Pembrolizumab + Paclitaxel in HR+/HER2- Non-luminal (by PAM50) Advanced Breast Cancer After CDK4/6 Inhibitor Progression

This is an open-label, single arm, multicenter phase II study evaluating treatment with pembrolizumab in combination with paclitaxel in patients with locally advanced or metastatic non-luminal hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) (hereafter referred to as HR+/HER2-) breast cancer who had recurrence or progression while receiving previous therapy with a cyclin-dependent kinase (CDK) inhibitor in the adjuvant setting or to treat advanced disease (or both).