Clinical Characteristics and Long-Term Outcome of Young Hairy Cell Leukemia Patients Treated With Cladribine: A Single Institution Series

Joshua D. Rosenberg, Carol Burian, Jill Waalen and Alan Saven

Key points

  • HCL patients ≤ 40 at diagnosis treated with cladribine obtain complete and durable responses, but ultimately relapse.

  • There was no increased risk of second primary malignancies in young hairy cell leukemia patients followed for protracted periods.


Hairy cell leukemia (HCL) is a rare, indolent B-cell disorder in which single courses of cladribine induce high rates of complete responses. We report on 88 young HCL patients (≤40 years at diagnosis) treated with cladribine from the Scripps Clinic HCL Database, of whom 83 were evaluable for response. 73 patients (88%) achieved an initial CR and 10 (12%) a PR, with a median response duration of 57 months. 48 patients (58%) relapsed, with a median time to first relapse for all responders of 54 months. 8 patients developed 11 second primary malignancies with an excess frequency of 1.60 (95% CI, 0.80 - 2.89). Thirteen (15%) patients died with a mortality ratio compared to age-matched normals of 1.85 (95% CI, 1.07 - 3.18). Median OS for all patients following the first cladribine course was 231 months, and 251 months from diagnosis. Single courses of cladribine induce high rates of complete and durable responses in the majority of young HCL patients, and is therefore recommended for HCL patients regardless of age.

  • Submitted June 18, 2013.
  • Accepted October 22, 2013.