Dexrazoxane and heart function among long-term childhood cancer survivors: A Children’s Oncology Group study

10513 Background: Dexrazoxane (DRZ) has cardioprotective effects among doxorubicin (DOX) treated childhood cancer survivors up to 5 years after therapy. However, longer-term data are lacking. Methods: P9404, P9425, P9426, and DFCI 95-01 were randomized trials of acute lymphoblastic leukemia and Hodgkin lymphoma, where patients were randomly assigned to DOX±DRZ. P9754 enrolled osteosarcoma patients who all received DOX+DRZ. In all studies, DRZ was given as an intravenous bolus before DOX (10:1mg ratio). DOX doses ranged from 100-600 mg/m2 across these 5 trials. A subset of COG institutions prospectively assessed cardiac function in long-term survivors from these trials, plus a matched group of osteosarcoma survivors treated with DOX alone. Echocardiograms (left ventricular [LV] Biplane ejection fraction [EF], shortening fraction [SF]) and blood biomarkers (b-type natriuretic peptides [BNP], N-terminal [NT] proBNP) were all analyzed centrally, with DRZ status masked. Lower LV function was defined as EF2) 17.6±2.4y since cancer diagnosis, DRZ+ participants were slightly younger (27.8 vs 29.6y, p=0.02), but baseline characteristics otherwise did not differ significantly by DRZ status. DRZ status was associated with higher FS (34.7±3.6% vs 33.4±4.3%, p=0.04) and EF (63.4±5.4% vs 61.4±5.5%, p=0.01), and lower BNP (median 10.4 pg/mL [IQR 6.0-18.0] vs 13.0 [IQR 6.0-28.2], p=0.03) and NT-proBNP (median 30.8 pg/mL [IQR 18.9-58.2] vs 47.1 [IQR 23.0-83.1], p2 (vs 2). Results from multivariate models were similar: DRZ was associated with higher SF (1.4% [95% CI 0.2, 2.6]) and EF (2.7% [95% CI 0.8, 4.6]), and reduced BNP (-4.0 pg/mL [95% CI -7.6, -0.4]) and NT-proBNP (-20.7 pg/mL [95% CI -33.5, -7.9]). Overall, DRZ was associated with a reduced risk of having lower LV function (odds ratio 0.27 [95% CI 0.08-0.96]). Conclusions: After >17y, childhood cancer survivors treated with DOX+DRZ had better LV systolic function and less myocardial wall stress compared with those treated with DOX alone. DRZ may preferentially benefit females and those treated with greater DOX doses.