Immunotherapy in patients with lung cancer with driver mutations: A single center experience.

Abstract

e21170 Background: Immunotherapy has revolutionized treatment in metastatic non small cell lung cancer (NSCLC)without driver mutations. Trial data shows that programme death-1/ PDL1 blockade in epidermal growth factor receptor(EGFR) and other driver mutation positive lung cancers is not beneficial. Here we evaluated the efficacy of immune check point inhibitors in a series of patients with EGFR and other driver mutation positive advanced NSCLC. Methods: We retrospectively analysed 75 patients who received PD1/ PDL1 inhibitors for advanced NSCL between January 2017 to January 2020. 10 patients were detected to have driver mutations on either tumor tissue or blood by NGS. Results: Out of 10 patients, 7 were male and 3 were female. EGFR was detected in 6 patients (3 on tumor and 3 in blood NGS). We found MET exon 14 skip mutation in 2 and RAS in 2 patients. Immunotherapy combined with chemotherapy was given in 5(50%) patients, immunotherapy + bevacizumab+chemotherapy in 2(20%) and immunotherapy alone in 3 patients(30%). Immunotherapy was as started as first line in 4 patients as tumor tissue was negative for EGFR, ALK, ROS1 by single gene testing. On NGS testing at progression, EGFR mutation was detected in 1 patient, MET exon 14 skip mutation was detected in 2 and Ras mutation in 2 patients. Immunotherapy alone was used in 3 patients in view of advanced age and multiple comorbidities.The progression free survival(PFS) ranged between 2 to 11months. Conclusions: Single agent checkpoint inhibitors seem to have a limited impact in treatment in patients with driver mutations. Molecular testing by NGS is recommended either on tumor tissue or on blood by NGS if single gene testing for EGFR/ ALK/ ROS1 alterations is negative. We do see benefit in patients who received PD1/PDL1 inhibitors in combination with chemotherapy with/ without Bevacizumab. In conclusion, patients progressing on EGFR TKIs who are planned for immunotherapy should always be given in combination with chemotherapy+/- Bevacizumab.[Table: see text]