SBE303

SBE303 is a novel antibody-drug conjugate (ADC) being developed by Samsung Bioepis for the treatment of advanced refractory solid tumors. It is engineered to target Nectin-4, a cell surface adhesion protein that is highly expressed in various cancers, including urothelial, lung, breast, and bladder cancers. As Samsung Bioepis' first novel ADC candidate, SBE303 aims to deliver a cytotoxic payload directly to tumor cells while minimizing systemic toxicity. The U.S. FDA cleared the Investigational New Drug (IND) application for SBE303 in December 2025, with a Phase 1 first-in-human clinical trial scheduled to begin in 2026 to evaluate its safety, tolerability, pharmacokinetics, and preliminary efficacy.