GTx, Inc. (NASDAQ: GTXI) today announced topline results of a Phase II
clinical trial evaluating Ostarine™ (MK-2866),
an investigational selective androgen receptor modulator (SARM), in
patients with cancer induced muscle loss, also known as cancer cachexia.
In this analysis, the study met its primary endpoint of absolute change
in total lean body mass (muscle) compared to placebo and the secondary
endpoint of muscle function (performance) after 16 weeks of treatment.
GTx and Merck & Co., Inc. are collaborating to develop Ostarine and
other SARMs, which are a new class of drugs with the potential to treat
sarcopenia, which is the loss of skeletal muscle mass resulting in
reduced physical strength and ability to perform activities of daily
living, cancer cachexia, and other musculoskeletal conditions.
GTx plans to present complete study results at an upcoming scientific
meeting in 2009.
"Cachexia continues to represent one of the most devastating features of
cancer," said an investigator in the Phase II clinical trial, Adrian
Dobs, MD, MHS, Professor of Medicine and Oncology and Vice Chair of the
Department of Medicine, Division of Endocrinology and Metabolism, The
Johns Hopkins University School of Medicine. "This study provided
encouraging evidence for using Ostarine to treat patients with cancer
cachexia by increasing lean body mass and improving functional
performance."
The clinical trial enrolled 159 cancer patients (average age of 66
years) with non-small cell lung cancer, colorectal cancer, non-Hodgkin
lymphoma, chronic lymphocytic leukemia, or breast cancer at 35 sites in
the US and Argentina. Participants were randomized to receive placebo, 1
mg or 3 mg oral capsule of Ostarine once daily for 16 weeks. Average
reported weight loss prior to entry among all subjects was 8.8 percent.
Subjects were allowed to have standard chemotherapy during the trial.
The drop out rate during the trial was 33 percent, lower than the
expected 50 percent rate which has been observed in other cancer
supportive care clinical trials.
The primary endpoint of the study was lean body mass measured by dual
energy X-ray absorptiometry (DEXA) scan. A prespecified analysis was
comparison of treatment arms with placebo using the exact Wilcoxon rank
sum test stratified by cancer type in patients with DEXA scans performed
at baseline and at the end of the study. Topline results show that
Ostarine treatment resulted in a statistically significant increase in
lean body mass compared to placebo. Ostarine treatment resulted in
clinically meaningful increases (greater than 1 kg) in lean body mass
compared to baseline in both the Ostarine 1 mg and 3 mg treatment arms.
Topline results also show that Ostarine treatment improved muscle
function (performance) in a 12 step stair climb test measuring speed and
calculating power, a secondary endpoint of the study. No improvement in
speed or power was observed for the placebo group.
