LEO Pharma announces FDA acceptance of dersimelagon NDA with Priority Review and closes acquisition from Tanabe Pharma

BALLERUP, Denmark, September 18, 2026 - LEO Pharma, a global leader in medical dermatology, today announced that the U.S. Food and Drug Administration (FDA) has accepted for filing and granted Priority Review to the New Drug Application (NDA) for dersimelagon, a potential first-in-class oral therapy for EPP and XLP. The FDA has set a Prescription Drug User Fee Act (PDUFA) action date by the end of February 2027.

LEO Pharma also announced that it has successfully closed the acquisition of worldwide rights to dersimelagon from Tanabe Pharma, following the fulfilment of customary closing conditions. The transaction combines Tanabe Pharma’s innovation with LEO Pharma’s six decades of dermatology expertise and global platform to support dersimelagon’s development as a potential oral treatment option for patients with EPP and XLP.

“We are pleased to have completed the acquisition of dersimelagon and to have reached this important regulatory milestone,” said Christophe Bourdon, CEO of LEO Pharma. “Patients living with EPP or XLP face a devastating lifelong burden of sunlight-induced pain and a significant impact on their daily lives. The FDA’s Priority Review brings us one step closer to potentially providing a new treatment option for patients and addressing the significant unmet medical need in these rare skin diseases.”

Dersimelagon is an investigational, once-daily oral small-molecule MC1R agonist being developed for EPP and XLP. The acquisition strengthens LEO Pharma’s late-stage rare dermatology pipeline and builds on the company’s recent innovation activities, including its acquisition of Replay’s next-generation HSV gene therapy platform and its partnership with Boehringer Ingelheim for Spevigo® (spesolimab).

EPP and XLP are rare, severe and lifelong genetic disorders that can cause intense sunlight-induced skin pain and significantly limit patients’ ability to spend time outdoors. Symptoms may include rash, swelling, redness and burning sensations. In some cases, patients may also experience liver damage. Earlier this year, Tanabe Pharma announced results from the global, randomized, double-blind, placebo-controlled Phase 3 INSPIRE study, which showed that dersimelagon demonstrated statistically significant and clinically meaningful outcomes across primary and secondary endpoints, including key functional outcomes such as a significant prolongation of average daily sunlight exposure time to first prodromal symptoms.

If approved, dersimelagon could become the first oral treatment for EPP and XLP, helping to address a significant unmet medical need. Dersimelagon has not yet been approved by the FDA or any other regulatory authority, and its safety and efficacy have not been established by any regulatory authority.

The terms and financial assumptions of the transaction remain unchanged from LEO Pharma’s announcement on 18 August 2026. LEO Pharma has acquired worldwide rights to dersimelagon for up to USD 435 million in upfront and near-term milestone payments, plus potential downstream milestones and double-digit up to mid-teens tiered royalties on net sales. The closing does not affect LEO Pharma’s 2026 financial outlook, which already reflects the acquisition and was set out in the H1 2026 Interim Report published on 18 August 2026.

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