsets of peripheral T-cell lymphomas and acute myeloid leukemia, both areas of major unmet clinical need. Thus, we can interrogate immune and other signatures across the spectrum of cancers to uncover potential biomarkers of response. The ABCG project will enable the comprehensive study of genomic and clinicopathological features of all blood cancers. We anticipate that our data, approaches and results will provide a lasting resource for molecular classification and therapeutic development in all leukemias and lymphomas. Citation Format: Jennifer Shingleton, Raju Pillai, Sarah Ondrejka, Govind Bhagat, Amy Chadburn, Matthew McKinney, Jean Koff, Dina Soliman, Magdalena Czader, Abner Louissaint, Shaoying Li, Choon Kiat Ong, Amir Behdad, Andrew Evens, Yaso Natkunam, Mette Pedersen, Sirpa Leppa, Eric Tse, Jennifer Chapman, Catalina Amador-Ortiz, Yuri Fedoriw, Andrew Evans, Jiong Yan, Mina Xu, Kikkeri Naresh, Clay Parker, David Hsu, Sandeep Dave. The Atlas of Blood Cancer Genomes: A resource for therapeutic and biomarker development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3910.

Abstract 1356: The VISTA blocking antibody HMBD-002 promotes type-I interferon signaling and drives anti-tumor responses through macrophage reprograming and cytotoxic CD8+ T cell activation

Abstract VISTA, a predominantly myeloid immune checkpoint, promotes an immunosuppressive tumor microenvironment and has been associated with resistance to approved checkpoint therapies. While blockade of VISTA with antibodies has shown anti-tumor efficacy in preclinical models, the biological mechanisms that underlie this effect remain poorly understood. To investigate the mechanistic basis of anti-tumor responses, we performed single-cell RNA sequencing of tumor infiltrating leukocytes from the cell-derived murine colon carcinoma xenograft model, CT26, which is known to be sensitive to VISTA blockade. We used HMBD-002, a uniquely blocking but non-depleting clinical-stage IgG4 anti-VISTA antibody, to identify the key immune cells and pathways impacted by VISTA blockade in the absence of Fc-mediated cell depletion. The translatability of these findings was validated in a human PBMC mixed leukocyte reaction assay. Subsequently, targeted depletion or inhibition of the identified immune populations and pathways was performed to confirm their contribution to the anti-tumor efficacy of HMBD-002.The blockade of VISTA by HMBD-002 significantly increased CD8+ T cells in the CT26 tumors, promoting an activated cytotoxic Tc1 program without inducing exhaustion. Concurrently, a substantial increase in proinflammatory M1 tumor-associated macrophages (TAMs) was noted within treated tumors, while other immune cell populations remained unaffected. Among the signaling pathways, the type-I interferon (IFN) response exhibited a significant upregulation, particularly in TAMs, indicating a type-I IFN-driven M1 reprogramming by HMBD-002. Validation experiments further demonstrated that the depletion of TAMs or CD8+ T cells, but not CD4+ T cells, abrogated the efficacy of HMBD-002. Moreover, blocking the type-I IFN signaling effectively impeded HMBD-002-induced TAM reprogramming and subsequent anti-tumor efficacy, thus confirming the pivotal roles of CD8+ T cells, TAMs, and type-I IFN signaling in driving the anti-tumor response to VISTA blockade. In conclusion, VISTA blockade with HMBD-002 promotes an anti-tumor response by type-I IFN mediated reprogramming of TAMs and activation of cytotoxic CD8+ T cells. Citation Format: Bhushan Dharmadhikari, Olga Zharkova, Dipti Thakkar, Roberto Tirado-Magallanes, Konrad Paszkiewicz, Piers J. Ingram, Jerome D. Boyd-Kirkup. The VISTA blocking antibody HMBD-002 promotes type-I interferon signaling and drives anti-tumor responses through macrophage reprograming and cytotoxic CD8+ T cell activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1356.

Abstract 2730: Beyond antibodies and CAR-T: Topologically-engineered, super-dimeric antibody-like molecules with dual Fc domains for trispecific, bivalent targeting of CD19, CD20, and Fcgamma receptors

