Brigatinib (BRG) in Crizotinib (Crz)-Refractory ALK+ Non-Small Cell Lung Cancer (NSCLC): Updates from ALTA, a Pivotal Randomized Phase 2 Trial.

e20503 Background: Most ALK+ NSCLC patients (pts) receiving CRZ eventually experience disease progression. Based on promising activity in a phase 1/2 trial, a randomized phase 2 trial of the ALK inhibitor BRG in pts with CRZ-refractory, advanced ALK+ NSCLC (ALTA; NCT02094573) was initiated. Responses and adverse events (AEs) varied with starting dose; therefore, ALTA was designed to evaluate 2 distinct BRG regimens. Methods: Pts were stratified by presence of baseline (BL) brain metastases and best response to prior CRZ and randomized 1:1 to receive BRG at 90 mg qd (arm A) or 180 mg qd with a 7-d lead-in at 90 mg (arm B). Primary endpoint was investigator-assessed confirmed objective response rate (ORR) per RECIST v1.1. Results: In 222 pts (arm A/B, n=112/n=110), median age was 51/57 y; 71%/67% had brain metastases. As of May 31, 2016, 51%/56% (A/B) continued to receive BRG; median follow-up was 10.2/11.0 mo. Table shows efficacy. In pts with measurable BL brain metastases (A/B, n=26/n=18), confirmed intracranial ORR was 46%/67%. Most common treatment-emergent AEs (A/B) were: nausea 36%/43%, diarrhea 21%/39%, cough 23%/36%, headache 28%/30%, vomiting 28%/26%; grade ≥3 AEs included increased CPK 3%/10%, hypertension 6%/6%, pneumonia 3%/5%, increased lipase 5%/3%. A subset of pulmonary AEs with early onset (median: Day 2) occurred in 14/219 (6%) treated pts (3%, grade ≥3); 7/14 pts were successfully retreated. Dose reductions (8%/23%, A/B) and discontinuations (3%/10%) due to AEs were reported. Conclusions: BRG showed substantial activity, robust PFS, and acceptable safety at both dose levels, with numerically improved efficacy (particularly PFS and intracranial ORR) at 180 mg (with lead-in). Clinical trial information: NCT02094573. [Table: see text]