Foundation Medicine assay measures tumor mutational burden from blood

September 8, 2017 – CAMBRIDGE. Foundation Medicine, Inc. announced presentations at the European Society for Medical Oncology (ESMO) Annual Meeting highlighting validation data for its novel assay to measure tumor mutational burden from blood (bTMB). These presentations will highlight retrospective data analysis from Roche/Genentech’s Phase II POPLAR and Phase III OAK studies that enabled analytic and clinical validation for the bTMB assay. The studies demonstrate that high bTMB as measured by Foundation Medicine’s assay is associated with response to atezolizumab in individuals with previously-treated non-small cell lung cancer (NSCLC), potentially offering a new option to expand personalized care options for patients with advanced cancer.

Based on these findings, Foundation Medicine also announced today that its bTMB assay will be integrated as part of Roche/Genentech’s prospective, randomized Phase III Blood First Assay Screening Trial (BFAST) as a companion diagnostic assay to investigate bTMB as a non-invasive biomarker of response to first-line atezolizumab in advanced NSCLC patients.

“Foundation Medicine has previously shown that measuring tumor mutational burden from tissue samples can help reliably predict responses to immunotherapies. However, a critical need exists for measuring TMB via a non-invasive solution for cancer patients for whom tissue is not available or when a biopsy is not feasible,” said Vincent Miller, M.D., chief medical officer at Foundation Medicine. “Our data at ESMO provide the first evidence that response to immunotherapy can be predicted using only a blood sample and we’re pleased that we recently received FDA clinical trial approval for the Phase III study to validate bTMB as a biomarker in first-line immunotherapy. Based on the study results, we expect further development of our bTMB assay as a companion diagnostic, providing an important predictive and complementary solution to FoundationACT® liquid biopsy, and ultimately enabling physicians to make informed selection of targeted or immunotherapy treatments in the absence of tissue.”

In the studies presented at ESMO, Foundation Medicine’s bTMB assay was analytically validated to determine TMB with high precision and accuracy from as little as one percent tumor content in a blood sample. The assay was used to retrospectively analyze a total of 794 plasma samples from the Phase II POPLAR and Phase III OAK clinical trials. The analysis showed that atezolizumab demonstrated a clear benefit for overall survival. Additionally, there was a correlation between patients with high bTMB in those studies and longer progression-free survival (PFS) when treated with atezolizumab. In addition, bTMB was not found to correlate with PD-L1 expression levels as measured by tissue-based immunohistochemistry, suggesting that bTMB, like tissue TMB, provides independent and critical predictive information in addition to the information furnished by PD-L1 testing.

The bTMB assay validation presentations will take place during the following times:

Abstract #1295O — Blood-based biomarkers for cancer immunotherapy: Tumor mutational burden in blood (bTMB) is associated with improved atezolizumab (atezo) efficacy in 2L+ NSCLC (POPLAR and OAK), Sept 8, 4:00pm - 5:30pm, Madrid Auditorium (Oral Presentation)

Abstract #102P — Analytic validation of a next generation sequencing assay to identify tumor mutational burden from blood (bTMB) to support investigation of an anti-PD-L1 agent, atezolizumab, in a first line non-small cell lung cancer trial (BFAST), Sept 11, 1:15pm - 2:15pm, Hall 8 (Poster Presentation)

In totality, the company and its collaborators will present a total of 19 studies at the ESMO Annual Meeting, including three oral presentations, seven poster discussions and nine posters, which support the integration of comprehensive genomic profiling (CGP) and biomarkers such as tissue- and blood-based TMB to help guide personalized cancer care. These new data include insights into the landscape of tissue-based TMB across various types of cancer, which may help further stratify molecular subtypes of disease and guide more personalized treatment. Results will be presented from a study of more than 80,000 solid tumors, a study of more than 22,000 gastrointestinal cancers and a study of more than 2,000 melanoma cases (the largest known cohort of metastatic melanoma cases with comprehensive genomic profiling released to date). Together these results reveal pan-tumor and disease-specific alterations that may inform rational selection of immunotherapy.

Furthermore, new studies show the prevalence of TMB in subtypes of certain cancers where immunotherapy is not often considered, such as breast and thymic cancers. These findings may help expand the utility of TMB into new indications.

Source: Foundation Medicine, Inc.