LEO Pharma, a global leader in medical dermatology delivering innovative solutions for skin disease, today announces that it has entered into an agreement to acquire worldwide rights to dersimelagon from Tanabe Pharma. Dersimelagon is an oral, once-daily small MC1R agonist being developed for EPP and XLP.

EPP and XLP are rare and severe genetic diseases that cause severe sunlight-induced skin damage and can significantly limit patients’ ability to spend time outdoors. Symptoms may include skin rash, swelling, redness, burning sensations and, in some cases, liver damage. Dersimelagon is designed to increase skin melanin, helping reduce sunlight penetration and protect against phototoxic reactions.2,3

“Patients living with EPP or XLP face the devastating lifelong burden of severe reactions to sunlight, and there is a clear need for treatment options that can make a meaningful difference in their everyday lives,” said Christophe Bourdon, CEO, LEO Pharma. “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. This acquisition is closely aligned with our strategy of identifying and investing in high-impact innovation in medical dermatology, where LEO Pharma brings deep disease understanding, and a global commercial footprint to bring this therapy to patients.”

“EPP and XLP are devastating lifelong diseases that can severely limit patients’ ability to live everyday lives free from sunlight-induced pain, and dersimelagon has the potential to become an important new treatment option,” said Akihisa Harada, CEO of Tanabe Pharma. “LEO Pharma’s established expertise in medical dermatology and global reach make it the ideal partner to realize the full potential of dersimelagon and, if approved, bring this innovative treatment to patients.”

The acquisition reflects LEO Pharma’s strategy to continue to strengthen its medical dermatology portfolio through targeted partnerships, acquisitions, and external innovation, with rare dermatology as a key focus area. Building on the 2025 partnership with Boehringer Ingelheim for Spevigo® (spesolimab) and the recent acquisition of Replay’s next-generation HSV gene therapy platform, LEO Pharma continues to pursue opportunities in rare skin diseases with high unmet need. This includes key innovation markets such as the U.S. and Japan, where the company’s dermatology expertise and global capabilities can help advance new treatment options for patients.

Dersimelagon has been granted both U.S. FDA Fast Track Designation and Orphan Drug Designation, and an NDA for the treatment of EPP and XLP was submitted to the U.S. FDA for regulatory review in June 2026, but has not yet been approved by the FDA or any other regulatory agency. Dersimelagon’s safety and efficacy have not been established by any regulatory authority. If approved, dersimelagon would represent the first oral therapy for the treatment of EPP and XLP and help address an area of significant unmet need.

Earlier this year, Tanabe Pharma announced results from the global, randomized, double-blind, placebo-controlled Phase 3 INSPIRE study of EPP and XLP which showed 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.4 The Phase 3 data was presented as a late breaker at the 2026 American Academy of Dermatology Annual Meeting (AAD).

Under the terms of the agreement, LEO Pharma will acquire worldwide rights to dersimelagon from Tanabe Pharma for up to USD 435 million in up front and near-term milestone payments together with potential downstream milestones and tiered royalties on net sales.

The transaction is subject to customary closing conditions, including applicable regulatory approvals. The acquisition is expected to increase LEO Pharma’s investments in 2026 for pre-launch activities and in 2027 for a potential launch. An update on the financial outlook for 2026 will be provided in connection with the publication of LEO Pharma’s H1 2026 Interim Report on 18 August 2026.

J.P. Morgan Securities plc acted as financial advisors to LEO Pharma in this transaction and Latham Watkins LLP acted as legal advisors.

About LEO Pharma

LEO Pharma is a global leader in medical dermatology. We deliver innovative solutions for skin health, building on a century of experience with breakthrough medicines in healthcare. We are committed to making a fundamental difference in people’s lives, and our broad portfolio of treatments serves close to 100 million patients in over 70 countries annually. LEO Pharma is co-owned by majority shareholder the LEO Foundation and, since 2021, Nordic Capital. Headquartered in Denmark, LEO Pharma has a team of 4,400 people worldwide. Together, we reach far beyond the skin. For more information, visit www.leo-pharma.com.

About Tanabe Pharma

Tanabe Pharma Corporation is a Japan-focused, innovation-driven pharmaceutical company guided by its mission, “Creating hope for all facing illness.” Founded in 1678, the Company is one of Japan’s oldest pharmaceutical companies and is committed to addressing unmet medical needs through R＆D, business development, and strategic partnerships with the aim of improving the lives of patients.

For more information, visit Tanabe Pharma Corporation

References:

  1. ClinicalTrials.gov. National Library of Medicine (U.S.). INcreased Sun Exposure Without Pain In Research Participants With EPP or XLP (INSPIRE). Identifier: NCT06144840. https://clinicaltrials.gov/study/NCT06144840.

  2. Wensink D, et al. Liver involvement in patients with EPP. 2021

  3. Balwani M. Erythropoietic Protoporphyria and X-Linked Protoporphyria: pathophysiology, genetics, clinical manifestations, and management. 2019

  4. Tanabe Pharma Corporation. Tanabe Pharma Announces Positive Data from Phase 3 INSPIRE Study of Dersimelagon in EPP and XLP. Press release. March 30, 2026. Available at: https://www.tanabe-pharma.com/en/news/rel_260330/main/0/link/e_rel_260330.pdf

Media gallery

About The Author
Business Wire