Eribulin mesylate in combination with ivonescimab as first-line treatment for unresectable locally advanced or metastatic triple-negative breast cancer(EMIT): study protocol for a single-arm, multicenter clinical trial

Background Advanced triple-negative breast cancer (TNBC) has an extremely poor prognosis, and current therapies offer limited benefits for patients with low programmed cell death ligand 1(PD-L1) expression. This study innovatively proposes a “novel chemotherapy + bispecific antibody” model. Eribulin Mesylate (hereinafter referred to as Eribulin), a novel microtubule inhibitor, kills tumor cells while remodeling the tumor microenvironment. When combined with the PD-1/VEGF bispecific antibody Ivonescimab, it concurrently dismantles immunosuppression and angiogenesis to synergistically overcome immunotherapy resistance. Methods This is a multicenter, open-label, single-arm clinical trial designed to enroll 29 patients with locally advanced or metastatic TNBC who have not received prior systemic anticancer therapy, and who are either ineligible for radical surgical resection or local therapy, or have experienced disease progression following postoperative adjuvant therapy. The primary endpoint is the objective response rate (ORR) assessed by Investigator Assessment (INV) at each participating center based on strict adherence to Response Evaluation Criteria in Solid Tumors version 1.1(RECIST v1.1) criteria. Secondary endpoints include progression-free survival (PFS), overall survival (OS), duration of response (DoR), and safety. Exploratory endpoints involve potential biomarkers, the correlation between PD-L1 expression and efficacy, and patient-reported outcomes (PROs). Discussion This combination regimen is expected to leverage the synergistic advantages of “chemotherapy-promoted immunity and potent bispecific antibody efficacy,” providing novel evidence-based medical evidence for the first-line treatment of metastatic TNBC and thereby effectively addressing significant unmet clinical needs. Clinical Trial Registration http://www.chictr.org.cn/ , identifier ChiCTR2600117652.