|Anti-PD-1 antibodies prolong overall survival of patients with squamous non-small-cell lung cancer receiving chemotherapy|
|Blocking programmed death receptor 1 (PD-1) signaling unleashes T cell function, which plays an important role in anti-tumor immunity. Anti-PD-1 antibodies (pembrolizumab) has been proven to be effective in squamous and nonsquamous non-small-cell lung cancer (NSCLC) patients. To determine the efficacy of pembrolizumab in addition to chemotherapy in squamous NSCLC patients, Dr. Paz-Ares and colleagues conducted this double-blind, multiple-centred, randomized, phase 3 trial (KEYNOTE-407 trial), which is published in a recent issue of NEJM (here).
A total of 559 adults untreated metastatic squamous NSCLC patients were analyzed in the present study. All patients were treated with carboplatin and either paclitaxel or nanoparticle albumin-bound-paclitaxel for the first 4 cycles. Patients (n=278) in the pembrolizumab group received 200 mg of pembrolizumab for up to 35 cycles, whereas those (n=281) in the placebo group received the matched placebo. The primary endpoints were overall survival and progression-free survival.
The median overall survival was 15.9 months in the pembrolizumab group and 11.3 months in the placebo group (p<0.0001). The estimated survival rate at 1 year was 65.2% in the pembrolizumab group and 48.3% in the placebo group, p<0.001. The median progression-free survival was 6.4 months in the pembrolizumab group and 4.8 months in the placebo group (p<0.0001). It is worth noting that all subgroups of patients indicated abovementioned survival benefits regardless of PD-L1 expression.
Results of the KEYNOTE-407 trial demonstrate that anti-PD-1 antibodies combined with chemotherapy improve survival of untreated metastatic squamous non-small-cell lung cancer compared to chemotherapy. The application of PD-1 blockade might be broader than patients with high expression of PD-L1. Adverse events observed in the trial were all related to chemotherapy.
This trial was supported by a pharmaceutical company.