PM1091

PM1091 is an investigational biparatopic antibody-drug conjugate (ADC) targeting Delta-like ligand 3 (DLL3), developed by Biotheus using its proprietary AI-guided antibody discovery platform. DLL3 is an atypical Notch ligand that is highly and selectively expressed on the surface of small cell lung cancer (SCLC) and other neuroendocrine neoplasms, while remaining largely absent in normal tissues. PM1091 features a biparatopic antibody design that binds to two distinct, non-overlapping epitopes on the DLL3 extracellular domain. This approach is engineered to enhance binding avidity and trigger superior receptor-mediated internalization compared to traditional monospecific antibodies. Once internalized, the ADC releases a cytotoxic payload, typically a topoisomerase I inhibitor, to induce DNA damage and apoptosis in the target tumor cells. Preclinical studies have demonstrated that PM1091 achieves potent cytotoxicity across various DLL3-expressing cell lines and significant tumor regression in xenograft models, while maintaining a favorable safety profile in non-human primate studies. PM1091 is currently being evaluated in Phase 1 clinical trials for patients with SCLC and other DLL3-positive solid tumors.

Other names

biparatopic anti-DLL3 antibody-drug conjugateAI-guided biparatopic DLL3-targeting ADC