PD16-12 PEMBROLIZUMAB PLUS ENZALUTAMIDE IN ABIRATERONE-PRETREATED PATIENTS WITH METASTATIC CASTRATION-RESISTANT PROSTATE CANCER: UPDATED RESULTS FROM KEYNOTE-365 COHORT C

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You have accessJournal of UrologyProstate Cancer: Advanced (including Drug Therapy) II (PD16)1 Apr 2020PD16-12 PEMBROLIZUMAB PLUS ENZALUTAMIDE IN ABIRATERONE-PRETREATED PATIENTS WITH METASTATIC CASTRATION-RESISTANT PROSTATE CANCER: UPDATED RESULTS FROM KEYNOTE-365 COHORT C Evan Y. Yu*, Peter Fong, Josep M. Piulats, Leonard Appleman, Henry Conter, Susan Feyerabend, Neal Shore, Gwenaelle Gravis, Brigitte Laguerre, Howard Gurney, Margitta Retz, Emanuela Romano, Loic Mourey, Johann S. de Bono, Audrey Kam, Urban Emmenegger, Helen Wu, Christian Poehlein, and William Berry Evan Y. Yu*Evan Y. Yu* More articles by this author , Peter FongPeter Fong More articles by this author , Josep M. PiulatsJosep M. Piulats More articles by this author , Leonard ApplemanLeonard Appleman More articles by this author , Henry ConterHenry Conter More articles by this author , Susan FeyerabendSusan Feyerabend More articles by this author , Neal ShoreNeal Shore More articles by this author , Gwenaelle GravisGwenaelle Gravis More articles by this author , Brigitte LaguerreBrigitte Laguerre More articles by this author , Howard GurneyHoward Gurney More articles by this author , Margitta RetzMargitta Retz More articles by this author , Emanuela RomanoEmanuela Romano More articles by this author , Loic MoureyLoic Mourey More articles by this author , Johann S. de BonoJohann S. de Bono More articles by this author , Audrey KamAudrey Kam More articles by this author , Urban EmmeneggerUrban Emmenegger More articles by this author , Helen WuHelen Wu More articles by this author , Christian PoehleinChristian Poehlein More articles by this author , and William BerryWilliam Berry More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000859.012AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The mechanisms of action of enzalutamide (enza) and pembrolizumab (pembro) may be synergistic in metastatic castration-resistant prostate cancer (mCRPC) and previous work has shown that some patients (pts) had durable response when pembro was added to enza. KEYNOTE-365 (NCT02861573) is a phase 1b/2 study to evaluate pembro in combination with other agents in mCRPC. A previous report of cohort C showed activity and acceptable safety with pembro + enza. Updated results from cohort C are reported. METHODS: Pts who did not respond or became intolerant to ≥4 weeks of abiraterone (abi) in the prechemotherapy mCRPC state and whose disease progressed within 6 months of screening per PSA progression or radiologic bone or soft tissue progression were enrolled. Pts received IV pembro 200 mg every 3 weeks with oral enza 160 mg/day. Primary end points were safety, PSA response rate (confirmed PSA decrease ≥50%), and objective response rate (ORR) per blinded independent central review (BICR). Key secondary end points were disease control rate (DCR), duration of response (DOR), time to PSA progression, rPFS, and OS. RESULTS: Of 102 treated pts, 73 discontinued, primarily because of progression (60%). Median age was 70 years (range, 43-87), 29% of pts were PD-L1+, 17% had visceral disease, and 39% had measurable disease. Median follow-up was 13 months for all pts (n=102) and 17 months for pts with ≥27 weeks’ follow-up (n=69). Confirmed PSA response rate was 22% in the total population. For pts with ≥27 weeks’ follow-up, ORR among pts with RECIST-measurable disease was 12%. See Table for additional efficacy outcomes. Treatment-related AEs occurred in 92 pts (90%); most frequent (≥20%) were fatigue (38%), nausea (22%), and rash (20%). Grade 3-5 treatment-related AEs occurred in 40 pts (39%). Three pts died of AEs (1 AE was treatment related [cause unknown]). CONCLUSIONS: With additional follow-up, pembro + enza continued to show activity in pts with abi-pretreated mCRPC. Safety of the combination was consistent with known profiles of pembro and enza. Source of Funding: Merck Sharpe & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e368-e368 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Evan Y. Yu* More articles by this author Peter Fong More articles by this author Josep M. Piulats More articles by this author Leonard Appleman More articles by this author Henry Conter More articles by this author Susan Feyerabend More articles by this author Neal Shore More articles by this author Gwenaelle Gravis More articles by this author Brigitte Laguerre More articles by this author Howard Gurney More articles by this author Margitta Retz More articles by this author Emanuela Romano More articles by this author Loic Mourey More articles by this author Johann S. de Bono More articles by this author Audrey Kam More articles by this author Urban Emmenegger More articles by this author Helen Wu More articles by this author Christian Poehlein More articles by this author William Berry More articles by this author Expand All Advertisement PDF downloadLoading ...