Phase 1 dose escalation of XMT-1522, a novel HER2-targeting antibody-drug conjugate (ADC), in patients (pts) with HER2-expressing breast, lung and gastric tumors.

2546Background: XMT-1522 is comprised of 10-15 molecules of the payload AF-HPA, an auristatin-derivative with two-step intra-tumor metabolism intended to optimize therapeutic index, conjugated to a...