Homologous Recombination Repair Testing Patterns and Outcomes in mCRPC by Alteration Status and Race.

Background: Alterations in DNA damage repair genes in advanced prostate cancer (PC) may impact responses to therapy and clinical outcomes. This study described homologous recombination repair (HRR) testing patterns and clinical outcomes among patients with metastatic castration-resistant prostate cancer (mCRPC) by HRR alteration status and race in the United States (US).
Methods: Clinical data in the nationwide (US-based) Flatiron Health-Foundation Medicine, Inc. (FMI) Metastatic PC Clinico-Genomic Database were evaluated (01/01/2011-12/31/2022). Patients initiating first-line (1L) mCRPC therapy on or after mCRPC diagnosis were included. Testing patterns, time-to-next treatment, overall survival (OS), and time-to-prostate specific antigen response were described.
Results: Of the 1367 patients with mCRPC and at least one HRR panel test prior to or on the date of 1L mCRPC therapy initiation, 332 (24.3%) were HRR positive (White patients: n = 219 [66.0%]; Black patients: n = 37 [11.1%]) and 1035 (75.7%) were HRR negative (White patients: n = 702 [67.8%]; Black patients: n = 84 [8.1%]). The mean time between first positive test and 1L mCRPC therapy initiation date was 588 days (White patients: 589 days; Black patients: 639 days). Among HRR positive relative to negative patients, trends for faster progression (respective 12-month rate overall: 71.1% and 63.7%; White patients: 72.5% and 64.0%; Black patients: 65.4% and 56.4%), shorter OS (respective 24-month rate overall: 46.8% and 51.9%; White patients: 48.6% and 46.2%; Black patients: 52.8% and 54.1%), and decreased treatment response (respective 12-month rate overall: 24.3% and 37.9%; White patients: 24.5% and 35.2%; Black patients: 17.0% and 43.9%) were observed.
Conclusion: Patients with mCRPC positive for HRR alterations tended to exhibit poorer treatment responses and clinical outcomes than those with a negative status. These findings highlight the importance of timely genetic testing in mCRPC, particularly among Black patients, and the need for improved 1L targeted therapies to address the unmet need in HRR positive mCRPC.
Competing Interests: Mehmet A. Bilen is a professor at Emory University School of Medicine and has acted as a paid consultant for and/or as a member of the advisory boards of Exelixis, Bayer, BMS, Eisai, Pfizer, AstraZeneca, Janssen, Calithera Biosciences, Genomic Health, Nektar, EMD Serono, SeaGen, and Sanofi; and has received grants to his institution from Merck, Xencor, Bayer, Bristol-Myers Squibb, Genentech/Roche, SeaGen, Incyte, Nektar, AstraZeneca, Tricon Pharmaceuticals, Genome & Company, AAA, Peloton Therapeutics, and Pfizer for work performed as outside of the current study. Ibrahim Khilfeh is an employee of Janssen Scientific Affairs, LLC and stockholder of Johnson & Johnson. Erik Muser was an employee of Janssen Scientific Affairs, LLC at the time the study was conducted. Carmine Rossi, Laura Morrison, Annalise Hilts, Lilian Diaz, Patrick Lefebvre, and Dominic Pilon are employees of Analysis Group, Inc., a consulting company that has provided paid consulting services to Janssen Scientific Affairs, LLC, which funded the development and conduct of this study and manuscript. Daniel J. George is a professor at Duke University School of Medicine and reports the following in the past 24 months: has acted in leadership role for Capio Biosciences; has acted as a paid consultant for and/or as a member of the advisory boards of Ambrx, AVEO, Corvus, Eisai, IdeOnocology, Medscape Educ., Nektar, Seattle Genetics, Sumitovant Biopharma, Surface Oncology, UroGPO, WebMD, Bayer, Exelixis, Pfizer, Sanofi, Astellas Pharma, Innocrin Pharma, Bristol Myers Squibb, Genentech, Janssen, Merck Sharp & Dohme, Myovant Sciences, AstraZeneca, Michael J. Hennessy Associates, Constellation Pharmaceuticals, Physicians’ Education Resource, Propella Therapeutics, RevHealth, and xCures; has been a member of the speakers’ bureau of Sanofi, Bayer, and Exelixis; has received honoraria from Sanofi, Bayer, Exelixis, EMD Serono, OncLive, Pfizer, UroToday, Acceleron Pharma, American Association for Cancer Research, Axess Oncology, Janssen Oncology, and Millennium Medical Publishing; has received research funding from Exelixis, Janssen Oncology, Novartis, Pfizer, Astellas Pharma, Bristol Myers Squibb, Acerta Pharma, Bayer, Dendreon, Innocrin Pharma, Calithera Biosciences, and Sanofi/Aventis; and has received other research support (travel, accommodations, expenses) from Bayer, Exelixis, Merck, Pfizer, Sanofi, Janssen Oncology, and UroToday.
(© 2024 Bilen et al.)