Paul K. Paik, MD of Memorial Sloan Kettering Cancer Center discusses Cobas EGFR mutation test v2 and the ability to sample patients for T790 serially. For the liquid biopsy diagnostic for lung cancer in required resistant setting, the FDA approval is very important because resistance biopsy testing is required. This means that bronchoscopic or CT-guided biopsy should be done. Not all patients is eligible however, even for those who are eligible, sometimes the materials are not sufficient.
The liquid biopsy is a CTDNA testing that supplements those who are not eligible to undergo biopsy. In addition, to be able to sample patients for the development of T790 M serially, so if in the first pass they may be negative and in the succeeding testing, they may end up positive, they will be eligible for osimertinib. The response rate to osimertinib in patients who have acquired resistance with T790 mutation is identical, but were not detected in the tissue or blood. Hence, theres a reliable biomarker and of course, its a great deal of flexibility because it is a non-invasive test.