Supplementary Table 1. Brigatinib in vitro activity (IC50s) in a kinase panel (N=289); Supplementary Figure 1. Chemical structures of brigatinib, crizotinib, ceritinib, and alectinib; Supplementary Figure 2. Brigatinib-mediated inhibition of native or mutant ALK-, ROS1-,FLT3-, and EGFR-driven tumor activity in vitro; Supplementary Figure 3. Cellular and in vivo activity of brigatinib in ROS1 harboring models, compared with crizotinib; Supplementary Figure 4. Comparison of IGF-1R and INSR inhibitory activity of brigatinib with NVP-TAE684; Supplementary Figure 5. Inhibition of ALK phosphorylation in ALK+ cellular models by brigatinib, compared with crizotinib; Supplementary Figure 6. Inhibition of ALK phosphorylation and downstream signaling, and tolerability of brigatinib in vivo, compared with crizotinib; Supplementary Figure 7. TKI activity against parental, and native and mutant EML4-ALK driven Ba/F3 cells; Supplementary Figure 8. TKI antitumor activity against native and mutant EML4-ALK tumors, TKI plasma levels, and tolerability, in vivo.
ARTICLE ABSTRACT
Purpose: Non–small cell lung cancers (NSCLCs) harboring ALK gene rearrangements (ALK+) typically become resistant to the first-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) crizotinib through development of secondary resistance mutations in ALK or disease progression in the brain. Mutations that confer resistance to second-generation ALK TKIs ceritinib and alectinib have also been identified. Here, we report the structure and first comprehensive preclinical evaluation of the next-generation ALK TKI brigatinib.Experimental Design: A kinase screen was performed to evaluate the selectivity profile of brigatinib. The cellular and in vivo activities of ALK TKIs were compared using engineered and cancer-derived cell lines. The brigatinib–ALK co-structure was determined.Results: Brigatinib potently inhibits ALK and ROS1, with a high degree of selectivity over more than 250 kinases. Across a panel of ALK+ cell lines, brigatinib inhibited native ALK (IC50, 10 nmol/L) with 12-fold greater potency than crizotinib. Superior efficacy of brigatinib was also observed in mice with ALK+ tumors implanted subcutaneously or intracranially. Brigatinib maintained substantial activity against all 17 secondary ALK mutants tested in cellular assays and exhibited a superior inhibitory profile compared with crizotinib, ceritinib, and alectinib at clinically achievable concentrations. Brigatinib was the only TKI to maintain substantial activity against the most recalcitrant ALK resistance mutation, G1202R. The unique, potent, and pan-ALK mutant activity of brigatinib could be rationalized by structural analyses.Conclusions: Brigatinib is a highly potent and selective ALK inhibitor. These findings provide the molecular basis for the promising activity being observed in ALK+, crizotinib-resistant patients with NSCLC being treated with brigatinib in clinical trials. Clin Cancer Res; 22(22); 5527–38. ©2016 AACR.
