Leo Pharma is sticking to its mission of strengthening its pipeline in 2026, penning a $435 million deal for a rare skin disease drug from Tanabe Pharma that's awaiting an approval decision by the FDA.
The drug, called dersimelagon, is an oral melanocortin-1 receptor agonist, designed to treat patients with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP). The two rare genetic conditions cause severe and painful skin reactions when exposed to the sun and sometimes certain artificial light.
By activating melanocortin-1, dersimelagon is meant to trigger production of melanin in the skin. This, in turn, stimulates pigmentation “almost like a protective shield,” so that patients can now spend time outdoors, Leo's Chief Scientific Officer Jacob Pontoppidan Thyssen, M.D., Ph.D., explained to Fierce.
In return for the worldwide rights to dersimelagon, Tanabe will be in line for up to $435 million in combined upfront and near-term milestone payments. There will potentially be more milestone payments down the line as well as tiered royalties, although the companies didn't offer a detailed breakdown of the financials.
Tanabe kicked off the year by touting a phase 3 win for dersimelagon in both EPP and XLP, later explaining that the drug had significantly increased time-to-first prodromal symptoms, such as burning, tingling, itching or stinging, from sunlight exposure to nearly 30 minutes at Week 16. Based on that study, the Japan-headquartered pharma submitted the drug to the FDA in June for approval.
Dersimelagon proved a tempting prize for Leo, whose CEO Christophe Bourdon told Fierce at the start of the year that the Danish dermatology specialist is on the hunt for more deals. The company's commercial portfolio includes the likes of the eczema drug Adbry, Enstilar foam for plaque psoriasis and the pustular psoriasis drug Spevigo.
But Leo didn't yet have a therapy for EPP, with the only FDA-approved treatment marketed by Australia's Clinuvel Pharmaceuticals. That treatment, branded as Scenesse, has a similar melanin-stimulating mechanism of action to dersimelagon. But Scenesse requires patients to receive an implant under the skin every eight weeks, while dersimelagon can be administered orally.
“Every dermatologist knows the Leo brand, and what we are now doing with dersimelagon is really strengthening the innovation pipeline and hope to bring the asset that will completely transform the life of patients,” Bourdon told Fierce.
Leo's hunt for new therapies has included the $105 million upfront payment to Boehringer Ingelheim last year for Spevigo, as well as $50 million four months ago for Replay and its preclinical gene therapy platform for the rare skin disease dystrophic epidermolysis bullosa.