Neoadjuvant Her2-targeted Therapy and Immunotherapy With Pembrolizumab [IIT2018-04-MCARTHUR-NEOHP]

A phase 2 open-label, randomized, multi-center trial to evaluate the efficacy and safety of neoadjuvant trastuzumab, pertuzumab and weekly paclitaxel (THP) as compared to neoadjuvant trastuzumab, pertuzumab, pembrolizumab and weekly paclitaxel (THP-pembrolizumab), or neoadjuvant trastuzumab, pembrolizumab and weekly paclitaxel (TH-pembrolizumab) in chemo naive patients with invasive human epidermal growth factor receptor 2 (HER2) positive breast cancer whose primary tumors are \> 2 cm and/or clinically lymph node positive. Patients will be randomized to either Arm A: THP (trastuzumab, pertuzumab and weekly paclitaxel), Arm B: THP-pembrolizumab (trastuzumab, pertuzumab, pembrolizumab) and weekly paclitaxel) or Arm C: TH-pembrolizumab (trastuzumab, pembrolizumab and weekly paclitaxel). Patients will be stratified according to hormone receptor status and lymph node status. All patients will be treated weekly every three weeks for four cycles (only paclitaxel will be administered weekly) and then undergo breast surgery. Arm A patients will be regarded as the reference group.