GTx Inc. is studying enobosarm (Ostarine, GTx-024) in Phase III clinical trials for the prevention and treatment of muscle wasting in patients with non-small cell lung cancer. Enobosam is an oral selective androgen receptor modulator.

The U.S. Food and Drug Administration (FDA) has designated enobosarm (Ostarine, GTx-024) as a Fast Track development program. Fast Track status is a process designed by FDA to facilitate the development and expedite the review of new drug candidates that are intended to treat serious diseases and have the potential to fill an unmet medical need. With a Fast Track designation, there is an increased possibility for a priority review of a new drug application (NDA) filed for the drug candidate and more opportunity for more frequent interactions with the FDA both prior to and following the filing of a NDA.

Many patients with non-small cell lung cancer report muscle weakness and functional limitations including difficulty climbing stairs, lifting and carrying 10 lbs, walking a quarter mile, or stooping, crouching, or kneeling. Patients with functional limitations are less likely to tolerate chemotherapy.

GTx is evaluating oral daily doses of Enobosarm 3 mg in patients with Stage III or IV non-small cell lung cancer in two pivotal Phase III clinical trials, POWER 1, and POWER 2, assessing the ability of the medication to prevent and treat muscle wasting.

The most common side effects reported in one Phase II trial included fatigue, anemia, nausea and diarrhea.