The oncology drug developer expects to file its third generation EGFR inhibitor for the treatment of NSCLC by the end of 2015, CEO Patrick Mahaffy told investors during an R&D day Jan. 27. Investors are enthusiastic about the potential of the drug, which could address a sizeable commercial market.

Lung cancer wasn’t viewed traditionally as a tumor that would respond to immunotherapy. But with checkpoint inhibitor data looking promising, big pharma is diving in and prioritizing the disease, reeled in by the large patient population and high unmet need.

FDA’s next patient-focused drug development meeting will ask what’s most important when diagnosed with a disease that has a median survival time of a little over a year.