Statistical methods
Nivo+CT
At the completion of the first stage (15 patients) of the Simon’s minimax two-stage design in each study arm, the number of MPR was evaluated. The study would proceed to the second stage if the number was greater than the critical value of two. In the Nivo+CT arm, six MPRs were achieved in the first stage, and, thus, the study proceeded to the second stage. In the Ipi+Nivo+CT arm, seven MPRs were achieved in the first stage, and, thus, the study proceeded to the second stage. As the primary analysis, a uniformly minimum variance unbiased estimator (UMVUE) of the MPR rate was obtained using the approach proposed by Jung and Kim