ALK and rhabdomyosarcoma: This is followed by extensive in vitro and in vivo validation of a humanized ALK-directed ADC, conjugated to the sequence-selective DNA minor-groove binding crosslinking agent pyrrolobenzodiazepine dimers35 (CDX0239-PBD), in ALK-expressing neuroblastoma, fusion-positive rhabdomyosarcoma and colorectal carcinoma supporting clinical development and a broad therapeutic application of an ALK-directed ADC.