Ipsen Expands Rare Disease Portfolio with $797 Million Acquisition of Memo

Rare Daily Staff

Paris-based Ipsen said it will acquire the Swiss biotech Memo Therapeutics in a deal worth up to $797 million (€700 million) as it bets on a potential first-in-class treatment for a serious complication that affects kidney transplant patients.

The deal includes a $228 million (€200 million) upfront payment and additional milestone payments tied to development, regulatory approvals, and sales. The transaction is expected to close in the third quarter of 2026.

The deal highlights growing industry interest in post-transplant complications—an area that has long lacked targeted therapies despite affecting tens of thousands of patients each year. If successful in late-stage trials, potravitug could become the first approved treatment specifically designed to combat BK virus infection, potentially improving long-term outcomes for kidney transplant recipients.

Ipsen, which has been steadily building its rare disease portfolio, said the acquisition aligns with its strategy of targeting conditions with high unmet medical need. The company will carve out Memo’s other assets, including its antibody discovery platform, into a separate entity retained by existing shareholders.

At the center of the deal is potravitug, an experimental monoclonal antibody designed to target BK polyomavirus (BKPyV), a common virus that can become dangerous in people with weakened immune systems. For kidney transplant recipients, reactivation of the virus can lead to BK virus–associated nephropathy (BKPyVAN), a condition that can damage the transplanted organ and ultimately cause graft failure.

There are currently no approved therapies that directly target BKPyV. Physicians often manage the condition by reducing immunosuppressive drugs, a strategy that can help control the virus but increases the risk that the body will reject the transplanted kidney.

Potravitug seeks to address that trade-off by neutralizing the virus itself. The antibody targets the virus’s outer protein, blocking its ability to enter cells and replicate.

In a mid-stage clinical trial involving 95 kidney transplant patients in the United States, the drug showed encouraging results. Patients treated with potravitug were more likely than those on placebo to see significant reductions in viral load, with some achieving undetectable levels of the virus. The therapy also led to improvements in kidney tissue damage linked to the infection, while appearing well tolerated, with no treatment-related serious adverse events reported.

Ipsen plans to advance potravitug into a pivotal phase 2/3 trial later this year, building on data from the SAFE KIDNEY II study presented at recent international transplant and nephrology meetings. The drug has already received fast-track designation from the U.S. Food and Drug Administration and orphan drug status in the European Union, both of which can help accelerate development.

While BK virus is usually harmless in healthy individuals, it reactivates in a substantial proportion of kidney transplant patients. Roughly 30 percent show elevated viral levels within the first year after transplant, and severe cases can lead to dialysis or the need for another transplant.

“With potravitug,” said Christelle Huguet, head of R&D for Ipsen, “we have the opportunity to add a promising first-in-class asset to our rare disease pipeline and address the significant clinical consequences of BK virus–associated nephropathy in kidney transplant recipients, where current standards of care can compromise transplant success and graft outcomes.”

Photo: Christelle Huguet, head of R&D for Ipsen