LEO Pharma Closes Dersimelagon Acquisition as FDA Accepts NDA

LEO Pharma announced that the US Food and Drug Administration (FDA) has accepted the New Drug Application (NDA) for dersimelagon for filing and granted Priority Review for the investigational treatment of erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP).

The FDA has set a Prescription Drug User Fee Act (PDUFA) action date by the end of February 2027. The company also completed its acquisition of worldwide rights to dersimelagon from Tanabe Pharma, according to the announcement. 

Dersimelagon Targets Rare Phototoxic Disorders EPP and XLP

The regulatory submission follows results from the global phase 3 randomized, double-blind, placebo-controlled INSPIRE trial. According to Tanabe Pharma, dersimelagon achieved statistically significant and clinically meaningful results across primary and secondary endpoints, including prolonging average daily sunlight exposure before the onset of prodromal symptoms. The press release did not provide numerical efficacy or safety results.

If approved, dersimelagon could become the first oral treatment for EPP and XLP. The drug has not been approved by the FDA or another regulatory authority.

“We are pleased to have completed the acquisition of dersimelagon and to have reached this important regulatory milestone,” Christophe Bourdon, CEO of LEO Pharma, said. “The FDA’s Priority Review brings us one step closer to potentially providing a new treatment option for patients.”

Source

LEO Pharma press release. September 18, 2026.