Abstract Background: Depletion of B cells has resulted in major therapeutic benefits in autoimmune diseases and hematological malignancies. Several FDA-approved B cell-depleting antibody-based therapies are available, including antibody-drug conjugates, T cell engagers, CAR-T cells, and antibody variants with enhanced effector functions through Fc engineering. However, a significant unmet need remains in both oncology and autoimmune disease. All currently approved B cell-depleting therapies target a single B cell antigen, increasing potential for incomplete depletion and emergence of escape mutants that give rise to relapse and treatment failure. Methods: Here we describe trispecific antibody-like molecules generated using GEM-DIMER technology. In addition to bivalent target binding of both CD19 and CD20, the GEM-DIMER candidates are designed to have two Fc domains to enable powerful effector functions via cooperative binding of Fcgamma receptors. The approach is based on incorporation of a super-dimerization domain into the hinge region of an immunoglobulin heavy chain, enabling the combination of all of the components of two IgG antibodies into a single molecule. Using this approach, we generated GEM-DIMER candidates from rituximab and FMC63, the parental anti-CD19 antibody for anti-CD19 scFv used in approved CAR-T cell therapies. Results: CD19/CD20-targeting GEM-DIMER molecules demonstrated binding to both CD19 and CD20 with affinities comparable to the individual parent antibodies. Importantly, CD19/CD20-targeting GEM-DIMER molecules demonstrated robust depletion of human B cells in overnight cultures of whole blood. Moreover, antibody-dependent cellular cytotoxicity (ADCC) was demonstrated in co-cultures of the human B cell lymphoma cell line Raji and human peripheral blood mononuclear cells (PBMC). As expected, due to the presence of dual Fc domains, CD19/CD20-targeting GEM-DIMER molecules exhibited enhanced binding to Fcgamma receptors, further explaining the robust effector functions observed. Conclusions: CD19/CD20-targeting GEM-DIMER molecules are promising candidates to provide efficient depletion of both CD19+ and CD20+ cells, providing potential for broad and deep depletion of B cells with reduced risk of emergence of antigen escape variants. These data support the advancement of CD19/CD20-targeting GEM-DIMER molecules in multiple indications where depletion of CD19+ and/or CD20+ B cells is needed. Preparations for clinical investigation are ongoing. Citation Format: Daniel J. Capon, Nelson L. Chan, Larisa Troitskaya, Marina Fomin, Ursula Edman, Brendon Frank, Benjamin Z. Capon, Brian Law, Steven J. Chapin, Gavin M. Lewis, Malcolm L. Gefter, Juha Punnonen. Beyond antibodies and CAR-T: Topologically-engineered, super-dimeric antibody-like molecules with dual Fc domains for trispecific, bivalent targeting of CD19, CD20, and Fcgamma receptors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2730.

Abstract 2652: NDI-101150 is a potent and highly selective HPK1 inhibitor that both synergizes with and differentiates from anti-PD1 immune checkpoint blockade

Abstract Introduction HPK1 is a member of the MAP4K family of protein serine/threonine kinases that negatively regulates activation signals in multiple immune cells and is an attractive therapeutic target for many cancers. Using structure-based drug design, we developed a highly selective HPK1 inhibitor, NDI-101150, with nanomolar potency and physiochemical properties suitable for once daily oral administration. Methods & Results HPK1 inhibition with NDI-101150 has a differentiated pharmacology profile when compared directly to PD1 blockade. NDI-101150 was able to overcome the immunosuppressive effects of prostaglandin E2, adenosine, and TGF-β on human T cell activation. HPK1 inhibition also directly limited the suppressive capacity of T regulatory cells. In contrast, anti-PD1 treatment was not able to overcome the immunosuppressive activity associated with any of these mechanisms. In vivo, HPK1 inhibition significantly enhanced the production of antigen-specific antibodies in response to immunization with both T-dependent and T-independent antigens, while anti-PD1 treatment had minimal to no effects on antibody production. In the EMT-6 syngeneic model, 7/10 mice receiving NDI-101150 exhibited complete tumor regressions, compared to only 1/10 from an anti-PD1 cohort. Furthermore, NDI-101150 established a robust and durable immune memory response as 100% of treated mice showed complete rejection of tumor growth upon subsequent re-challenge. HPK1 inhibition with NDI-101150 also shows robust synergy with PD1 blockade in vitro and in vivo. Both NDI-101150 and anti-PD1 were able to reinvigorate exhausted human T cells, restoring cytokine production and proliferative effects in mixed lymphocyte reactions. Further, in combination HPK1 inhibition and PD1 blockade synergized to enhance the activity of exhausted human T cells to an extent exceeding that observed with naïve human T cells in similar experiments. In vivo, while NDI-101150 or anti-PD1 treatments alone induced tumor growth inhibition in the murine CT-26 syngeneic tumor model, NDI-101150 and anti-PD1 in combination mediated complete tumor regressions in several mice. Furthermore, NDI-101150 seemed to induce a durable immune memory response as evidenced by the combination-treated animals showing complete rejection of tumor growth upon subsequent re-challenge, without any further dosing of NDI-101150. Conclusions Pharmacological inhibition of HPK1 with NDI-101150 represents a powerful system-wide immunomodulatory approach with the potential to enhance anti-tumor immunity in patients failing to respond to currently approved immune checkpoint therapies or in combination with immune checkpoint blockade therapies. NDI-101150 is currently being tested in a Phase 1/2 trial (NCT05128487) in patients with advanced solid tumors. Citation Format: David Ciccone, Fu-Shan Kuo, Scott Daigle, Neelu Kaila, Gene Yau, Mark Carlson, Denise Levasseur, Bhaskar Srivastava, Frank G. Basile, Christine Loh. NDI-101150 is a potent and highly selective HPK1 inhibitor that both synergizes with and differentiates from anti-PD1 immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2652.

