[Sustaining molecular response with very low dose ponatinib and further response after hemodialysis initiation in a patient with chronic myeloid leukemia].

A 46-year-old man was diagnosed with chronic myeloid leukemia (CML) in chronic phase. He was treated with imatinib, nilotinib, and dasatinib, but failed to achieve a complete cytogenetic response (CCyR). After tyrosine kinase inhibitor therapy, F317L BCR-ABL1 kinase domain mutation was detected. At age 66, the patient started ponatinib (PON) at 45 mg/day, and achieved CCyR within three months. Subsequently, PON was tapered to 15 mg once weekly due to arterial-occlusive events. PON was discontinued after a 3-year deep molecular response (≥ MR). However, the patient lost MR within two months, and PON (15 mg once weekly) was restarted. He achieved MR again within one month, and then a deeper molecular response (MR) after starting dialysis therapy at the same PON dose. The trough value of PON (15 mg once weekly) was 5.8 ng/ml, which suppressed F317L mutation in the CML clone. Currently, the patient is 77 years old and is sustaining MR. Chronic renal failure may cause hyperabsorption and metabolic retardation in patients receiving PON. Initiation of hemodialysis may improve homeostasis resulting in enhanced anti-tumor immunity against CML.