Tarsus Pharmaceuticals is acquiring Alkeus Pharmaceuticals in a deal worth up to $800 million, adding an experimental drug for a rare, blinding eye disease.
Under the agreement, Tarsus will pay $270 million in cash plus $180 million in stock up front, with up to $350 million more tied to regulatory approval and first sale, plus sales royalties to Alkeus’s backers (Bain Capital Life Sciences and TCGX). It is expected to close later in 2026.
The drug
The prize is gildeuretinol (ALK-001), a modified form of vitamin A designed to prevent the formation of damaging deposits in the eye. It is being developed for Stargardt disease, an inherited condition that causes progressive vision loss. More than 400 patients have received it — some for seven years — and one placebo-controlled study showed a 29.5% slowing of the yearly growth of those deposits; the FDA granted breakthrough therapy designation in 2021. A Phase 3 trial of roughly 230 patients is ongoing, with results expected in 2029.
A notable backer
Vertex founder and veteran chemist Josh Boger served as Alkeus’s executive chairman and has called gildeuretinol “the most elegant possible way for a drug” to work — potentially “the most perfect drug” if it succeeds. For Tarsus, the deal is a bet on a rare-disease program with long follow-up but a readout still years away.