Treatment of hepatitis C virus (HCV) aims for a viral cure in order to prevent liver disease and other complications associated with chronic HCV infection. Response to treatment is determined by measuring the amount of HCV in the blood at specific times before, during, and after therapy. The goal is for the HCV levels to be undetectable 24 weeks after the end of treatment. This benchmark is known as a sustained viral response (SVR). Achieving SVR remains a challenge for many patients with chronic HCV.
HCV is a genetically diverse virus classified into 6 major variants, known as genotypes (G) and labelled G1 to G6. Each genotype can be further subdivided into more than 50 subtypes. HCV genotypes play a particular role in disease management as each genotype responds differently to treatment.
Treatment of chronic HCV has evolved over the past several decades, leading to a rise in rates of SVR. The first advancement in the treatment of chronic HCV came in 2001 with the approval of a pegylated interferon (PegIFN), which could be administered once a week. The subsequent approval of dual therapy with PegIFN in combination with ribavirin (RBV) resulted in a near doubling of SVR rates in patients infected with G1 HCV.
Combination therapy with PegIFN plus RBV remained the standard of care until 2011, when 2 protease inhibitors, telaprevir and boceprevir, were approved for use as triple therapy with PegIFN plus RBV in patients with G1 HCV. Although adding protease inhibitors to the HCV treatment regimen improved response rates in patients with G1 HCV, it also increased the complexity of treatment. Certain protease inhibitors have complicated dosing algorithms that vary according to individual patient factors. Some agents require lead-in therapy, and the duration of treatment changes based on the patient’s treatment history and severity of disease. Multiple rules for stopping treatment are necessary to monitor for HCV treatment-resistant variants.
Not only is treatment for HCV complex, it is expensive. Depending on the duration of treatment, the cost of dual therapy with PegIFN plus RBV can vary from $18,000 to $36,000. The addition of telaprevir or boceprevir more than doubles the cost of treatment to a range of $48,000 to $85,000.
In the first half of 2014, 2 new drugs were approved to treat HCV infection, adding to the cost and complexity of treatment. Sovaldi (sofosbuvir) is an oral agent approved for use in combination with RBV or in combination with RBV plus PegIFN in patients with G1, G2, G3, or G4 chronic HCV. The cost for Sovaldi varies based on the exact use. When used with RBV, a 12-week course costs approximately $84,000 wholesale, or $1000 a day. Olysio (simeprevir) is another oral agent whose efficacy has been established in combination with RBV plus PegIFN in G1 HCV-infected patients with compensated liver disease (including cirrhosis). A 3-month course of Olysio costs approximately $66,000 wholesale, or nearly $733 a day.
Hayes, Inc. is in the process of completing health technology assessments on these new agents and their impact on patient outcomes. Look for these reports to be released later this year.