Abstract 6573: Targeting DLK1, a Notch ligand, with an antibody-drug conjugate in adrenocortical carcinoma

Abstract Adrenocortical carcinoma (ACC) is an aggressive and rare endocrine malignancy with poor prognosis. First-line therapy (adrenolytic agent mitotane in combination with chemotherapy) for recurrent and metastatic ACC has limited efficacy and there are no approved second-line therapies. Antibody-drug conjugates (ADCs) are an emerging immunotherapeutic class in which a cytotoxic payload is directed to tumor cells via antibodies to cell surface proteins. As Notch ligands, such as DLL3, are ADC targets in neuroendocrine cancers, we screened for expression of Notch ligands in ACC. Among Notch ligands (DLL1, DLL3, DLK1, JAG1, JAG2), DLK1 (delta-like non-canonical Notch ligand 1) was the most highly expressed. Moreover, ACC had the near highest expression of DLK1 across all TCGA tumors likely because this ligand is of adrenal origin (with limited expression in other normal tissues apart from the pituitary gland and ovaries). By immunohistochemistry, we verified DLK1 to be expressed, at variable levels, in 97% of ACC tumors (n=30/31). We then tested a DLK1-directed antibody-drug conjugate (ADCT-701; DLK1-PBD), consisting of a humanized anti-DLK1 monoclonal antibody coupled to DNA damaging pyrrolobenzodiazepine (PBD) dimers (SG3199; drug-to-antibody ratio~1.8) via a cleavable linker in ACC pre-clinical models. ADCT-701 exhibited potent, nanomolar cytotoxicity in DLK1-expressing ACC cell lines and ACC patient-derived short-term organoid cultures. ADCT-701 cytotoxicity was dependent on DLK1 expression as DLK1 knockout and DLK1 overexpression abrogated and facilitated cytotoxicity, respectively. Mechanistically, ADCT-701 induced cytotoxicity through DLK1 dependent receptor-mediated internalization and DNA damage (γH2AX) as well as apoptosis (annexin V/PI positive cells, cleaved PARP, and cleaved caspase-3). In vivo studies showed that ADCT-701 was highly effective against DLK1-positive ACC xenografts and PDX models with durable anti-tumor activity. Our pre-clinical data demonstrate DLK1 as an important therapeutic target in ACC and support an upcoming phase I clinical trial of ADCT-701 in patients with neuroendocrine tumors including ACC (NCT06041516). Citation Format: Nai-Yun Sun, Suresh Kumar, Amber Weiner, Yoo Sun Kim, Arnulfo Mendoza, Rosa Nguyen, Reona Okada, Yves Pommier, Dan Martinez, Jennifer Pogoriler, Sharon Diskin, John Maris, Jaydira Del Rivero, Nitin Roper. Targeting DLK1, a Notch ligand, with an antibody-drug conjugate in adrenocortical carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6573.

Abstract 7281: Targeting the YAP/TAZ-TEAD pathway with TEAD inhibitors synergizes with chemotherapy and blocks diffuse gastric cancer progression

Abstract Introduction: Diffuse gastric cancer (DGC) accounts for one third of gastric cancers and is associated with poor differentiation, discohesive growth, chemoresistance, and worse survival compared to intestinal-type tumors. DGC is typically genomically stable, and there are no approved DGC-targeted therapies. Recent studies have identified a potential tumor-promoting role for Yes-associated protein 1 and transcriptional coactivator with PDZ-binding motif (YAP/TAZ), which interact with TEAD transcription factors to regulate gene expression. Therefore, we evaluated the activity and mechanism of TEAD inhibitors in DGC preclinical models. Methods: Gastric cancer patient-derived organoids (PDOs) and cell lines were treated with TEAD inhibitors (K-975, VT103, VT104, VT107) and/or 5-fluorouracil (5-FU) for in vitro assays evaluating cell proliferation or invasion. Additional experiments were conducted to test the in vivo activity of TEAD inhibitors or shRNA-mediated knockdown of YAP in subcutaneous xenograft, orthotopic xenograft, and lung metastasis models using a genetically engineered mouse model of gastric cancer driven by oncogenic KrasG12D and loss of Trp53/Cdh1. Results: TEAD inhibitors K-975, VT103, VT104, and VT107 reduced proliferation, colony formation, and invasion in DGC cell lines and PDOs. We observed no effect of TEAD inhibitors on the viability of normal gastric organoids. Combining the TEAD1-selective inhibitor VT103 with 5-FU chemotherapy resulted in further reduction of DGC PDO viability relative to monotherapy, including in a PDO derived from a patient with locally advanced DGC that demonstrated intrinsic resistance to neoadjuvant chemotherapy. In flank tumors and orthotopic models, inhibition of the YAP/TAZ-TEAD pathway using YAP shRNA and VT103, either alone or in combination with 5-FU, abrogated primary tumor formation, with the strongest inhibition observed with combination treatment. Loss of YAP or VT103 treatment also significantly reduced lung metastasis after tail vein injection of mouse gastric cancer cells. We hypothesized that TEAD inhibition blocks an epithelial-to-mesenchymal transition (EMT) program and generation of cancer stem-like cells (CSCs). Consistent with this hypothesis, TEAD1 inhibition with VT103 or YAP knockdown reduced expression of the CSC marker CD44 in vitro and decreased expression of CD44 and the EMT marker Slug in tumor xenografts. Conclusions: The YAP/TAZ-TEAD pathway is an important driver of gastric cancer growth and metastasis, particularly in DGC where it may promote EMT and cancer stemness. TEAD inhibition reduces gastric cancer growth and invasion in vitro and in vivo in preclinical models and demonstrates synergistic activity with 5-FU chemotherapy. These results suggest a potential role for evaluating the efficacy of TEAD inhibitors in patients with DGC. Citation Format: Anastasiia Bulakhova, Jin Sun Cho, Jack T. Rifkin, Jaewon Kim, Thomas J. Ryan, Tracy T. Tang, Ryan H. Moy. Targeting the YAP/TAZ-TEAD pathway with TEAD inhibitors synergizes with chemotherapy and blocks diffuse gastric cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7281.

