Phase IIIb TOPAZ-II study of Viekira Pak (ombitasvir + paritaprevir + ritonavir + dasabuvir) meets secondary endoints in hepatitis C- AbbVie

AbbVie has announced new data from its ongoing Phase IIIb TOPAZ-II study evaluating Viekira Pak (ombitasvir, paritaprevir, ritonavir tablets; dasabuvir tablets), with or without ribavirin (RBV), in adult patients with genotype 1a (GT1a) or genotype 1b (GT1b) chronic hepatitis C virus (HCV) infection. The TOPAZ-II study, a multicentre trial in the US, evaluates the impact of SVR12 on the progression of liver diseases over the course of five years in a diverse patient population, including GT1 HCV patients with or without cirrhosis and those who were treatment-naïve or pegylated interferon (pegIFN)/RBV treatment-experienced.

Results show that 95% (n=586/615) of patients in the TOPAZ-II trial achieved a sustained virologic response at 12 weeks post-treatment (SVR12) after 12 or 24 weeks of treatment, a secondary endpoint for the study. Both GT1a and GT1b patients achieved high sustained virologic response rates when treated with Viekira Pak, with or without ribavirin, for 12 or 24 weeks, which reinforces efficacy data from previous studies. On-treatment virologic failure was experienced by 0.8% (n=5/615) of study patients, while 1.9% (n=11/590) experienced relapse. One percent (n=6/615) of patients prematurely discontinued treatment due to adverse events. Four percent (n=25/615) experienced serious adverse events. These data will be presented at The Liver Meeting 2015.

Comment: Viekirax Pak has joined Sovaldi (sofosbuvir) and Harvoni (sofosbuvir + ledispavir) from Gilead as oral therapies in the treatment of Chronic Hepatitis C, replacing the pegylated interferon injectable drugs that carried serious side effects. The new drugs carry impressive cure rates of 90% or more in patients after 8 weeks or 12 weeks of treatment contrasting with the 65–70% cure rates with the pegylated interferons.