Health Canada approved a new indication for the use of Xtandi (enzalutamide) capsules to treat patients with metastatic castration-resistant prostate cancer who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy.
The drug, sponsored by Astellas Pharma Canada Inc., was initially approved for use in patients with mCRPC who previously received docetaxel in the setting of medical or surgical castration.
This new approved use follows a Priority Review of the Supplementary New Drug Submission by Health Canada that was based on results of the phase III PREVAIL trial.
The trial was a randomized, placebo-controlled, multinational clinical trial that enrolled 1,717 chemotherapy-naïve patients with progressive metastatic prostate cancer who had failed ADT. The PREVAIL trial included thirteen Canadian trial sites including Kelowna, Vancouver, Victoria, Calgary, Edmonton, Winnipeg, London, Hamilton, Toronto, Ottawa, Montreal, Quebec City, and Halifax.
In the trial, men receiving enzalutamide therapy exhibited a statistically significant improvement in both overall survival and delayed time to radiographic progression or death as compared to those on placebo.
Specifically, enzalutamide significantly reduced the risk of radiographic progression or death by 81 percent compared with placebo (HR=0.19; p < 0.0001). Enzalutamide also significantly reduced the risk of death by 29 per cent compared with placebo (HR=0.71; p < 0.0001) and significantly delayed the start of chemotherapy by a median of 17 months compared with placebo (HR=0.35, p<0.001).