Abstract 6344: Engineering of ICAM-1 refractory antibodies for the development of therapeutic antibodies and antibody drug conjugates (ADCs) in ICAM-1 over-expressing cancers

Abstract Human cancers employ a number of mechanisms to evade host immune responses against novel antigens generated from aberrant over-expression, mutations and/or epigenetic alterations. Humoral immunity utilizes antibodies and immune-effector cells as well as molecular immune complexes involving the complement system to mediate the killing of dysregulated cancer cells. We refer to these anti-cancer mechanisms as Humoral Immuno-Oncology (HIO). HIO suppression is mediated by tumor-produced proteins called HIO factors. One such factor is CA125, which was previously shown to bind IgG-type antibodies and inhibit their immune-effector activities, including antibody dependent (ADCC) and complement dependent (CDC) cellular cytotoxicity. Using a combination of experimental screening and literature searches, a second protein produced by tumors and associated with a variety of cancer indications was discovered and found to be soluble ICAM-1 (sICAM-1). Through various functional studies we reported that sICAM-1 and membrane ICAM-1 (mICAM-1) are capable of binding IgG1-type antibodies that in turn inhibits their immune-effector activity. Through a combination of truncation and substitution mutagenesis, we identified a four amino acid motif within the CH3 domain of IgG1 essential for ICAM-1 binding, resulting in the inhibition of ADCC activity. While traditional glycine and alanine substitutions in this region abrogated ICAM-1 binding, these modifications caused tertiary structural changes in the Fc domain that resulted in loss of ADCC activity. Through a combinatorial amino acid substitution approach, we identified a four amino acid combination within the 407YSKL410 to 407FARV410 motif that resulted in antibodies refractory to sICAM-1 binding with robust ADCC activity. Additionally, isogenic wildtype and ICAM-1 knockdown target cell lines showed mICAM-1 inhibited target cell killing of a saporin antibody drug conjugate (ADC) and this was the direct result of mICAM-1 reducing antibody internalization, a requisite for maximal ADC target cell killing. The inhibitory activity of mICAM-1 could be overcome employing antibodies containing the 407FARV410 substitution. These findings highlight yet another mechanism by which tumors can suppress the host’s immune system for survival and offer new concepts for developing antibody-based therapies that can aid in the treatment of various cancer indications, especially those over-expressing ICAM-1. Moreover, the findings here offer diagnostic and therapeutic clinical design opportunities to improve upon existing approved immune-mediated therapies for which this factor is present. Citation Format: Brad Kline, Luigi Grasso, Nicolas Nicolaides. Engineering of ICAM-1 refractory antibodies for the development of therapeutic antibodies and antibody drug conjugates (ADCs) in ICAM-1 over-expressing cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6344.

Abstract 3599: Recombinant chimeric antibody-based gamma-delta TCR targeting GPC3 induces potent antitumor response against hepatocellular carcinoma

