Safety of Combination Triplet for Lung Cancer in KEYNOTE-189
Posted: Tuesday, July 14, 2020
According to a post hoc analysis of KEYNOTE-189, presented as part of the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting I (Abstract CT085), the combination triplet of pemetrexed, platinum, and pembrolizumab appears to be well tolerated in patients with metastatic nonsquamous non–small cell lung cancer. The treatment had previously been found to prolong overall and progression-free survival in this population.
“Most [adverse events] first occurred within 3 months from the first study treatment administered and resolved within 2 weeks from the onset,” noted Edward B. Garon, MD, of the University of California, Los Angeles, and colleagues.
The study included 607 patients, 405 of whom were treated with pemetrexed/platinum/pembrolizumab and 202 of whom were treated with pemetrexed/platinum/placebo. The median patient age was 64 years, and the median duration of treatment was 7.4 months in the pembrolizumab arm and 5.4 months in the placebo arm. A total of 72% of patients had received carboplatin, and 18% had a history of brain metastases.
Overall, 272 patients (67.2%) in the pembrolizumab arm and 133 patients (65.8%) in the placebo arm experienced adverse events between grades 3 and 5. The shortest median time to initial occurrence was 6 days for nausea, whereas the longest was 125 days for pneumonitis. Vomiting had the quickest median time to resolution at 4 days, whereas pneumonitis and anemia tied for the longest at 25 days.
Because of adverse events, 112 patients (27.7%) in the pembrolizumab arm and 30 patients (14.8%) in the placebo arm discontinued medication use. Among those who discontinued therapy in the pembrolizumab group, 33% were due to pemetrexed and 40% were due to pembrolizumab; they occurred during the first four cycles of treatment. The rates of discontinuation of pemetrexed were similar in both groups (2.0% in the pembrolizumab arm vs. 1.4% in the placebo arm.)
Disclosure: For full disclosures of the study authors, visit abstractsonline.com.