Abstract
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm driven by the BCR::ABL tyrosine kinase. Tyrosine kinase inhibitors (TKIs) have significantly improved the outcome of CML patients. Dasatinib, a second-generation TKI, is highly effective but associated with off-target effects, including pulmonary toxicities. While pleural effusion induced by dasatinib has been linked to therapeutic efficacy, its role remains controversial. Severe pulmonary complications, such as diffuse alveolar hemorrhage (DAH), can lead to treatment failure and increased mortality. We report a 72-year-old man with de novo blast-phase CML on clopidogrel who developed respiratory failure due to DAH 16 days after initiating dasatinib and prednisolone as induction therapy. Immediate steroid pulse therapy with methylprednisolone (1,000 mg/day for three days) was administered, and both dasatinib and clopidogrel were discontinued. Maintenance prednisolone (1 mg/kg/day) was then tapered by 10 mg per week. The patient's symptoms and radiographic findings improved without recurrence during tapering. This case highlights the importance of early recognition and management of severe complications like DAH in patients receiving dasatinib. Careful monitoring is essential to mitigate the risk of life-threatening respiratory failure and optimize CML treatment outcomes.