Time trends of overall survival and other outcomes in patients with mHSPC: An observational study of U.S. EHR data (TIMES).
Authors: Shore Neal D. , McKay Rana R. , Preston Mark A. , Gregg Justin R , Salami Simpa Samuel , Ross Ashley , Bruno Amanda , Srinivasan Shankar , Ortiz Jorge A. , Constantinovici Niculae 
Published: June 2022

e17051 Background: Patients (pts) with metastatic hormone-sensitive prostate cancer (mHSPC) are responsive to androgen deprivation therapy (ADT), but within 1–3 years most will develop metastatic castration-resistant prostate cancer (mCRPC). The CHAARTED trial showed a clear benefit of adding docetaxel (DTX) to ADT, prolonging median overall survival (OS) by 10.4 months (mo). ARASEC is a single-arm US study evaluating darolutamide + ADT in pts with mHSPC. Participants will be matched for comparison using patient-level data to the ADT alone arm of CHAARTED. The TIMES study evaluated a potential time bias in treatment patterns and clinical outcomes in pts with mHSPC before and after the OS analysis of CHAARTED was reported. Methods: This retrospective study used Flatiron Metastatic PC Core Registry data from January 1, 2013, to June 30, 2020, and the sample was divided into two cohorts: before and after June 30, 2016 (cohort 1: pre-CHAARTED; cohort 2: post-CHAARTED). Differences in OS and time to mCRPC were assessed using Cox proportional hazard models, controlling for baseline characteristics, including age, initial mHSPC treatment, Gleason score, and time from PC diagnosis to mHSPC. The test for equivalence used hazard ratio (HR) limits of 0.80 to 1.25 at a 2-sided 0.05 level. Results: Data from 9256 pts with mHSPC (4503 in cohort 1; 4753 in cohort 2) were analyzed; median age was 73 years for both cohorts. M1 status at initial diagnosis was 55% in cohort 1 and 60% in cohort 2. All other clinical characteristics and laboratory values were similar. Initial mHSPC treatment with DTX was 10.5% and 13.9%, whereas treatment with novel anti-hormonal agents (NAH) was 1.6% and 18.3% in cohorts 1 and 2, respectively. The percentage of pts who started with first-generation androgen receptor inhibitors decreased from 29.3% in cohort 1 to 19.6% in cohort 2, whereas the percentage of pts receiving ADT alone and/or supportive care remained stable (25.7% and 26.5%, respectively). In cohorts 1 and 2, treatment records during the mHSPC period could not be retrieved for 32.9% and 21.7% of pts, respectively. Median OS was 5.4 months longer for cohort 1 (43.7 mo) vs cohort 2 (38.3 mo). In multivariate analyses, cohort 2 had poorer survival, with an HR slightly outside the predefined limits for equivalence (HR 1.19; 95% CI 1.09, 1.29; P < 0.0001). The HR for time to mCRPC fell within the predefined limits (HR 1.16; 95% CI 1.09, 1.23). Conclusions: Changes in treatment patterns were observed following CHAARTED. Although DTX and NAH have demonstrated prolonged survival, their use increased only from 12% to 32%, comparing the cohorts before and after 2016, which is not in line with guideline recommendations. Clinical outcomes, despite the influence of multiple factors, have changed minimally during the past 5 years, suggesting that the risk of historical time bias associated with using the CHAARTED ADT alone arm as a comparator for ARASEC is low.