Molecular Partners presents three posters at AACR 2026, with new preclinical data for first Switch-DARPin T cell engager MP0632 and DLL3 Radio-DARPin MP0712

ZURICH-SCHLIEREN, Switzerland and CONCORD, Mass, April 19, 2026 (GLOBE NEWSWIRE) — 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 new preclinical data across three posters at the American Association for Cancer Research (AACR) Annual Meeting 2026.

The first poster outlines preclinical data supporting proof-of-concept for MP0632, a logic-gated Switch-DARPin CD3 T cell engager with CD2 co-stimulation designed to selectively kill cells co-expressing mesothelin (MSLN) and epithelial cell adhesion molecule (EpCAM). MP0632 leads to regression of established tumors expressing both EpCAM and MSLN, with minimal impact on tumors expressing only one antigen, indicating a favorable therapeutic window. In addition, the Switch-DARPin candidate allowed for safe use of potent costimulation for efficient tumor cell killing with low cytokine release profile. The data support MP0632’s potential as clinical lead candidate for the treatment of ovarian cancer and other MSLN- and EpCAM-positive solid tumors.

“We are excited to present new data on MP0632, our first logic-gated T cell engager candidate leveraging our Switch-DARPin technology. We designed MP0632 to achieve potent yet safe tumor-localized immune activation through incorporation of CD2 costimulation and through unmasking of the CD3 binder upon binding to two co-expressed tumor antigens – MSLN and EpCAM. We are looking forward to advancing MP0632 and building on the strong preclinical data package, which indicates its potential to make a difference to cancer patients,” said Martin Steegmaier, Ph.D., CSO of Molecular Partners.

The second poster presents a computational workflow to identify and prioritize tumor-associated antigen pairs for improved tumor-selectivity and safety in support of designing novel Switch-DARPin candidates, such as MP0632. This scalable, data-driven platform provides a strong foundation for the discovery of next-generation multispecific immunotherapies. This workflow could also be leveraged for the identification of complementary tumor antigen pairs to address heterogeneous tumors, which could enable the design of next-generation multispecific Radio-DARPin candidates.

The third poster outlines the molecular characteristics of MP0712, the Company’s first ²¹²Pb-based Radio-DARPin candidate, with high affinity binding to DLL3 and optimized half-life extended properties. MP0712’s properties are hypothesized to facilitate sustained tumor uptake through repeated DLL3 internalization-replenishment despite low cell surface density of the target, thereby supporting the attractive biodistribution profile of MP0712 observed in preclinical studies as well as in first patient imaging data from a Named Patient Access Program in South Africa using MP0712 with ²⁰³Pb.

MP0712, co-developed with strategic partner Orano Med, is evaluated in an ongoing Phase 1/2a trial in the US for the treatment of patients with small cell lung cancer (SCLC) and other DLL3-expressing neuroendocrine cancers.

Details of the presentations at AACR 2026:

Logic-gated Switch-DARPin T cell engager with CD2 co-stimulation for improved safety and efficacy in MSLN and EpCAM co-expressing ovarian cancer
Session Category: Immunology
Session Title: T Cell Engagers 1
Session Start: 4/20/2026 9:00 AM PT
Session End: 4/20/2026 12:00 PM PT
Location: Poster Section 10
Poster Board Number: 16
Poster Number: 1624

Logic-gated Switch-DARPin–based immune cell engagers guided by data-driven tumor-antigen profiling: A computational workflow for the development of cancer immunotherapies
Session Category: Bioinformatics / Computational Biology / Systems Biology / Convergent Science
Session Title: Application of Bioinformatics to Cancer Biology 3
Session Start: 4/20/2026 2:00 PM PT
Session End: 4/20/2026 5:00 PM PT
Location: Poster Section 1
Poster Board Number: 16
Poster Number: 2691

Molecular characteristics of MP0712, a clinical stage ²¹²Pb-based Radio-DARPin candidate for targeted anti-DLL3 radiotherapy of small cell lung cancer (SCLC)
Session Category: Experimental and Molecular Therapeutics
Session Title: Targeted Radiopharmaceuticals and Combination Strategies in Cancer Therapy
Session Start: 4/22/2026 9:00 AM PT
Session End: 4/22/2026 12:00 PM PT
Location: Poster Section 17
Poster Board Number: 16
Poster Number: 7197

The posters will be made available on Molecular Partners’ website after the presentations.