Enanta Pharmaceuticals Inc, a research and development-focused biotechnology company, announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) has granted priority review for AbbVie’s investigational, two direct-acting antiviral (2-DAA) combination of ombitasvir/paritaprevir/ritonavir for the treatment of genotype 1 (GT1) chronic hepatitis C (HCV) infection.

This all-oral treatment is ribavirin (RBV)-free and interferon (IFN)-free and will be dosed once daily. The MHLW grants priority review to certain medicines on the basis of clinical usefulness and severity of the disease, including diseases like hepatitis C, which affects an estimated 1.5 to 2 million people in Japan. AbbVie’s investigational HCV treatment was submitted for marketing approval in Japan in February 2015. The New Drug Application is supported by the phase 3 GIFT-I study in Japanese GT1b HCV patients.

AbbVie studied the 2-DAA regimen without RBV in Japan due to patient and viral characteristics specific to the Japanese population, including high prevalence of GT1b. In Japan, GT1 HCV accounts for 60 to 70 per cent of all HCV patients and, of those, about 95 per cent are infected with the GT1b sub-type.

AbbVie has previously announced that it expects regulatory approval in Japan in the second half of 2015. Upon commercialization regulatory approval in Japan, Enanta will be entitled to a $30 million milestone payment from AbbVie. In addition, Enanta will be eligible to receive annually tiered royalties, ranging from the low double digits up to twenty percent, on 45% of AbbVie’s worldwide net sales of any 2-DAA paritaprevir-containing regimen.

Paritaprevir is Enanta’s lead protease inhibitor identified within the ongoing Enanta-AbbVie collaboration and is one of the two DAAs in the treatment regimen under the NDA in Japan. AbbVie is responsible for all development and commercialization activities for regimens that contain paritaprevir. Paritaprevir is included in AbbVie’s HCV treatment regimens approved in the US in late 2014 and in the EU in early 2015.

Enanta Pharmaceuticals is a research and development-focused biotechnology company that uses its robust chemistry-driven approach and drug discovery capabilities to create small molecule drugs for viral infections and liver diseases.