The hepatitis C market is highly competitive and dominated by direct-acting-antivirals (DAAs) that boast remarkably high cure rates. Furthermore, these treatment options are well-tolerated and require only 12-week treatment durations for most patients. Hence, the margin for improvement is relatively small.

Nevertheless, during the Liver Meeting of the European Association for the Study of the Liver (EASL), AbbVie has again demonstrated that its late-stage pipeline product glecaprevir/pibrentasvir (G/P), which is currently under review by the FDA and EMA, will likely improve the patient’s experience even further. By presenting data from two Phase III studies, ENDURANCE-3 and EXPEDITION-1, AbbVie demonstrated excellent efficacy data, particularly for difficult-to-treat patients.

In the EXPEDITION-1 trial, the efficacy of G/P was evaluated for a 12-week treatment duration in 146 patients with compensated liver cirrhosis infected with genotype 1 (GT1), 2, 4, 5, or 6. Out of these participants, 25% were treatment-experienced, 69% of which with interferon-based treatments. Only one patient, infected with GT1a who relapsed at week eight, did not achieve sustained viral response at 12-weeks post treatment completion (SVR12), resulting in an overall cure rate of 99%. No treatment-related severe adverse events were reported, and no patient discontinued the treatment.

"The ENDURANCE-3 trial positions G/P as an excellent treatment option for patients with GT3, and in particular for active drug users."

The ENDURANCE-3 trial included non-cirrhotic patients infected with GT3, predominantly those with fibrosis scores of F0 and F1. Unlike most other Phase III trials for DAAs, this study did not exclude drug users and over 50% of study participants were active drug users during the trial. The study also evaluated the efficacy after 12-week (arm 1, N = 233) and 8-week treatment duration (arm 3, N = 157) and compared efficacy to a 12-week treatment with sofosbuvir and daclatasvir (arm 2, N = 115). G/P demonstrated noninferiority in arm 1 and arm 3 compared with arm 2, as the SVR12 rates between those arms varied between 95% and 97%.

The EXPEDITION-1 trial demonstrated the strong overall efficacy of G/P in patients with compensated cirrhosis after 12 weeks of treatment, and consequently G/P will represent a strong alternative to other currently available Daa regimens, including Gilead’s Harvoni and Epclusa. The ENDURANCE-3 trial, however, positions G/P as an excellent treatment option for patients with GT3, and in particular for active drug users.

Dr. Foster, the lead study author, highlighted the high incidence rates among drug users and that GT3 has a higher prevalence among this group than within the overall population. Furthermore, the shortened treatment duration from 12 to eight weeks for patients without liver cirrhosis, a criterion matching most individuals with more recent hepatitis C infections, is expected to provide a significant advantage for AbbVie since the compliance rate among this group is expected to be lower than among the general population.

Combining the data presented at EASL with data recently published during the American Association for the Study of Liver Diseases (AASLD), GlobalData anticipates that G/P will achieve a significant patient share for non-cirrhotics or patient with compensated liver cirrhosis.