Aldeyra Therapeutics Inc. (NASDAQ: ALDX) received a Complete Response Letter from the U.S. Food and Drug Administration rejecting its New Drug Application for reproxalap, a treatment for dry eye disease.

The FDA stated there was "a lack of substantial evidence consisting of adequate and well-controlled investigations" that the drug would be effective under proposed conditions. The agency said the application "failed to demonstrate efficacy in adequate and well controlled studies in the treatment of signs and symptoms of dry eye disease."

The FDA cited "inconsistency of study results" that raised "serious concerns about the reliability and meaningfulness of the positive findings." The agency concluded that "the totality of evidence from the completed clinical trials does not support the effectiveness of the product."

No safety or manufacturing concerns were identified in the review, consistent with prior evaluations of reproxalap. The FDA provided label drafts in December 2025 and March 2026, though Aldeyra said label negotiations were not completed.

The FDA recommended exploring reasons for trial failures and identifying populations where reproxalap may be effective. The agency did not recommend additional trials or request submission of confirmatory evidence.

Aldeyra does not currently plan to pursue additional clinical trials and intends to request a Type A meeting with the FDA to understand actions needed for approval. The target meeting date is within 30 days of the request under Prescription Drug User Fee Act goals.

As of December 31, 2025, Aldeyra reported $70 million in cash, cash equivalents, and marketable securities, expected to support operations into 2028.

The Lexington, Massachusetts-based biotechnology company develops therapies for immune-mediated diseases. Its product candidates include RASP modulators and ADX-2191 for retinal conditions.