Molecular Partners AG, a clinical-stage biotech developing DARPin-based therapeutics, announced a development agreement with Eckert & Ziegler to advance its pipeline of Radio-DARPin candidates for imaging and therapeutic alpha isotopes, including Actinium-225 and Lutetium-177. The non-exclusive agreement will leverage Eckert & Ziegler’s infrastructure, including its Alpha Laboratory in Berlin, Germany, dedicated to work with alpha emitters.

The partnership will support Molecular Partners’ wholly-owned Radio-DARPin pipeline, enabling the development of candidates tailored to specific targets and disease biology. The lead candidate, MP0712, targeting DLL3, recently entered a Phase 1/2a trial for small cell lung cancer (SCLC), underlining the clinical progress of the program. The company plans to present preclinical data on multiple isotopes at the 3rd Global Radiopharmaceuticals Development Summit in Shanghai in March 2026.

Alexander Zürcher, chief operating officer at Molecular Partners, said: “We are pleased to work with Eckert & Ziegler, a global leader in radiopharmaceutical manufacturing. This agreement will expand the potential of Radio-DARPins as vectors for precise delivery of therapeutic alpha-emitting isotopes to tumors, now including Actinium-225, in addition to Lead-212 through our long-term strategic partnership with Orano Med.” He added: “The promise of Radio-DARPins is underlined by the progress of our lead candidate MP0712, targeting DLL3, having just opened the Phase 1/2a trial for the treatment of patients with small cell lung cancer.”

Under the agreement, Eckert & Ziegler will provide development support for Radio-DARPins with Actinium-225 and Lutetium-177 payloads, using state-of-the-art laboratories and expertise in radiochemistry. The collaboration allows Molecular Partners to accelerate technical development while tailoring candidates to patient needs based on vector and isotope properties.

Dr Harald Hasselmann, CEO of Eckert & Ziegler, said: “Supporting highly innovative companies such as Molecular Partners in developing their promising technology platforms is a key objective of our group. Bringing together our expertise in isotopes, radiochemistry and development infrastructure with our partners’ innovations will enable patients worldwide to benefit from new treatments in the future.”

The agreement strengthens Molecular Partners’ position in targeted alpha therapy, combining DARPin technology with precise delivery of therapeutic isotopes, while leveraging specialized manufacturing capabilities. The collaboration and clinical advancement of MP0712 demonstrate the potential of Radio-DARPin therapeutics to address high unmet needs in oncology.