Combining standard chemotherapy with a PD-1/PD-L1 inhibitor holds great appeal in the treatment of SCLC. While this approach may be appropriate for many cancer types, SCLC may be particularly vulnerable to this treatment strategy. Early studies have suggested greater efficacy with agents targeting PD-1/PD-L1 in tumors that are more mutationally complex, such as those associated with tobacco use. SCLC has a strong association with tobacco use and indeed, genome-wide sequencing studies have consistently shown that SCLC carries one of the highest rates of non-synonymous mutations [37, 38]. In addition, MPDL3280A has been safely combined with platinum based chemotherapy doublets in the treatment of NSCLC [39]. Thus, a combination of carboplatin, etoposide and MPDL3280A may significantly improve outcomes in the treatment of SCLC.