Molecular Partners presents new MP0712 data

Molecular Partners (MOLN) announced the presentation of new data on MP0712, its Radio-DARPin targeting DLL3, at the Targeted Radiopharmaceuticals Summit Europe, highlighting first human images and supporting mechanism of action data. MP0712 is being developed with strategic partner Orano Med for the treatment of patients with small cell lung cancer and other neuroendocrine cancers. Molecular Partners presents a case with images of a patient as courtesy of the Nuclear Medicine Research Infrastructure in South Africa. The NuMeRI team plans to report the full imaging and dosimetry data of MP0712 at the Theranostics World Congress in January 2026. The presented case study of a patient who received 203Pb-MP0712 indicates specific uptake in the tumor lesions visible at 24 hours and sustained over 4 days, with limited accumulation in healthy organs, as intended. To promote tumor uptake via internalization over time, MP0712 is half-life engineered to maintain sufficient amounts of drug in the blood, visible at the early imaging time points. These early results are in line with previously presented pre-clinical data and further support the intended mechanism of action of MP0712. The imaged patient was initially diagnosed with Stage 3 small cell lung cancer and had a treatment history of radiotherapy and chemotherapy; the patient was then re-classified as Stage 4 post imaging with MP0712 due to observed liver metastases. This patient is a case example of a series of patients who received MP0712 for imaging use as part of a Named Patient Access Program under the legal framework in South Africa for compassionate care. The company believes that, due to the prior treatment and tumor stage of the patient, this case is illustrative of the patient population likely to be recruited in its planned Phase 1/2a in the US. In addition to first-in-human images, the presentation at TRP highlights that MP0712 is rapidly internalized and accumulates intracellularly in DLL3-expressing cells in vitro. The data suggests that MP0712 can achieve high tumor uptake in spite of very low DLL3 expression levels, leveraging internalization and replenishment pathways of DLL3 as well as optimal binding properties and tunable half-life of the DLL3-binding DARPin. The Phase 1 investigational new drug application for MP0712, for the treatment of small cell lung cancer and other DLL3-expressing neuroendocrine cancers, has been filed. Dialogue with the FDA is ongoing and, pending regulatory clearance, the Phase 1 trial is expected to initiate by the end of 2025. The Phase 1/2a study is a multi-center study in the US, with the objectives to assess safety and determine a recommended phase 2 dose for MP0712. The study contains an imaging and dosimetry step with 203Pb-labeled MP0712. The Company expects initial clinical data from the study in 2026.