Imatinib mesylate therapy for polycythemia vera: final result of a phase II study initiated in 2001.

Abstract

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm (MPN) characterized by excessive production of red blood cells. Patients with PV are at a risk of thrombosis, bleeding, and transformation to myelofibrosis or acute myeloid leukemia. Therapy for PV is based on the use of phlebotomy, aspirin, and in high-risk patients, cytoreductive agents such as hydroxyurea. Anecdotal evidence suggests that imatinib mesylate, a selective tyrosine kinase inhibitor of ABL1, ARG, PDGFR, and KIT kinases has activity in PV. We conducted an open-label phase II clinical trial of imatinib at the standard dose of 400 mg daily in 24 patients with PV. The median duration of imatinib therapy was 5.1 months (range 0.2-86.4). Overall, 4 (17%) patients responded: one had a complete and three partial hematological response. The median time to response was 17.5 months (range 6-28), and the median duration of response was 17 months (range 9-68). No significant changes in JAK2(V617F) mutation burden were noted during imatinib therapy when compared with pretreatment values (P = 0.46). Therapy with imatinib was generally well tolerated. Our data indicate that imatinib has minimal clinical activity in PV.

• Authors: Roberto H Nussenzveig, Jorge Cortes, Matjaz Sever, Alfonso Quintás-Cardama, Pat Ault, Taghi Manshouri, Carlos Bueso-Ramos, Josef T Prchal, Hagop Kantarjian, Srdan Verstovsek
• Journal: International journal of hematology (Int J Hematol) Vol. 90 Issue 1 Pg. 58-63 (Jul 2009) ISSN: 1865-3774 [Electronic] Japan
• PMID: 19484334 (Publication Type: Clinical Trial, Phase II, Comparative Study, Journal Article)

Chemical References

• Benzamides
• Piperazines
• Protein Kinase Inhibitors
• Pyrimidines
• Imatinib Mesylate
• Proto-Oncogene Proteins c-kit
• Receptors, Platelet-Derived Growth Factor
• JAK2 protein, human
• Janus Kinase 2
• Proto-Oncogene Proteins c-abl

Topics

• Adult
• Aged
• Aged, 80 and over
• Amino Acid Substitution
• Benzamides
• Female
• Humans
• Imatinib Mesylate
• Janus Kinase 2 (antagonists & inhibitors, genetics)
• Male
• Middle Aged
• Mutation, Missense
• Piperazines (administration & dosage, adverse effects)
• Polycythemia Vera (drug therapy, enzymology, genetics)
• Protein Kinase Inhibitors (administration & dosage, adverse effects)
• Proto-Oncogene Proteins c-abl (antagonists & inhibitors, genetics)
• Proto-Oncogene Proteins c-kit (genetics)
• Pyrimidines (administration & dosage, adverse effects)
• Receptors, Platelet-Derived Growth Factor (antagonists & inhibitors, genetics)
• Time Factors