Tarsus Pharmaceuticals has completed its previously announced acquisition of Alkeus Pharmaceuticals, adding worldwide rights to the investigational retinal disease candidate gildeuretinol acetate (ALK-001) to its ophthalmic pipeline. The acquisition, initially announced August 6, 2026, closed following satisfaction of the customary closing conditions under the companies’ definitive merger agreement.

Under terms of the agreement, Tarsus paid approximately $450 million upfront, consisting of $270 million in cash and $180 million in Tarsus common stock. The deal also includes milestone payments of up to $350 million upon potential regulatory approval and first commercial sale, and low single-digit tiered descending royalties as a percentage of gildeuretinol net sales. 

With the transaction complete, Tarsus gains ALK-001, an investigational, late-stage small molecule being developed for Stargardt disease. The once-daily oral therapy is designed to reduce the formation and accumulation of toxic vitamin A dimers in the retina while preserving the normal visual cycle.

“Completing the Alkeus acquisition marks an important step forward in our vision to build a leading eye care company,” said Bobby Azamian, MD, PhD, CEO and chairman of Tarsus. “ALK-001 is highly complementary to our core strengths and has the potential to become a foundational medicine for people living with Stargardt disease, a potentially blinding disease with no FDA-approved treatment.”

ALK-001 is currently being evaluated in the global phase 3 NORTHSTAR trial, with topline results anticipated in 2029. According to Tarsus, the investigational therapy has been studied in more than 400 individuals and has demonstrated what the company characterized as a promising tolerability and efficacy profile.

The FDA has granted ALK-001 Breakthrough Therapy, Orphan Drug, Fast Track, and Rare Pediatric Disease designations for Stargardt disease.