Pembrolizumab PFS2, OS results support first-line NSCLC strategy
medwireNews: Pembrolizumab offers better survival outcomes than platinum-doublet chemotherapy for treatment-naïve, non-small-cell lung cancer (NSCLC) patients with a programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) of 50% or greater, the KEYNOTE-024 investigators say.
Progression-free survival (PFS) and overall survival (OS) benefits for pembrolizumab 200 mg every 3 weeks versus chemotherapy, after a median follow-up of 11.2 months, were previously reported for the 305 participants with stage IV NSCLC without an activating EGFR mutation or ALK translocation.
Now PFS in the second-line (PFS2) results and updated OS findings from data cutoff in January 2017, both of which are in favor of pembrolizumab, have been presented at the 2017 annual meeting of the American Society of Clinical Oncology, held in Chicago, Illinois, USA.
After a median of 19.1 months, 46 patients were continuing with pembrolizumab therapy and one patient had completed the 2-year course. Almost a third (31.2%) of patients in the pembrolizumab arm had received a second-line treatment for a median of 3.6 months, most commonly platinum-doublet chemotherapy (87.5%).
Meanwhile in the chemotherapy arm of the trial, one patient was continuing therapy, 29 had completed treatment, and 64.2% of patients went onto receive a second-line agent for a median of 3.5 months. The majority (81.4%) received pembrolizumab on trial, 12.4% nivolumab or pembrolizumab off trial, and 6.2% were given pemetrexed or platinum-based regimens.
By Kaplan–Meier estimation, PFS2 was significantly higher in the pembrolizumab arm than the chemotherapy arm, at 18.3 versus 8.4 months and a significant hazard ratio (HR) of 0.54. The PFS2 rates at 12 months were 59.7% versus 38.5%, and by 18 months were 51.0% versus 24.6%.
The updated OS by Kaplan–Meier estimation indicated that median OS had not been reached for the pembrolizumab-treated patients but was 14.5 months with chemotherapy (HR=0.63). The 12- and 18-month OS rates were 70.3% versus 54.8% and 61.2% versus 43.0%, respectively.
“[P]embrolizumab continues to show an OS benefit over chemotherapy as first-line treatment for advanced NSCLC with PD-L1 TPS ≥50%,” presenting author Julie Brahmer (Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, USA) told the meeting.
She described PFS2 as “substantially improved” with first-line pembrolizumab, and highlighted the “high degree of separation of the OS curves” despite a crossover rate to pembrolizumab of 60.3% for the chemotherapy group.
Brahmer concluded: “Along with a favorable safety profile, these data support pembrolizumab as a standard of care for first-line treatment of NSCLC with a PD-L1 TPS of 50% or higher.”
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