M3554

M3554 is a novel antibody-drug conjugate (ADC) targeting GD2, designed using a humanized ch14.18 anti-GD2 antibody linked to the topoisomerase I inhibitor (TOP1i) exatecan via a cleavable beta-glucuronide linker. This design aims to deliver potent cytotoxic activity specifically to GD2-expressing tumor cells, with demonstrated subnanomolar cytotoxicity against neuroblastoma cell lines and improved bystander effects compared to other TOP1i payloads. The drug is being developed for the treatment of advanced solid tumors with high GD2 prevalence, including neuroblastoma, soft tissue sarcoma, glioblastoma (IDH-wildtype), osteosarcoma, and other solid tumors. It is currently in Phase 1 clinical trials for these indications.