WCLC 2018: Immunotherapy for Lung Cancers With Oncogenic Driver Mutations
Posted: Monday, October 1, 2018
Patients with non–small cell lung cancer (NSCLC) and oncogenic driver mutations responded to immunotherapy, albeit with lower response rates than in those with KRAS-mutant NSCLC, according to findings presented at the International Association for the Study of Lung Cancer (IASLC) 19th World Conference on Lung Cancer (WCLC) in Toronto (Abstract MA04.03). The study, conducted by Oliver Gautschi, MD, of the Department of Medical Oncology at Luzerner Kantonsspital, Lucerne, Switzerland, and colleagues, showed that “PD-L1 expression may not accurately predict clinical benefit from immunotherapy in some molecular subgroups, [and] better markers are needed.”
In 2017, the researchers started an international retrospective registry study, IMMUNOTARGET, focusing on patients with NSCLC, known driver mutations (KRAS, EGFR, ALK, ROS1, BRAF, HER2, MET, and RET) and PD-L1 immune checkpoint inhibitor therapy. Anonymous personal health data were submitted to the coordinating center, where patient and tumor characteristics, mutation test methods and results, systemic therapy lines, among other metrics, were organized.
By April 2018, their registry totaled 551 patients, half of whom were women, from Europe, the United States, Israel, and Australia. Most patients received nivolumab (n = 466) or pembrolizumab (n = 48) and received a treatment of immunotherapy in the second or third line (67%). The percentage of PD-L1–positive cells was available for 177 patients.
From the start of immunotherapy, the median overall survival was 13.3 months, and the median progression-free survival was 2.8 months. The best response (including both partial and complete responses) was reported in those with KRAS (26%) and BRAF (24%) driver mutations, with 0% responses in those with ALK driver mutations. As for the predictive ability of PD-L1 positivity, it was predictive for improved progression-free survival in both KRAS- and EGFR-mutant tumors.
