Xtandi success in Phase III PREVAIL study for Prostate cancer-Astellas/Medivation

Updated results are announced by Astellas from PREVAIL study.Treatment with enzalutamide demonstrated a statistically significant overall survival benefit compared with placebo treatment. Enzalutamide reduced the risk of death by 29% (HR=0.71; p<0.0001), compared with placebo. this benefit was observed despite substantial use of subsequent therapies (40% in the enzalutamide and 70% in the placebo groups).>

Treatment with enzalutamide significantly reduced the risk of radiographic progression or death by 81% compared with placebo treatment (HR=0.19; p<0.0001). consistent benefits on these co-primary endpoints of overall survival and radiographic progression-free survival were observed across patient subgroups.>

Men taking enzalutamide experienced a 17-month delay in the time to initiation of chemotherapy compared with men taking placebo (28.0 months versus 10.8 months; HR=0.35; p<0.0001).the majority of men (58.8%) with soft tissue metastatic disease treated with enzalutamide versus 5% of patients treated with placebo had objective responses (complete responses or partial responses) including complete responses in 19.7% of enzalutamide patients compared with 1% of placebo patients. enzalutamide extended the median time to psa progression from 2.8 months (placebo) to 11.2 months (hr="0.169;" p><0.0001).>

Data is to be presented at the American Society of Clinical Oncology (ASCO) 2014 Genitourinary (GU) Cancers Symposium.

With positive results from the phase III PREVAIL study, Medivation and Astellas will seek FDA and European approval to expand use of Xtandi to treat men with advanced prostate cancer who have not yet received chemotherapy.