FDA issues ‘study may proceed’ letter for clinical trial for MDD treatment

The FDA has issued a “study may proceed” letter to biopharmaceutical company Vistagen for its newly filed investigational new drug application for the clinical development of PH10, a treatment for major depressive disorder.

The letter greenlights a phase 1 clinical trial of 12 participants that intends to confirm the safety profile of PH10, which was established through three previous clinical trials conducted in Mexico.

“People living with major depressive disorder urgently need new and differentiated therapies — we are committed to addressing that need,” Vistagen CEO Shawn Singh said in a release from the company. “The FDA’s clearance to advance our clinical program for PH10 in the U.S. is another important milestone for our company.”

In a small (n = 30) exploratory randomized, double-blind, placebo-controlled parallel design phase 2A study, a 6.4 µg dose of PH10 — administered intranasally twice a day for 8 weeks — reduced depressive symptoms within 1 week.

PH10 was well-tolerated and did not cause psychological side effects or safety concerns that may be associated with other approved pharmacological therapies for MDD.

“The FDA’s greenlight will now enable us to first confirm its favorable safety profile in a small Phase 1 study next quarter and then seek consensus with the FDA regarding our Phase 2B development plan for PH10 in major depressive disorder,” Singh said in the release.