Among patients with metastatic castration-sensitive prostate cancer, apalutamide plus androgen deprivation therapy (ADT) improves overall survival (OS) with a significant reduction in risk of death, according to a final analysis of the TITAN trial presented at the virtual 2021 ASCO Genitourinary Cancers Symposium.

These results were presented by Kim Chi, MD, FRCPC, BC Cancer and Vancouver Prostate Centre, Canada.

The phase 3 TITAN trial evaluated the addition of apalutamide to ADT in metastatic castration-sensitive prostate cancer. A total of 1052 patients were randomized 1:1 to receive apalutamide or placebo plus ADT.

"The primary analysis which we reported on in 2019 was conducted after a median follow-up of 22.7 months. Both RPFS and overall survival met statistical significance,” explained Dr Chi during his presentation.

“The TITAN study was unblinded at that time on the recommendation of the independent data monitoring committee,” he continued. This allowed for 39.5% of patients who did not progress on placebo to cross over to apalutamide.

This analysis reports final efficacy and safety results from the TITAN trial.

Median follow-up was 44 months and a total of 405 OS events occurred. After unblinding, 208 patients receiving placebo crossed over to apalutamide. Median treatment duration was 39.3 months for the apalutamide group, 20.2 months for the placebo group, and 15.4 months for those patients who started on placebo and crossed over to apalutamide.

Apalutamide was associated with superior OS vs placebo (not estimable vs 52.2 months, respectively; hazard ratio [HR]: 0.65; P <.0001). When adjusting for crossover, OS with apalutamide was not estimable vs 39.8 months with placebo (HR: 0.52; P <.0001). Survival rates at 48 months were 65% with apalutamide vs 52% with placebo.

“In conclusion, the final analysis of TITAN, with almost 4 years of median follow-up and nearly 40% of patients in the placebo group crossing over to receive apalutamide, demonstrates the continued benefit in OS with the addition of apalutamide to ADT for a broad population of patients with metastatic castration sensitive prostate cancer,” concluded Dr Chi.—Janelle Bradley

Chi KN, Chowdhury S, Bjartell A. Final analysis results from TITAN: A phase III study of apalutamide (APA) versus placebo (PBO) in patients (pts) with metastatic castration-sensitive prostate cancer (mCSPC) receiving androgen deprivation therapy (ADT). Presented at: the virtual 2021 ASCO Genitourinary Cancers Symposium; February 11-13, 2021. Abstract 11.