Extensive Pleural and Pericardial Effusion In 4 CML Patients Treated with Dasatinib at 100 Mg or 50 Mg Once Daily.

Abstract 4496

The multikinase BCR/ABL inhibitor dasatinib exerts major growth-inhibitory effects in imatinib-resistant patients with chronic myeloid leukemia (CML). Although previously reported to be a well-tolerated drug, several side effects such as pleural and pericardial effusion have been reported at a dose of 140 mg daily. Therefore, the approved standard dose of dasatinib was reduced to 100 mg daily. More recent data suggest that freshly diagnosed patients with CML treated with dasatinib at 100 mg once daily may still develop pleural effusions, but the frequency of this side effect was reported to be lower compared to patients receiving 140 mg daily dasatinib. Moreover, effusion formation was reported to be less severe, with almost no grade 3/4 events, in patients receiving 100 mg daily dasatinib. We examined a cohort of CML patients (n=13) treated with dasatinib at 100 mg or 50 mg daily, for development of severe non-hematologic side effects. Patients received dasatinib for at least 3 months (range: 3–38 months; observation period: March 2005 to June 2010). Of these 13 patients, 4 had previously received 140 mg dasatinib daily. In all 4 patients, the dose of dasatinib was reduced to 100 mg or 50 mg daily because of effusion formation. In the other 9 patients, the initial dose of dasatinib was 100 mg daily. Of these 9 patients, 2 patients in chronic phase (CP) received dasatinib as frontline therapy. Four of our 13 patients developed severe effusions (grade 3/4) while on dasatinib at 100 mg or 50 mg daily, including one CP patient receiving dasatinib as frontline therapy. In two patients, massive pleural effusions were recorded, and two developed pericardial effusion together with pleural effusions. In two patients, effusion formation required paracentesis and surgical intervention. No pre-existing cardiac or pulmonary diseases were known in these 4 patients. In 3 patients, dasatinib had to be discontinued despite treatment with low dose glucocorticosteroids and diuretics. After switching to an alternative BCR/ABL inhibitor, no further effusion formation occurred. In summary, dasatinib-treated patients are at risk for the development of pleural and pericardial effusions even when the drug is administered at a dose of 100 mg or 50 mg daily. Therefore, all patients should be examined carefully for pre-existing relevant comorbidities and cardiovascular risk factors before dasatinib is started, and all patients should have repeated chest × ray controls during long-term treatment with dasatinib.