Abstract Background and Significance: Hepatocellular carcinoma (HCC), a major type of primary liver cancer, is the third leading cause of cancer-related death worldwide. While Glypican-3 (GPC3) is highly upregulated in HCC, it is minimally expressed in normal tissues. The research in our laboratory has been focused on the development of GPC3 as an immunotherapeutic target for liver cancer. Despite many clinical trials, there has not been any approved therapy targeting GPC3 largely due to the combination of antigen heterogeneity, poor tumor penetration, and the inability to induce a durable, potent immune response in the tumor microenvironment (TME). Here, we made a recombinant chimeric antibody-based T cell receptors (named AbTCR) targeting GPC3 and explored its anti-tumor efficacy in xenograft mouse models. Methods: The AbTCR constructs were built by fusing an antigen recognition domain (hYP7 scFv or HN3 VH) specific for GPC3 to the gamma-delta TCR constant region along with a secondary T cell signaling activation motif. The NFAT-tdTomato reporter cell line was established and used to measure the AbTCR-triggered T cell signaling upon stimulation with tumor cells. Anti-tumor efficacy of AbTCR-T cells was determined via luciferase-based cell killing assay as well as multiple HCC xenograft mouse models. Results: The hYP7 GPC3 AbTCR-T cell not only enhances antigen-binding capacity and T cell activity, but also induces infiltration and expansion of T cells in the TME, thereby causing robust liver tumor regression in mice. Conclusion: Our data show that new hYP7-directed GPC3 AbTCR is a promising strategy for treating liver cancer. This work provides a rationale for the use of hYP7 GPC3 AbTCR in clinical studies for treating HCC and other GPC3-positive solid tumors. Citation Format: Dan Li, Tianyuzhou Liang, Zhijian Duan, Hongbing Zhang, Cheng Liu, Mitchell Ho. Recombinant chimeric antibody-based gamma-delta TCR targeting GPC3 induces potent antitumor response against hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3599.

Abstract 3136: Towards development of a novel biparatopic trop2-ADC

Abstract Background: Trophoblast cell surface antigen 2 (TROP-2) is a member of Tumor-associated Calcium Signal Transducer family (TACSTD2), which is a 35kDa transmembrane protein with 4 N-linked glycosylation sites. The overexpression of TROP2 in various cancers is associated with poor prognosis and increased risk of metastasis. Anti-TROP2 antibody drug conjugates (ADCs) are emerging as an innovative therapeutic intervention for cancer treatment. While these efforts were rewarded by the FDA approval of Trodelvy (Sacituzumab govitecan), a Trop2 targeted ADC, in 2020 for the TNBC patients, tumor heterogeneity could present one of the limitations for the Trop2-targeting therapy, leading to drug resistance. Here, we report our effort in developing a novel biparatopic TROP2 ADC which demonstrate superior cell killing activity compared with the monospecific TROP2 ADC, including certain resistant cell lines for the approved therapy. Methods: Various biparatopic Abs were engineered using two different mAbs targeting the two non-overlapping epitopes of Trop2. The physical stability and biological activities were characterized. Binding competition assay was utilized for epitope binning using SPR. Cell binding affinity was determined using flow cytometry. Cellular internalization activity was measured using Incucyte system, and tumor cell killing efficacy was evaluated in multiple cancer cell lines. CDX mouse models were utilized to investigate the TROP2-ADC in vivo efficacy. Results: We identified a biparatopic TROP2 mAb using two monospecific TROP2 mAbs with A recognizing the same epitope as Trodelvy, and B binding to a non-overlapping epitope vs Sacituzumab’s. mAb-B demonstrates superior ability to recognize a few resistance cell lines to mAb-A. The biparatopic TROP2 mAb-A/B displays a KD of 0.81 nM protein binding compared with 6.42 nM and 0.26 nM, respectively for mAb-A and mAb-B. Importantly, the biparatopic mAb-A/B demonstrates significantly faster cellular internalization activity compared to those of the individual mAbs, signifying the biparatopic scaffold could drive receptor clustering and subsequently enhance the internalization, trafficking to the lysosome and degradation of the target. As expected, the ADC of the biparatopic mAb-A/B conjugated with a TOPi payload shows cancer cell killing efficacy in both in vitro and in vivo experiments. Furthermore, we tested mAb-A, -B and biparatopic mAb-A/B for their binding affinity to 14 missense mutations in TROP2 ECD expressed in HEK293 cells. Interestingly, mAb-A showed decreased binding in 5 mutant cell lines, while mAb-B and biparatopic mAb-A/B maintains activity. Conclusion: We have engineered a novel TROP2 biparatopic antibody with unique biological features as well as superior in vitro and in vivo activities. Such a biparatopic ADC presents its potential to be a best-in-class ADC therapy by overcoming the limitation of the monospecific ADC therapy such as drug resistance. Citation Format: Yinan Wu, Brittany Jiang, Julliet Rivera, Fang Wang, Jing Zhou, Lin Liu, Silvia Hudson, Will Draper, Jennifer Li, Xiaoshan Min, Hang Chen, Zhulun Wang. Towards development of a novel biparatopic trop2-ADC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3136.

