Results from the TALAPRO-2 trial supported the use of first-line talazoparib plus enzalutamide for the treatment of metastatic castration-resistant prostate cancer. The radiographic progression-free survival of patients treated with talazoparib plus enzalutamide (n=402) was significantly improved compared with those treated with placebo plus enzalutamide (n=403).
Results that will be presented at the American Society of Clinical Oncology 2023 Annual Meeting outlined patient-reported outcomes (PROs) from the TALAPRO-2 trial.
During the trial, PROs were assessed at day 1 for a baseline measurement and were then assessed at scheduled visits until radiographic progression (every 4 weeks until week 53 and then every 8 weeks) using the EORTC Quality of Life of Cancer Patients questionnaire and its prostate cancer module. The prespecified PRO analyses included overall mean change from baseline (per longitudinal repeated measures mixed-effects model) and time to definitive clinically meaningful (≥10-point change) deterioration (TTD). Comparisons of TTD between trial arms were made using a stratified log-rank test and a Cox proportional hazards model.
Of the 805 total patients who were randomized and treated during the trial, 793 had a baseline score followed by at least 1 post-baseline score (talazoparib plus enzalutamide [n=395] and placebo plus enzalutamide [n=398]). While treatment effect on global health status (GHS) and quality of life (QOL) favored placebo plus enzalutamide, the predefined threshold of clinical meaningfulness was not met, and there were no significant differences between trial arms. A longer TTD in GHS and QOL was noted for talazoparib plus enzalutamide (hazard ratio [HR], 0.780; 95% CI, 0.62-0.99; P=.038; median, 30.8 months vs 25.0 months). Delay in TTD in urinary symptoms was also longer for talazoparib plus enzalutamide (HR, 0.759; 95% CI, 0.543-1.061; P=.105; median, not reached vs 35.9 months).
When compared with placebo plus enzalutamide, talazoparib plus enzalutamide demonstrated a nonclinically meaningful deterioration disfavoring GHS and QOL and showed maintenance in all functioning scales. TTD in GHS and QOL was significantly longer with talazoparib plus enzalutamide versus placebo plus enzalutamide, showing improved disease control.