pembrolizumab based treatment
pembrolizumab alone pembrolizumab plus SoC
mEC - (neo)adjuvant (NA) 1
mEC - 1st line (L1) 1   
mEC - 2nd line (L2) 3   
Comparator:  vs placebo plus SoC;   vs Standard of Care (SoC); 
Risk of bias:  low;   some concerns;   high;  NA;