Ipsen agreed to acquire Switzerland-based Memo Therapeutics in a deal valued at up to roughly $800 million, adding potravitug, an investigational antibody for BK polyomavirus–associated kidney disease in transplant recipients. Memo investors will receive €200 million (about $227 million) upfront with additional milestone payments tied to development, regulatory, and sales milestones. Ipsen said potravitug targets a virus that lacks approved targeted therapies for the indication, with Phase 2 results reported as showing viral load suppression and resolution of biopsy-proven nephropathy in a significant proportion of patients. The company expects to initiate a pivotal Phase 2/3 trial later this year, after the regulatory designations of fast-track and orphan-drug status. Strategically, the transaction follows Ipsen’s recent move to buy Kartos Therapeutics for a separate hematology opportunity, reinforcing Ipsen’s focus on building late-stage rare-disease capacity through acquisitions rather than internal discovery alone.