In a mid-stage study, Mereo BioPharma Group PLC's medicine BGS-649 was found to be safe and helped restore hormone levels in men with an infertility disorder.
The London-based biopharmaceutical company evaluated BGS-649 in an extended phase 2b trial to treat men with hypogonadotropic hypogonadism, or HH, with a body mass index over 30. HH occurs as a result of inadequate levels of the sex hormone testosterone, and symptoms include reduced or loss of libido, erectile dysfunction, lack of motivation and mood disturbance. There are about seven million cases of HH in obese men in the U.S., the company said in a Dec. 17 press release.
BGS-649 works by inhibiting the aromatase enzyme, which causes the conversion of testosterone into the steroid hormone oestradiol, thereby restoring normal testosterone levels.
The safety extension study, which enrolled 143 patients, met its main goal of reaching a predetermined safe level of reduction in bone mineral density. The trial showed that at 48 weeks, following the initial 24 weeks treatment, none of three doses of BGS-649 showed a greater than 3% reduction in lumbar spine or hip bone mineral density. The patients receiving the medicine did not develop osteoporosis, a disease in which increased bone weakness can cause bones to break easily.
Mereo said the efficacy results in the safety study were consistent with phase 2b results reported in March, which evaluated BGS-649 against placebo. At the end of the safety study, all three doses of the drug helped in normalization of total testosterone levels in over 75% of patients. The safety study also showed normalization of testosterone in at least 90% of patients at all three doses compared to the two highest doses in the initial six months.
The company said side effects were similar to the original phase 2b trial. Patients receiving the drug saw an increase in their hematocrit levels, or the ratio of red blood cells to total blood, and small increases in blood pressure at the two highest doses, consistent with increasing testosterone.