Clinical definitions of resistance.
| Primary . | Acquired . |
|---|---|
| Absence of a hematologic response within 3 months of starting treatment with at least 300 mg/day | Loss of hematologic response |
| Failure to achieve at least a minor cytogenetic response (> 35% Ph-negativity) after 3 months’ treatment with at least 400 mg/day | Loss of a complete cytogenetic response |
| Failure to achieve a major cytogenetic response after 6 months’ treatment with at least 400 mg/day | An increase of 30% or more in the number of Ph-positive bone marrow metaphases examined at intervals of 3 months or longer |
| Failure to achieve a complete cytogenetic response after 12 months’ treatment with at least 400 mg/day | Acquisition of new cytogenetic abnormalities in the Ph-positive clone |
| An increase in the BCR-ABL/control gene ratio of one log or more on serial testing or to the range associated with Ph-positivity |
| Primary . | Acquired . |
|---|---|
| Absence of a hematologic response within 3 months of starting treatment with at least 300 mg/day | Loss of hematologic response |
| Failure to achieve at least a minor cytogenetic response (> 35% Ph-negativity) after 3 months’ treatment with at least 400 mg/day | Loss of a complete cytogenetic response |
| Failure to achieve a major cytogenetic response after 6 months’ treatment with at least 400 mg/day | An increase of 30% or more in the number of Ph-positive bone marrow metaphases examined at intervals of 3 months or longer |
| Failure to achieve a complete cytogenetic response after 12 months’ treatment with at least 400 mg/day | Acquisition of new cytogenetic abnormalities in the Ph-positive clone |
| An increase in the BCR-ABL/control gene ratio of one log or more on serial testing or to the range associated with Ph-positivity |