Randomised, multicentre phase II study of bevacizumab and paclitaxel induction followed by atezolizumab and nab-paclitaxel in patients with PD-L1-positive metastatic triple-negative breast cancer: protocol for the INDUCE trial (JBCRG-M10)

Introduction Addition of bevacizumab and paclitaxel as induction therapy prior to standard atezolizumab and nab-paclitaxel in patients with programmed death-ligand 1 (PD-L1)-positive metastatic triple-negative breast cancer (mTNBC) may help to overcome vascular endothelial growth factor-associated resistance mechanisms that limit the immune-mediated antitumour efficacy of atezolizumab and nab-paclitaxel. Methods and analysis The Induction Therapy of PTX+BV Followed by Atezolizumab+Nab-PTX for PD-L1+TNBC (INDUCE) study is a multicentre, randomised, open-label, phase II trial designed to evaluate the efficacy and safety of two cycles of induction therapy with bevacizumab and paclitaxel followed by atezolizumab and nab-paclitaxel compared with standard atezolizumab and nab-paclitaxel in patients with PD-L1-positive mTNBC.

The primary outcome of the study is progression-free survival (PFS) per Response Evaluation Criteria In Solid Tumours, V.1.1. We have estimated that 89 PFS events are needed to allow a power of 80% to detect a difference between treatment groups at a one-sided significance level of 10% in this study.

The target sample size is set to 106 patients to account for dropouts.