Data from GTx's enobosarm Phase IIb study on cancer to be presented at SIOG meeting

Oct 8 2012

GTx, Inc. (NASDAQ: GTXI) announced today there will be two scientific poster presentations on the effects of enobosarm, a selective androgen receptor modulator (SARM), on improving physical function and quality of life in middle aged and elderly cancer patients. The posters will be displayed on October 26^th and 27^th, 2012, at the 12th Meeting of the International Society of Geriatric Oncology to be held at the Manchester Central Convention Centre in Manchester, United Kingdom. Ryan P. Taylor, PhD, GTx's Associate Director of Medical Affairs, will present data from the company's Phase IIb clinical study of enobosarm, providing evidence that enobosarm may play an important role in the management of cancer patients with muscle wasting by improving physical function and quality of life, regardless of baseline weight loss or age.

The first poster presentation will present data exploring patient response to treatment by grouping subjects according to their baseline weight loss (less or greater than 5% in the 6 month period prior to randomization), and the age of the patient (above and below the median age of 66 years). Of the 159 subjects randomized into the study, 103 had physical function (by stair climb test) assessed at both baseline and following 16 weeks of treatment and 24% of these subjects had lost less than 5% of weight. Significant improvement in physical function was observed in enobosarm treated subjects, while placebo subjects failed to improve, regardless of baseline weight loss or age.

The second poster presentation will present data indicating that patients, who responded to treatment during the enobosarm clinical study (>10% improvement in stair climb power), significantly increased three separate measures of quality of life, regardless of age. Quality of life questionnaires from 95 of the 159 subjects randomized into the study were analyzed to determine if there was an association between improvement in stair climb power (the physical function test assessed during the clinical study) and quality of life. Generally, a 5% increase in physical function from baseline is regarded as a minimal clinically meaningful change in physical function, while a 10% increase in physical function from baseline is thought to be a substantial clinically meaningful change. Subjects who showed improvements in stair climb power also were found to have improvements in quality of life, and subjects with the greatest stair climb improvement also had the greatest measured improvements in quality of life.

Enobosarm is a SARM which binds to the androgen receptor and is designed to deliver the beneficial effects of androgens while minimizing unwanted clinical side effects. GTx conducted its Phase IIb clinical study of enobosarm in 159 cancer patients (average age of 66 years) in 35 sites in the United States and Argentina. Participants were randomized to receive placebo, 1 mg or 3 mg oral tablet of enobosarm once daily for 16 weeks. Average reported weight loss prior to entry among all subjects was 8.8%, and subjects were allowed to have standard chemotherapy during the trial. The drop-out rate during the trial was 33%. The study met its primary endpoint of absolute change in total lean body mass (muscle) compared to placebo after 16 weeks of treatment.

GTx is conducting two pivotal Phase III clinical trials (POWER 1 and POWER 2) in the United States, Europe and South America, evaluating a once daily 3 mg dose of enobosarm for the prevention and treatment of muscle wasting in patients with non-small cell lung cancer.