French biopahram company Ipsen and Schlieren-based Memo Therapeutics AG announced today they have entered into a definitive share purchase agreement under which Ipsen has agreed to acquire all issued and outstanding shares of Memo Therapeutics AG. The anticipated acquisition is focused on potravitug, which is a Phase II clinical-stage antibody against the BK polyomavirus (BKPyV). BK polyomavirus associated nephropathy (BKPyVAN) is a serious and frequent clinical complication in renal transplanted patients that can lead to graft loss and transplant failure. Potravitug was granted fast-track designation from the U.S. Food and Drug Administration (FDA) in May 2023 and orphan drug designation in the European Union in December 2025.
Under the terms of the agreements, shareholders of Memo Therapeutics AG will receive a 200 million EUR payment on a cash-free and debt-free basis at closing of the transaction, and deferred payments contingent upon the achievement of specified development, regulatory approval and sales-based milestones, for a total potential consideration in excess of 700 million EUR. Memo Therapeutics is backed by investors including Ysios Capital, Kurma Partners, Pureos Bioventures, Swisscanto, Redalpine, Verve Ventures, Vesalius Biocapital and Adjuvant Capital.
Memo Therapeutics AG’s assets not related to potravitug, notably including its collaboration with CSL on the Rec-IgG Project and the DROPZYLLA antibody discovery platform, as well as Memo Therapeutics AG’s employees who are not directly involved in the potravitug program, will be transferred to a newly incorporated subsidiary, Memorises Bio, and retained by Memo Therapeutics AG’s shareholders via a carve-out implemented prior to the closing of the transaction. Memorises Bio has already been registered in the canton of Zurich. Board members include Erik van den Berg, Christoph Esslinger and Lars Spenger.
The transaction is expected to close during Q3 2026, subject to fulfilment of customary closing conditions. The impact of this proposed mid-stage acquisition is factored into Ipsen’s current full-year guidance.
Potravitug is a monoclonal antibody directed against the BK virus VP1 capsid protein. It acts by blocking viral attachment and cellular entry, thereby preventing infection of host cells and subsequent viral replication. The Phase II SAFE Kidney II trial[i] is the largest placebo-controlled clinical trial for the treatment of BKPyVAN in kidney transplanted patients with 95 patients across 22 sites in the U.S. Topline results demonstrated efficacy with potravitug. The SAFE KIDNEY III trial initiation is planned later this year.
The DROPZYLLA technology is an antibody repertoire copying engine with high-throughput screening capabilities. By retrieving and expressing antibody genes from millions of B cells at single-cell resolution and preserving cognate heavy- and light-chain pairing, DROPZYLLA also perfectly enables the development and manufacture of recombinant polyclonal IgG.