title: Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine) by subcutaneous bolus injection: a phase II study.
abstract: BACKGROUND
  To assess the activity and toxicity of 2-chlorodeoxyadenosine (cladribine, CDA) given by subcutaneous bolus injections to patients with hairy cell leukemia (HCL).
  
  
  METHODS
  Sixty-two eligible patients with classic or prolymphocytic HCL (33 non-pretreated patients, 15 patients with relapse after previous treatment, and 14 patients with progressive disease during a treatment other than CDA) were treated with CDA 0.14 mg/kg/day by subcutaneous bolus injections for five consecutive days. Response status was repeatedly assessed according to the Consensus Resolution criteria.
  
  
  RESULTS
  Complete and partial remissions were seen in 47 (76%) and 13 (21%) patients, respectively, for a response rate of 97%. All responses were achieved with a single treatment course. Most responses occurred early (i.e. within 10 weeks) after start of CDA therapy, but response quality improved during weeks and even months after treatment completion. The median time to treatment failure for all patients was 38 months. Leukopenia was the main toxicity. Granulocyte nadir (median 0.2 x 10(9)/l) was strongly associated with the incidence of infections (P = 0.0013). Non-specific lymphopenia occurred early after CDA treatment, and normal lymphocytes recovered slowly over several months. No significant associations were found between infections and nadir count of lymphocytes or any lymphocyte subpopulation. No opportunistic infections were observed.
  
  
  CONCLUSIONS
  One course of CDA given by subcutaneous bolus injections is very effective in HCL. The subcutaneous administration is more convenient for patients and care providers, and has a similar toxicity profile to continuous intravenous infusion. The subcutaneous administration of CDA is a substantial improvement and should be offered to every patient with HCL requiring treatment with CDA.
authors.affiliation: Institute of Medical Oncology, Inselspital, Bern. avonrohr@onkozentrum.ch
authors.forename: A
authors.initials: A
authors.lastname: von Rohr
authors.forename: S-F H
authors.initials: SF
authors.lastname: Schmitz
authors.forename: A
authors.initials: A
authors.lastname: Tichelli
authors.forename: U
authors.initials: U
authors.lastname: Hess
authors.forename: D
authors.initials: D
authors.lastname: Piguet
authors.forename: M
authors.initials: M
authors.lastname: Wernli
authors.forename: N
authors.initials: N
authors.lastname: Frickhofen
authors.forename: G
authors.initials: G
authors.lastname: Konwalinka
authors.forename: G
authors.initials: G
authors.lastname: Zulian
authors.forename: M
authors.initials: M
authors.lastname: Ghielmini
authors.forename: B
authors.initials: B
authors.lastname: Rufener
authors.forename: C
authors.initials: C
authors.lastname: Racine
authors.forename: M F
authors.initials: MF
authors.lastname: Fey
authors.forename: T
authors.initials: T
authors.lastname: Cerny
authors.forename: D
authors.initials: D
authors.lastname: Betticher
authors.forename: A
authors.initials: A
authors.lastname: Tobler
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D017338:Cladribine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D007943:Leukemia, Hairy Cell / Q000188:drug therapy* / Q000473:pathology; D007970:Leukopenia / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013534:Survival
chemical_list: D000970:Antineoplastic Agents; D017338:Cladribine