Mutations of BCR-ABL1 are observed in 50% of patients with imatinib-resistant chronic myeloid leukemia (CML). The T315I mutation is resistant to imatinib and second-generation tyrosine kinase inhibitors (TKIs). We report the case of a 57-year-old man diagnosed with CML in 2003 in whom imatinib therapy failed after which he acquired the T315I mutation. He was treated sequentially with an anti-T315I-specific agent, KW-2449, that led to eradication of the mutation without any further improvement. Subsequent introduction of combination therapy that included dasatinib and pegylated interferon led to the achievement of a sustained complete cytogenetic and major molecular response (MMR). This case illustrates the benefit of combination therapy that includes a TKI and a second agent with a different mechanism of action, either sequentially (TKI followed by KW-2449) or concomitantly (TKI + interferon), in eradicating resistant disease with the T315I clone.
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