A multiple center, open-label, single-arm, phase II clinical trial of MRG002, an HER2-targeted antibody-drug conjugate, in patients with HER2-low expressing advanced or metastatic breast cancer.

1102 Background: MRG002 is a novel HER2-targeted ADC, composed of a sugar-modified trastuzumab, MMAE payload and a cleavable vc-linker. MRG002 was effective in HER2-low expressing breast cancer in preclinical studies. Hence, we conducted the phase II study to evaluate the safety and anti-tumor efficacy of MRG002 in HER-low breast cancer. Methods: HER2 low tumor expression was determined by a central lab and had to be …