medwireNews: Long-term follow-up findings from the KEYNOTE-010 trial support the use of a 2-year course of pembrolizumab for patients with previously treated advanced non-small-cell lung cancer (NSCLC) positive for PD-L1 expression, the investigators believe.
Earlier reports from the study demonstrated a significant progression-free survival (PFS) benefit versus docetaxel with pembrolizumab given at a dose of 2 mg/kg or 10 mg/kg every 3 weeks to patients with a tumor proportion score (TPS) of at least 50%, while both this group and those with a TPS of at least 1% derived an overall survival (OS) benefit.
Now, the team reports in the Journal of Clinical Oncology long-term outcomes from the study including for the 79 patients who completed all 35 cycles or a full 2 years of pembrolizumab therapy and for a second group of 14 patients who went onto receive a second course of pembrolizumab.
After a median 42.6 months of follow-up, OS remained significantly longer with pembrolizumab than docetaxel, with a hazard ratio for death of 0.53 for patients with a TPS of at least 50% and 0.69 for those with a TPS of at least 1%.
This gave estimated 36-month OS rates with pembrolizumab of 34.5% for the TPS of at least 50% group and 22.9% for those with a TPS of at least 1% versus 12.7% and 11.0% with docetaxel, respectively.
For the patients who completed 2 years of pembrolizumab, the PFS and OS rates at 12 months after completion were 72.5% and 98.7%, respectively. Indeed, 94.9% of these patients had an objective response, which was ongoing at time of data analysis in 64.0%.
Among those given a second course of pembrolizumab, five completed 17 cycles of treatment, achieving a partial response in 43% and stable disease in 36%.
“These are the first data to demonstrate that a 2-year treatment duration with pembrolizumab may be an appropriate approach,” say Roy Herbst, from Yale School of Medicine in New Haven, Connecticut, USA, and co-authors.
“The majority of patients who completed 2 years of treatment remain in remission, and those who had recurrence could be rechallenged with pembrolizumab at the time of progression and achieve disease control.”
The team describes pembrolizumab as having “manageable” toxicity and “no new safety signals” in the latest data, with grade 3–5 treatment-related adverse events reported in 16% of the whole pembrolizumab cohort, and 18% of the patients who completed the full course, versus 37% of those given docetaxel.
“Importantly, these data show that a 2-year treatment duration with pembrolizumab is reasonable and suggest that patients who experience disease progression after stopping treatment can be successfully retreated and achieve disease control,” the investigators conclude.
“Additional molecular studies are needed to better understand the characteristics of responding patients,” they remark.
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J Clin Oncol 2020; doi:10.1200/JCO.19.02446