The US Food & Drug Administration (FDA) has advised GTx to stop development of GTx-758 (also known as Capesaris), its oral drug intended for the treatment of men with advanced prostate cancer, after it became apparent that there was an increase in risk for blood clots in men taking active drug compared to those being treated with a placebo.
The company issued a detailed media release which is available on line.
GTx-758 is a drug that was in development for the first-line treatment of hormone-sensitive prostate cancer and also for the treatment of castration-resistant prostate cancer. The clinical hold requested by the FDA (which has already taken effect) has stopped three ongoing clinical Phase II trials. The Company has also suspended further enrollment into these studies. The Company has reported the occurrence of blood clots (venous thromboembolic events or VTEs) in subjects treated with GTX-758 in patients receiving 1000 mg (or more) of the active agent, and the Company has asked the FDA to consider changes in its clinical development program for GTX-758.
It is not yet clear whether GTx will be able to make appropriate changes to the clinical development program for GTx-758. The Company seems to think that GTx-758 may still prove to be effective and safe at lower doses for the treatment of men with metastatic, hormone-sensitive or castration-resistant forms of prostate cancer. The “New” Prostate Cancer InfoLink hopes that the Company will be able to find common ground with the FDA and identify an appropriate method to be able to refocus on evaluation of GTx-758 in these patient populations. However, making such determinations can be time-consuming, and it is not yet clear how many cases of VTEs have occurred in men receiving active drug or in men treated with a placebo.