Despite the success of immune checkpoint inhibitors in cancer, many patients do not respond or relapse following treatment. Therefore, new approaches to augment existing immunotherapies are needed. CRISPR screens have revealed the importance of TNF-α signal transduction mediators, such as TAK1, in facilitating tumor susceptibility to cytotoxic T cells. Here, we demonstrate that inhibition of TAK1 in tumor cells lowers the threshold for TNF-α-induced cytotoxicity. Upon TNF-α signaling, pharmacologic inhibition of TAK1 sensitized tumor cells to RIPK1-dependent apoptosis. However, RIPK1-independent apoptosis occurred upon genetic deletion of Tak1, suggesting a novel scaffolding function of TAK1 is required to induce RIPK1 kinase activity during cell death. Deleting Tak1 impaired in vivo tumor growth, enhanced α-PD-1 immunotherapy, and lead to durable anti-tumor memory, dependent on CD8 T cells and intact TNF-α signaling. Our results collectively demonstrate that compromising TAK1 function within tumor cells leverages the cytotoxic capacity of TNF to enhance anti-tumor immunity and generate deeper and more durable anti-tumor immune responses in preclinical models of cancer.

Overexpression of the antiapoptotic protein B-cell lymphoma-extra large (BCL-X-L) is associated with drug resistance and disease progression in numerous cancers. The compelling nature of this protein as a therapeutic target prompted efforts to develop selective small-molecule BCL-X-L inhibitors. Although efficacious in preclinical models, we report herein that selective BCL-X-L inhibitors cause severe mechanism-based cardiovascular toxicity in higher preclinical species. To overcome this liability, antibody-drug conjugates were constructed using altered BCL-X-L-targeting warheads, unique linker technologies, and therapeutic antibodies. The epidermal growth factor receptor-targeting antibody-drug conjugate AM1-15 inhibited growth of tumor xenografts and did not cause cardiovascular toxicity nor dose-limiting thrombocytopenia in monkeys. While an unprecedented BCL-X-L-mediated toxicity was uncovered in monkey kidneys upon repeat dosing of AM1-15, this toxicity was mitigated via further drug-linker modification to afford AM1-AAA (AM1-25). The AAA drug-linker has since been incorporated into mirzotamab clezutoclax, the first selective BCL-X-L-targeting agent to enter human clinical trials.

Introduction Identifying effective cancer drugs remains an inefficient process. Drug efficacy in traditional preclinical cancer models translates poorly into therapy in the clinic. Implementation of preclinical models that incorporate the tumor microenvironment (TME) is needed to improve selection of active drugs prior to clinical trials.Areas covered Progression of cancer results from the behavior of cancer cells in concert with the host's histopathological background. Nonetheless, complex preclinical models with a relevant microenvironment have yet to become an integral part of drug development. This review discusses existing models and provides a synopsis of active areas of cancer drug development where implementation would be of value. Their contribution to finding therapeutics in immune oncology, angiogenesis, regulated cell death and targeting tumor fibroblasts as well as optimization of drug delivery, combination therapy, and biomarkers of efficacy is considered.Expert opinion Complex tumor models in vitro (CTMIVs) that mimic the organotypic architecture of neoplastic tumors have boosted research into TME influence on traditional cytoreductive chemotherapy as well as the detection of specific TME targets. Despite advances in technical prowess, CTMIVs can only address specific aspects of cancer pathophysiology.

Amino Acid Sequence of AM-1 VH Region

qPCR primer sequences for Apopanel of BCL2 family members

Correlation of mRNA expression of BCL2 family members and sensitivity to venetoclax or navitoclax in HMCLs

