STRO-003

STRO-003 is a next-generation, site-specifically conjugated antibody-drug conjugate (ADC) designed to target the receptor tyrosine kinase-like orphan receptor 1 (ROR1), which is overexpressed in various solid tumors and hematological malignancies. The ADC consists of a monoclonal antibody directed against ROR1, precisely engineered to carry eight exatecan payloads via β-glucuronidase-cleavable linkers. Exatecan acts as a DNA topoisomerase I inhibitor, causing DNA disruption and inducing potent tumor cell killing, bystander activity, and immunogenic cell death. Preclinical studies have demonstrated robust anti-tumor efficacy in models of non-small cell lung cancer (NSCLC) and triple-negative breast cancer (TNBC), including those with low or heterogeneous ROR1 expression. The linker technology aims to improve safety by reducing off-target toxicity such as neutropenia and lung injury commonly seen with other TOPO-1 inhibitor-based ADCs. STRO-003 is being developed for broad application across both solid tumors and hematologic cancers[1][3][4][5][6].