Pilot study of pegylated interferon-alpha 2b in patients with essential thrombocythemia

Cancer Chemother Pharmacol. 2003 Jan;51(1):81-6. doi: 10.1007/s00280-002-0533-4. Epub 2002 Nov 21.

Abstract

Purpose: Interferon-alpha (IFN-alpha) has been shown to control symptoms, reduce platelet counts, and reduce the bone marrow megakaryocyte mass in patients with essential thrombocythemia (ET). A semisynthetic protein-polymer conjugate of IFN-alpha 2b (PEG-IFN2b) increases the serum half-life of IFN-alpha 2b. We conducted a pilot study of Peg-IFN2b in patients with ET.

Patients and methods: Patients with a history of persistent (greater than 2 months) platelet counts >600 x 10(9)/l, with hyperplasia of bone marrow megakaryocytes in the absence of an alternate identifiable cause of thrombocytosis were eligible. Patients were required to have either thrombohemorrhagic signs and/or symptoms if previously untreated; persistence of thrombohemorrhagic signs and/or symptoms if receiving anagrelide, IFN-alpha, or hydroxyurea; or intolerance to anagrelide, IFN-alpha, or hydroxyurea. The initial PEG-IFN2b dose was from 1.5 to 4.5 micro g/kg per week subcutaneously with subsequent dose adjustments as indicated by response and adverse events.

Results: Eleven patients (nine female, median age 54 years, range 26-69 years) were treated. PEG-IFN2b rapidly controlled platelet counts and resolved symptoms in all patients. The median duration of PEG-IFN2b therapy on-study was 9 months (range 4-17 months). No patient had signs or symptoms of thrombosis or hemorrhage while on study. After 2 months of therapy, 10 patients (91%) were in complete remission, and 11 (100%) after 4 months. One patient discontinued therapy at 4 months because of persistent grade 3 fatigue and a second at 5 months because of anxiety and depression.

Conclusion: PEG-IFN2b has significant activity in patients with ET. Long-term follow-up of a larger cohort of patients is needed to define its role in this disease.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Interferon alpha-2
  • Interferon-alpha* / adverse effects
  • Interferon-alpha* / therapeutic use*
  • Male
  • Middle Aged
  • Pilot Projects
  • Platelet Count
  • Polyethylene Glycols*
  • Recombinant Proteins
  • Thrombocytosis / blood
  • Thrombocytosis / drug therapy*

Substances

  • Interferon alpha-2
  • Interferon-alpha
  • Recombinant Proteins
  • Polyethylene Glycols
  • peginterferon alfa-2b
  • peginterferon alfa-2a