DXA038-CPT113

DXA038-CPT113 is a novel 2+2 IgG-like bispecific antibody-drug conjugate (ADC) designed for the selective treatment of nasopharyngeal carcinoma (NPC). Developed by Hangzhou DAC Biotechnology, the agent co-targets the Epstein-Barr virus (EBV) envelope glycoprotein GP220/350 and the epidermal growth factor receptor (EGFR). The bispecific antibody (DXA038) consists of a high-affinity humanized VHH targeting GP220/350 and a low-affinity EGFR-binding arm derived from nimotuzumab, a design intended to enhance tumor selectivity and minimize on-target/off-tumor toxicity. The antibody is conjugated to CPT113, a topoisomerase I inhibitor payload, via a cleavable linker with an average drug-to-antibody ratio (DAR) of 4. In preclinical studies, DXA038-CPT113 demonstrated superior in vitro and in vivo efficacy compared to monospecific EGFR-targeted ADCs, particularly in EBV-positive NPC models.