I squam, you squam.
The Trial: The benefit of adding pembro to chemo has already been established in adenocarcinoma non-small cell lung cancer (NSCLC) regardless of PD-L1 expression. Now it's squam's turn. The phase 3 KEYNOTE-407 trial randomized 559 patients with newly diagnosed metastatic squamous cell NSCLC to carboplatin with a taxane q3 weeks x 4 cycles +/- pembrolizumab 200 mg q3 weeks x 35 cycles (i.e., >2 years). Enrollees were pretty evenly divided into three cohorts by tumor PD-L1 expression:  <1%,  1-49% and  ≥50%. Differences in rates of overall survival at one year without → with the addition of pembro were:  43 → 64%,  50 → 66%, and  51 → 63%.
The Takeaway: The addition of pembro to chemo prolongs overall survival in patients with metastatic squamous cell NSCLC, regardless of PD-L1 expression. Whether or not they need the chemo remains unclear until someone finally publishes KEYNOTE-042. | Paz-Ares, N ENgl J Med 2018