Brigatinib (BRG) in ALK+ crizotinib (CRZ)-refractory non-small cell lung cancer (NSCLC): Final results of the phase 1/2 and phase 2 (ALTA) trials.

Abstract

9071 Background: BRG is a kinase inhibitor approved for the treatment of patients (pts) with ALK+ metastatic NSCLC; specific details for BRG use vary by indication and country. We report long-term efficacy and safety results of the Phase 1/2 and Phase 2 (ALTA) trials of BRG. Methods: The Phase 1/2 study was a single-arm, open-label trial (NCT01449461) of BRG 30–300 mg/d in pts with advanced malignancies. ALTA (NCT02094573) randomized pts with CRZ-refractory ALK+ NSCLC to receive BRG at 90 mg qd (arm A) or 180 mg qd with 7-d lead-in at 90 mg (arm B). For the Phase 1/2 study, investigator assessments of confirmed objective response rate (cORR; RECIST v1.1), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety in pts with ALK+ NSCLC are reported. The primary endpoint of ALTA was cORR per investigator; secondary endpoints included cORR per independent review committee (IRC), DoR, PFS, and OS. Results: In the Phase 1/2 study, 137 pts received BRG; of these, 79 pts had ALK+ NSCLC (71/79 had prior CRZ; 28/79 received 180 mg qd [7-d lead-in at 90 mg]; 14/79 received 90 mg qd). In ALTA, 222 pts with CRZ-refractory ALK+ NSCLC were randomized (n = 112/110, arm A/B). At the end of the Phase 1/2 study (Feb 18, 2020), with median 27.7 mo follow-up (̃67 mo after last pt enrolled), 4 pts remained on BRG. At the end of ALTA (Feb 27, 2020), with median 19.6/28.3 mo follow-up in arm A/B (̃53 mo after last pt enrolled), 10/17 pts in arm A/B were still on treatment. Table shows efficacy results from final analyses with long-term follow-up. In ALTA, the IRC-assessed intracranial cORR in pts with measurable baseline brain metastases was 50% (13/26) in arm A and 67% (12/18) in arm B; Kaplan-Meier (KM) estimated median intracranial DoR was 9.4 mo (95% CI, 3.7, not reached [NR]) in arm A and 16.6 mo (3.7, NR) in arm B. With long-term follow-up, no new safety signals were identified. Treatment-emergent adverse events led to dose interruption (Phase 1/2: 59%; ALTA arm A/B: 49%/61%), dose reduction (13%; 8%/33%), or discontinuation (10%; 4%/13%). Conclusions: BRG showed sustained long-term activity, PFS, and manageable safety in pts with CRZ-refractory ALK+ NSCLC. The 180 mg/d dose after 7-d lead-in at 90 mg/d led to numerically higher median PFS and OS. Final results are similar to those reported for other approved ALK tyrosine kinase inhibitors in this setting. Clinical trial information: NCT01449461, NCT02094573. [Table: see text]