A Phase III Study of SYS6010 Versus Chemotherapy in HER2-Negative, EGFR-Positive Recurrent or Metastatic Breast Cancer

This is a randomized, open-label, multicenter study designed to evaluate the efficacy and safety of SYS6010 injection versus investigator's choice of standard chemotherapy in patients with unresectable locally advanced or metastatic breast cancer that is HER2-negative with centrally confirmed EGFR expression, who have received at least one but no more than two prior lines of systemic chemotherapy for advanced or metastatic disease. Approximately 400 patients will be enrolled and randomized in a 1:1 ratio to receive either SYS6010 injection or investigator's choice of chemotherapy. Patients randomized to the experimental arm will receive SYS6010 injection。 Patients randomized to the control arm will receive investigator's choice of standard chemotherapy, which may include eribulin, capecitabine, gemcitabine, or vinorelbine, administered per local label and institutional standard practice. This study aims to determine whether SYS6010 provides clinically meaningful improvement in PFS compared with standard chemotherapy in patients with HER2-negative, EGFR-expressing advanced breast cancer. The primary endpoint is progression-free survival (PFS) assessed by a blinded independent central review (BICR) per RECIST v1.1. Secondary endpoints include overall survival (OS), investigator-assessed PFS, objective response rate (ORR), clinical benefit rate (CBR), disease control rate (DCR), duration of response (DoR), safety and tolerability, quality of life, pharmacokinetics, and immunogenicity.