Introduction: Glucocorticoids are key components of standard-of-care treatment regimens (e.g., R-CHOP, Hyper-CVAD) for several B-cell malignancies. However, prolonged systemic glucocorticoid treatment results in glucocorticoid-associated adverse events and acquired resistance that limit its therapeutic potential. ABBV-319 is a novel CD19-targeting ADC engineered to reduce glucocorticoid-associated toxicity observed with systemic glucocorticoids while possessing three distinct mechanisms of action (MoA) to increase efficacy: 1) antibody-mediated delivery of GRM to activate glucocorticoid receptor (GR) induced cell death in cancer cells, 2) inhibition of CD19 signaling, and 3) enhanced Fc-mediated cancer cell killing via afucosylation of the antibody backbone. Results: We identified a GRM agonist that is 15 and 150 times more potent at driving GR transcriptional activation and cell death compared to clinical glucocorticoids dexamethasone and prednisolone, respectively. The conjugation of GRM agonist as the payload on ABBV-319 enables potent GRM-driven anti-cancer activity against malignant B-cell lines in vitro as well as in cell-line and patient derived xenograft (CDX and PDX) models in vivo. Remarkably, a single-dose of ABBV-319 induced sustained tumor regression and enhanced anti-tumor activity compared to repeat dosing of systemic glucocorticoids (e.g., prednisolone) at its maximum tolerated dose in mice. The CD19 monoclonal antibody (mAb) also reduced proliferation of a subset of B-cell malignant cell lines through inhibition of the PI3K/AKT pathway. Moreover, afucosylation of the CD19 mAb in ABBV-319 enhanced Fc-mediated antibody-dependent cellular cytotoxicity (ADCC), and this activity was maintained after conjugation with GRM payloads. ABBV-319 bound similarly to both V158 (high-affinity) and F158 (low-affinity) FcγRIIIa allotypes and mediated potent ADCC in co-culture assays with human peripheral blood mononuclear cells (PBMCs). Notably, ABBV-319 displayed superior efficacy compared to afucosylated CD19 mAb in human CD34+ hematopoietic stem cell-engrafted NSG-Tg(Hu-IL15) mice, demonstrating that the three MoA (GR-driven cell death, CD19 signaling inhibition, and ADCC) collectively contribute to anti-tumor activity in vivo. ABBV-319 also displayed on-target depletion of normal human B-cells but did not affect peripheral NK cell counts in mice. Furthermore, CITE-seq profiling revealed that ABBV-319 treatment of human PBMCs activated GRM-induced signature genes restricted to B-cells, demonstrating the specificity of CD19-mediated delivery of GRM. Conclusion: ABBV-319 has potent anti-tumor activity from three distinct MoA and exhibits safety improvements compared to systemic glucocorticoids, supporting its recent progression into Phase I clinical trial. Citation Format: Chewei Anderson Chang, Ethan Emberley, Aloma L. D'Souza, Weilong Zhao, Cormac Cosgrove, Axel Hernandez Jr, Anatol Oleksijew, Paul Ellis, Luis Rodriguez, Gail Bukofzer, David Peetz, Wissam Assaily, Raghuveer Singh Mali, Wei Liu, Danqing Xu, Gregory K. Potts, Shaun McLoughlin, Kimberley McCarthy, Zhaomei Zhang, Jos Campbell, Isabella Sturdevant, Gloria Zhang, Tyler Curran, Jon D. Williams, Erwin Boghaert, Milan Bruncko, Christopher C. Marvin, Adrian Hobson, Michael Mcpherson, Tamar Uziel, Marybeth Pysz, Xi Zhao, Alex Bankovich, Kevin J. Freise, Susan Morgan-Lappe, James W. Purcell. Preclinical development of ABBV-319: a CD19-targeting glucocorticoid receptor modulator (GRM) agonist antibody-drug conjugate (ADC) for the treatment of B-cell malignancies. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6308.

