MP29-14 PROSTATE-SPECIFIC ANTIGEN RESPONSE AND TIME-TO-CASTRATION RESISTANCE AMONG PATIENTS WITH METASTATIC CASTRATION SENSITIVE PROSTATE CANCER INITIATED ON APALUTAMIDE, ENZALUTAMIDE, OR ABIRATERONE ACETATE

Abstract

You have accessJournal of UrologyCME1 Apr 2023MP29-14 PROSTATE-SPECIFIC ANTIGEN RESPONSE AND TIME-TO-CASTRATION RESISTANCE AMONG PATIENTS WITH METASTATIC CASTRATION SENSITIVE PROSTATE CANCER INITIATED ON APALUTAMIDE, ENZALUTAMIDE, OR ABIRATERONE ACETATE Benjamin Lowentritt, Shawn Du, Carmine Rossi, Frederic Kinkead, Dexter Waters, Bronwyn Moore, Patrick Lefebvre, Dominic Pilon, and Erik Muser Benjamin LowentrittBenjamin Lowentritt More articles by this author , Shawn DuShawn Du More articles by this author , Carmine RossiCarmine Rossi More articles by this author , Frederic KinkeadFrederic Kinkead More articles by this author , Dexter WatersDexter Waters More articles by this author , Bronwyn MooreBronwyn Moore More articles by this author , Patrick LefebvrePatrick Lefebvre More articles by this author , Dominic PilonDominic Pilon More articles by this author , and Erik MuserErik Muser More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003257.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Next-generation androgen inhibitors (AI), including apalutamide (APA), enzalutamide (ENZ), and abiraterone acetate (ABI), are approved to treat patients with metastatic castration sensitive prostate cancer (mCSPC). Among patients with mCSPC, prostate-specific antigen (PSA) response is associated with increased overall survival and decreased castration resistance (CR), an important indicator of disease progression. This study described real-world PSA response and progression to CR among patients with mCSPC treated with APA, ENZ, or ABI in the US. METHODS: Data from 77 community-based urology practices (9/2018–4/2022) were used to evaluate patients with mCSPC newly initiated on APA, ENZ, or ABI using in-office dispensing data (index date is first dispensation date). On-treatment PSA response was defined as: 1) a post-index ≥90% decline in PSA (PSA90) from baseline (using the closest PSA value within 13 weeks prior to or on the index date) and 2) a post-index decline to ≤0.2 ng/mL (PSA0.2) among those with baseline PSA >0.2 ng/mL. The descriptive proportion of patients achieving a PSA response or progressing to CR was described separately for each cohort using Kaplan-Meier (KM) analysis up to 12- and 24-months post-index, respectively. RESULTS: A total of 589 APA, 597 ENZ, and 553 ABI patients were evaluated. Mean age at index was 76 years in each group. Mean baseline PSA was 19.2 ng/mL (APA), 18.8 ng/mL (ENZ), and 24.3 ng/mL (ABI). KM rates for PSA response and progression to CR are shown in the Table. PSA90 by 12 months was achieved by 72% (APA), 62% (ENZ), and 55% (ABI) of patients. PSA0.2 by 12 months was achieved by 81% (APA), 63% (ENZ), and 58% (ABI) of patients. By 24 months, progression to CR was observed in 34% (APA), 39% (ENZ), and 45% (ABI) of patients. CONCLUSIONS: This is among the first observational studies to describe real-world PSA response and progression to CR in mCSPC patients treated with AIs in US community urology practices. While AIs with higher proportions achieving PSA90 or PSA0.2 were observed to have lower rates of progression to CR, further studies adjusting for baseline characteristics are needed to understand this relationship. Source of Funding: Janssen Scientific Affairs, LLC. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e387 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Benjamin Lowentritt More articles by this author Shawn Du More articles by this author Carmine Rossi More articles by this author Frederic Kinkead More articles by this author Dexter Waters More articles by this author Bronwyn Moore More articles by this author Patrick Lefebvre More articles by this author Dominic Pilon More articles by this author Erik Muser More articles by this author Expand All Advertisement PDF downloadLoading ...