NRx Pharmaceuticals Inc. (NASDAQ: NRXP) announced it received correspondence from the FDA's Bioequivalence Program stating the agency has not identified bioequivalence deficiencies in the company's preservative-free ketamine application.

The FDA communication regarding the Abbreviated New Drug Application is considered preliminary until final supervisory review. The company continues to expect an FDA decision in summer 2026 as previously announced.

The proposed NRx product would be the first ketamine formulation without benzethonium chloride, a preservative not listed by FDA as Generally Recognized as Safe. Current ketamine formulations contain this preservative, which is no longer permitted in certain topical consumer applications.

NRx stated it anticipates demonstrating three years of room temperature stability and sterility for its preservative-free product. The company has filed patents in the US and internationally to support the formulation.

The preservative-free product is manufactured in the United States. The FDA recently awarded a Commissioner's National Priority Voucher to support establishment of a new US manufacturing source of ketamine drug substance.

"We deeply appreciate the FDA's timely review of the bioequivalence aspects of our generic drug application," said Dr. Jonathan C. Javitt, NRx's CEO and Chairman.

The ANDA process for the preservative-free ketamine is separate from NRx's New Drug Application to use ketamine for depression treatment, which is being pursued through the FDA Division of Psychiatry Products.

NRx is also preparing a New Drug Application under Fast Track Designation to expand intravenous ketamine use for treating patients with severe depression who may have suicidal ideation.