Molecular Partners Announces Presentation of First Imaging and Dosimetry Data of DLL3-Targeting Radiotherapy MP0712 in Patients at TWC 2026

ZURICH-SCHLIEREN, Switzerland and CONCORD, Mass., Feb. 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” or the “Company”), today announced the presentation of first patient imaging and dosimetry data of MP0712, its DLL3-targeted Radio-DARPin candidate co-developed with strategic partner Orano Med, at the 8th Theranostics World Congress (TWC), taking place in Cape Town, South Africa on January 29-February 1.

The data, presented in two posters and an oral presentation, are highly supportive of the clinical development plans of MP0712 carrying the therapeutic isotope ²¹²Pb for patients with small cell lung cancer (SCLC) and other DLL3-expressing neuroendocrine cancers. The data from five evaluable patients were generated with MP0712 carrying the diagnostic isotope ²⁰³Pb under the leadership of Dr. Mike Sathekge as part of a Named Patient Access Program under the legal framework for compassionate care in South Africa (also referred to as Section 21 of the Medicines and Related Substances Act).

“I am highly encouraged by the data generated in my group suggesting a favorable distribution profile of MP0712, a DLL3-targeted radiopharmaceutical for patients with SCLC and NEC cancers,“ said Dr. Mike Sathekge, Professor and Head of Nuclear Medicine at the University of Pretoria and Steve Biko Academic Hospital, and President and CEO of the Nuclear Medicine Research Infrastructure (NuMeRI). During the imaging step with ²⁰³Pb, we observed in our patients a promising tumor uptake, paired with a clean profile in healthy organs indicating a therapeutic potential for MP0712. I look forward to seeing this confirmed in the upcoming Phase 1 study.”

The images show specific uptake as well as robust accumulation of MP0712 in tumor lesions, with limited uptake in healthy tissues, as intended. MP0712 is half-life engineered to promote tumor uptake over time via the DLL3 internalization and replenishment mechanism. Biodistribution of MP0712 in patients with various DLL3-expressing cancers, including small cell lung, urothelial, and other neuroendocrine cancers, provides a strong rationale for broad clinical development of MP0712 in SCLC and neuroendocrine cancers. The dosimetry extrapolations support the Phase 1/2a study design of MP0712 with ²¹²Pb as therapeutic radioactive payload.

“The clinical data presented at TWC 2026 validate our assumptions and support the ongoing U.S. Phase 1/2a study, enabling us to initiate dosing of MP0712 within a potentially therapeutic range,” said Patrick Amstutz, Ph.D., CEO of Molecular Partners. “These encouraging results reinforce our ambition to become a leader in alpha‑targeted therapies for patients with small cell lung cancer and other neuroendocrine malignancies. We thank the NuMeRi team for the strong collaboration and look forward to continuing our work together across our emerging pipeline. The biodistribution and dosimetry data demonstrate exactly what we aim to achieve with Radio‑DARPins — strong tumor accumulation with rapid clearance from healthy tissues. We look forward to sharing initial Phase 1 safety and activity data in 2026 as we advance our Radio-DARPin platform to deliver potent alpha‑emitting radioisotopes to solid tumors across multiple indications.”

The Phase 1/2a study of MP0712 (ClinicalTrials.gov: NCT07278479) is a multi-center study in the U.S., with the objectives to assess safety and determine a recommended phase 2 dose for MP0712 carrying the potent therapeutic isotope ²¹²Pb. The study, which contains an imaging and dosimetry step with ²⁰³Pb-labeled MP0712, is ongoing with initial clinical data expected in 2026.

Details of the presentations at TWC 2026

Two Poster Presentations:

• Abstract 207: First-in-human evaluation of DLL3-Targeting ²⁰³Pb/²¹²Pb DARPin MP0712 SPECT/CT in high-grade neuroendocrine malignancies: safety, biodistribution, and optimal imaging windows
• Abstract 260: First-in-human dosimetry of the DLL3-targeting ²⁰³Pb/²¹²Pb theranostic DARPin MP0712 in patients with small cell lung cancer and high-grade neuroendocrine tumours

Time & Presenters: Friday January 30, 2026, 17:30-18:30 SAST, by the NuMeRI team of Dr. Mike Sathekge.

Oral Presentation:
Title: From DARPins to Radio-DARPin Therapeutics – Progressing the first Radio-DARPin Therapeutic MP0712 (²¹²Pb x DLL3) for SCLC into the clinic

Time: Saturday January 31, 2026; 10:30-12:00 SAST;
Session: “Antibody Drug Conjugates and Diversification of the Mechanisms of Action”
Presented by Molecular Partners

Webcast to be held on Monday February 2 at 8:00 ET (14:00 CET):
In addition to the presentations at TWC, Molecular Partners will host a webcast to discuss the new clinical data. Prof. Ken Herrmann, Chairman of the Scientific Advisory Board at Molecular Partners, will comment on the clinical data in the webcast.

Details as follows:
For Participants who want to listen and view slides: Please register here.

For Participants who may want to ask a question following the presentation: Please register here. These participants will be provided with additional dial-in instructions to join the live conference call and will have the ability to “raise their hand” and ask a verbal question during the Q&A.