Successful immune checkpoint inhibition in an EGFR-mutant lung cancer patient refractory to epidermal growth factor receptor tyrosine kinase inhibitor treatment.

It is widely assumed that immune checkpoint inhibition does not give rise to clinical benefits in patients with lung cancer and activating epidermal growth factor receptor (EGFR) mutations. Clinical trial data have predominantly demonstrated low activity of immunotherapy in this patient group, although some evidence has been obtained that implies outcome improvement with checkpoint inhibitors even in EGFR-positive disease. The case presented here demonstrates excellent activity of the PD-L1 inhibitor atezolizumab and the PD-1 inhibitor pembrolizumab as the sixth- and seventh-line treatments in a patient with EGFR-mutant metastatic non-small-cell lung cancer who had not responded to EGFR-targeted agents. Chemotherapy had led to partial remission, and immunotherapy was initiated as a last-line option. The patient achieved complete remission with both atezolizumab for 1 year, and pembrolizumab after progression on atezolizumab. At present, the patient is receiving pembrolizumab and shows stable remission. Later-line immunotherapy might be particularly suitable for patients with EGFR-mutant tumors who did not respond to EGFR tyrosine kinase inhibition therapy. Although further studies are necessary, for patients who are in need of effective treatment, checkpoint inhibition should not be avoided just because EGFR mutations are present.