An experimental medication safely increases muscle strength and physical functioning among cancer patients with low testosterone levels, a new drug study finds. The results will be presented Sunday at The Endocrine Society's 94th Annual Meeting in Houston.
The medication, called enobosarm, is the first of a new class of drugs known as selective androgen receptor modulators, which are similar to steroids in their growth-enhancing effects but, potentially, have fewer side effects.
Muscle wasting is a significant problem for many cancer patients due to imbalances in body systems caused by the underlying cancer. In addition, this muscle wasting may be related to low testosterone levels, or hypogonadism, which affects approximately 50 percent of men undergoing treatment for late-stage cancer. Muscle wasting can seriously limit mobility, functioning, and quality of life for affected patients.
In this multi-center drug trial, enobosarm significantly improved physical function among patients with low testosterone, as well as normal hormone levels. Among the low testosterone group, physical function improved by 19 percent, while patients with normal hormone measurements increase their functional ability by 13 percent. At the study's start, 60 percent of patients had subnormal testosterone levels, lost more weight, and suffered greater declines in physical functioning than patients with normal hormone concentrations.
"These data provide evidence that enobosarm may play an important role in the management of cancer-related muscle-wasting even in the setting of low testosterone," said study lead author Adrian Dobs, M.D., M.H.S., professor of medicine and oncology, and vice-chair of the Department of Medicine, Faculty Development at Johns Hopkins University Medical School in Baltimore, MD.
The overall study included 159 cancer patients, of which 65 percent were men. Female participants were post-menopausal, and males were >45 years old. Participants had lost on average about 8 percent of their body weight in the six months preceding the study, and had a body mass index, which is a calculation of weight to height, of <35. Additionally, all patients had received a cancer diagnosis, which included one of the following: non-small-cell lung carcinoma, colorectal cancer, non-Hodgkin's lymphoma, chronic lymphocytic leukemia, and breast cancer.