A 12-week regimen of ombitasvir, paritaprevir, ritonavir, and dasabuvir achieved sustained viral response for 90% of patients with genotype 1 hepatitis C virus (HCV) infection and stage 4 or 5 chronic kidney disease (CKD), researchers reported in the April issue of Gastroenterology.
“The regimen is well tolerated, though ribavirin use may require a reduction or interruption to manage anemia,” said Dr. Paul Pockros at Scripps Clinic and Scripps Translational Science Institute in La Jolla, Calif., and his associates. The second phase of the study will evaluate the regimen in treatment-experienced CKD patients and those with compensated cirrhosis, they said.
Between 8% and 44% of hemodialysis patients are HCV positive, and CKD is known to heighten the risk of HCV-associated cirrhosis, hepatocellular carcinoma, and liver-related death, the researchers noted. While sofosbuvir is cleared renally, ombitasvir, paritaprevir, ritonavir, and dasabuvir undergo hepatic metabolism and needed no dose adjustment in phase I studies of patients with mild, moderate, or severe renal impairment. To further investigate the safety and efficacy of these direct-acting antivirals in patients with severe kidney disease, the researchers performed a single-arm, open-label, multicenter study of 20 treatment-naive, noncirrhotic, HCV-infected adults with stage 4 CKD (estimated glomerular filtration rate, 15-30 mL/min per 1.73 m2) or stage 5 (eGFR, less than 15 mL/min per 1.73 m2 or requiring hemodialysis). Patients received once-daily ombitasvir (25 mg), paritaprevir (150 mg), and ritonavir (100 mg) plus dasabuvir (250 mg) for 12 weeks. The 13 patients with genotype 1a infections also received once-daily ribavirin (200 mg). Most patients were black men with stage 5 CKD, and 14 were on hemodialysis, the researchers said (Gastroenterology. 2016 Apr 16. doi: 10.1053/j.gastro.2016.02.078 ).
All 20 patients completed treatment, and 18 (90%) achieved sustained viral response (SVR) at posttreatment week 12 (SVR12; 95% confidence interval, 70%-97%). No patients developed hepatic decompensation, the researchers said. The most common adverse effects were anemia (45%), fatigue (35%), diarrhea (25%), and nausea (25%). Anemia developed only in patients receiving ribavirin and was more pronounced than in phase III studies of this regimen, the researchers said. Hemoglobin levels dropped an average of 1.38 plus or minus 1.54 g/dL among patients who received ribavirin, compared with 0.02 plus or minus 0.9 g/dL among patients who did not receive ribavirin. There was one case of grade 3 anemia related to incorrect dosing of ribavirin; the lowest measured hemoglobin level was 7.0 g/dL, which improved to more than 10 g/dL after stopping ribavirin and starting erythropoietin treatment. This patient also achieved SVR12. The other eight patients who developed anemia also stopped ribavirin, although three were able to resume it after their hemoglobin levels improved.
Of the two patients who did not achieve SVR12, one relapsed 4 weeks after treatment, and one died of cardiac arrest 14 days after treatment. The patient who died had a history of hypertension; his hemoglobin level was stable (9-11 g/dL) during the last 6 weeks of treatment, and was 10 g/dL at admission, suggesting that ribavirin-induced anemia did not cause the cardiac event, the investigators said.
“The results of this study are important for hepatologists, gastroenterologists, and infectious disease specialists who are accustomed to treating HCV-infected patients with DAA [direct-acting antiviral] therapy but who may not yet have seen sufficient data to initiate DAA therapy in patients with ESRD [end-stage renal disease],” the researchers concluded. “Nephrologists, who may not be accustomed to treating HCV, should also be aware that treatment options may now be available that can help prevent the end-stage sequelae of HCV. How treatment of HCV infection affects early or intermediate stages of CKD and how achievement of SVR impacts strategies for kidney transplantation in patients with ESRD require more study.”
AbbVie makes the regimen and sponsored the study. Dr. Pockros and six coinvestigators disclosed financial relationships with AbbVie and numerous other pharmaceutical companies. Seven coinvestigators reported being employed by AbbVie.