Thierry Facon, MD, of Lille University Hospital in France, spoke to The ASCO Post about the preliminary results of the pembrolizumab studies. Dr. Facon cautioned that a response rate of 76% overall “is not so impressive,” given about 65% of patients respond to lenalidomide/dexamethasone alone.

“This is not much better than the 60% to 70% we can get with len/dex, but then it’s difficult to be amazing, and there are still so few patients in the studies,” he commented.

Thierry Facon, MD

What was more impressive to Dr. Facon were the positron-emission tomography scans of two highly refractory patients who achieved complete responses and a striking reduction in lesions with pembrolizumab/lenalidomide/dexamethasone. “You might say these are anecdotal, but anecdotal experiences are good! When you see pictures like this, it means the drug is active,” he said. “You don’t know if is active in 50% of patients or 80%, but it is active.”

The lower response rate for the pembrolizumab/pomalidomide/dexamethasone regimen should be understood in context, since pomalidomide is indicated for more heavily pretreated patients. “Len relapse and pom relapse populations are not the same,” he noted. ■

Disclosure: Dr. Facon reported no potential conflicts of interest.