FDA Expands Approval of Pembrolizumab for First-Line Treatment of NSCLC
The U.S. Food and Drug Administration (FDA) recently granted accelerated approval to the immune checkpoint inhibitor pembrolizumab (Keytruda) for use in combination with chemotherapy as a first-line treatment for patients with metastatic non–small cell lung cancer (NSCLC).
KEYNOTE-021
This new approval of pembrolizumab was based on the results of the phase II KEYNOTE-021 clinical trial of 123 patients with advanced or metastatic nonsquamous NSCLC without mutations in the EGFR gene or alterations in the ALK gene, for which there are existing targeted therapies. Patients in the trial had not been treated previously and were randomly assigned to receive either pembrolizumab plus chemotherapy or chemotherapy alone.
In the trial, 55% of the patients who received pembrolizumab and chemotherapy had at least a partial response to the treatment, compared with 29% of patients who received chemotherapy alone. Median progression-free survival for the two groups was 13 months and 8.9 months, respectively.
The most common severe side effects among patients who received pembrolizumab with chemotherapy included fatigue, dyspnea, and nausea. More patients in the pembrolizumab group had side effects than patients in the solely chemotherapy group. Pembrolizumab was discontinued for 10% of patients because of severe side effects—most commonly, acute kidney injury.
Researchers further analyzed the patients by how much programmed cell death ligand 1 (PD-L1) their tumors expressed, defining subgroups by patients whose tumors had PD-L1 expression in less than 1% of cells and those with expression in at least 1% of cells. But because of the small sample sizes of each group, the researchers wrote, more studies are needed to assess the relationship between PD-L1 expression and response to treatment with pembrolizumab plus chemotherapy.
Initial results from a phase III trial with an expected enrollment of 570 patients are expected within the next year.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
