Study design
As previously described,Eligible patients were randomized 2:1 in a double‐blind manner to receive pembrolizumab plus chemotherapy or placebo plus chemotherapy. Pembrolizumab 200 mg IV or saline placebo was administered every 3 weeks for up to 35 cycles (approximately 2 years). Chemotherapy comprised the investigator's choice of nab‐paclitaxel 100 mg/m