Table 1.
Definition of Resistance/Intolerance to HU in Patients With PV13
| 1. Need for phlebotomy to keep HCT < 45% after 3 months of ≥ 2 g/d HU, OR |
| 2. Uncontrolled myeloproliferation (ie, PLT count > 400 × 109/L AND WBC count > 10 × 109/L) after 3 months of ≥ 2 g/d HU, OR |
| 3. Failure to reduce massive splenomegalya by > 50% as measured by palpation OR failure to completely relieve symptoms related to splenomegaly after 3 months of ≥ 2 g/d HU, OR |
| 4. ANC < 1.0 × 109/L OR PLT count < 100 × 109/L OR HGB < 10 g/dL at the lowest dose of HU required to achieve a complete or partial clinicohematologic response,b OR |
| 5. Presence of leg ulcers or other unacceptable HU-related nonhematologic toxicities, such as mucocutaneous manifestations, gastrointestinal symptoms, pneumonitis, or fever at any dose of HU |
Abbreviations: ANC = absolute neutrophil count; HCT = hematocrit; HGB = hemoglobin; HU = hydroxyurea; PLT = platelet; PV = polycythemia vera; WBC = white blood cell.
a
Organ extending > 10 cm below the costal margin.
b
Complete response defined as HCT < 45% without phlebotomy, PLT count ≤ 400 × 109/L, WBC count ≤ 10 × 109/L, and no disease-related symptoms. Partial response defined as HCT < 45% without phlebotomy or response in ≥ 3 other criteria.