With the expanded label, the treatment is indicated for use in combination with pemetrexed and platinum as first-line treatment of patients with metastatic NSqNSCLC, with no EGFR or ALK genomic tumor aberrations. Pembrolizumab was previously granted accelerated approval for this indication in May 2017.
The expanded label is based on results from the KEYNOTE-189 clinical trial, which evaluated overall response rate and progression-free survival (PFS) for patients treated with pembrolizumab in combination with chemotherapy compared with chemotherapy alone.
In the phase 3 trial, 616 patients were enrolled to receive first-line treatment for metastatic NSqNSCLC. Patients were treated with pembrolizumab (or placebo) in combination with pemetrexed and the investigator’s choice of either cisplatin or carboplatin every 3 weeks for 4 cycles, followed by pembrolizumab (or placebo) and pemetrexed. Patients continued treatment until disease progression, unacceptable toxicity, or a maximum of 24 months.
According to the data, patients treated with pembrolizumab plus chemotherapy demonstrated a statistically significant improvement in overall survival (OS) in a pre-specified interim analysis. Median OS was not reached at the time of the data cut-off in pembrolizumab-treated patients and was 11.3 months for those in the chemotherapy arm. Additionally, the trial demonstrated an improvement in PFS, with a median PFS of 8.8 months for patients in the pembrolizumab arm compared with 4.8 months for those receiving chemotherapy alone.
The overall response rate was significantly higher (48% vs 19%) for those receiving pembrolizumab plus chemotherapy compared with those treated with chemotherapy alone and the median response duration was 11.2 months and 7.8 months, respectively.
Additionally, safety was evaluated in 405 patients who received pembrolizumab in combination with chemotherapy and 202 patients who received a placebo plus chemotherapy. The most common adverse effects reported in the trial were fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, and pyrexia. The treatment was discontinued in 20% of patients.
According to the press release, the recommended pembrolizumab dose and schedule for NSqNSCLC is 200 mg as an intravenous infusion over 30 minutes every 3 weeks.
FDA grants regular approval for pembrolizumab in combination with chemotherapy for first-line treatment of metastatic nonsquamous NSCLC [news release]. FDA’s website. https://bit.ly/2N77Sx1. Accessed August 21, 2018.
FDA Approves Expanded Label for Merck’s KEYTRUDA® (pembrolizumab) in Combination with Pemetrexed (ALIMTA®) and Platinum Chemotherapy for First-Line Treatment of Patients with Metastatic Nonsquamous NSCLC, with No EGFR or ALK Genomic Tumor Aberrations [news release]. Merck’s website. https://bit.ly/2BuQOQp. Accessed August 21, 2018.