Abstract 3306: RGT-M001, a first-in-class small molecule mRNA degrader of the oncogenic transcription factor c-Myb, demonstrated remarkable single agent anti-tumor efficacy in cancer patient-derived xenograft model

Abstract Dysregulated transcription factors (TFs) represent a unique class of drug targets that drive aberrant gene expression programs involved in the major hallmarks of cancers. However, developing drug-like small molecules targeting TF proteins for clinical purposes has proven to be extremely challenging. Here, we present a novel and innovative approach to degrade the RNA transcript of the master oncogenic transcription factor C-MYB, thereby preventing its undesirable expression, using potent and orally available small molecules. C-MYB is a transcription factor that regulates differentiation and proliferation programs in normal cells, including hematopoietic, stem and epithelial cells. In numerous cancer types, such as adenoid cystic carcinoma (ACC), leukemia, colorectal cancer, and breast cancer, C-MYB is a well-established oncogenic transcription factor, overactivated via different mechanisms, including chromosomal translocations and gene amplification. Here, we leveraged our integrative RNA-targeting platform to identify and validate actionable cryptic exon target sites in the human C-MYB gene. We identified RGT-M001, a potent small molecule that can selectively induce the inclusion of the cryptic exon into the final C-MYB transcripts, resulting in a robust decrease of C-MYB canonical transcripts and C-MYB protein in cells. In a functional assay, we demonstrated that RGT-M001 has potent cell-killing activity against a large panel of cancer cell lines overexpressing C-MYB (EC50 ~ 20 - 300nM), while sparing normal cells. To confirm RGT-M001's on-target effect, we demonstrated a robust correlation between RGT-M001 cell-killing activity and the knockdown of C-MYB RNA and protein. We further investigated the anti-tumor activity of RGT-M001 in an ACC patient-derived xenograft (PDx) mouse model harboring C-MYB-NFBI fusion. Recurrent or metastatic ACC is a malignant neoplasm of predominantly salivary gland origin for which effective approved therapies are lacking; the best reported ORR being 15.6% for lenvatinib. As a single agent, RGT-M001 reduced in vivo C-MYB transcript levels by >80% at peak drug exposure and induced a remarkable tumor growth inhibition response (~70% TGI) in the ACCX11 PDx mouse model, surpassing the therapeutic benchmark Lenvatinib (40% TGI). Importantly, the RGT-M001 regimen was well tolerated. Finally, we showed that the combination of RGT-M001 with the Notch Inhibitor AL-101 resulted in complete inhibition of tumor growth. In conclusion, these data demonstrate that small molecules targeting RNA are a safe and effective approach to address previously undruggable protein targets. Down-regulation of C-MYB by our RNA-targeting small molecules is an attractive therapeutic strategy to treat ACC and other cancers driven by C-MYB dysregulations. Citation Format: Norman Lu, Patricia Soulard, Kay Li, Heather Sadlish, Chris Yates, Xiubin Gu, Ibrahim Kays, Jae Lee, Sam Hasson, Zhiping Weng, Simon Xi, Travis Wager. RGT-M001, a first-in-class small molecule mRNA degrader of the oncogenic transcription factor c-Myb, demonstrated remarkable single agent anti-tumor efficacy in cancer patient-derived xenograft model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3306.

Deucrictibant for angioedema due to acquired C1-inhibitor deficiency: A randomized-controlled trial

BackgroundAngioedema due to acquired C1-inhibitor deficiency is a very rare but serious disease, with an estimated prevalence of 1 per 500,000 persons. There are no approved therapies to treat or prevent angioedema swellings in patients with this condition. Deucrictibant is a specific, orally bioavailable, competitive antagonist of the bradykinin B2 receptor currently under investigation for hereditary angioedema. ObjectiveTo assess the efficacy and safety of deucrictibant as acute and prophylactic treatment for angioedema due to acquired C1-inhibitor deficiency. MethodsA two-part, randomized, double-blind, placebo-controlled crossover study was conducted. In Part 1, four consecutive angioedema attacks were treated with three doses of deucrictibant (10 mg, 20 mg, and 30 mg) or placebo. In Part 2, deucricibant 20 mg or placebo was administered bidaily for two treatment periods of eight weeks. ResultsThree patients were enrolled of which one completed both study parts and two completed only Part 2. In Part 1, a reduction in attack severity was observed in the three attacks treated with deucrictibant as opposed to an increase in severity of the attack treated with placebo. In Part 2, the individual mean monthly attack rates were 2.0, 0.6 and 1.0 during the placebo period and 0.0 across all patients during treatment with deucrictibant. There were no severe adverse events, and one self-limiting treatment-emergent adverse event (abdominal pain). ConclusionsDeucrictibant has the potential to effectively and safely treat and prevent angioedema attacks due to acquired C1-inhibitor deficiency.

Human norovirus cultivation systems and their use in antiviral research.

