An analysis from the phase 3 clinical trial has shown that the frontline combination nivolumab plus ipilimumab significantly improved progression-free survival than chemotherapy among metastatic, mutation-negative, treatment-naive NSCLC patients with high TMB (≥10 mutations/Mb), irrespective of PD-L1 expression level (mPFS: 7.2 vs. 5.5 months; hazard ratio for disease progression or death=0.58; P<0.001). The objective response rate was 45.3% and 26.9%, respectively. Among patients with a low tumor mutational burden (<10 mutations/Mb), there was no difference in terms of progression-free survival (3.2 vs. 5.5 months). Grade 3 or 4 treatment-related adverse events occurred in 31.2% of the nivolumab plus ipilimumab group versus 36.1% of the chemotherapy group. This study shows the potential role of TMB as a biomarker for NSCLC patient selection. The cutoff value for high TMB will need to be validated for overall survival.
Hellmann, M. D. et al. N. Engl. J. Med. https://doi.org/10.1056/NEJMoa1801946 (2018)