Late Breaking News: Positive results from enzalutamide study

15 April 2014

The results of the Phase 3 Prevail Study on enzalutamide showed significant benefit to prostate cancer patients including delaying the progression of metastatic disease, reducing the risk of death and delaying the start of cytotoxic chemotherapy.

Enzalutamide did translate to significant overall survival to an unprecedented extent,” said Prof. Bertrand Tombal (BE) during the Late Breaking News segment of the concluding plenary session of the 29th Annual EAU Congress which ends today in Stockholm, Sweden.

Bertrand said the results of the main study and the European regional results of the phase 3 randomised PREVAIL study also has to be considered in a very rapidly changing treatment landscape when new prostate cancer drugs are emerging.

“Enzalutamide also has impact on other points such as time- to-PSA progression and has demonstrated a tolerability profile comparable to placebo,” he noted. “One of the clinical benefits is the ability to use this agent in second-line hormonal manipulation.”

The PREVAIL study involved 1,717 chemotherapy-naive patients with asymptomatic or mildly symptomatic metastatic prostate cancer that progressed on androgen deprivation therapy (ADT). They were randomly assigned to receive 160 mg/day of enzalutamide or placebo in a double-blind fashion. More than 200 centres in 22 countries participated in the study which was stopped at the interim phase when results showed significant benefit.

Result showed that at the time of the interim analysis and after a median follow-up of 20 months, enzalutamide significantly reduced the risk of death by 29% (HR 0.706, 95% CI [0.60-0.84]; p < 0.0001) and reduced the risk of radiographic progression by 81% (HR 0.186, 95% CI [0.15-0.23]; p < 0.0001).Most common adverse events included fatigue, back pain, constipation, arthralgia and hypertension, among others.

“In both the full population and the European subpopulation treatment with enzalutamide significantly delayed the progression of metastatic disease, reduced the risk of death, and delayed the time to initiation of chemotherapy,” said Tombal, adding that the safety outcomes in the European subpopulation were consistent with those of full population.

“Enzalutamide added to ADT at progression provides meaningful clinical benefit to men with metastatic prostate cancer,” he said.