TY - JOUR
T1 - Response criteria for essential thrombocythemia and polycythemia vera
T2 - Result of a European LeukemiaNet consensus conference
AU - Barosi, Giovanni
AU - Birgegard, Gunnar
AU - Finazzi, Guido
AU - Griesshammer, Martin
AU - Harrison, Claire
AU - Hasselbalch, Hans Carl
AU - Kiladjian, Jean Jacques
AU - Lengfelder, Eva
AU - McMullin, Mary Frances
AU - Passamonti, Francesco
AU - Reilly, John T.
AU - Vannucchi, Alessandro M.
AU - Barbui, Tiziano
PY - 2009/11/17
Y1 - 2009/11/17
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=66549086134&partnerID=8YFLogxK
U2 - 10.1182/blood-2008-09-176818
DO - 10.1182/blood-2008-09-176818
M3 - Article
C2 - 19278953
AN - SCOPUS:66549086134
SN - 0006-4971
VL - 113
SP - 4829
EP - 4833
JO - Blood
JF - Blood
IS - 20
ER -