Molecular Partners Presents New Preclinical Data Highlighting Radio-DARPins’ Amenability to Multiple Isotopes

Core Insights - Molecular Partners AG is advancing its Radio-DARPin candidates, which are designed for targeted alpha therapy, and will present new preclinical data at the 3rd Global Radiopharmaceuticals Development Summit in Shanghai on March 19-20, 2026 [1][2] Group 1: Radio-DARPin Candidates - The presentation will highlight the suitability of Radio-DARPin candidates for different isotopes, showcasing two candidates with comparable biodistribution profiles when labeled with Lutetium-177 (Lu) or Lead-203 (Pb) [2] - Studies in tumor-bearing mice indicate similar uptake and washout rates for both Radio-DARPin candidates, suggesting that imaging with Lu can predict behavior with the therapeutic isotope Actinium-225 (Ac) [2] Group 2: Development Flexibility - The CEO of Molecular Partners stated that the Radio-DARPin design allows for the interchangeability of alpha-isotopes, providing flexibility to evaluate candidates in an isotope-agnostic manner [3] - This feature enables the selection of the most suitable therapeutic isotope based on initial clinical data without restarting the entire drug discovery process, which is a significant advantage for tailoring treatments to patient needs [3] Group 3: Clinical Trials and Collaborations - The DLL3-targeted Pb-based Radio-DARPin candidate MP0712 is currently in a Phase 1/2a trial in the US, with imaging data supporting its clinical development for small cell lung cancer and other DLL3-expressing neuroendocrine cancers [5] - In February 2026, Molecular Partners entered into an agreement with Eckert & Ziegler to support the development and manufacturing of Radio-DARPin therapeutics, covering activities for Radio-DARPins with Ac as the therapeutic payload and Lu as the imaging payload [6] Group 4: Technology and Innovation - Molecular Partners' Radio-DARPins are designed to deliver potent alpha-emitting isotopes to tumor lesions, addressing limitations of traditional radioligand therapy such as kidney accumulation and toxicity [7] - The proprietary Radio-DARPin platform enhances the delivery of radioactive payloads while preserving the advantages of small protein formats, thus unlocking a broad range of tumor targets for targeted radiopharmaceuticals [7] Group 5: Company Overview - Molecular Partners AG is a clinical-stage biotech company focused on developing DARPin therapeutics for medical challenges that other treatment modalities cannot address, with proprietary programs in various stages of development [10]