Efficacy
The median follow up in the pembrolizumab plus chemotherapy group was 13.0 months (IQR 6.4-26.6) and in the EXTREME group was 10.7 months (IQR 6.6-19.7). Pembrolizumab plus chemotherapy was superior to EXTREME at improving OS in the overall population (HR 0.77, 95% confidence interval [CI] 0.63-0.93, p = 0.0034) with a median overall survival of 13.0 months (10.9-14.7 months) and 10.7 months (9.3-11.7 months) respectively. The OS benefit was also seen in patients with PDL1 CPS ≥ 1 (HR 0.65, 95% CI 0.53-0.8, p < 0.0001) and in PDL1 combined positive score (CPS) ≥ 20 (HR 0.60, 95% CI 0.45-0.82, p = 0.0004) groups.r
Compared to the EXTREME protocol, pembrolizumab plus chemotherapy did not improve PFS in the overall population (HR 1.34, 95% CI 1.13-1.59, p = 0.17) or in the PDL1 CPS ≥ 20 patients (HR 0.73, 95% CI 0.55-0.97, p = 0.016) and further analysis was not performed in the PDL1 CPS ≥ 1 groups.r
For secondary end points, radiographically objective response rates was similar between the pembrolizumab plus chemotherapy group and the EXTREME group (36% vs. 36%). However, response rates were higher in the PDL1 CPS ≥ 20 subgroup with response rates of 43% in the pembrolizumab plus chemotherapy group vs. 38% in the EXTREME group. Duration of response was 7.1 months in the pembrolizumab plus chemotherapy group, and 4.1 months in the EXTREME group; with similar outcomes in the PDL1 CPS ≥ 1 and CPS ≥ 20 groups. Quality of life outcomes are not yet available.r
Kaplan-Meier curve of overall survivalr
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Kaplan-Meier curve of progression free survivalr
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