Molecular Partners, Orano Med present MP0712 data at SNMMI

Molecular Partners and Orano Med announced the debut of their lead Radio-DARPin therapy, or RDT, candidate MP0712, targeting DLL3, in an oral presentation. The data presented provide support for MP0712’s clinical development in small-cell lung cancer, or SCLC, and other DLL3+ neuroendocrine tumors. MP0712 features 212Pb as a potent therapeutic payload. The data were presented at the Society of Nuclear Medicine and Molecular Imaging, or SNMMI, 2024 annual meeting taking place June 8-11 in Toronto, Canada. MP0712 is the first high-affinity DLL3-targeting RDT combining the advantages of DARPins as small protein-based delivery vectors and the short-lived alpha particle-emitting radioisotope 212Pb. DLL3 is expressed in greater than 85% of SCLC patients and in other neuroendocrine tumors, while its expression in healthy tissues is low, making it a priority target for radiopharmaceutical therapy. SCLC is an aggressive form of lung cancer, with a poor five-year survival prognosis and a high unmet need for patients. The preclinical package presented at SNMMI includes in vivo data demonstrating strong and homogeneous tumor uptake of 212Pb-DLL3 RDT, as well as significant and durable inhibition of tumor growth at clinically-relevant doses. The safety results seen across the tested dosing levels in mice suggest a favorable safety profile and potential for clinical use. 212Pb-DLL3 RDT candidates were engineered by tuning their biophysical properties to achieve an optimal safety/antitumor activity profile in vivo. The selected lead candidate, MP0712, demonstrated a biodistribution profile in mouse xenograft tumor models, with close to 60% of injected dose detectable in the tumor and encouraging tumor to kidney ratios over two. The replicable DARPin learnings from the development of MP0712, as well as additional platform improvements, are being taken forward to the broader RDT portfolio. The intrinsic properties of DARPins, such as small size, high affinity and selectivity, and a broad range of potential targets, make them ideal vector candidates for radiopharmaceutical therapeutics. Historically, small protein-based vectors faced challenges with kidney accumulation and toxicity, as well as suboptimal tumor uptake. Molecular Partners has evolved its RDT platform to address these limitations with its half-life extension technologies and surface engineering approaches, while preserving the advantages of the small protein format. In addition, Molecular Partners’ DARPin candidates have been clinically validated with over 2500 patients treated worldwide and multiple DARPin mechanisms have been demonstrated as biologically active in for different indications, contributing to validation of the drug class and Molecular Partners in the field of DARPin engineering and development.