Molecular Partners and Orano Med Announce First Patients Dosed in Phase 1/2a Trial of DLL3 Radio-DARPin MP0712

ZURICH-SCHLIEREN, Switzerland and CONCORD, Mass. and VILLEJUIF, France, July 02, 2026 (GLOBE NEWSWIRE) — Ad hoc announcement pursuant to Art. 53 LR – Molecular Partners AG (SIX: MOLN; NASDAQ: MOLN), a clinical-stage biotech company developing a novel class of custom-built protein drugs known as DARPin therapeutics (“Molecular Partners”), and Orano Med, a clinical-stage radiopharmaceutical company and a pioneer in the development of lead-212 (²¹²Pb) based targeted alpha therapies (TAT), today announced that the first patients were dosed in the ongoing US multicenter Phase 1/2a study of drug candidate MP0712.

MP0712, targeting the tumor-associated protein delta-like ligand 3 (DLL3) and carrying the therapeutic payload ²¹²Pb, is the lead Radio-DARPin candidate being developed under a strategic partnership between Molecular Partners and Orano Med. DLL3 is a highly relevant target for radiopharmaceutical therapy due to its abundant expression in tumors of patients with small cell lung cancer (DLL3 is present in over 85% of SCLC tumors) and multiple other aggressive neuroendocrine tumors, while expression in healthy tissues is low.

“MP0712 is a Radio-DARPin designed to attack tumors by specifically leveraging DLL3 biology. With the first patient now in repeat dosing and Cohort 1 now recruited, we are establishing the clinical safety profile of this novel therapy in real time. Working closely with investigators in our trial, we remain on track to report initial study data in 2026, and, also paving the way for other Radio-DARPin candidates to move forward,” said Patrick Amstutz, Ph.D., CEO of Molecular Partners.

“The dosing of the first patients in this study marks an important step for Orano Med and our collaboration. It further illustrates the potential of lead-212 to support a broad clinical pipeline of targeted alpha therapies, leveraging its versatility across different vector formats to address a wide range of cancer types,” said Frédéric Desdouits, Ph.D., CEO of Orano Med.

The program employs a “matched-pair” approach, in which a diagnostic imaging agent and a therapeutic agent share the same targeting molecule, allowing for accurate prediction of tumor uptake prior to treatment. Following an imaging and dosimetry step with ²⁰³Pb-labeled MP0712, patients in the Phase 1/2a study receive up to four doses of ²¹²Pb-labeled MP0712 within their assigned dose level cohort. Dosing of patients is ongoing in cohort 1, with patients moving to repeat dosing. The study contains up to four dose levels. At present, five centers are open and actively recruiting in the US, with additional sites planned to open this year (ClinicalTrials.gov: NCT07278479). Initial data from the MP0712 Phase 1/2a study are expected in the upcoming months, with a more comprehensive dataset on safety and efficacy in 2027.