GTx, Inc. suffered a setback recently with its phase III candidate, enobosarm, failing to meet overall requirements for the co-primary responder endpoints of lean body mass and physical function as agreed upon with the U.S. Food and Drug Administration (FDA). Results were presented from the placebo controlled, double blind POWER studies that were conducted in patients receiving chemotherapy for non-small cell lung cancer (NSCLC).
The studies were evaluating the use of enobosarm for the prevention and treatment of muscle wasting in patients with non-small cell lung cancer.
As far as the pre-specified continuous variable analysis discussed with the European regulators using the same endpoints were concerned, GTx said that enobosarm demonstrated a consistently positive effect on lean body mass relative to placebo in both studies. Enobosarm was well tolerated with the occurrence of serious adverse events and the overall occurrence of adverse events being similar to placebo.
Although the company expressed disappointment in enobosarm’s failure to meet the pre-specified responders analyses criteria in both studies, GTx said that it intends to discuss the future development path for enobosarm with the regulatory authorities given the consistent positive effects on muscle, the tolerability profile and the association of lean body mass with a survival signal.
The phase III results are a major setback for GTx – shares were down more than 60% on the news. Although the company is looking to discuss the future path with the U.S. and the EU regulatory authorities, we expect investor focus to shift to Capesaris, which is in phase II development as a secondary hormonal therapy in men with metastatic castration resistant prostate cancer.
GTx currently carries a Zacks Rank #3 (Hold). At present, companies like Actelion Ltd. , Biogen Idec (BIIB - Free Report) and Gilead Sciences, Inc. (GILD - Free Report) look well-positioned with all three being Zacks Rank #1 (Strong Buy) stocks.