Some bad news was reported today. Results from the Phase 3 randomized, double-blind clinical trial (Study 043) comparing Yervoy 10 mg/kg (ipilimumab) (n=399) to placebo (n=400) following radiation in men with advanced metastatic castration-resistant prostate cancer (mCRPC) who have received prior treatment with docetaxel showed no increase in overall survival. Yervoy is an immunotherapy which was designed to take the brakes off of the immune system. Unfortunately, despite its success with Melanoma it does not seem to work for men in this disease state.

The study’s primary endpoint of overall survival (OS) did not reach statistical significance (HR = 0.85; 95% CI = 0.72-1.00; p = 0.053). However, anti-tumor activity was observed across some efficacy endpoints, including progression free-survival. Based on the current standards for FDA approval this might be the last we hear about Yervoy for mCRPC for men in this disease category.

These data will be presented at the 2013 European Cancer Congress in an oral session on September 28 (Abstract # 2850).

As with all potential treatments there were treatment-related adverse events. These side effects included immune-related (irAEs), and were managed using standard Yervoy management protocols. Grade ?3 irAEs in the Yervoy and placebo arms, respectively, were gastrointestinal (GI; 18% vs. 1%), liver (5% vs. 1%), endocrine (2% vs. 1%), and dermatologic (1% vs. 0%). The incidence of drug-related death was 1%.

Yervoy 3 mg/kg monotherapy is currently approved in more than 40 countries for the treatment of patients with metastatic melanoma, however we will not see its use in very advanced prostate cancer.

There is still a second large trial of Yervoy in men with less advanced prostate cancer which could still yield positive results. This study includes Study 095, an ongoing Phase 3 randomized double-blind trial comparing the efficacy of Yervoy 10 mg/kg versus placebo in patients with mCRPC who have not received prior cytotoxic treatment chemotherapy).

Reported with great sadness

Joel T. Nowak, M.A., M.S.W.