HANXBIO-B (03378) has announced the initiation of a Phase I clinical trial for its self-developed drug candidate, HX111, an OX40-targeting antibody-drug conjugate (ADC). The trial, which focuses on relapsed or refractory lymphoma and solid tumors, has recently completed the first patient dosing. HX111 exhibits high affinity and specificity in binding to the OX40 molecule on the surface of tumor cells. Following efficient internalization into the tumor cells, the linker is cleaved by lysosomal proteases, releasing a potent payload that induces tumor cell apoptosis. The OX40 molecule is highly expressed in certain lymphomas and solid tumors, which currently lack effective treatments, representing a significant unmet clinical need. HX111, developed by the company, is the first OX40-targeting ADC drug worldwide to have publicly entered the clinical stage, making it a first-in-class (FIC) candidate. This therapeutic area remains in the early stages of exploration, granting HX111 a notable first-mover advantage with the potential to address a critical gap in the treatment landscape for these cancers.