A new cancer drug showed rapid tumor targeting in a South African patient with small cell lung cancer, paving the way for a U.S. trial starting late 2025.

Molecular Partners shared initial human imaging data from a South African patient with small cell lung cancer treated with MP0712, a radiotherapy drug targeting DLL3, showing rapid and sustained tumor uptake within 24 hours using the isotope 203Pb, with minimal accumulation in healthy organs. The results support MP0712’s mechanism, which enables high tumor targeting even at low DLL3 levels due to rapid internalization and recycling. The company has filed a Phase 1 IND application with the FDA, and a U.S. Phase 1/2a trial, including imaging and dosimetry, is expected to start by year-end 2025, with initial data anticipated in 2026.