Antibody-drug conjugate (ADC) technology is founded on the premise that antigen-mediated payload delivery selectively targets tumor cells and spares normal tissue. While approval of several ADCs has proven this to be a successful therapeutic approach, there remain opportunities to generate optimized ADCs with tailored selection of antigen matched with payload highly active in the target indication. To this end, ABBV-400 has been developed as an ADC that targets c-Met and topoisomerase-1 (Top1), both of which are overexpressed in solid tumors. The antibody is directed to the cell surface tyrosine kinase receptor, c-Met, a key driver of tumor cell growth and development of resistance to EGFR-targeted and other targeted therapeutics. Supporting this, Teliso-V, a c-Met-targeted ADC with MMAE payload, has been granted Breakthrough Therapy Designation in non-small cell lung cancer (NSCLC). To extend activity of a c-Met-targeted ADC to patients with tumors expressing lower c-Met levels and to indications, such as colorectal cancer (CRC), where MMAE-based ADCs have not been effective, a novel topoisomerase-1 inhibitor linker-drug was developed. Screening over 400 linker-drugs identified a unique, potent Top1 inhibitor with a cleavable valine-alanine linker and stable bromoacetamide attachment designed to minimize systemic payload release. Preclinically ABBV-400 exhibits favorable pharmacokinetics, anti-proliferative activity in vitro, and compelling efficacy in NSCLC, gastroesophageal, and CRC xenograft models. Furthermore, ABBV-400 is well tolerated by cynomolgus monkeys with bone marrow and gastrointestinal tract toxicities common to other Top1 inhibitors. This pairing of a novel linker-drug and an antibody with demonstrated clinical activity provides an exciting opportunity to treat patients with c-Met expression in indications sensitive to Top1 inhibition. ABBV-400 has progressed through dose escalation, and dose expansion is currently ongoing in a Phase 1 FIH clinical study (NCT05029882). All authors were employees of AbbVie during this research. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication Citation Format: Regina M. Reilly, Cheng Ji, Ryan P. Matuszak, Mark G. Anderson, Lora Tucker, Nadezda Klunder, Adelyn L. Lazo, Erwin R. Boghaert, Marybeth A. Pysz, Aloma D’Souza, Laura Kreckler, Milan Bruncko, Brittney J. Mills, Matthew Ravn, George Doherty, Kevin J. Freise, Andrew C. Phillips. ABBV-400: An ADC delivering a novel topoisomerase 1 inhibitor to c-Met-positive solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6311.

Abstract Antibody-drug conjugate (ADC) technology is founded on the premise that antigen-mediated payload delivery selectively targets tumor cells and spares normal tissue. While approval of several ADCs has proven this to be a successful therapeutic approach, there remain opportunities to generate optimized ADCs with tailored selection of antigen matched with payload highly active in the target indication. To this end, ABBV-400 has been developed as an ADC that targets c-Met and topoisomerase-1 (Top1), both of which are overexpressed in solid tumors. The antibody is directed to the cell surface tyrosine kinase receptor, c-Met, a key driver of tumor cell growth and development of resistance to EGFR-targeted and other targeted therapeutics. Supporting this, Teliso-V, a c-Met-targeted ADC with MMAE payload, has been granted Breakthrough Therapy Designation in non-small cell lung cancer (NSCLC). To extend activity of a c-Met-targeted ADC to patients with tumors expressing lower c-Met levels and to indications, such as colorectal cancer (CRC), where MMAE-based ADCs have not been effective, a novel topoisomerase-1 inhibitor linker-drug was developed. Screening over 400 linker-drugs identified a unique, potent Top1 inhibitor with a cleavable valine-alanine linker and stable bromoacetamide attachment designed to minimize systemic payload release. Preclinically ABBV-400 exhibits favorable pharmacokinetics, anti-proliferative activity in vitro, and compelling efficacy in NSCLC, gastroesophageal, and CRC xenograft models. Furthermore, ABBV-400 is well tolerated by cynomolgus monkeys with bone marrow and gastrointestinal tract toxicities common to other Top1 inhibitors. This pairing of a novel linker-drug and an antibody with demonstrated clinical activity provides an exciting opportunity to treat patients with c-Met expression in indications sensitive to Top1 inhibition. ABBV-400 has progressed through dose escalation, and dose expansion is currently ongoing in a Phase 1 FIH clinical study (NCT05029882). All authors were employees of AbbVie during this research. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication Citation Format: Regina M. Reilly, Cheng Ji, Ryan P. Matuszak, Mark G. Anderson, Lora Tucker, Nadezda Klunder, Adelyn L. Lazo, Erwin R. Boghaert, Marybeth A. Pysz, Aloma D’Souza, Laura Kreckler, Milan Bruncko, Brittney J. Mills, Matthew Ravn, George Doherty, Kevin J. Freise, Andrew C. Phillips. ABBV-400: An ADC delivering a novel topoisomerase 1 inhibitor to c-Met-positive solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6311.

