MQX-5904

MQX-5904 is a topical formulation of the antimetabolite methotrexate, developed by MediQuest Therapeutics for the treatment of nail psoriasis (fingernail psoriasis). The formulation utilizes MediQuest's proprietary topical amphiMatrix (TAM) drug delivery technology, which is designed to facilitate the penetration of the active ingredient through the thickened nail plate and skin to reach the underlying site of inflammation. As a methotrexate-based therapy, MQX-5904 acts by inhibiting dihydrofolate reductase (DHFR) and thymidylate synthase, enzymes critical for folate metabolism and DNA synthesis. This mechanism suppresses the rapid cell proliferation and inflammatory processes characteristic of psoriasis. The drug was evaluated in a Phase IIb dose-response and safety clinical trial (NCT00666354) in the UK, but development appears to have stalled following the completion of this study in 2009.