Human norovirus (HuNoV) is a major cause of acute gastroenteritis and foodborne diseases, affecting all age groups. Despite its clinical needs, no approved antiviral therapies are available. Since the discovery of HuNoV in 1972, studies on anti-norovirals, mechanism of HuNoV infection, viral inactivation, etc., have been hampered by the lack of a robust laboratory-based cultivation system for HuNoV. A recent breakthrough in the development of HuNoV cultivation systems has opened opportunities for researchers to investigate HuNoV biology in the context of de novo HuNoV infections. A tissue stem cell-derived human intestinal organoid/enteroid (HIO) culture system is one of those that supports HuNoV replication reproducibly and, to our knowledge, is most widely distributed to laboratories worldwide to study HuNoV and develop therapeutic strategies. This review summarizes recently developed HuNoV cultivation systems, including HIO, and their use in antiviral studies.

Hyperbaric Oxygen‐Facilitated Cancer Treatment: A Minireview

Hypoxia in malignant tumors is a major factor in inducing the failure of clinical cancer treatment. Although several strategies have been developed to relieve hypoxia, most are still in the preclinical research phase. Therefore, hyperbaric oxygen (HBO), an approved adjuvant therapy for alleviating hypoxia clinically, is an excellent choice for enhancing the efficacy of cancer treatment that is impeded by tumor hypoxia. In this minireview, recent advances in HBO‐facilitated cancer treatment, including clinical applications and nanomedicine‐mediated cancer therapy are introduced. At the end of this minireview, the potential challenges faced by HBO therapy before clinical use are discussed. It is hoped that this review will provide a reference for future clinical research on the application of HBO in cancer treatment.

The effect of Omega-3 fatty acid fish oil and seed oilon the prevention of Alzheimers disease

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are known to reduce cognitive degeneration and potentially prevent Alzheimers disease (AD). Unfortunately, while preventive measures like dietary therapy exist, there are few approved clinical healing therapies for AD. This study aims to investigate the effects of seed oil and fish oil separately in preventing Alzheimers disease. We conducted a systematic literature search to find experimental trials based on animal models and human observational studies examining the relationship between Alzheimers disease and oil supplements rich in n-3 PUFA. The study uses meta-analysis, t-tests, and regression analysis to determine the significance of each type of oil in regulating Alzheimers diseases development. The results suggest that seed oil may help prevent AD by slowing cognitive deterioration, whereas fish oil may not. Overall, omega-3 fatty acids may serve as potential dietary supplements for improving memory and preventing Alzheimers disease.

Multiple treatments with human embryonic stem cell-derived mesenchymal progenitor cells preserved the fertility and ovarian function of perimenopausal mice undergoing natural aging

ObjectivesCurrently, no approved stem cell-based therapies for preserving ovarian function during aging. To solve this problem, we developed a long-term treatment for human embryonic stem cell-derived mesenchymal progenitor cells (hESC-MPCs). We investigated whether the cells retained their ability to resist ovarian aging, which leads to delayed reproductive senescence.Materials and methodsIn a middle-aged female model undergoing natural aging, we analyzed whether hESC-MPCs benefit the long-term maintenance of reproductive fecundity and ovarian reservoirs and how their transplantation regulates ovarian function.ResultsThe number of primordial follicles and mice with regular estrous cycles were increased in perimenopausal mice who underwent multiple introductions of hESC-MPCs compared to age-matched controls. The estradiol levels in the hESC-MPCs group were restored to those in the young and adult groups. Embryonic development and live birth rates were higher in the hESC-MPC group than in the control group, suggesting that hESC-MPCs delayed ovarian senescence. In addition to their direct effects on the ovary, multiple-treatments with hESC-MPCs reduced ovarian fibrosis by downregulating inflammation and fibrosis-related genes via the suppression of myeloid-derived suppressor cells (MDSCs) produced in the bone marrow.ConclusionsMultiple introductions of hESC-MPCs could be a useful approach to prevent female reproductive senescence and that these cells are promising sources for cell therapy to postpone the ovarian aging and retain fecundity in perimenopausal women.

The microbiota-gut-brain axisin Huntington's disease: pathogenic mechanisms and therapeutic targets.

Huntington's disease (HD) is a currently incurable neurogenerative disorder and is typically characterized by progressive movement disorder (including chorea), cognitive deficits (culminating in dementia), psychiatric abnormalities (the most common of which is depression), and peripheral symptoms (including gastrointestinal dysfunction). There are currently no approved disease-modifying therapies available for HD, with death usually occurring approximately 10-25 years after onset, but some therapies hold promising potential. HD subjects are often burdened by chronic diarrhea, constipation, esophageal and gastric inflammation, and a susceptibility to diabetes. Our understanding of the microbiota-gut-brain axis in HD is in its infancy and growing evidence from preclinical and clinical studies suggests a role of gut microbial population imbalance (gut dysbiosis) in HD pathophysiology. The gut and the brain can communicate through the enteric nervous system, immune system, vagus nerve, and microbiota-derived-metabolites including short-chain fatty acids, bile acids, and branched-chain amino acids. This review summarizes supporting evidence demonstrating the alterations in bacterial and fungal composition that may be associated with HD. We focus on mechanisms through which gut dysbiosis may compromise brain and gut health, thus triggering neuroinflammatory responses, and further highlight outcomes of attempts to modulate the gut microbiota as promising therapeutic strategies for HD. Ultimately, we discuss the dearth of data and the need for more longitudinal and translational studies in this nascent field. We suggest future directions to improve our understanding of the association between gut microbes and the pathogenesis of HD, and other 'brain and body disorders'.

