AstraZeneca has tapped Guardant Health to develop blood-based companion diagnostics for its cancer treatments Tagrisso and Imfinzi.
Under the multiyear agreement, Guardant will pursue an FDA approval for a Guardant360 CDx liquid biopsy test to help identify non-small cell lung cancer patients for treatment with Tagrisso, an EGFR inhibitor.
It will also develop a plasma-based test using the GuardantOMNI assay, which scores tumor mutational burden (TMB) to predict responses to AstraZeneca’s immunotherapies and targeted drugs.
The TMB test is currently being used in a phase 3 clinical trial of Imfinzi, with or without tremelimumab, in NSCLC. Tremelimumab, an anti-CTLA4 antibody, recently failed to improve outcomes in both NSCLC and head and neck cancer.
In an interview with FiercePharma, Mika Sovak, M.D., Ph.D., AstraZeneca's VP of lung cancer immuno-oncology, pointed to exploratory data from the trial that showed an association between better survival outcomes and high levels of TMB in the blood, describing it as “the first time TMB has demonstrated an association with improved overall survival.”
However, there are a “bunch of additional analyses that we need to do in order to understand what the potential implications of blood TMB could be,” Sovak said.
The agreement with Guardant also allows for future development of liquid biopsy tests for AstraZeneca’s other clinical development programs.
“Precision medicine is at the heart of our ambition to eliminate cancer as a cause of death,” said Ruth March, Ph.D., senior VP of precision medicine and genomics for AstraZeneca’s Innovative Medicines and Early Development biotech unit, in a release. “We are committed to matching life-changing medicines to patients most likely to benefit, and we believe our partnership with Guardant Health will help us achieve this.”
The FDA recently granted a breakthrough device designation to the GuardantOMNI assay for its proprietary plasma-based TMB score, according to Guardant. The assay applies Guardant360’s platform to a broader genomic footprint.