by Bruce Sylvester – Researchers report that combination ABT-450 with ritonavir (ABT-450/r, Abbott) plus ABT-333 plus ribavirin (RBV) is both well tolerated and led to high sustained virological response (SVR) in treatment-naive hepatitis C virus (HCV) genotype 1patients.
The investigators from the CO-PILOT study also found high SVR among prior interferon-based non-responders.
Arms 1 and 2 of the trial enrolled treatment naïve patients with chronic HCV genotype 1 infection treated with ABT-333 400 mg twice daily plus RBV 1,000-1,200 mg once daily plus ABT-450/r either 250/100 mg once daily (arm 1, n = 19) or 150/100 mg once daily ( arm 2, n = 14). Treatment in arm 3 was identical to arm 2, but it included prior partial or null responders to previous pegylated interferon plus RBV treatments (n = 17).
Patients underwent treatment for 2 weeks, and they had 48 weeks of follow-up.
The primary endpoint was extended rapid virological response (eRVR) based on HCV RNA lower than the limit of detection from treatment weeks 4 to 12.
Lead investigator Fred Poordad, M.D., Chief of Hepatology and Liver transplantation at Cedars-Sinai Medical Center in Los Angeles, California, USA reported that eRVR was 90% in arm 1, 79% in arm 2 and 59% in arm 3.
For SVR at week 4 (SVR4) and week 12 (SVR12), the investigators reported for arm 1 an SVR4 of 95% and an SVR12 of 93%. For arm 2 they reported an SVR4 of 95% and an SVR12 of 93%. And for the previous non-responding patients in arm 3 they reported an SVR4 and an SVR12 both of 47%.
There were no deaths or serious adverse events. with 1 adverse event in arm 1 leading to a discontinuation of treatment.
“ABT-450 with ritonavir plus ABT-333 and ribavirin for 12 weeks has the potential to achieve sustained virological response in a high proportion of subjects, without interferon,”said Dr. Poordad
Abbott supported the study.