Nano cap Repros Therapeutics (NASDAQ:RPRX) craters 48% premarket on light volume in response to its announcement that the FDA will maintain its partial clinical hold on its Proellex (telapristone acetate) program after reviewing the existing liver function safety data. The company will be required to compile a large pre-approval safety data set in order to support further development. In other words, a much larger clinical trial will be necessary.
Considering the time and expense of an new clinical study, the company is mulling increasing its focus on the uterine fibroid and endometriosis indications using a vaginal drug delivery approach. It also will assess drug delivery technology that will enable less frequent dosing than once per day.
Proellex is a small molecule compound that selectively blocks the progesterone receptor.
Previously: FDA continues partial clinical hold for Repros Therapeutics' fibroids drug (April 10)