CTLA4 and cancer: Recently published results from a small phase 1b clinical study show a good safety profile for this combination as well as an intriguing early activity signal (DCR 100 %, ORR 86 %).33 The rationale for this combination regimen is based on the ability of melphalan/HDS to enhance antigen presentation by killing cancer cells, resulting in immunomodulation, whereas anti–CTLA-4 and anti–PD-1/PD/L1 antibodies enhance immune responses to weak tumor antigens and activation of tumor-reactive immune cells.