Pembrolizumab and Monoclonal Antibody Therapy in Advanced Cancer

Pembrolizumab 2mg/kg administered intravenously over 30 minutes every 3 weeks. Pembrolizumab will be infused prior to the start of the assigned monoclonal antibody (Mab) arm. . Dosing for the Mab arms will begin as follows: Arm 1: Cycle length is 21 days. Intravenous (i.v.) trastuzumab 6 mg/kg on day 1 every 21 days. Arm 2: Cycle length is 21 days. i.v. ado-trastuzumab emtansine 3.6 mg/kg on day 1 every 21 days. Arm 3: Cycle length is 21 days. i.v. cetuximab 400 mg/m2 on cycle 1 day 1, then i.v. cetuximab 250 mg/m2 on day 8. Each subsequent cycle will be i.v. cetuximab 250 mg/m2 on days 1 and 8 every 21 days.