南予医学雑誌　第18巻

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南予医誌　Vol.18　No. １　2017－75－　Successful resolution of relapsed mixed-phenotype acute leukemia with t(9;22) (q34.1;q11.2); BCR-ABL1 with ponatinib and prednisolone after withdrawal of dasatinib due to lower gastrointestinal bleeding 　　　症例報告受稿日　平成29年10月25日受理日　平成29年11月６日Correspondence and reprint requests: Hisaharu Shikata M.D., Ph.D.Hisaharu SHIKATA, Hideyuki NAKANISHI, Masahiko KANEKO Department of Hematology, Uwajima City HospitalAbstractA 74-year-old man was referred to our hospital because of an elevated WBC count．He was diagnosed as having Philadelphia chromosome-positive mixed-phenotype acute leukemia（Ph＋MPAL）．He was administered imatinib plus combination acute lymphoblastic leukemia-like induction chemotherapy．We discontinued imatinib due to prolonged nausea and switched to dasatinib．Although cytogenetic complete remission（CR）was achieved after induction chemotherapy， relapse occurred during consolidation chemotherapy．Although a second hematological CR was achieved with dasatinib and prednisolone， the patient suffered two episodes of lower gastrointestinal bleeding， suggesting intolerance to dasatinib．He was therefore treated with ponatinib and prednisolone， and obtained molecular CR（mCR）， which was maintained for ７ months without serious adverse effects．To our knowledge， this is the first report of a patient with relapsed Ph+MPAL who was able to obtain a rapid mCR with a combination of ponatinib and prednisolone．This case suggests that a combination of ponatinib and prednisolone is effective and safe for elderly patients with relapsed Ph+MPAL．（Nan-yo Med J 2017; 18:75-82.）Key words： ponatinib， Philadelphia chromosome-positive mixed-phenotype acute leukemia， mixed-phenotype acute leukemiaDepartment of Hematology, Uwajima City Hospital, Goten-machi, Uwajima, Ehime 798-8510, Japan