Efficacy of Brigatinib in Patients With Advanced ALK-Positive NSCLC Who Progressed on Alectinib or Ceritinib: ALK in Lung Cancer Trial of brigAtinib-2 (ALTA-2)

Introduction: Brigatinib is a potent next-generation ALK tyrosine kinase inhibitor approved for treatment-naive and crizotinib-refractory advanced ALK-positive (ALK+) NSCLC. We evaluated brigatinib after other next-generation ALK tyrosine kinase inhibitors. Methods: In this single-arm, phase 2, ALK in Lung Cancer Trial of brigAtinib-2 (NCT03535740), patients with advanced ALK+ NSCLC whose disease progressed on alec-tinib or ceritinib received brigatinib 180 mg once daily (after 7-d 90-mg lead-in). Primary end point was indepen-dent review committee (IRC)-assessed overall response rate (ORR). Circulating tumor DNA (ctDNA) was analyzed. Results: Among 103 patients (data cutoff: September 30, 2020; median follow-up [range]: 10.8 [0.5-17.7] mo), confirmed IRC-ORR was 26.2% (95% confidence interval [CI]: 18.0-35.8), median duration of response, 6.3 months (95% CI: 5.6-not reached), and median progression-free survival (mPFS), 3.8 months (95% CI: 3.5-5.8). mPFS was 1.9 months (95% CI: 1.8-3.7) in patients with ctDNA-detectable baseline ALK fusion (n = 64). Among 86 pa-tients who progressed on alectinib, IRC-ORR was 29.1% (95% CI: 19.8-39.9); mPFS was 3.8 months (95% CI: 1.9- 5.4). Resistance mutations were present in 33.3% (26 of 78) of baseline ctDNA; 54% (14 of 26) of mutations were G1202R; 52% (33 of 64) of patients with detectable ALK fusion had EML4-ALK variant 3. Most common all-grade treatment-related adverse events were increased creatine phosphokinase (32%) and diarrhea (27%). The mean dose intensity of brigatinib (180 mg once daily) was 85.9%. Conclusions: In ALK in Lung Cancer Trial of brigAtinib-2, brigatinib was found to have a limited activity in patients with ALK+ NSCLC post-ceritinib or post-alectinib therapy. mPFS was longer with brigatinib in patients without base-line detectable plasma ALK fusion. (c) 2022 International Association for the Study of Lung Cancer. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).