Figure 2. Acquired KRAS Mutation During Osimertinib Therapy.

In 1 patient with osimertinib resistance, next-generation sequencing of a tumor biopsy showed loss of T790M and an acquired KRAS Q61K mutation. Serial plasma genotyping confirmed the acquired KRAS mutation but also detected reemergence of the EGFR T790M mutation. ND indicates not detected.