Purpose We report CNS efficacy of osimertinib versus standard epidermal growth factor receptor ( EGFR) tyrosine kinase inhibitors (TKIs) in patients with untreated EGFR-mutated advanced non-small-cell lung cancer from the phase III FLAURA study. Patients and Methods Patients (N = 556) were randomly assigned to osimertinib or standard EGFR-TKIs (gefitinib or erlotinib); brain scans were not mandated unless clinically indicated. Patients with asymptomatic or stable CNS metastases were included. In patients with symptomatic CNS metastases, neurologic status was required to be stable for ≥ 2 weeks after completion of definitive therapy and corticosteroids. A preplanned subgroup analysis with CNS progression-free survival as primary objective was conducted in patients with measurable and/or nonmeasurable CNS lesions on baseline brain scan by blinded independent central neuroradiologic review. The CNS evaluable-for-response set included patients with ≥ one measurable CNS lesion. Results Of 200 patients with available brain scans at baseline, 128 (osimertinib, n = 61; standard EGFR-TKIs, n = 67) had measurable and/or nonmeasurable CNS lesions, including 41 patients (osimertinib, n = 22; standard EGFR-TKIs, n = 19) with ≥ one measurable CNS lesion. Median CNS progression-free survival in patients with measurable and/or nonmeasurable CNS lesions was not reached with osimertinib (95% CI, 16.5 months to not calculable) and 13.9 months (95% CI, 8.3 months to not calculable) with standard EGFR-TKIs (hazard ratio, 0.48; 95% CI, 0.26 to 0.86; P = .014 [nominally statistically significant]). CNS objective response rates were 91% and 68% in patients with ≥ one measurable CNS lesion (odds ratio, 4.6; 95% CI, 0.9 to 34.9; P = .066) and 66% and 43% in patients with measurable and/or nonmeasurable CNS lesions (odds ratio, 2.5; 95% CI, 1.2 to 5.2; P = .011) treated with osimertinib and standard EGFR-TKIs, respectively. Probability of experiencing a CNS progression event was consistently lower with osimertinib versus standard EGFR-TKIs. Conclusion Osimertinib has CNS efficacy in patients with untreated EGFR-mutated non-small-cell lung cancer. These results suggest a reduced risk of CNS progression with osimertinib versus standard EGFR-TKIs.

Purpose In patients with epidermal growth factor receptor ( EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC), there is an unmet need for EGFR-tyrosine kinase inhibitors with improved CNS penetration and activity against CNS metastases, either at initial diagnosis or time of progression. We report the first comparative evidence of osimertinib CNS efficacy versus platinum-pemetrexed from a phase III study (AURA3; ClinicalTrials.gov identifier: NCT02151981) in patients with EGFR T790M-positive advanced NSCLC who experience disease progression with prior EGFR-tyrosine kinase inhibitor treatment. Methods Patients with asymptomatic, stable CNS metastases were eligible for enrollment and were randomly assigned 2:1 to osimertinib 80 mg once daily or platinum-pemetrexed. A preplanned subgroup analysis was conducted in patients with measurable and/or nonmeasurable CNS lesions on baseline brain scan by blinded independent central neuroradiological review. The CNS evaluable for response set included only patients with one or more measurable CNS lesions. The primary objective for this analysis was CNS objective response rate (ORR). Results Of 419 patients randomly assigned to treatment, 116 had measurable and/or nonmeasurable CNS lesions, including 46 patients with measurable CNS lesions. At data cutoff (April 15, 2016), CNS ORR in patients with one or more measurable CNS lesions was 70% (21 of 30; 95% CI, 51% to 85%) with osimertinib and 31% (5 of 16; 95% CI, 11% to 59%) with platinum-pemetrexed (odds ratio, 5.13; 95% CI, 1.44 to 20.64; P = .015); the ORR was 40% (30 of 75; 95% CI, 29% to 52%) and 17% (7 of 41; 95% CI, 7% to 32%), respectively, in patients with measurable and/or nonmeasurable CNS lesions (odds ratio, 3.24; 95% CI, 1.33 to 8.81; P = .014). Median CNS duration of response in patients with measurable and/or nonmeasurable CNS lesions was 8.9 months (95% CI, 4.3 months to not calculable) for osimertinib and 5.7 months (95% CI, 4.4 to 5.7 months) for platinum-pemetrexed; median CNS progression-free survival was 11.7 months and 5.6 months, respectively (hazard ratio, 0.32; 95% CI, 0.15 to 0.69; P = .004). Conclusion Osimertinib demonstrated superior CNS efficacy versus platinum-pemetrexed in T790M-positive advanced NSCLC.