Hepatitis - Hepatitis C

Failure can be due to other, modifiable factors, which should be assessed before stopping treatment, particularly in patients who had interferon alone. They include the following:

Interferon dose is too low.
Patient did not comply fully with the treatment.
Patient was consuming alcohol.
Treatment time was too short. Some evidence suggests that response can significantly improve for many patients with genotype 1 if treatment time is extended to 48 weeks.

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Even if viral levels persist, there is some evidence the interferon treatment may still have benefits. For example, patients with normal liver enzyme levels appear to have almost no risk for liver damage, even if viral levels persist after treatment. Also of note, there is some evidence that interferon still reduces liver scarring and may even reduce the risk for liver cancer in some patients, even if the treatment does not eliminate the virus. More research is needed, however, to confirm these early findings.

Investigative Drugs for Hepatitis C. The current drugs used for HCV still do not meet the needs of all patients. They are expensive, have significant side effects, do not work in half the patients who take them, and are unsuitable in many others. Investigation then is ongoing to find better solutions. Some showing promise include the following:

Nucleoside analogs. Several new nucleoside analogs are in clinical development. Viramidine is a drug related to ribavarin. It is being studied in Phase III trials alone and in combination with pegylated interferon-alfa. Valopicitabine (NM283) is being tested in Phase II trials as alone and in combination with pegylated interferons.
Albuferon. This long-acting form of interferon-alfa may have fewer side effects and require less dosing than pegylated interferons. It is currently being tested in Phase II trials for patients who have not been treated with or have not responded to standard interferon-alfa.
IMPDH Inhibitors. Mycophenylate mofetil and VX-497 are agents that inhibit an enzyme known by its brief name, IMPDH, which may block replication of the hepatitis C virus. If effective, they would most likely be used in combination with interferon and ribavirin.
Amantadine (Symmetrel) is an anti-viral agent being investigated in various combinations. For example, triple therapy with amantadine, pegylated interferon, and ribavirin is showing particular promise. In some cases, the side effects of amantadine can be severe, and include vertigo, insomnia, nervousness, and depression. They are particularly disabling among older patients who receive inappropriately high doses.
Thymosin Alpha 1 (Zadaxin), also called thymalfasin, is a synthetic version of a peptide derived from the thymus gland (which is responsible for maturation of immune factors call T-cells). It is being used for hepatitis B and is under investigation for hepatitis C in combinations with natural interferons and pegylated interferon.
Protease Inhibitors. Novel protease inhibitors (similar to those used for HIV) are under investigation for hepatitis C patients who fail other treatments. These agents are based on molecular therapies that target proteins involved in viral reproduction.