Cloning and phylogenetic analysis of N protein gene from Rift Valley Fever Virus (RVFV).

Rift Valley Fever (RVF) is a mosquito-borne viral zoonosis caused by RVFV in humans and livestock. Currently, there are no approved vaccines or antiviral therapies available. Additionally, in Saudi Arabia, there is a lack of a routine screening system to monitor RVFV in humans and animals which hinders to design and develop the preventive measures as well as the prediction of future outbreaks and the potential re-emergence of RVFV. Hence, we have performed the cloning, sequencing, and phylogenetic analysis, of nucleocapsid (N) protein gene. The sequence analysis showed high similarities with RVFV isolates reported from humans and animals. The highest similarity (99.5%) was observed with an isolate from Saudi Arabia (KU978775-Human) followed by 99.1% with four RVFV isolates (Human and Bovine) from other locations. A total of 51 nucleotides and 31 amino acid variations were observed throughout the N protein gene sequences. The phylogenetic relationship formed closed clusters with other isolates collected from Saudi Arabia. Thus, we report of the cloning, sequencing, and phylogenetic analysis of the RVFV-N protein gene from Saudi Arabia.

CD38-Specific Gallium-68 Labeled Peptide Radiotracer Enables Pharmacodynamic Monitoring in Multiple Myeloma with PET.

The limited availability of molecularly targeted low-molecular-weight imaging agents for monitoring multiple myeloma (MM)-targeted therapies has been a significant challenge in the field. In response, a first-in-class peptide-based radiotracer, [68Ga]Ga-AJ206, is developed that can be seamlessly integrated into the standard clinical workflow and is specifically designed to noninvasively quantify CD38 levels and pharmacodynamics by positron emission tomography (PET). A bicyclic peptide, AJ206, is synthesized and exhibits high affinity to CD38 (KD: 19.1 ± 0.99× 10-9 m) by surface plasmon resonance. Further, [68Ga]Ga-AJ206-PET shows high contrast within 60 min and suitable absorbed dose estimates for clinical use. Additionally, [68Ga]Ga-AJ206 detects CD38 expression in cell line-derived xenografts, patient-derived xenografts (PDXs), and disseminated disease models in a manner consistent with flow cytometry and immunohistochemistry findings. Moreover, [68Ga]Ga-AJ206-PET successfully quantifies CD38 pharmacodynamics in PDXs, revealing increased CD38 expression in the tumor following all-trans retinoic acid (ATRA) therapy. In conclusion, [68Ga]Ga-AJ206 exhibits the salient features required for clinical translation, providing CD38-specific high-contrast images in multiple models of MM. [68Ga]Ga-AJ206-PET could be useful for quantifying total CD38 levels and pharmacodynamics during therapy to evaluate approved and new therapies in MM and other diseases with CD38 involvement.

Molecular Profiling and the Impact of Treatment on Outcomes in Adenoid Cystic Carcinoma Type I and II.

Adenoid cystic carcinoma (ACC) is an uncommon salivary gland cancer with no approved therapies available to treat advanced, incurable disease. Recent molecular profiling efforts have identified two important subtypes: the more aggressive ACC-I is characterized by Notch pathway alterations and MYC amplification whereas ACC-II demonstrates a more indolent phenotype and TP63 overexpression. This retrospective observational cohort study involved de-identified samples from 438 patients with ACC with tumor samples sent for commercially-available molecular profiling (Caris Life Sciences). Next-generation whole-exome and whole-transcriptomic sequencing was performed on primary and metastatic samples. Immunostaining for PD-L1 and RNA deconvolution (quanTIseq) was used to explore the tumor immune microenvironment (TME). Real-world clinical and survival outcome metrics were extracted from insurance claims data. MYC expression was 1.61-fold higher (39.8 vs. 24.7; P < 0.0001) among NOTCH1-mutant ACC-I tumors, whereas MYB/L1 fusion rates were similar among ACC-I/II. The median B-cell fraction in the TME was higher among ACC-II (7.1% vs. 5.8%; P < 0.01), although infiltrating T cells subsets were low among either ACC subgroup (both <1%). When pooling systemic treatment categories, ACC-I patients had worse outcomes with available therapies (HR, 3.06; 95% confidence interval, 1.65-5.68; P < 0.01), with no significant difference in overall survival between ACC-I/II based on chemotherapy or VEGFR tyrosine kinase inhibitor exposure in smaller subsets. We confirmed the previously reported associations with MYC and TP63 in the prognostically relevant subgroups of ACC-I and -II, respectively, and report immunologic differences among these subtypes. Survival outcomes are comparatively worse in ACC-I regardless of treatment type.