Leo Pharma is paying $50 million for Replay, a US gene-writing biotech, and its preclinical gene therapy program for a rare skin disease. The purchase is focused on Replay’s high-payload engineered HSV delivery vector and platform aimed at reprogramming biology for next-generation genomic products. The announced target is a preclinical HSV therapy designed as a topical gel for dystrophic epidermolysis bullosa, intended to deliver corrective gene function directly to skin. Leo said the acquisition supports its strategy to invest in dermatology-focused innovation, while Replay emphasized HSV’s suitability for skin-cell targeting and redosing.