FDA to convene an advisory committee meeting to review use of Bristol Myers Squibb’s Opdivo and Merck & Co.’s Keytruda in gastrointestinal cancer.

The advisory committee will be tasked with evaluating PD-L1 expression as a “predictive biomarker” of the drugs’ effectiveness in this setting, for which both are approved broadly. Data now suggest PD-L1 expression is important, the FDA said, but trials of the drugs measured expression differently. The FDA is seeking advice on how to judge this data and whether use of the immunotherapies should be restricted based on PD-L1 levels.