There is ongoing debate regarding the suitability of tumor mutational burden (TMB) for use across various types of cancer and the reliability of TMB assays produced by different manufacturers. The KEYNOTE 158 trial supported the use of the Foundation Medicine test (FoundationOne®CDx, an FDA-approved TMB measurement test) for solid tumors, regardless of disease, with TMB ≥ 10 mut/Mb as a companion diagnostic for single-agent pembrolizumab in 2nd+ line treatment. To evaluate the clinical validity of the FDA-approved TMB measurement test, this study analyzed a large real-world dataset of over 8,000 patients with 24 different cancer types who received single-agent immune checkpoint inhibitors.
Why this matters
The findings from this study can help establish the reliability of the FoundationOne®CDx test and provide valuable insights into the use of TMB as a predictive biomarker for immunotherapy in clinical practice.