The PEAK Study: Global, Randomized, Open-Label Phase 3 Study Evaluating the Efficacy and Safety of Bezuclastinib + Sunitinib vs Sunitinib as Second-Line Treatment After Imatinib in Advanced Gastrointestinal Stromal Tumors

In this OncLive Rapid Readout, Neeta Somaiah, MD, chair of sarcoma medical oncology at The University of Texas MD Anderson Cancer Center, reviews findings from the phase 3 PEAK trial presented at the 2026 ASCO Annual Meeting. The study evaluated bezuclastinib plus sunitinib versus sunitinib alone in patients with gastrointestinal stromal tumors (GIST) who progressed on or were intolerant to imatinib. The combination reduced the risk of progression or death by 50% compared with sunitinib alone, with a median progression-free survival of 16.5 months versus 9.2 months and a hazard ratio of 0.50. Overall response rate was also significantly higher with the combination (45.6% vs 25.8%). Safety was manageable, with no new signals and lower rates of hand-foot syndrome, stomatitis, and thrombocytopenia versus sunitinib alone. Somaiah notes that mutational heterogeneity driving imatinib resistance may be more effectively addressed through dual kinase inhibition, and discusses how these results could reshape second-line sequencing in GIST pending regulatory approval.