Response criteria for essential thrombocythemia and polycythemia vera: Result of a European LeukemiaNet consensus conference

Giovanni Barosi, Gunnar Birgegard, Guido Finazzi, Martin Griesshammer, Claire Harrison, Hans Carl Hasselbalch, Jean Jacques Kiladjian, Eva Lengfelder, Mary Frances McMullin, Francesco Passamonti, John T. Reilly, Alessandro M. Vannucchi, Tiziano Barbui

Research output: Contribution to journalArticle

Abstract

European experts were convened to develop a definition of response to treatment in polycythemia vera (PV) and essential thrombocythemia (ET). Clinicohematologic (CH), molecular, and histologic response categories were selected. In ET, CH complete response (CR) was: platelet count less than or equal to 400 × 109/L, no disease-related symptoms, normal spleen size, and white blood cell count less than or equal to 10 × 10 9/L. Platelet count less than or equal to 600 × 10 9/L or a decrease greater than 50% was partial response (PR). In PV, CH-CR was: hematocrit less than 45% without phlebotomy, platelet count less than or equal to 400 × 109/L, white blood cell count less than or equal to 10 × 109/L, and no disease-related symptoms. A hematocrit less than 45% without phlebotomy or response in 3 or more of the other criteria was defined as PR. In both ET and in PV, molecular CR was a reduction of any molecular abnormality to undetectable levels. Molecular PR was defined as a reduction more than or equal to 50% in patients with less than 50% mutant allele burden, or a reduction more than or equal to 25% in patients with more than 50% mutant allele burden. Bone marrow histologic response in ET was judged on megakaryocyte hyperplasia while on cellularity and reticulin fibrosis in PV. The combined use of these response definitions should help standardize the design and reporting of clinical studies.

Original languageEnglish
Pages (from-to)4829-4833
Number of pages5
JournalBlood
Volume113
Issue number20
DOIs
Publication statusPublished - 2009

ASJC Scopus subject areas

  • Hematology
  • Biochemistry
  • Cell Biology
  • Immunology

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    Barosi, G., Birgegard, G., Finazzi, G., Griesshammer, M., Harrison, C., Hasselbalch, H. C., Kiladjian, J. J., Lengfelder, E., McMullin, M. F., Passamonti, F., Reilly, J. T., Vannucchi, A. M., & Barbui, T. (2009). Response criteria for essential thrombocythemia and polycythemia vera: Result of a European LeukemiaNet consensus conference. Blood, 113(20), 4829-4833. https://doi.org/10.1182/blood-2008-09-176818