Dr. Mok Discusses Updated Data With Pembrolizumab in NSCLC

Tony S. K. Mok, BMSc, MD, FRCPC, professor, Department of Clinical Oncology, Chinese University of Hong Kong, discusses updated data with pembrolizumab (Keytruda) in patients with non—small cell lung cancer (NSCLC).

The KEYNOTE-042 study is a sister study of KEYNOTE-024, Mok says. The difference between the 2 trials is that KEYNOTE-024 selected patients who had PD-L1 expression ≥50% and randomized them to receive either pembrolizumab or chemotherapy, using progression-free survival as the primary endpoint. On the other hand, KEYNOTE-042 selected patients with PD-L1 ≥1%, and then did the same randomization of the PD-1 inhibitor versus chemotherapy. Though, the primary endpoint in this trial was overall survival (OS) in patients with a tumor proportion score (TPS) ≥50%, ≥20%, and ≥1%.

Updated data for KEYNOTE-042 presented by Mok at the 2019 European Lung Cancer Congress showed a confirmed improvement in OS with pembrolizumab versus chemotherapy at 20 months versus 13 months in patients with a TPS ≥50%. A similar benefit was observed in patients with TPS ≥20% and ≥1%, Mok adds.

Researchers also looked at the exploratory analysis of patients with a TPS <50%, where an initial OS improvement was not seen. These data suggested that a lot of the benefit seen in the overall population was driven by patients with a TPS ≥50%, Mok says. Notably, the standard of care for patients with a TPS <50% is pembrolizumab plus chemotherapy. However, single-agent pembrolizumab appears to be a feasible option, Mok concludes.