This is the third recent acquisition conducted by Denmark’s LEO Pharma in medical dermatology, a portfolio that marked 12% growth in the first half of the year.
LEO Pharma has put up $435 million to acquire a rare disease drug for two conditions that cause photosensitivity, expanding the Danish biotech’s dermatology portfolio.
The once-daily oral melanocortin 1 receptor (MC1R) agonist, called dersimelagon, was owned by Tanabe Pharma and has completed Phase 3 development for erythropoietic protoporphyria (EPP) and X-linked proto-porphyria (XLP). The drug was submitted for approval to the FDA for both indications in June, according to LEO’s Tuesday morning announcement.
Both conditions cause photosensitivity that can trigger severe reactions to sunlight. These include skin rashes, swelling, redness, burning sensations and sometimes liver damage, and limits a patient’s ability to be outside. Dersimelagon is designed to increase skin melanin to reduce the penetration of sunlight and guard against such reactions.
In the Phase 3 INSPIRE trial, which read out in March, dersimelagon prolonged average sun exposure by 23 minutes during weeks 12 through 16 as compared to placebo. The effect grew to 29 minutes by week 16 in a supplementary analysis. The therapy also reduced pain events.
LEO will now take over the worldwide rights to dersimelagon for $435 million, including an upfront payment and additional undisclosed milestones and royalties offered later on.
Dersimelagon has been granted fast track and orphan drug designations from the FDA. If approved, the therapy would be the first treatment for EPP and XLP to make it to market, LEO said.
LEO plans to launch the drug in 2027, with preparations in 2026 expected to increase the company’s overall investments for the year.
The deal with Japan’s Tanabe is the latest conducted by LEO in medical dermatology, after the 2025 partnership with Boehringer Ingelheim for IL-36R antagonist Spevigo. LEO also recently acquired Replay Therapeutics’ next-generation HSV gene therapy platform.
Also on Tuesday, LEO reported 10% revenue growth at constant currencies to DKK 7.26 billion ($1.12 billion) for the first half. This was led by growth in the dermatology portfolio, which grew 12%. Key drugs Anzupgo, Spevigo and Adtralza/Adbry had a combined revenue increase of 50%.
