The characterization of EGFR (epidermal growth factor receptor) mutations revolutionized treatment for a large subset of advanced and metastatic lung cancer patients. Patients are living longer with a good quality of life with drugs targeting EGFR. Knowledge of EGFR mutations have expanded past just knowing the presence of a mutation to identifying the specific gene alterations that cause that patient’s EGFR dysregulation. We now know that the currently available FDA-approved EGFR inhibitors (erlotinib, gefitinib, afatinib, dacomitinib, and osimertinib) are effective for patients with EGFR mutations mainly in exon 19 and 21, with specific ones also being effective for other rare mutations (afatinib for G719X mutations and osimertinib for T790M mutations, for example). Unfortunately, these inhibitors have been notoriously less effective for patients harboring insertion mutations in exon 20. There are currently no EGFR inhibitors approved for exon 20 insertion mutations (that is not to be confused with the T790M mutation, which is in exon 20 but is not an insertion mutation). Interest in EGFR exon 20 insertion mutations has increased quickly and several clinical trials are testing a variety of drugs. Please reach out to us at (562) 590-0345 if you are a patient with an EGFR exon 20 mutation and are interested in participating in one of our clinical trials.

-Danny Nguyen, MD
Pacific Shores Medical Group