For many years, chemotherapy for advanced or metastatic NSCLC had been limited to the use of “doublet” (two-drug) therapy using different combination regimens that were overall found to have very similar outcomes, but with different toxicity (side effect) profiles. Attempts to add a third chemotherapy agent for a triplet regimen, and numerous attempts to add different targeted-therapy agents, had dismal success. Not only did most of the combinations fail to improve on the survival outcomes, they increased the number of side effects compared with doublet chemotherapy alone.