Nivolumab infusion (Per Section 5.12.1) 9. Vital Signs (including ambulatory O2 sat) per Section 11 5.8 Day 1 of Cycle 4 (+/- 3 days) 1. Bone marrow and aspirate to assess disease response. 2. Bone marrow aspirate for research samples 5.9 Day 1 of Cycles 4-6 (+/- 3 days) 1. History, physical examination, height and weight 2.