An antibody‑drug conjugate, M‑3554, demonstrated strong antitumor activity in neuroblastoma xenograft models and shows engineered features intended to reduce GD2‑associated pain, according to disclosed preclinical data. The ADC couples a GD2‑targeting antibody to an exatecan payload via a β‑glucuronide linker, and developers report efficacy signals that support further development in soft tissue sarcoma and pediatric neuroblastoma. The data suggest M‑3554 may address tolerability limitations of prior anti‑GD2 antibodies; ADC design choices such as linker stability and payload class will determine therapeutic index. Sponsors will need to validate safety and pain mitigation in clinical studies to advance the program.