Maintenance therapy is the continuation of treatment even though there has not been a sustained virologic response (SVR).
In the past there had been evidence suggesting that the continuation of treatment whilst not clearing the virus could have beneficial effects. These included:
- Decreasing the rate of fibrosis progression
- Decreasing the rate of development of complications of end-stage liver disease
- Reducing the risk of developing HCC
The uncertainty about maintenance therapy led to the HALT-C trial. The aim of this trail was to determine "if continuing interferon long term over several years will suppress the hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation"
Because earlier studies had shown interferon can suppress hepatitis C RNA levels, decrease serum aminotransferase levels, and improve liver histological findings, even if the virus was not eradicated, the researchers thought extended treatment might be indicated.
The researchers randomized 1,050 patients with chronic disease and advanced fibrosis or cirrhosis to get either 90 micrograms of peginterferon a week for 3.5 years or no treatment at all. All the patients had previously failed standard therapy with peginterferon and ribavirin.
The researchers found that for 34.1% of the patients treated with peginterferon their illness progressed. This compared to 33.8% of the control group who did not receive interferon. The results, published in 2008, made clear that maintenance therapy did not stop liver disease from progressing.
See link to access HALT-C trial information - http://www.haltctrial.org/publications.html
Analysis also found that in one subgroup the treatment appeared to worsen outcomes. Among treated patients with non-cirrhotic fibrosis, 5% died, compared with 1.9% of control patients, a difference that was significant. There was no difference in mortality among cirrhotic patients.