FDA has approved pembrolizumab (Keytruda) for the first-line treatment of patients with stage III non-small cell lung cancer who are not candidates for surgical resection or definitive chemoradiation or metastatic NSCLC. Patients’ tumors must have no EGFR or ALK genomic aberrations and express PD-L1 (Tumor Proportion Score ≥1%) determined by an FDA-approved test.
Keytruda is sponsored by Merck.
Pembrolizumab was previously approved as a single agent for the first-line treatment of patients with metastatic NSCLC whose tumors express PD-L1 TPS ≥50%.
Approval was based on KEYNOTE‑042 (NCT02220894), a randomized, multicenter, open-label, active-controlled trial conducted in 1274 patients with stage III or IV NSCLC who had not received prior systemic treatment for metastatic NSCLC and whose tumors expressed PD-L1 (TPS ≥1%). PD-L1 expression was determined by an immunohistochemistry assay using the PD-L1 IHC 22C3 pharmDx Kit.
Patients were randomized (1:1) to receive pembrolizumab 200 mg intravenously every 3 weeks or investigator’s choice of a carboplatin-containing regimen with either pemetrexed or paclitaxel. Randomization was stratified by ECOG performance status, histology, geographic region, and PD-L1 expression (TPS ≥50% vs. TPS 1 to 49%).
Overall survival in the TPS ≥50% NSCLC subgroup, the TPS ≥20% NSCLC subgroup, and the overall population (TPS ≥1%) were the major efficacy measures. The trial demonstrated statistically significant OS improvements for those randomized to pembrolizumab compared with chemotherapy in all three populations.
In the TPS ≥1% population (overall population), the median OS was 16.7 and 12.1 months for the pembrolizumab and chemotherapy arms, respectively (HR 0.81; 95% CI: 0.71, 0.93; p=0.0036).
For the TPS ≥ 20% subgroup, the median OS was 17.7 months for the pembrolizumab arm and 13.0 months for the chemotherapy arm (HR 0.77; 95% CI: 0.64, 0.92; p=0.004). For the TPS ≥50% subgroup, the estimated median OS was 20 months and 12.2 months for those receiving pembrolizumab and chemotherapy, respectively (HR 0.69; 95% CI: 0.56, 0.85; p=0.0006).
There were no significant differences in progression-free survival or overall response rate between arms in any population.
