Pembrolizumab as Initial Treatment Works for Most Advanced Lung Cancers
The large, randomized phase III Keynote-042-trial shows that the immunotherapy pembrolizumab is a more effective initial treatment than chemotherapy (the current standard of care) for the majority of patients with the most common type of lung cancer.
Source: ASCO Annual Meeting 2018
People with advanced non-small-cell lung cancer (NSCLC) with a PD-L1 expression of 1% or more who were first treated with immunotherapy pembrolizumab lived a median of 4-8 months longer than those who received chemotherapy. In addition, severe side effects occurred in fewer patients receiving pembrolizumab than chemotherapy (18% vs. 41%).
According to the authors, this study is the largest clinical trial of pembrolizumab as a standalone therapy. The findings will be presented in ASCO’s Plenary Session, which features four studies deemed to have the greatest potential impact on patient care, out of the more than 5,800 abstracts featured as part of the ASCO 2018.
“A large number of patients with lung cancer now have a new treatment option with better efficacy and fewer side effects than standard chemotherapy,” said lead study author Gilberto Lopes, MD, MBA, from the Sylvester Comprehensive Cancer Center, University of Miami Health System in Florida. “Our study shows that pembrolizumab provides more benefit than chemotherapy for two-thirds of all people with the most common type of lung cancer.”
About the Study
Researchers randomly assigned 1,274 people with locally advanced or metastatic NSCLC to receive chemotherapy (paclitaxel/carboplatin or pemetrexed/carboplatin) or pembrolizumab. Both squamous and non-squamous cancers were included, but not cancers with targeted therapies (EGFR and ALK inhibitors).
For the analysis, researchers explored treatment benefits in three patient groups according to tumor PD-L1 expression score: > 50% (599 patients), > 20% (818 patients), > 1% (1,274 patients). Equal numbers of patients in each PD-L1 expression group received pembrolizumab and chemotherapy.
The median follow-up time was 12.8 months. Compared to those receiving standard chemotherapy, patients who received pembrolizumab had a longer median overall survival, regardless of PD-L1 expression in the tumor. The benefit of pembrolizumab was greater when the level of PD-L1 expression was higher:
- PD-L1 50% or more: 20 months with pembrolizumab vs. 12.2 months with chemotherapy
- PD-L1 20% or more: 17.7 months with pembrolizumab vs. 13 months with chemotherapy
- PD-L1 1% or more: 16.7 months with pembrolizumab vs. 12.1 months with chemotherapy
More research is needed to define patient groups who benefit most from pembrolizumab.
Additionally, it is not yet clear whether pembrolizumab combined with chemotherapy is better than pembrolizumab alone in patients who express PD-L1, as there have not been head-to-head comparison trials of the two approaches.
Ongoing research is also exploring use of pembrolizumab in an adjuvant setting and combinations of immunotherapy with bevacizumab-containing combination regimens as part of initial therapy for NSCLC.
“Immunotherapy with pembrolizumab alone benefits a much larger number of patients than we had previously thought. This is yet another promising result with immunotherapy in lung cancer that brings new momentum to the treatment of this notoriously difficult disease,” said ASCO Expert John Heymach, MD, PhD.
Lopes G et al, Pembrolizumab (pembro) versus platinum-based chemotherapy (chemo) as first -line therapy for advanced/metastatic NSCLC with a PD-L1 tutor proportion score (TPS)>1%: open-label, phase 3 KEYNOTE-042-study