Evaluating an Unsatisfactory or Suboptimal Response

The majority of patients with Ph+ CML receiving tyrosine kinase inhibitor (TKI) treatment respond with normalization of peripheral blood counts within 3 months and of cell cytogenetics within 12 months. There are, however, some patients who respond to treatment, but at a slower pace—and others for whom initial treatment will be ineffective.^1,2

Consensus guidelines issued by European LeukemiaNet have set benchmarks for determining when a patient is experiencing a suboptimal response or treatment failure (Table). Monitoring at the recommended intervals helps the clinician to evaluate if and when a treatment should be adjusted or changed.

Abbreviations:TKI, tyrosine kinase inhibitor; CHR, complete hematologic response; PCyR, partial cytogenetic response; CCyR, complete cytogenetic response; MMR, major molecular response; ACA, additional chromosomal abnormalities; Ph+ CML, Philadelphia chromosome-positive chronic myelogenous leukemia; HR, hematologic response; CyR, cytogenetic response; Del 9q+, deletion of the abl-bcr rearrangement on the derivative chromosome 9q+; AP, accelerated phase; BC, blast crisis.

^aTo be confirmed on 2 occasions unless associated with CHR or CCyR loss.

^bMutations should be interpreted within clinical context.

^cTo be confirmed on 2 occasions unless associated with progression to AP or BC.

^dTo be confirmed on 2 occasions unless associated with CHR loss or progression to AP or BC.

Click to view and/or download the criteria for hematologic, cytogenetic, and molecular response.