Characteristics and treatment patterns among US patients with hairy cell leukemia: a retrospective claims analysis

Aim: Describe hairy cell leukemia (HCL) treatment patterns using a large, nationally representative US database. Patients & methods: Adults newly diagnosed with HCL (1 January 2006 to 30 June 2014) with continuous health plan enrollment >= 180 days pre- and 90 days post-diagnosis were identified from the QuintilesIMS PharMetrics Plus Health Plan Claims Database. Treatment patterns by line of therapy were assessed over the variable follow-up. Results: Among 749 HCL patients (77.4% male; mean age 55.6; mean 32.3 months follow-up), only 37.7% initiated first-line therapy during the available follow-up in a mean of 4.4 months following diagnosis; the majority (75.5%) received cladribine (mean duration 7.3 days). Thirty-eight patients (5.1%) received second-line treatment. Conclusion: Over 2.7 years follow-up, more than a third of patients initiated first-line therapy which appeared to provide a long-lasting response.