RESUMO
PURPOSE: Children with hematological malignancies and chronic hepatitis C virus (HCV) infection are at a higher risk for rapid progression of liver disease and malignancy relapse due to multiple hepatitis flares and chemotherapy interruption. They are therefore potential candidates for microelimination of HCV infection. This study aimed to assess the effect of acute lymphoblastic leukemia (ALL) on the pharmacokinetic (PK) profile of direct-acting antivirals, namely ledipasvir/sofosbuvir (LDV/SOF) and the SOF major metabolite GS-331007. METHODS: This was a 24-week, prospective, controlled, open-label, 2-arm PK study of patients receiving 45/200 mg once-daily LDV/SOF orally for 12 weeks. Eligible patients were HCV-RNA-positive, treatment-naive children aged 6 to <12 years and/or weighing 17 to <35 kg with genotype 4 chronic HCV infection without cirrhosis. The primary efficacy and safety end points were the achievement of sustained virologic response for all patients with absence of any adverse events leading to permanent discontinuation of the study drug. Steady-state noncompartmental analysis was performed to determine the PK parameters of SOF, GS-331007, and LDV as the primary PK outcome. Dose suitability was based on the 90% CI of exposure geometric mean ratio percentage within 50% to 200% compared with adults. FINDINGS: Ten HCV-infected children with ALL (chemotherapy treatment group) and 12 eligible children with no malignancy (control group) were enrolled and completed the study period. All 22 patients achieved the sustained virologic response with no adverse events leading to interruption or permanent discontinuation of the study drug. Compared with the control group, the ALL group patients had similar SOF, GS-331007, and LDV exposure. Compared with adults, the AUCτ of GS-331007 was lower and the AUCτ and Cmax,ss of SOF and the Cmax,ss of LDV were modestly higher in the ALL group (acceptance limit, 50%-200%). However, the observed efficacy and favorable safety profile made these changes not clinically significant. IMPLICATIONS: Weight-based dosing of LDV/SOF (45/200 mg) is highly effective and safe among genotype 4 HCV-infected children weighing 17 to <35 kg and diagnosed with ALL undergoing maintenance chemotherapy. The similarity in the drug exposure, efficacy, and safety clinical end points between patients with and without hematological malignancy support their therapeutic equivalence. Further studies with a larger sample size may be required to confirm the safety of LDV/SOF in patients with ALL and to recommend appropriate dosing in children with hematological malignancies, if needed. CLINICALTRIALS: gov identifier: NCT03903185.
