Efficacy
After a median follow up of 10.5 months, the estimated rate of OS at 12 months was 69.2% (95% confidence interval [CI], 64.1 to 73.8) in the pembrolizumab-chemotherapy group compared to 49.4% (95% CI, 42.1 to 56.2) in chemotherapy alone group (HR= 0.49; CI 95% 0.38 to 0.64; p < 0.001). This improvement was seen irrespective of PD-L1 tumour proportion scores; however, the greatest relative benefit was seen in the PD-L1 > 50% subgroup.r
There was also an improvement in median PFS with pembrolizumab-chemotherapy combination compared to chemotherapy alone (median PFS 8.8 months [95% CI 7.6 to 9.2] and 4.9 months [95% CI 4.7 to 5.5] respectively, HR= 0.52; 95% CI 0.43 to 0.64; p < 0.001), however this was not statistically significant for the PD-L1 < 1% subgroup. The tumour response rates were higher with pembrolizumab-chemotherapy compared to chemotherapy alone (47.6% [95% CI, 42.6 to 52.5] versus 18.9% [95% CI, 13.8 to 25.0]; p<0.001).r
111 of 405 patients (27.4%) received cisplatin and 294 of 405 patients (72.6%) received carboplatin in the pembrolizumab-chemotherapy arm. This was similar to the control arm (28.2% and 71.8% respectively). Similar benefits in overall survival and progression free survival were seen irrespective of platinum agent used.r
At final analysis with a median follow-up of 31.0 months, the median OS was 22.0 months (95% CI, 19.5 to 24.5) in the pembrolizumab-chemotherapy group and 10.6 months (95% CI, 8.7 to 13.6) in the chemotherapy alone group (HR= 0.56; 95% CI, 0.46 to 0.69).r The improvement was seen irrespective of PD-L1 tumour proportion scores. Median PFS was 9.0 months (95% CI, 8.1 to 10.4) in the pembrolizumab-chemotherapy group and 4.9 months (95% CI, 4.7 to 5.5) in the chemotherapy alone group (HR= 0.49; 95% CI, 0.41 to 0.59).
Kaplan-Meier curve of overall survivalr
© Ann Oncol 2021
Overall survival, subgroup analysisr
© Ann Oncol 2021
Kaplan-Meier curve of progression free survivalr
© Ann Oncol 2021
Progression free survival, subgroup analysisr
© Ann Oncol 2021