• Phase I study (N = 76) of anti-PD-1 (MDX-1106) in heavily pretreated, advanced squamous and nonsquamous NSCLC
• ORR 18% and durable clinical benefit (duration of response 2 to 31 mo, PFS at 24 wk 26%)
• Treatment is safe, with primarily Grade 1 and 2 AEs

Part of the most exciting corner of cancer research, this report of durable responses to monotherapy with this checkpoint inhibitor was particularly noteworthy because activity was seen in patients with both squamous and nonsquamous cell lung cancer. Even more impressive, it appears that this agent may be better tolerated than another emerging immunotherapy, ipilimumab, although pulmonary toxicity clearly occurs with anti-PD-1 and can be fatal. As part of this effort, investigators are attempting to correlate PD-L1 expression in pretreatment tumor biopsies with clinical outcomes. However, it is uncertain whether this variable will define a population that does not benefit from treatment.