Pembrolizumab not better than PTX for advanced gastric cancer

(HealthDay)—For patients with previously treated advanced gastric cancer or gastro-esophageal junction cancer, pembrolizumab does not result in a significant improvement in overall survival compared with paclitaxel, according to a study published online June 4 in The Lancet.

Kohei Shitara, M.D., from National Cancer Center Hospital East in Kashiwa, Japan, and colleagues randomized patients with advanced gastric or gastro-esophageal junction cancer that progressed on first-line chemotherapy with a platinum and fluoropyrimidine to receive 200 mg of pembrolizumab every three weeks for up to two years or standard-dose paclitaxel.

A total of 592 patients were enrolled, and of the 395 patients who had a programmed cell death ligand 1 (PD-L1) combined positive score (CPS) of 1 or higher, 196 were in the pembrolizumab group and 199 were in the paclitaxel group. The researchers found that as of Oct. 26, 2017, 326 of the patients in the population with CPS of 1 or higher had died (77 percent of the pembrolizumab group and 88 percent of the paclitaxel group). In the pembrolizumab group, median overall survival was 9.1 months versus 8.3 months with paclitaxel (hazard ratio [HR], 0.82; 95 percent confidence interval, 0.66 to 1.03; one-sided P = 0.0421). Median progression-free survival was 1.5 months with pembrolizumab versus 4.1 months with paclitaxel (HR, 1.27; 95 percent confidence interval, 1.03 to 1.57). In the total population, grade 3 to 5 treatment-related adverse events occurred in 14 and 35 percent of patients treated with pembrolizumab and paclitaxel, respectively.

"Pembrolizumab did not significantly improve overall survival compared with paclitaxel as second-line therapy for advanced gastric or gastro-esophageal junction cancer with PD-L1 CPS of 1 or higher," the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including Merck, which manufactures pembrolizumab and funded the study.