Anlotinib plus tislelizumab combined with chemotherapy as neoadjuvant treatment in triple-negative breast cancer: A prospective, single-arm, open-label phase II study.

Abstract

TPS618 Background: Neoadjuvant anti-PD-(L)1 therapy confers an improvement in pathological complete response (pCR) rate in unselected triple-negative breast cancer (TNBC). Combination of antiangiogenic agent plus immune checkpoint inhibitor and chemotherapy therapy for advanced TNBC is reported as a promising anti-tumor strategy presented in the FUTURE-C-PLUS study. Tislelizumab is a humanized immunoglobulin G4 anti-PD-1 monoclonal antibody engineered to minimize binding to FcγR on macrophages. Anlotinib is a novel multi-target tyrosine kinase inhibitor that effectively inhibit VEGFR, FGFR, c-KIT, c-MET and RET. Previous studies have proven the efficacy of both anlotinib monotherapy and combination with immune checkpoint inhibitor in advanced breast cancer. This phase II study aims to evaluate the efficacy and safety of anlotinib plus tislelizumab combined with chemotherapy as neoadjuvant treatment in TNBC. Methods: This is a prospective, single-arm, open-label, phase II trial. Eligible patients (pts) were women, aged 18-75 years, ECOG status 0-1, previously untreated invasive TNBC with histologically confirmed (cT1N1-2M0 or cT2-4N0-2M0). 32 pts will be enrolled and received 5 cycles of anlotinib (8 mg qd, d1-14; 21 days per cycle) with 6 cycles of tislelizumab (200 mg, once every 3 weeks) plus nab-paclitaxel (260 mg/m2, once every 3 weeks) and anthracycline (epirubicin 75 mg/m2 or doxorubicin 60 mg/m2), followed by surgery. The primary endpoint is pathological complete response rate (pCR, ypT0/Tis ypN0) and the secondary endpoints include invasive disease-free survival (iDFS), event-free survival (EFS), overall survival (OS), and safety. A sample size of 32 patients was estimated to provide a 80% power to detect a difference of 25% in pCR at a significance level of α = 0.05. The study was initiated in August 2021. Clinical trial information: NCT04914390.