ST1571 is an effective agent for the patients with chronic myeloid leukemia (CML). But, complete molecular response with ST1571 is rarely reported in accelerated phase CML. Here we report a patient with accelerated phase CML who achieved complete molecular response with ST171. A 60-year old female patient visited emergency room with syncope. Her white blood cell count was 30,800/μL (basophil 23%), hemoglobin 8.9g/dL, and platelet counts 2,748,000/μL. Bone marrow was hypercellular with increase in megakaryocyte and basophils (15%). She was diagnosed as an accelerated phase CML. Seven days after stopping hydroxyurea, we used St1571 in a daily oral dose of 600mg. Generalized edema and skin rash were observed 15 days after treatment (all grade 1) and were controlled well with conservative management. Complete hematologic and cytogenetic responses were achieved after 1 month and 3 months of therapy with ST1571 respectively. Complete molecular response was simultaneously proven by conventional reverse transcriptase PCR and real-time PCR analysis. The patient still remained in complete hematologic, cytogenetic, and molecular responses for 24 months. Treatment with ST1571 was well tolerated and rapid hematologic improvement was observed. This case shows ST1571 can induce complete molecular response as well as cytogenetic response in accelerated phase CML.

Keywords: Chronic myelogenous leukemia, ST1571, Molecular response