title: Treatment of hairy-cell leukemia with cladribine: response, toxicity, and long-term follow-up.
abstract: OBJECTIVE
  To analyze initial and long-term outcomes after treatment of patients with active hairy-cell leukemia (HCL) with a single cycle of cladribine (2-CdA).
  
  
  METHODS
  Forty-nine patients with active HCL were treated with 2-CdA by continuous intravenous infusion at 0.1 mg/kg/d for a total of 7 days at the Long Island Jewish Medical Center between September 1990 and August 1992. Here we report on all patients followed-up until April 1996.
  
  
  RESULTS
  At 3 months after treatment, complete response (CR) occurred in 37 patients (76%) and partial response (PR) occurred in 12 patients (24%), for an overall response rate of 100% (95% confidence interval, 94% to 100%). At a median follow-up of 55 months, the relapse-free survival is 80% and overall survival is 95%. Ten patients (20%) have relapsed. Of the 26 patients in whom lymphocyte phenotyping was performed, four were found to have a CD25-negative phenotype. All four of these patients had PRs only and all relapsed. Eight patients have been re-treated with 2-CdA, and all achieved at least a partial remission; two of these have already relapsed with remission durations of less than 1 year. Five second malignancies have occurred in four patients.
  
  
  CONCLUSIONS
  With a median follow-up of more than 4 years, 39 patients (80%) continue in remission. Only two deaths have occurred. A CD25-negative phenotype may predict for a poorer response to 2-CdA. Patients who relapse may be re-treated with 2-CdA, but subsequent remissions may be of shorter duration. There has not been a markedly increased incidence of second malignancies or late opportunistic infections.
authors.affiliation: Department of Medicine, Long Island Jewish Medical Center campus of the Albert Einstein College of Medicine, New Hyde Park, NY 11040, USA. hoffman@lij.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Hoffman
authors.forename: D
authors.initials: D
authors.lastname: Janson
authors.forename: E
authors.initials: E
authors.lastname: Rose
authors.forename: K R
authors.initials: KR
authors.lastname: Rai
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D017338:Cladribine / Q000009:adverse effects / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced; D010641:Phenotype; D012008:Recurrence; D012074:Remission Induction
chemical_list: D000970:Antineoplastic Agents; D017338:Cladribine