KEYNOTE-365 cohort A updated results: Pembrolizumab (pembro) plus olaparib in docetaxel-pretreated patients (pts) with metastatic castration-resistant prostate cancer (mCRPC).
Evan Y. Yu, Josep M. Piulats, Gwénaëlle Gravis, Brigitte Laguerre, Jóse Ángel Arranz Arija, Stéphane Oudard, Peter C.C. Fong, Michael Kolinsky, Marinela Augustin, Susan Feyerabend, Audrey E. Kam, Howard Gurney, Ali Tafreshi, Margitta Retz, William R. Berry, Nataliya Mar, Helen Wu, Charles Schloss, Christian Poehlein, Johann S. de Bono
Abstract
100 Background: KEYNOTE-365 (NCT02861573) is a phase 1b/2 study evaluating pembro + other agents in mCRPC. Updated results from cohort A (pembro + olaparib) are reported. Methods: Docetaxel-pretreated, molecularly unselected pts with mCRPC with progression within 6 mo of screening per PSA or radiologic bone/soft tissue progression enrolled. Pts may have received 1 other chemotherapy and ≤2 2nd-generation hormone therapy (HT). Pts received pembro 200 mg IV Q3W + olaparib 400 mg PO BID. Primary end points: safety, PSA response rate (confirmed PSA decline ≥50%), and ORR per blinded independent central review. Results: Of 84 treated pts, 42 discontinued, primarily due to progression (n=29). Median age was 71 y (range, 47-83); 26% were PD-L1+, 26% had visceral disease, and 57% had RECIST-measurable disease. Median follow-up was 3 mo for all pts (n=81) and 14 mo for pts with ≥27 wks’ follow-up (n=41). See Table for efficacy outcomes. Treatment-related AEs occurred in 70 (83%) pts. Most frequent (≥30%) were nausea (33%) and anemia (31%). Grade 3-5 treatment-related AEs occurred in 29 (35%) pts. Three pts died of AEs (2 treatment related [l myocardial infarction, 1 unknown cause]). Conclusions: With additional follow-up, pembro + olaparib continued to show activity in docetaxel-pretreated, molecularly unselected pts who previously received HT for mCRPC. Safety of the combination was consistent with individual profiles of each agent. Clinical trial information: NCT02861573. [Table: see text]