Molecular Response to Nilotinib in a Patient with Imatinib-intolerant e19a2-positive Chronic Myeloid Leukemia

The BCR-ABL1 fusion gene is the molecular marker of chronic myeloid leukemia (CML). The e19a2 transcript is a rare variant associated with various clinical presentations and courses of CML. We herein present a case of e19a2-positive CML who was intolerant to initial treatment with imatinib and successfully responded to subsequent nilotinib therapy. She achieved a major molecular response and has since be able to sustain it. According to the literature, achieved molecular response by imatinib monotherapy has not yet been reported in e19a2-positive CML patients. Second generation tyrosine kinase inhibitors may therefore be a more effective treatment for e19a2-positive CML patients.