AbbVie released top-line phase 3 results for its investigational, all-oral, ribavirin (RBV)-free, two direct-acting antiviral treatment with ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) in patients with genotype 1b (GT1b) chronic hepatitis C virus (HCV) infection in Japan. The primary endpoint of the GIFT-I study was achieved, demonstrating a 95 per cent (n=106/112) sustained virologic response rate at 12 weeks post treatment (SVR12) in the sub-group of previously untreated, non-cirrhotic adult GT1b Japanese patients who were eligible for therapy with interferon (IFN) and had a high viral load.

"AbbVie is committed to advancing HCV care with the goal of evaluating our treatment in a broad range of patients around the world," says Scott Brun, MD, vice president, pharmaceutical development, AbbVie. "The GIFT-I results are encouraging and support moving forward with our Japan development programme, with a local regulatory submission anticipated in the first quarter of 2015."

In Japan, up to two million people are currently living with hepatitis C.1 Genotype 1b is the most common sub-genotype, affecting nearly half of the people infected with HCV.

In the GIFT-I study, the primary efficacy population comprised a sub-group of treatment-naive GT1b chronic HCV infected patient population. This sub-group consisted of treatment-naive patients without cirrhosis who were eligible for therapy with IFN with or without RBV, had a high viral load (> 100,000 IU/mL) and received at least one dose of the double-blind active study drug. The primary endpoint was assessed at 12 weeks post treatment (SVR12).

In patients without cirrhosis, the most commonly reported adverse events in the treatment arm were nasopharyngitis (16.7 per cent OBV/PTV/r vs. 13.2 per cent placebo), headache (8.8 per cent OBV/PTV/r vs. 9.4 per cent placebo), and oedema peripheral (5.1 per cent OBV/PTV/r vs. 0 per cent placebo). Two patients without cirrhosis (0.9 per cent) discontinued treatment due to adverse events.

Within the primary efficacy patient population, there were no on-treatment virologic failures and 2.8 per cent of patients (n=3/109) experienced relapse.

AbbVie will disclose detailed GIFT-I study results at future scientific congresses and in publications.

GIFT-I (M13-004) is a phase 3, multi-centre study designed to evaluate the efficacy and safety of 12 weeks of treatment with ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) in adult Japanese patients (n=363) with chronic genotype 1b hepatitis C virus infection. Patients included those without cirrhosis and with compensated cirrhosis who were new to therapy (treatment-naive) or had failed previous treatment with interferon with or without ribavirin (treatment-experienced). The study consists of two sub-studies. Sub-study one included patients without cirrhosis randomised to OBV/PTV/r or placebo. Sub-study two included patients with compensated cirrhosis, who received open-label treatment with OBV/PTV/r.

For the treatment of genotype 1b chronic hepatitis C virus (HCV) infection in Japan, AbbVie's investigational two direct-acting antiviral treatment consists of the fixed-dosed combination of paritaprevir/ritonavir (150/100 mg) with ombitasvir (25 mg), dosed once daily.

AbbVie's chronic HCV treatment combines two direct-acti`ng antivirals, each with a distinct mechanism of action that targets and inhibits specific HCV proteins of the viral replication process.

AbbVie's HCV clinical development programme in Japan will focus on our investigational, two direct-acting antiviral treatment and is designed with the goal of achieving high sustained virologic response rates in chronic HCV infected patients, including additional genotypes and patients with compensated cirrhosis.

Paritaprevir was discovered during the ongoing collaboration between AbbVie and Enanta Pharmaceuticals for HCV protease inhibitors and regimens that include protease inhibitors. Paritaprevir has been developed by AbbVie for use in combination with AbbVie's other investigational medicines for the treatment of hepatitis C.

Ombitasvir/paritaprevir/ritonavir is an investigational product and its safety and efficacy have not been established in Japan.