Immunoblots of BCL-2, BCL-XL and MCL-1 in HMCL tumor xenografts

BCL2, BCL2L1 and MCL1 mRNA in CD138 primary MM patient samples and sensitivity to veneteclax ex vivo

Conceptual workflow for establishing BCL-2 family IHC cut-offs for analysis of MM patient tumor samples

Table S1: Mouse Strains Used for Xenograft Studies; Table S2: ABT-414 Growth Inhibition of Xenograft Tumors; Figure S1: Efficacy of ABT-414, ABT-806-vcMMAE, and unconjugated MMAE co-dosed with ABT-806 in U87MGde2-7 Tumor-Bearing Mice.

Legends for Tables S1 to S3 and Figures S1 to S5

BCL-2 and BCL-XL IHC correlates with qPCR and immunobot analysis of HMCLs

Antibody-drug conjugate (ADC) technology is founded on the premise that antigen-mediated payload delivery selectively targets tumor cells and spares normal tissue. While approval of several ADCs has proven this to be a successful therapeutic approach, there remain opportunities to generate optimized ADCs with tailored selection of antigen matched with payload highly active in the target indication. To this end, ABBV-400 has been developed as an ADC that targets c-Met and topoisomerase-1 (Top1), both of which are overexpressed in solid tumors. The antibody is directed to the cell surface tyrosine kinase receptor, c-Met, a key driver of tumor cell growth and development of resistance to EGFR-targeted and other targeted therapeutics. Supporting this, Teliso-V, a c-Met-targeted ADC with MMAE payload, has been granted Breakthrough Therapy Designation in non-small cell lung cancer (NSCLC). To extend activity of a c-Met-targeted ADC to patients with tumors expressing lower c-Met levels and to indications, such as colorectal cancer (CRC), where MMAE-based ADCs have not been effective, a novel topoisomerase-1 inhibitor linker-drug was developed. Screening over 400 linker-drugs identified a unique, potent Top1 inhibitor with a cleavable valine-alanine linker and stable bromoacetamide attachment designed to minimize systemic payload release. Preclinically ABBV-400 exhibits favorable pharmacokinetics, anti-proliferative activity in vitro, and compelling efficacy in NSCLC, gastroesophageal, and CRC xenograft models. Furthermore, ABBV-400 is well tolerated by cynomolgus monkeys with bone marrow and gastrointestinal tract toxicities common to other Top1 inhibitors. This pairing of a novel linker-drug and an antibody with demonstrated clinical activity provides an exciting opportunity to treat patients with c-Met expression in indications sensitive to Top1 inhibition. ABBV-400 has progressed through dose escalation, and dose expansion is currently ongoing in a Phase 1 FIH clinical study (NCT05029882). All authors were employees of AbbVie during this research. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication Citation Format: Regina M. Reilly, Cheng Ji, Ryan P. Matuszak, Mark G. Anderson, Lora Tucker, Nadezda Klunder, Adelyn L. Lazo, Erwin R. Boghaert, Marybeth A. Pysz, Aloma D’Souza, Laura Kreckler, Milan Bruncko, Brittney J. Mills, Matthew Ravn, George Doherty, Kevin J. Freise, Andrew C. Phillips. ABBV-400: An ADC delivering a novel topoisomerase 1 inhibitor to c-Met-positive solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6311.

In vivo Efficacy of ABBV-321 tumor targeting.

Caspase-dependent degradation of MCL-1 in NCI-H929 HMCL following treatment with bortezomib treatment