Commenting on the pembrolizumab (Keytruda) phase Ib study, Noah Hahn, MD, of Johns Hopkins Sidney Kimmel Cancer Center, Baltimore, called the overall response rate of 28% with pembrolizumab “pretty impressive. Nearly two-thirds of patients had some response or tumor reduction, and overall survival was also impressive,” Dr. Hahn noted.
“Over the last 25 years, response rates to new agents have ranged from 10% to 15%, and median overall survival was about 10 months. Pembrolizumab more than doubles overall response rate, and overall survival of 13 months stacks up nicely against historical treatments post platinum,” Dr. Hahn noted.
Pembrolizumab was well tolerated, Dr. Hahn continued, with low rates of grade 3 and 4 toxicities.
Turning to the atezolizumab study presented by Dr. Petrylak, Dr. Hahn said that the overall response rate of 34% for the entire poor-prognosis, heavily pretreated cohort is “independent of marker status and impressive.”
“PD-L1 is not panning out as a biomarker for atezolizumab. For right now, we have no marker for treatment selection,” Dr. Hahn said.
“With new agents like pembrolizumab and atezolizumab, therapeutic options are expanded, and outcomes are improving in [urothelial bladder cancer],” he said. ■
Disclosure: Dr. Hahn reported no potential conflicts of interest.
Two immunotherapy agents show promise in preliminary studies of advanced urothelial bladder cancer: the anti–PD-1 (programmed cell death protein 1) antibody pembrolizumab (Keytruda) and the anti–PD-L1 (programmed cell death ligand 1) antibody atezolizumab. Separate phase I studies of each drug...