Receptor CDCP1 is a potential target for personalized imaging and treatment of poor outcome HER2+, triple negative and metastatic ER+/HER2- breast cancers.

Purpose: Receptor CUB-domain containing- protein 1 (CDCP1) was evaluated as a target for detection and treatment of breast cancer.

Experimental Design: CDCP1 expression was assessed immunohistochemically in tumors from 423 patients (119 triple-negative breast cancer (TNBC); 75 HER2+; 229 ER+/HER2- including 228 primary tumors, 229 lymph node and 47 distant metastases). Cell cytotoxicity induced in vitro by a CDCP1-targeting antibody-drug conjugate (ADC), consisting of the human/mouse chimeric antibody ch10D7 and the microtubule disruptor monomethyl auristatin E (MMAE), was quantified, including in combination with HER2-targeting ADC T-DM1.