Impact of Dose Reduction on the Efficacy of Triple Therapy for Patients Infected with Genotype 1b and High Viral Loads

To examine the impact of dose reduction on the efficacy of pegylated interferon (PEG-IFN) plus ribavirin (RBV) plus telaprevir (TVR) triple therapy for patients infected with genotype 1b and high viral loads.

A total of 51 patients were recruited for this study. Patients were divided into groups receiving either 2,250 mg of TVR for 12 weeks and 600 – 1,200 mg of RBV for 24 weeks according to body weight (Group 1, N = 39) or 1,500 mg of TVR for 12 weeks and 400 mg of RBV for 24 weeks (Group 2, N = 13) plus 1.5 μg/Kg (range: 1.3 - 2.0 μg/Kg) of peg-IFN alpha-2b for 24 weeks. Patients of Group 1 were less than 65 years old or IL28 non T/T and over 65 to less than 70 years old. Patients of Group 2 were IL28B T/T and over 65 to less than 70 years old or over 70 years old.

Rapid virological response (RVR) rates were 66.7% in Group 1 and 84.2% in Group 2 (NS). Early virological response (RVR) rates were 79.5% in Group 1 and 91.7% in Group 2 (NS). End of treatment response (ETR) rates were 71.8% in Group 1 and 69.2% in Group 2 (NS). Sustained virological response (SVR) rates were 60.5% in Group 1 and 69.2% in Group 2 (NS). In multivariate analysis, significant contribution factors for SVR were IL28B (genotype TT; OR 1.83, P = 0.0032) and platelet counts (< 120,000; OR 2.14, P = 0.0140).

It was concluded that the treatment strategy of dose reduction based on patient background (age and IL28B SNP polymorphism) was proper in Japanese patients.

Keywords: Dose reduction, Genotype 1b, HCV, Triple therapy, TVR.