OBJECTIVES: To evaluate treatment and response patterns among patients with chronic myeloid leukemia (CML) in Canada, Australia, and South Korea (S.Korea).
METHODS: Oncologists and hematologists in Australia (N31), Canada (N28), and South Korea (N34) abstracted medical records of adults with CML between 1/1/ 2005 and 9/30/2010. Patient selection criteria included: chronic phase at diagnosis, either Ph or BCR-ABL, received 1st-line imatinib, and had not participated in a clinical trial. A subset received 2nd-line therapy with nilotinib or dasatinib. Rates of complete hematological response (CHR) at 3 months, complete cytogenetic response (CCyR) at 12 months, and complete or major molecular response (CMR/ MMR) at 18 months were assessed, stratified by 1st- and 2nd-line therapy.
RESULTS: Data on 610 patients (200/country) were collected. Patients’ mean age was 57 years and 59% were male. Patients received 1st-line therapy for 23 months on average (range: 16 [Canada] to 27 [S.Korea]). Among patients on 1st-line therapy, 78% had CHR at 3 months of treatment (67 [Australia] to 86 [Canada]), 48% had CCyR at 12 months (range: 42% [Australia] to 60% [S.Korea]), and 70% had CMR/MMR at 18 months (67 [S.Korea] to 77 [Australia]). Approximately 10% of patients (7% [Canada] to 14% [Australia]) had dose escalation to a median dose of 600mg. Twenty-two percent of patients discontinued imatinib (17% [S.Korea] to 27% [Australia]). Among those who discontinued, the most common reason was intolerance in Australia (60%) and Canada (37%), and other/no response in S.Korea (25%). Eighty-seven patients had 2nd-line treatment (68 dasatanib, 19 nilotinib). S.Korea had a greater proportion of 2nd-line nilotinib use (41%) than Australia (22%) and Canada (12%), and the mean time to 2nd-line therapy was 22 months post-diagnosis.
CONCLUSIONS: This study further illustrates cross-country variations in CML treatment and response patterns, and emphasizes the need to understand CML populations in individual countries.
