According to a new study published in the international peer-reviewed journal Clinical Therapeutics, researchers have found that imatinib was used more often than other tyrosine kinase inhibitors (TKIs) for the first-line treatment of chronic myeloid leukemia (CML) between 2007 and 2011.
For the study, researchers sought to investigate treatment patterns of TKI therapy among patients with CML in the United States as the U.S. Food and Drug Administration has approved two second-generation TKIs since the approval of imatinib in 2001. Those two newer agents are dasatinib, approved in 2006, and nilotinib, approved in 2007.
For the study, the researchers analyzed data from U.S. health plan claims of 695 patients between 2007 and 2011. Patients were only included if they were at least 18 years of age, filled a prescription for a TKI, and had a diagnosis of FML.
Results showed that imatinib was the most common first-line TKI for CML (82%), while dasatinib and nilotinib were each used as first-line TKI therapy in 9% of patients. Of the 695 patients, 148 initiated a second-line TKI and 86% of those switched from imatinib to dasatinib or nilotinib. Furthermore, the median duration of first-line TKI was 39.8 months and 22.4 months for second-line TKI use.
The objective of this study was to explore treatment patterns of TKI therapy (adherence, duration, and switching) among patients with CML in the United States, following the availability of second–generation TKIs. For the US patients studied, the authors found that imatinib was used more frequently than other TKIs in the first–line setting, but there was an increased use of second–generation TKIs in the first–line setting over time (9% in 2008 vs 43% in 2011 were nilotinib or dasatinib users). Only about one fifth of patients switched to a second–line TKI during the period of data collection.