Posted: Monday, November 14, 2022
Mark N. Stein, MD, of Columbia University Irving Medical Center, New York, and colleagues aim to evaluate vudalimab—a PD-1/CTLA-4 bispecific antibody—plus chemotherapy or targeted therapy in patients with metastatic castration-resistant prostate cancer. Since enrollment is still underway, preliminary safety and activity data were presented during the 2022 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 668). The investigators reported that the combination regimen demonstrated clinical activity in a small number of patients, with reductions in prostate-specific antigen (PSA) levels of more than 50% from baseline in three of nine treated patients. Tolerability necessitated the deintensification of the chemotherapy regimen while maintaining the study dose of vudalimab (10 mg/kg administered every 2 weeks).
This phase II study aims to enroll patients with metastatic castration-resistant prostate cancer whose disease progressed following treatment with two prior therapy lines. Participants are being stratified based on the following metastatic states: aggressive variant (cohort 1); homologous recombination–deficient or CDK12 mutation–positive PARP inhibitor progressor (cohort 2); PARP inhibitor–naïve (cohort 3); microsatellite instability–high or mismatch-repair–deficient (cohort 4); and no targetable mutation (cohort 5).
Patient in cohorts 1, 2, and 5 (n = 20 each) will receive intravenous vudalimab every 2 weeks plus either carboplatin/cabazitaxel or docetaxel every 3 weeks. Individuals in cohort 3 (n = 20) will be administered vudalimab every 2 weeks plus olaparib twice a day, and those in cohort 4 (n = 5) will receive vudalimab alone.
Of the preliminary findings reported thus far, a patient in cohort E with an 89% reduction in PSA level from baseline had a partial response at week 18 and was continuing treatment at 35 weeks. In addition, treatment was continuing for one additional patient in cohort C, at 4 weeks
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