Memo Therapeutics AG Presents Long Term Follow-Up Data from its Phase II SAFE KIDNEY Trial of Potravitug and Real World Data on the Challenges and Re-source Utilization of Managing Kidney Transplant Recipients at ASN Kidney Week Meeting

PRESS RELEASE

Memo Therapeutics AG Presents Long Term Follow-Up Data from its Phase II SAFE KIDNEY Trial of Potravitug and Real World Data on the Challenges and Resource Utilization of Managing Kidney Transplant Recipients at ASN Kidney Week Meeting

• Long term follow-up data shows a sustained and improved (vs. week 20) benefit of potravitug on BK polyomavirus viral load in kidney transplant recipients at week 38 (study end)
• Potravitug was well tolerated, with no treatment related serious adverse events reported

Schlieren / Zurich, Switzerland, 7 November, 2025 – Memo Therapeutics AG (“MTx”), a late-stage biotech company translating unique immune responses into superior medicines to treat viral infections and cancer, today announces that it has presented long term follow-up data from its Phase II SAFE KIDNEY trial of therapeutic antibody potravitug for the treatment of BK polyomavirus (BKPyV) infection in kidney transplant recipients (KTRs) at the American Society of Nephrology (ASN) Kidney Week Meeting from November 5–9, 2025, in Houston, Texas.

The data was presented under the title: ‘Potravitug for the Treatment of BK Polyomavirus Infection in Kidney Transplant Recipients: A Phase II, Randomized, Double-Blind, Placebo-Controlled Clinical Trial,’ demonstrated a sustained and improved (vs. week 20) benefit of potravitug on BKPyV viral load in KTRs at week 38 (study end). The treatment was well tolerated, with no treatment-related serious adverse events reported.

Viral levels lower than the lower limit of quantitation (<LLOQ) were observed in 17.5% and 12.9% for potravitug 1,000 mg and placebo at week 20 and 24.4% and 13.0% at week 38. Furthermore, at this follow-up timepoint, ≥2-log₁₀ reductions, indicating a drop in viral levels of ≥99% vs baseline, occurred in 35.6 vs. 22.5% (adjusted OR 1.93 [0.67-5.54]) at week 20 and in 40.3 vs 24.7% (OR 2.11 [0.76-5.88]) in the potravitug and placebo groups, respectively, indicating a longer term response and reduction of viral load with potravitug.

Potravitug 1,000 mg showed a higher composite virologic response, defined as ≥1-log₁₀ decline in BKPyV-DNAemia in the absence of BKPyV-associated nephropathy (BKPyVAN): (57.2%) vs placebo (33.4%) (adjusted OR 2.79 [1.00-7.75]; nominal p=0.05). While biopsy proven BKPyVAN in the potravitug arm dropped from 51.2% at baseline to 31.6% at week 20; no change was seen in placebo group (23.8% to 24.4%).

"These long-term follow-up Phase II results provide further evidence that potravitug has the potential to become a transformative treatment for kidney transplant patients with BKPyV infection, with continued therapeutic benefit beyond our initial week 20 data," said Erik van den Berg, CEO of MTx. "There are currently no approved therapeutic treatments for BKPyV infection in kidney transplant recipients. We look forward to continuing discussions with regulatory bodies and progressing into Phase III development in 2026.”

Further data to be presented at the conference tomorrow will feature real world evidence from a study of first year outcomes, healthcare resource utilization and costs among kidney transplant patients in the United States. The data shows that in the year following kidney transplantation, patients experience many post-transplant care changes and have a high healthcare resource consumption, necessitating therapies like potravitug, to address these complications. Acute rejection and other adverse outcomes sometimes occur within the first 12 months following transplant. This was one of the largest studies ever conducted in a kidney transplant population, including over 35,000 patients followed via administrative claims to determine their post-transplant care journeys.

Potravitug was awarded U.S. FDA Fast Track designation in May 2023.

In July 2025, MTx announced promising topline results from its Phase II placebo-controlled clinical trial of potravitug at the World Transplant Congress.     

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Contacts
Memo Therapeutics AG
info@memo-therapeutics.com
ICR Healthcare	Amber Fennell, Ashley Tapp
memotx@icrhealthcare.com	+44 (0)20 3709 5700

About Memo Therapeutics AG
Memo Therapeutics AG (“MTx”) is a late-stage biotech company translating unique human immune responses into superior medicines through the development of best-in-class antibodies to treat viral infections and cancer. The Company’s lead program, potravitug, targeting BKPyV infection in kidney transplant recipients is planned to start Phase III clinical development in 2026. BKPyV infections decrease kidney functionality and longevity, and reduce patient survival. Potravitug has the potential to become a first-in-class BKPyV disease-modifying therapy for kidney transplant patients with a market potential of up to $2bn p.a..

Alongside potravitug, MTx is focused on discovering novel antibody-target-pairs in oncology. Underpinning MTx’s core assets is its proprietary DROPZYLLA^® technology, an antibody repertoire copying engine with high-throughput screening capabilities. MTx is a private company located in Schlieren / Zurich and backed by investors including Ysios Capital, Kurma Partners, Pureos Bioventures, Swisscanto, Vesalius Biocapital and Adjuvant Capital. Learn more at  www.memo-therapeutics.com, and on LinkedIn.

About BK polyomavirus in kidney transplant recipients
More than 100,000 kidney transplants are conducted worldwide every year. BKPyV can become reactivated in up to 50% of these patients and up to 70% of patients with BKPyV viremia develop BKPyV nephropathy, which significantly increases the risks of kidney loss and patient death.