The first data from the phase III CheckMate-227 trial of ipilimumab plus 
nivolumab for the treatment of non-small cell lung cancer suggests that the two 
drugs boost progression-free survival in patients with a high tumor mutation 
burden. After 1 year, progression-free survival was 43% for patients treated 
with the checkpoint inhibitor combination, compared with 13% for patients 
treated with chemotherapy.