LEO Pharma plans $435M Dersimelagon rights deal

LEO Pharma announced the acquisition of worldwide rights to dersimelagon from Tanabe Pharma for up to $435 million in upfront and near-term milestone payments, with potential downstream milestones and tiered royalties on net sales. Dersimelagon is an oral MC1R agonist in late-stage development for erythropoietic protoporphyria and X-linked protoporphyria, two rare conditions that cause severe sun sensitivity, and it aims to increase skin melanin to shield against phototoxic reactions. The therapy has shown encouraging Phase 3 results, including extended sunlight exposure time and reduced pain events, and an NDA was submitted to the FDA in 2026, with Fast Track and Orphan Drug designations in place. If approved, dersimelagon would be the first oral treatment for EPP and XLP, addressing a significant unmet need and potentially enabling a commercial launch in 2027. The deal aligns with LEO’s strategy to strengthen its medical dermatology portfolio through targeted acquisitions and partnerships, building on recent activity with Spevigo and Replay’s HSV gene therapy platform. By expanding into rare genetic skin diseases, LEO aims to diversify and accelerate growth while pursuing future listings and broader global reach.