EP1.14-50 The Effectiveness of the Combined Therapy of Osimertinib and Vemurafenib in a Patient with Coexistance of EGFR and BRAF Mutation

Abstract

included in the biomarker analysis. Baseline characteristics: Chinese, 100%; female, 70.3%; mean age, 57.4 years; EGFR mutations: L858R, 50%; Del19, 42.2%. All patients experienced 1 drug-related AE, most commonly (grouped terms; any grade/3): diarrhea (n¼63/9, 98.4%/14.1%) and rash or acne (n¼52/5, 81.3%/7.8%). SAEs were reported for 15 patients (23.4%), most commonly cerebral infarction (n¼3, 4.7%), malignant neoplasm progression, CNS metastases (both n¼2, 3.1%). Median TTSP was 13.5 months (95% CI: 10.9, 18.0). At baseline, 19 of 42 patients analyzed (45.2%) had additional non-EGFR mutations; 17 (89.5%) progressed/died. Median PFS was 8.1 months in these patients, versus 12.5 months for patients with EGFR-only mutations (HR, 1.72; 95% CI 0.88, 3.36; p¼0.1054). At Visit 3, mutation status had changed from EGFRm+ to EGFR mutation-negative in 33 of 40 patients analyzed (82.5%). Of these, 29 (87.9%) progressed/died; median PFS was 11.0 months versus 5.5 months for patients who remained EGFRm+ (HR, 1.25; 95% CI: 0.47, 3.30; p¼0.6556). Conclusion:In this analysis, safety data were consistent with the known safety profile of afatinib. Median PFS was twice as long in patients who became EGFR mutation-negative compared with those who remained EGFRm+; however, the difference was not statistically significant. There was no significant difference in PFS for patients with additional non-EGFR versus those with EGFR-only mutations. This exploratory analysis suggests that afatinib has clinical benefit for patients with EGFRm+ NSCLC across all the subgroups assessed.