Aldeyra Therapeutics, Inc. Receives Special Protocol Assessment Agreement Letter from the U.S. Food and Drug Administration for Adx-2191 for the Treatment of Primary Vitreoretinal Lymphoma

Published: 2025-06-26 11:37:54 ET ALDX

Published on 06/26/2025 at 11:37

Aldeyra Therapeutics, Inc. announced receipt of a Special Protocol Assessment Agreement Letter from the U.S. Food and Drug Administration (FDA) for ADX-2191 (methotrexate injection, USP), an investigational drug candidate, for the treatment of primary vitreoretinal lymphoma (PVRL), a rare and potentially fatal cancer currently lacking FDA-approved therapy. Based on a pre-New Drug Application (NDA) meeting with the FDA in December 2022, Aldeyra submitted a literature-based NDA of ADX-2191 for the treatment of PVRL, which was accepted for Priority Review in March 2023. In June 2023, Aldeyra received a Complete Response Letter that stated that the available literature was not sufficient to demonstrate efficacy and that adequate and well-controlled trials were required for approval.

The FDA subsequently agreed that a single clinical trial in addition to literature references will be sufficient to support NDA resubmission. The clinical trial proposed in the Special Protocol Assessment will compare cancer cell clearance after 30 days of therapy in up to 20 patients following 1:1 randomization to receive either a single intraocular injection or eight intraocular injections of ADX-2191. The frequency of methotrexate injections has been linked to cancer cell clearance in patients with PVRL, and approximately five injections are required on average to achieve cancer cell clearance.

The clinical trial is expected to begin in the second half of 2025 and conclude in 2026. ADX-2191 has received FDA Orphan Drug Designation for the treatment of primary vitREoretinal lymphoma and retinitis pigmentosa. The approach is to develop pharmaceuticals that modulate protein systems, instead of directly inhibiting or activating single protein targets, with the goal of optimizing multiple pathways at once while minimizing toxicity.