Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive subtype of prostate cancer (PC) without curative treatments. Antibody-drug conjugates (ADCs) emerged as promising cancer therapeutics that selectively deliver cytotoxic agents (payloads) to the tumors. Although ADCs have been successfully applied in the treatment of hematological and solid tumors, ADC monotherapy has not demonstrated durable responses in mCRPC, and the mechanisms of PC resistance to ADCs have not been thoroughly investigated. Our study aimed to improve ADC efficacy using a new integrated approach for the custom ADC design and multiplexing. To nominate rational combinations of ADC targets and ADC payloads, we (1) examined protein co-expression of three clinically relevant surface antigens - B7 homolog 3 (B7-H3), prostate specific membrane antigen (PSMA), and six-transmembrane epithelial antigen of prostate-1 (STEAP1) - in a series of human mCRPCs, and (2) screened established ADC payloads and their combinations in mCRPC cell lines with different molecular backgrounds. Identified synergistic interactions between DNA-damaging payloads and BCL-XL inhibitor A-1331852 as well as their coordinated induction of intrinsic apoptosis pathway were evaluated in a panel of PC cell lines. Functional relevance between isolated p53 loss and PC responses to three genotoxic ADCs - B7-H3 - seco-DUBA (vobramitamab duocarmazine), PSMA - SG3249, and STEAP1 – DXd and their combinations with A-1331852 was established using genetic knockout models. Lastly, enhanced in vivo antitumor activity of vobramitamab duocarmazine by systemic A-1331852 was shown. Collectively, our findings provide rationale for the development of ADC therapies combining genotoxic payloads with BCL-XL inhibitors for mCRPC.
Galina Semenova, Sander B. Frank, Ruth Dumpit, Wanting Han, Ilsa Coleman, Roman Gulati, Canan D. Dirican, Tarana Arman, Jessica Maruwan, Colm Morrissey, Michael C. Haffner, Peter S. Nelson, John K. Lee
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.