Repros shares slide after FDA advises new Androxal study

Regulators at the FDA have told Repros Therapeutics that its testosterone drug Androxal is not ready for Phase III.

Regulators at the FDA have told Repros Therapeutics ($RPRXD) that its testosterone drug Androxal is not ready for Phase III. Instead, the developer says the agency has asked for a fresh Phase IIb trial to test two doses of the therapy, a topical standard of care and a placebo in a four-arm study. And if Repros decides to ignore the agency, the developer will be doing so "at its own risk."

Androxal is in development for secondary hypogonadism, a condition that leads to low levels of testosterone. The Texas-based biotech has been seeking a special protocol agreement on its Phase III study of the therapy. Repros says its next move will be to submit data from a patient subset tracked in a completed trial. But investors weren't happy about the agency's position and RPRXD shares slid 19 percent after the announcement.

"Although the FDA did not agree with our proposal for moving into Phase 3 trials under an SPA at this time, they clearly stated that they are in support