Treatment patterns and healthcare costs among newly-diagnosed patients with chronic myeloid leukemia receiving dasatinib or nilotinib as first-line therapy in the United States.

Objective: To compare treatment patterns and economic outcomes of dasatinib and nilotinib as 1st-line therapies for chronic myeloid leukemia (CML).

Methods: Adult CML patients initiated on first-line dasatinib or nilotinib in 2010-2014 were identified from two large US administrative claims databases. Treatment patterns, tyrosine kinase inhibitor (TKI) adherence and healthcare resource utilization (HRU) and costs were measured from the 1st-line TKI initiation (index date) to the end of follow-up.

Results: A total of 604 and 418 patients were included in the dasatinib and nilotinib cohorts (mean ages = 50.9 and 52.5 years, 46.4% and 45.7% female), respectively. Among the dasatinib patients, 91% started with 100 mg/day, 3% with <100 mg/day, and 6% with >100 mg/day. Among the nilotinib patients, 76% started with 600 mg/day, 16% with >600 mg/day, and 8% <600 mg/day. The dasatinib cohort had a higher hazard of dose decrease (hazard ratio [HR] = 1.66; p = .002) and of switching to another TKI (HR =1.62; p = .019) compared to the nilotinib cohort. The hazard of dose increase (HR =0.76; p = .423) and treatment discontinuation (HR =1.10; p = .372) were not significantly different between cohorts. There was also no significant difference in TKI adherence levels (mean proportion of days covered [PDC] difference over first 6 months = -0.0003, p = .981; mean PDC difference over first 12 months = -0.0022, p = .880) and HRU (inpatient day incidence rate ratio [IRR] = 1.03, p = .930; emergency room IRR =1.26, p = .197; and days with outpatient services IRR = 1.01, p = .842). The dasatinib cohort incurred higher healthcare costs by $749 per patient per month (p = .044) compared to the nilotinib cohort.

Limitation: Information on CML phase and Sokal score was not available.

Conclusions: Dasatinib was associated with an increased hazard of dose decrease and switching to another TKI and higher healthcare costs, vs nilotinib.