Resistance time to Osimertinib

Patients treated with Osimertinib typically develop resistance within about 10 months. Resistance mediated by the exon 20 C797S mutation is responsible for the majority of resistance cases, which has led to multiple attempts using non-ATP competitive or allosteric inhibitors in an attempt to counteract this acquired resistance by targeting other regions of the RTK kinase domain. Osimertinib resistance has become a major obstacle in the treatment of non-small cell lung cancer with EGFR mutations. A study that received osimertinib showed that 31 patients achieved objective tumor response, with an objective response rate of 71.1% and a median disease-free survival of 9.0 months.