Once-daily treatment with glecaprevir-pibrentasvir for either 8 weeks or 12 weeks achieved high rates of sustained virologic response among patients with HCV genotype 1 or 3 infection who did not have cirrhosis. (Funded by AbbVie; ENDURANCE-1 and ENDURANCE-3 ClinicalTrials.gov numbers, NCT02604017 and NCT02640157 .).

No abstract

Although direct‐acting antiviral (DAA) therapies for chronic hepatitis C virus (HCV) infection have demonstrated high rates of sustained virologic response, virologic failure may still occur, potentially leading to the emergence of viral resistance, which can decrease the effectiveness of subsequent treatment. Treatment options for patients who failed previous DAA‐containing regimens, particularly those with nonstructural protein 5A inhibitors, are limited and remain an area of unmet medical need. This phase 2, open‐label study (MAGELLAN‐1) evaluated the efficacy and safety of glecaprevir (GLE) + pibrentasvir (PIB) ± ribavirin (RBV) in HCV genotype 1–infected patients with prior virologic failure to HCV DAA‐containing therapy. A total of 50 patients without cirrhosis were randomized to three arms: 200 mg GLE + 80 mg PIB (arm A), 300 mg GLE + 120 mg PIB with 800 mg once‐daily RBV (arm B), or 300 mg GLE + 120 mg PIB without RBV (arm C). By intent‐to‐treat analysis, sustained virologic response at posttreatment week 12 was achieved in 100% (6/6, 95% confidence interval 61‐100), 95% (21/22, 95% confidence interval 78‐99), and 86% (19/22, 95% confidence interval 67‐95) of patients in arms A, B, and C, respectively. Virologic failure occurred in no patients in arm A and in 1 patient each in arms B and C (two patients were lost to follow‐up in arm C). The majority of adverse events were mild in severity; no serious adverse events related to study drug and no relevant laboratory abnormalities in alanine aminotransferase, total bilirubin, or hemoglobin were observed. Conclusion: The combination of GLE and PIB was highly efficacious and well tolerated in patients with HCV genotype 1 infection and prior failure of DAA‐containing therapy; RBV coadministration did not improve efficacy. (Hepatology 2017;66:389–397).

ClinicalTrials.gov ( https://clinicaltrials.gov/ ) identifier: NCT01741493.

Patients with hepatitis C virus (HCV) who have virological failure (VF) after treatment containing a nonstructural protein 5A (NS5A) inhibitor have limited retreatment options. MAGELLAN‐1 Part 2 was a randomized, open‐label, phase 3 study to evaluate the efficacy and safety of ribavirin (RBV)‐free glecaprevir and pibrentasvir (G/P; 300 mg/120 mg) in patients with chronic HCV and past VF on at least one NS3/4A protease and/or NS5A inhibitor‐containing therapy. Patients with compensated liver disease, with or without cirrhosis, and HCV genotype (GT) 1, 4, 5, or 6 were randomized 1:1 to receive 12 or 16 weeks of G/P. The primary endpoint was sustained virological response (SVR) at 12 weeks posttreatment (SVR12). Among 91 patients treated, 87 had GT1 and 4 had GT4 infection. SVR12 was achieved by 89% (39 of 44) and 91% (43 of 47) of patients who received 12 and 16 weeks of G/P, respectively. Virological relapse occurred in 9% (4 of 44) of patients treated with 12 weeks of G/P; there were no relapses with 16 weeks of treatment. Past treatment history with one class of inhibitor (protease or NS5A) had no impact on SVR12, whereas past treatment with both classes of inhibitors was associated with lower SVR12 rate. The most common adverse event (AE) was headache (≥10% of patients), and there were no serious AEs assessed as related to study drugs or AEs leading to discontinuation. Conclusion: Sixteen weeks of G/P treatment achieved a high SVR12 rate in patients with HCV GT1 infection and past failure to regimens containing either NS5A inhibitors or NS3 protease inhibitors. (Hepatology 2018;67:1253‐1260)