*January 29, 2019* Lungevity, by Juhi Kunde. In 2004, after the discovery of mutations in the EGFR gene in lung cancer, the FDA approved a targeted therapy that increased survival in EGFR-positive NSCLC patients. However, the tumors inevitably became resistant to the treatment, and the cancer returned unchecked.

To understand what was causing the cancer to come back, researchers studied the genomic changes in the tumors that had recurred. What they found was surprising! Tumor cells are shrewd—they were developing additional mutations that allowed the tumor to survive and thrive. Researcher developed new drugs (third-generation treatment options) to target these new mutations, with the goal of overcoming drug resistance.

One third-generation treatment, osimertinib (Tagrisso®), is currently FDA-approved. This drug has had excellent results, and is also now approved for first-line treatment for patients with advanced-stage EGFR-positive NSCLC.

Eventually, though, whether patients begin with this third-generation therapy or progress through other treatments to end up on it, their cancers also become resistant to this treatment. Read more.