Nordic Capital-backed LEO Pharma to acquire dersimelagon rights from Bain-owned Tanabe for $435m

• The deal covers worldwide rights to an oral, once-daily treatment for two rare, sunlight-triggered genetic skin disorders
• The therapy has completed Phase 3 testing, with an FDA new-drug application already under review
• The acquisition follows LEO Pharma’s 2025 Boehringer Ingelheim partnership and its purchase of Replay’s gene-therapy platform

Nordic Capital-backed LEO Pharma has agreed to acquire worldwide rights to dersimelagon, an investigational oral therapy, from Tanabe Pharma, a Japanese pharmaceutical company owned by Bain Capital since 2025, for undisclosed terms. The deal adds a late-stage rare-disease asset to LEO Pharma’s dermatology pipeline as the company builds out its position in high-unmet-need skin conditions.

Dersimelagon is a once-daily, small-molecule MC1R agonist being developed for erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP), rare genetic disorders that cause severe sunlight-induced skin pain, rash and, in some cases, liver damage. The drug is designed to raise skin melanin levels, helping protect against phototoxic reactions.

The compound has completed Phase 3 testing, and an application for FDA approval was submitted for review in June 2026, though it has not yet been approved by any regulatory authority. Dersimelagon has also received FDA Fast Track and Orphan Drug designations. If approved, it would be the first oral therapy available for EPP and XLP.

Under the agreement, LEO Pharma will pay up to $435 million in upfront and near-term milestone payments, plus potential downstream milestones and tiered royalties on net sales. The transaction is subject to customary closing conditions, including regulatory approvals.

“By addressing a clear unmet need in a rare skin disease, dersimelagon represents a compelling opportunity to expand our rare dermatology pipeline with a late-stage oral therapy candidate,” said Christophe Bourdon, CEO of LEO Pharma. Bourdon added that the deal fits the company’s strategy of “identifying and investing in high-impact innovation in medical dermatology.”

The acquisition builds on LEO Pharma’s 2025 partnership with Boehringer Ingelheim around Spevigo (spesolimab) and its recent purchase of Replay’s gene-therapy platform, part of a broader push into rare dermatology in markets including the US and Japan. LEO Pharma said the deal is expected to raise its 2026 investment for pre-launch activities and its 2027 spending for a potential launch; an updated financial outlook is due alongside its H1 2026 results, also published today.

JP Morgan Securities advised LEO Pharma on the transaction, and Latham & Watkins acted as legal counsel.

Editor’s note: This news brief was produced with the assistance of artificial intelligence.