LAUSR

in 2016, KeYNOte-024 established the superior efficacy of first-line pembrolizumab over chemotherapy for metastatic non-small-cell lung cancer (NsCLC) with a programmed cell death 1 ligand 1 (PD-L1) tumour proportion score (tPs) ≥50%. Now, overall survival (Os) data from the second interim analysis of KeYNOte-042, which investigated the efficacy of pembrolizumab in patients with a lower PD-L1 tPs, have been reported. the phase iii trial enrolled 1,274 patients with previously untreated, PD-L1-positive (tPs ≥1%), locally advanced or metastatic NsCLC without a sensitizing EGFR or ALK alteration. Patients were randomized 1:1 to receive pembrolizumab or platinum-based chemotherapy. the primary end point was Os across three predefined subgroups (tPs ≥50%, ≥20% and ≥1%). at a median follow-up duration of 12.8 months, Os was significantly longer in patients receiving pembrolizumab than in those receiving chemotherapy across all PD-L1 subgroups (tPs ≥50% Hr 0.69, 95% Ci 0.56–0.85, P = 0.0003; tPs ≥20% Hr 0.77, 95% Ci 0.64–0.92, P = 0.0020; tPs ≥1% Hr 0.81, 95% Ci 0.71–0.93, P = 0.0018). Median Os for pembrolizumab versus chemotherapy was 20.0 versus 12.2 months, 17.7 versus 13.0 months and 16.7 versus 12.1 months for the tPs ≥50%, ≥20% and ≥1% subgroups, respectively. any grade (63% versus 90%) and grade ≥3 (18% versus 42%) treatment-related adverse events (traes) were lower with pembrolizumab. in each arm, traes led to death in 2% and to treatment discontinuation in 9% of patients. Overall, these findings have led the FDa to extend the indication for pembrolizumab to patients with a PD-L1 tPs as low as 1%.