pembrolizumab based treatment
pembrolizumab plus SoC
mBC - Triple negative (TNBC) - 1st Line (L1) 1
mBC - TNBC - L1 - all population 7   
mBC - TNBC - L1 - PDL1 positive 4    
Comparator:  vs placebo plus SoC; 
Risk of bias:  low;   some concerns;   high;  NA;