Memo Therapeutics presents full Phase II potravitug data at ATC 2026

Memo Therapeutics AG has presented complete Phase II data for potravitug, its lead monoclonal antibody candidate targeting BK polyomavirus (BKPyV), at the American Transplant Congress 2026 in Boston. The full SAFE KIDNEY II dataset, including long-term follow-up to 38 weeks, was delivered as an oral presentation by Dr Darshana Dadhania of Weill Cornell Medicine and New York Presbyterian Hospital.

BKPyV reactivates in up to half of all kidney transplant recipients. Of those who develop viraemia, up to 70% progress to BKPyV-associated nephropathy, a condition that materially raises the risk of graft failure and death. Despite this burden, no approved treatment exists, leaving clinicians reliant on reducing immunosuppression, a strategy that carries its own risk of rejection.

Trial results

The randomised, double-blind, placebo-controlled study showed potravitug produced a sustained antiviral effect well beyond the active dosing period. By week 38, 24.4% of patients in the treated arm had achieved undetectable BKPyV-DNAemia, compared with 13.0% in the placebo group. A greater than two-log reduction in viral load was recorded in 40.3% of potravitug patients versus 24.7% of controls. On the tissue endpoint, the proportion of patients with biopsy-proven BKPyV-associated nephropathy fell from 51.2% to 31.6% in the potravitug arm by week 20, with no corresponding improvement observed in placebo recipients. The compound was well tolerated, with no treatment-related serious adverse events reported across the study.

Dr Dadhania, a principal investigator on the trial, said the data demonstrate "sustained antiviral activity observed six months after the last active treatment," describing potravitug as a potential targeted therapy for a patient group with no current options.

A companion poster at the congress, presented by researchers from UT Southwestern Medical Center and UCLA, offered supportive epidemiological context. A systematic literature review found a significant correlation between the duration of BKPyV viraemia and the incidence of nephropathy (r=0.625, p=0.0019), strengthening the clinical rationale for early viral suppression.

Regulatory path and market context

Potravitug received orphan drug designation from the European Medicines Agency in December 2025. Memo Therapeutics plans to initiate the pivotal SAFE-KIDNEY 3 trial later this year, with the company positioning the therapy as a potential first-in-class disease-modifying treatment in the indication. The company has cited a peak annual market potential of up to $2 billion, though this figure is a company estimate and has not been independently validated.

Chief executive Erik van den Berg said the ATC presentations, following earlier data readouts at the European Renal Association Congress earlier in June, continue to build the clinical case ahead of Phase III.

The transplant nephrology space currently has no approved antiviral specifically licensed for BKPyV, leaving a clear regulatory opportunity for the first product to demonstrate efficacy and safety in a pivotal study. Potravitug's dual profile of viral load reduction and nephropathy regression across a randomised placebo-controlled design positions it well for regulatory discussions, though the pivotal trial will need to demonstrate effects on hard clinical endpoints such as graft survival to support full approval. The Zurich-based company is privately held, backed by a syndicate that includes Ysios Capital, Kurma Partners and Adjuvant Capital.