LEO Pharma buys Replay to expand rare skin gene therapy push

LEO Pharma said on April 30, 2026, that it has entered a definitive agreement to acquire Replay, a San Diego-based gene therapy company developing treatments for rare genetic skin diseases. The deal gives LEO a high-payload herpes simplex virus, or HSV, platform designed for topical delivery to the skin, with Replay’s lead preclinical program aimed at dystrophic epidermolysis bullosa, or DEB. LEO said the Replay team will join the company, while Reuters reported the transaction includes $50 million upfront, plus milestone payments and tiered single-digit royalties. (leo-pharma.com)

Why it matters: For veterinary professionals, this is another sign that dermatology drug development is moving deeper into gene-based, precision approaches for fragile-skin disorders. While the deal is in human medicine, it reflects growing confidence in topical gene delivery for skin disease, especially after recent regulatory progress in DEB, including FDA approvals for Vyjuvek in 2023 and Zevaskyn in 2025. For clinicians who follow translational dermatology, the platform is notable because HSV vectors can carry larger genes and may be redosed, features LEO says could make the approach useful across multiple rare genetic skin diseases. (leo-pharma.com)

What to watch: Watch for whether LEO moves Replay’s DEB program from preclinical work into the clinic and whether it expands the platform into additional rare dermatology indications, as executives told Reuters they see proof-of-concept potential beyond a single disease. (wdez.com)