A phrase like “silent killer” sounds creepy enough on its own, but it’s an often-used one for a virus that, according to the Centers for Disease Control and Prevention, infects 1.3% to 1.9% of people in the United States.
New hepatitis C infections have fallen dramatically over the last decade, according to the CDC, from 28,000 in 2003 to 18,000 in 2008. However, the virus, which is mostly spread through unprotected sex and sharing of needles by drug abusers, remains dangerous, and as many as 3.2 million Americans may be infected. According to the C. Everett Koop Institute at Dartmouth Medical School, hepatitis B and C account for 75% of all cases of liver disease around the world, but unlike its cousin, more than 80% of infections by hepatitis C, also known as HCV, become chronic and lead to liver disease.
But HCV has one silver lining: It’s curable. The standard of care for HCV infection is a combination of the generic antiviral drug ribavirin with a biotech drug known as a pegylated interferon, usually Genentech’s Pegasys (peginterferon alfa-2a) or Merck’s PegIntron (peginterferon alfa-2b). The treatment can produce a sustained virologic response, or SVR, meaning that the virus is rendered at least undetectable and thus considered cured, though cure rates are lower in patients with genotype 1 of the virus, at 40% to 50%, while cure rates for genotypes 2 and 3 are much higher.
But in May, the Food and Drug Administration approved two drugs that could be the start of a new trend in HCV treatment: Vertex Pharmaceuticals’ Incivek (telaprevir) and Merck’s Victrelis (boceprevir), both protease inhibitors. “It’s going to have a major, huge, big impact — pick your favorite superlative,” analyst Seamus Levine-Wilkinson of healthcare market research firm Decision Resources told Drug Store News.
What’s significant about the two drugs is that, taken in combination with ribavirin-interferon alfa therapy, they greatly increase the cure rate for patients with genotype 1, bringing it up to 65% or more. “These drugs are a huge advance,” Levine-Wilkinson said. “They’ll really up the treatment rates.”
The drugs aren’t perfect, however, and they include side effects, such as rashes and anemia. But they could be a taste of the future of HCV treatment. Tibotec, a division of Johnson & Johnson, is developing TMC435, a protease inhibitor that may have fewer side effects than Incivek and Victrelis. Meanwhile, Pharmasset is working with Roche to develop RG7128 (mericitabine) and with J&J to develop PSI-7977. The latter two drugs are polymerase inhibitors, which differ from protease inhibitors in that they have the potential to work against all genotypes of the virus rather than just one. Levine-Wilkinson sees the new drugs launching as early as 2015. In addition, he said, they could even lead to the elimination of the need for interferons.
The development of new drugs is particularly significant for specialty pharmacy providers, for which genotypes are an important aspect of treatment. Recently, Accredo Health Group, the specialty pharmacy division of pharmacy benefit manager Medco Health Solutions, said it was able to drive down the cost of HCV treatment by $13,000 per patient by using genotype information, as well as by increasing medication adherence, as patients must be at least 80% adherent for their HCV treatment to be effective.