Association Between BCR-ABL Tyrosine Kinase Inhibitors for Chronic Myeloid Leukemia and Cardiovascular Events, Major Molecular Response, and Overall Survival

IMPORTANCE: A phase 3 trial with ponatinib in patients with chronic myeloid leukemia (CML) was interrupted due to an important increase of vascular occlusive events. A similar risk was also suspected with nilotinib, another BCR-ABL tyrosine kinase inhibitor (TKI) used in patients with CML. OBJECTIVE: To assess the risk of vascular occlusive events in patients with CML treated by new generations of TKIs and provide an overall assessment of the clinical benefit. DATA SOURCES: Two independent reviewers selected studies from PubMed, Scopus, and the Cochrane library database from their inception to October 21, 2014. Abstracts published during the past 3 years at international congresses and a trial register were also searched. STUDY SELECTION: Two independent reviewers screened abstracts and titles against inclusion and exclusion criteria published previously in the PROSPERO 2014 protocol: CRD42014014147. Among the 249 abstracts identified, 10 studies fulfilled the established criteria. DATA EXTRACTION AND SYNTHESIS: Two investigators independently extracted data using a standard form. MAIN OUTCOMES AND MEASURES: Information extracted included study and patients characteristics, type of intervention and data on vascular occlusive events, overall survival, and major molecular response (MMR). The meta-analysis was performed using a fixed-effects model. Odds ratios (ORs) with 95% CIs were computed using the Peto method. RESULTS: Ten randomized clinical trials (3043 patients) were analyzed. Risk of vascular occlusive events was increased with dasatinib (OR, 3.86; 95% CI, 1.33-11.18), nilotinib (OR, 3.42; 95% CI, 2.07-5.63), and ponatinib (OR, 3.47; 95% CI, 1.23-9.78) compared with imatinib in patients with CML. No significant difference was found with bosutinib (OR, 2.77; 95% CI, 0.39-19.77). New-generation TKIs increased the rate of MMR at 1 year compared with imatinib (overall OR, 2.22; 95% CI, 1.87 to 2.63). No statistical difference in overall survival at 1 year was found (overall OR, 1.20; 95% CI, 0.63-2.29). Inaccessibility to individual data and time-to-event data and differences in evaluation criteria between studies could have introduced bias. CONCLUSIONS AND RELEVANCE: Dasatinib, nilotinib, and ponatinib increase vascular occlusive events. New-generation TKIs improve MMR but not the overall survival at 1 year in patients with CML.