Protease Inhibitors 

Telaprevir and boceprevir are the first two of this class of drugs that stop hep C from splitting in two in order to reproduce itself. Dozens more  are in development, including Roche’s danoprevir, but so far it looks like resistance to one means resistance to all.

Polymerase Inhibitors 

This class (about a dozen are in development, none further along than Phase II clinical trials) also jams a key step in hep C’s viral replication. Some are stronger against resistance than protease inhibitors and are active against more than one hep C genotype. (Of the six major hep C genotypes, type 1 is by far the most common in this country. Telaprevir works against types 1 and 2 but not 3; boceprevir has only been tested against genotype 1.) In the long run, polymerase inhibitors may become the true backbone of hep C treatment.

NS5A Inhibitors

NS5A inhibitors—easier-to-take forms of interferon and immune-based therapies—block a key protein hep C uses to replicate. Immune-based therapies, such as therapeutic vaccines, juice up the body’s own response to hepatitis C. They’re in very early trials, all part of the arsenal of hep C therapies in development. You can follow their progress and cheer them on at poz.com, treatmentactiongroup.org and natap.org.

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