TMB – TUMOR MUTATIONAL BURDEN

TMB – for immunotherapy decisions

Tumor Mutational Burden (TMB) is an emerging, independent predictive biomarker of immunotherapies in multiple tumor types, including lung cancer. TMB is an FDA approved biomarker for immunotherapy decisions.

TMB refers to the total number of somatic mutations that exist within a tumor’s genome.

A subset of these mutations may result in expressed proteins, termed neo-antigens that are not recognized by the host’s immune system as self, and therefore have the potential to be immunogenic, leading to an anti-tumor immune-mediated response.

Tumors with a high mutation burden may have a higher rate of neo-antigens which, in principle, would be expected to be more immunogenic (and consequently more responsive to immunotherapy) than tumors with comparatively low mutation burden.