European approval denied for hypogonadism medicine
A new treatment for men with hypogonadotrophic hypogonadism is likely to be refused authorisation for use in Europe. The European Medicines Agency’s expert committee on the assessment of drugs, the Committee for Medicinal Products for Human Use, concluded that the four clinical trials which evaluated enclomifene (EnCyzix) in 588 men showed that the drug increased testosterone levels but did not provide enough evidence of its safety. Specifically, the studies did not investigate the effects of treatment on bone strength, weight gain, impotence and libido, or on the risk of venous thromboembolism.
Enclomifene is an isomer of clomifene, an oestrogen receptor antagonist available for many years and used to treat infertility in women. A recent review concluded that it may have a role in the treatment of testosterone deficiency associated with secondary hypogonadism when testosterone therapy is unsuccessful (Expert Opin Pharmacother 2016; 17: 1561–1567).