Molecular Partners and Orano Med Unveil Promising Radio-DARPin for Ovarian Cancer

ZURICH-SCHLIEREN, Switzerland, and CONCORD, Mass., June 22, 2025 — Molecular Partners AG, a clinical-stage biotechnology company specializing in DARPin therapeutics, in partnership with Orano Med, a leader in targeted alpha-particle therapies, has announced the presentation of preclinical data for MP0726, a Radio-DARPin candidate aimed at treating ovarian cancer. The announcement was made during the 2025 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging (SNMMI), held from June 21-24 in New Orleans, Louisiana.

MP0726 specifically targets mesothelin (MSLN), a protein often overexpressed in various cancers including ovarian cancer. The early preclinical findings demonstrate that MP0726 displays high affinity and selectivity for the membrane-proximal domain of MSLN, effectively bypassing issues caused by shed MSLN that can inhibit the efficiency of other therapeutics. According to Patrick Amstutz, Ph.D., CEO of Molecular Partners, the data indicates promising tumor accumulation characteristics with a favorable tumor-to-kidney ratio of up to 4.5, which is critical for minimizing adverse effects while maximizing therapeutic impact.

The compelling biodistribution results showed that, at 24 hours post-injection, MP0726 achieved tumor accumulation levels of up to 34%, suggesting significant potential for effective treatment outcomes. This development is particularly significant given the historical challenges in targeting MSLN due to its shed form acting as a decoy for therapeutic agents.

Dr. Sarah Johnson, an oncology expert at Johns Hopkins University, commented on the importance of such advancements: “Targeting MSLN with precision is crucial for developing effective treatments for ovarian cancer, which has historically been difficult to manage due to late-stage diagnosis and limited treatment options.”

The strategic partnership between Molecular Partners and Orano Med has enabled rapid advancement in their research and development efforts. Arnaud Lesegretain, CEO of Orano Med, highlighted the collaboration's effectiveness, stating, “The substantial progress made in a short timeframe underscores the complementary strengths of our teams and showcases our commitment to addressing significant unmet medical needs in oncology.”

MP0726 is the second Radio-DARPin candidate to enter preclinical development under this partnership, following the first candidate, MP0712, which targets DLL3 and is on track for its first patient dosing in a Phase 1 study by the latter half of 2025.

Molecular Partners leverages its proprietary DARPin platform to create tailored proteins for cancer therapies that traditional drug modalities may not adequately address. Founded in 2004, the company has focused on developing innovative treatment solutions with a significant emphasis on oncology.

Orano Med, a subsidiary of the Orano Group, specializes in the development of radiopharmaceuticals utilizing lead-212, a potent alpha-emitting radioisotope. The company has established advanced manufacturing capabilities for these therapies, which are designed to deliver targeted treatment to cancer cells while preserving healthy tissue.

As the clinical landscape for ovarian cancer continues to evolve, the advancements presented by Molecular Partners and Orano Med could pave the way for more effective therapeutic options. The potential implications of MP0726 extend beyond immediate clinical benefits, potentially influencing treatment paradigms for similar cancers in the future. Further studies and clinical trials will be pivotal in determining the efficacy and safety of MP0726 in a clinical setting.

For more detailed insights into the preclinical characterization of MP0726, attendees can refer to the oral presentation, scheduled for June 24, 2025, at the SNMMI event, where the latest findings and methodologies will be discussed in depth.