The US Food and Drug Administration (FDA) has granted Fast Track designation for development of ADX-2191 (Aldeyra Therapeutics). ADX-2191 has already received Orphan Drug Designation from the FDA for both retinitis pigmentosa (RP) and primary vitreoretinal lymphoma, as well as from the European Medicines Agency for inherited retinal dystrophies and primary large B-cell lymphomas of immune-privileged sites. Aldeyra also received a Special Protocol Assessment from the FDA for a clinical trial of ADX-2191 in primary vitreoretinal lymphoma, which is expected to begin in the second half of 2025. A phase 2/3 clinical trial is expected to be initiated this year as well.

ADX-2191 is a sterile intravitreal formulation of methotrexate, designed to be vitreous-compatible and optimized for administration in the eye. Phase 2 trial results announced in 2023 showed improvements in retinal sensitivity among patients receiving ADX-2191, and its new fast track status provides more frequent interactions with the FDA. Specifically, the designation may allow for rolling review, priority review, or accelerated approval if criteria are met. This designation, combined with orphan status, creates a regulatory pathway that is intended to expedite development. 

There are currently no FDA-approved treatments for most forms of retinitis pigmentosa, which is characterized by progressive retinal cell death and vision loss.