Balazs Halmos, MD

The study’s invited discussant, Balazs Halmos, MD, Director of Thoracic Oncology and Clinical Cancer Genomics at Montefiore Medical Center and Albert Einstein College of Medicine, New York, called tumor mutation burden a “highly promising” biomarker of response to immune checkpoint inhibitors.

“The results of the CheckMate 032 exploratory analysis were very impressive,” he announced. “High tumor mutation burden was associated with higher response rates, progression-free survival, and overall survival, vs low or median tumor mutation burden.”

He also noted that the results were more robust in the combination immunotherapy group, further commenting: “You have to be a little bit taken aback by the response rate of 46% in the second-line treatment of extensive-stage small cell lung cancer (SCLC), and a pronounced overall survival benefit noted in the high tumor mutation burden group with combination immunotherapy, albeit with the caveat of small numbers of patients in the subsets…. It’s a very promising lead.”

Based on this study, and others, tumor mutation burden shows potential as a biomarker for immunotherapy benefit not only in SCLC but also more broadly in bladder cancer, non–small cell lung cancer, and microsatellite instability–high tumors of any tissue origin, added Dr. Halmos. ■

DISCLOSURE: Dr. Halmos reported no conflicts of interest.