Long-term efficacy of imatinib for treatment of metastatic GIST

Purpose: Imatinib is an effective and approved treatment for advanced gastrointestinal stromal tumor (GIST). Continuous imatinib treatment is recommended by current guidelines. This review summarizes the long-term efficacy and safety of imatinib for patients with metastatic GIST. Methods: Key clinical studies were reviewed - including B2222, S0033, and BFR14 - with particular emphasis on recently reported results of the long-term clinical outcome of imatinib for metastatic GIST. Results: The B2222 and S0033 studies recently reported 10-year follow-up results that demonstrate the long-term efficacy of imatinib. Furthermore, results from the BFR14 study demonstrate that imatinib treatment should not be interrupted and that the efficacy of imatinib following reintroduction is inferior compared with the continuous administration group. The S0033 study also supports the importance of dose optimization and dose escalation of imatinib in patients with KIT exon 9 mutations or progressive disease. These studies demonstrate that individual patient characteristics should be evaluated for optimal patient management. Managing adverse events proactively is very important to maintain compliance. Conclusions: The results from these studies demonstrate that long-term imatinib extends survival in patients with advanced GIST. Furthermore, these studies support the safety of long-term imatinib therapy in this patient population.