Ipsen agreed to acquire Memo Therapeutics AG in a deal valued at up to €700 million ($800 million), adding a first-in-class monoclonal antibody candidate targeting BK polyomavirus associated nephropathy. The transaction includes €200 million ($228 million) plus development, regulatory, and sales milestone payments. Memo’s lead asset, potravitug, is in Phase II evaluation (NCT05769582) and targets the BK virus VP1 capsid protein. BK polyomavirus frequently reactivates in immunosuppressed kidney transplant recipients, contributing to nephropathy and threatening graft outcomes. Potravitug has received US FDA Fast Track designation (granted in 2023) and EU orphan drug designation (December 2025), supporting regulatory engagement in a rare but high-impact transplant complication. Ipsen framed the acquisition as reinforcing its rare disease and nephrology ambitions, while Memo positioned the transaction as a path to full clinical and commercial development for transplant patients with BKPyV infection.