AbbVie, a global biopharmaceutical company, announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) approved Viekirax (ombitasvir/paritaprevir/ritonavir), as a new interferon and ribavirin-free treatment option for adult patients with chronic genotype 1 (GT1) hepatitis C virus (HCV) infection, including those with compensated liver cirrhosis. Viekirax consists of a 12-week, two direct-acting antiviral, fixed-dose combination of paritaprevir/ritonavir with ombitasvir, dosed once daily.

Viekiraxis indicated for the improvement of viremia in chronic hepatitis C or compensated hepatic cirrhosis C in patients of serogroup 1 (genotype 1).

"Today's approval represents an important step forward for the treatment of Japanese patients, a population with specific needs based on patient and viral characteristics," said Jean-Michel Pawlotsky, MD, PhD, professor of medicine at the University of Paris-Est, France.

"Viekirax is a valuable new addition to a number of treatments that are changing the face of hepatitis C, making it possible to achieve high virologic cure rates, even in patients whose disease has progressed to compensated liver cirrhosis."

Japan has one of the highest rates of hepatitis C infection in the industrialized world, with approximately 1.5 to 2 million people living with HCV. Genotype 1 is the most common HCV genotype in Japan with 60 to 70 per cent of patients infected and, of those, about 95 per cent are infected with the genotype 1b (GT1b) sub-type.

"We are pleased to provide Viekirax as a new treatment that offers a high probability of virologic cure for GT1b HCV patients and are working to support access to our treatment in Japan," said Michael Severino, M.D., executive vice president, research and development and chief scientific officer, AbbVie.

"We are also prioritizing disease education and awareness by collaborating with stakeholders to identify and address the diverse challenges across Japan, such as supporting screening and diagnosis initiatives, and providing accurate information to the medical community about treatment options."

The approval is supported by the phase 3 GIFT-I study. An overall 95 per cent (n=140/148) of treatment-naïve and 94 per cent (n=102/109) of treatment-experienced GT1b HCV infected patients achieved SVR12 with Viekirax.

The primary endpoint was achieved, demonstrating 95 per cent (n=106/112) SVR12 in a sub-group of treatment-naïve, non-cirrhotic, adult GT1b HCV infected Japanese patients who were eligible for therapy with interferon (IFN) and had a high viral load. A secondary endpoint in GT1b HCV patients with compensated cirrhosis achieved 91 per cent (n=38/42) SVR12.5

Across all treatment arms three patients (n=3/363) experienced on-treatment virologic failure, eight patients (n=8/354) experienced post-treatment relapse and three patients discontinued treatment due to adverse events. The most commonly reported adverse events (>5 per cent in any arm) were nasopharyngitis, headache, peripheral edema, nausea, pyrexia and decreased platelet count. In April 2015, AbbVie was granted priority review by the MHLW for Viekirax, on the basis of clinical usefulness of the treatment and recognising the severity and unmet need of the disease in Japan.

In sub-study 1, 321 genotype 1b (GT1b) patients without cirrhosis, both treatment-naïve and interferon (IFN) [with or without ribavirin (RBV)] treatment-experienced, were randomized to receive either ombitasvir/paritaprevir/ritonavir (Arm A) [OBV/PTV/r] or placebo (Arm B) [2:1 randomization ratio, stratified by treatment history, past response, viral load and IFN eligibility]. Patients initially randomized to placebo (Arm B) then received OBV/PTV/r for an additional 12 weeks of open-label treatment. Sustained virologic response was assessed 12 weeks post-treatment (SVR12) as a primary efficacy endpoint in a sub-group of previously untreated, non-cirrhotic GT1b patients who were eligible for therapy with IFN and had a high viral load, defined as an HCV RNA level = 100,000 IU/ml and received at least one dose of the double-blind, active study drug.

In sub-study 2, 42 GT1b treatment-naïve and IFN (with or without RBV) treatment-experienced patients with compensated cirrhosis received open-label treatment for 12 weeks (Arm C) with SVR12 and assessed as a secondary efficacy endpoint.

One patient from each arm (n=3/363) experienced on-treatment virologic failure [Arm A, 0.5Viekirax(n=1/215); Arm B, 0.9 Viekirax (n=1/106); Arm C, 2.4 Viekirax (n=1/42)]. Across all arms, eight patients (n=8/354) experienced post-treatment relapse [Arm A, 2.4 Viekirax (n=5/209); Arm B, 1.0 Viekirax (n=1/105); Arm C, 5.0 Viekirax (n=2/40)].

AbbVie studied its two direct-acting antiviral treatment regimen without RBV in Japan due to patient and viral characteristics specific to the Japanese population, including high prevalence of GT1b.

Major adverse reactions included peripheral edema in 15 subjects (4.1 per cent), headache in 12 subjects (3.3 per cent) and nausea in 10 subjects (2.8 per cent).

AbbVie's HCV clinical development programme in Japan focuses on our two direct-acting antiviral treatment and is designed with the goal of achieving high SVR 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.