Pembrolizumab, Pemetrexed, and Carboplatin Improve Lung Cancer Survival

First-line pemetrexed/carboplatin (PC) plus pembrolizumab for advanced nonsquamous non–small-cell lung cancer (NSCLC) is associated with improved overall survival two years after treatment, according to an updated analysis from the phase I/II KEYNOTE-021 clinical trial (abstract 9026), presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 1–5 in Chicago.

“In this updated analysis from cohort G of KEYNOTE-021 after approximately 2 years median follow-up, the risk of death was nearly halved (hazard ratio, 0.56; P = .015) with the combination of pembrolizumab and PC compared with PC alone in patients with previously untreated, advanced, nonsquamous NSCLC, irrespective of PD-L1 expression,” reported Ryan D. Gentzler, MD, of the University of Virginia Health System in Charlottesville, and coauthors of a poster presentation.

Long-term objective response rate (ORR) was also nearly doubled (57% vs 30%; P = .0016).

“Pembrolizumab plus PC continues to demonstrate a manageable safety profile that is, overall, similar to that of standard chemotherapy” at 24 months, the team concluded.

At the time the updated analysis was performed, the median duration of treatment was 10.1 months for patients in the pembrolizumab plus PC study group and 4.9 months for those receiving PC alone.

No new or late-emerging safety signals for the pembrolizumab plus PC regimen were identified in the updated analysis. However, 55 patients (93%) in the pembrolizumab plus PC study group experienced treatment-related adverse events of any grade, and 24 patients (41%) experienced grade 3 or worse treatment-related toxicities, including one patient who died. In contrast, 92% of patients in the PC-only study group experienced treatment-related toxicities (any grade), and 27% had grade ≥ 3 toxicities, including two cases leading to patient deaths.

Grade ≥ 3 treatment-related adverse events for patients receiving pembrolizumab plus PC included anemia (11.9% vs 12.9% in the PC-only group), fatigue (3.4% vs 0%), and decreased neutrophil counts (6.8% vs 3.2%).