An analysis of a large group of people retreated for hepatitis C virus (HCV) after a failed cure attempt suggested that their subsequent chances of success are very good. Researchers analyzed data on 3,300 people treated with interferon-free hep C regimens; the data was drawn from a large European hep C database concerning resistance to hep C drugs. Findings were presented at the 51st International Liver Congress in Barcelona.

A total of 192 people in the group failed eight to 24 weeks of hep C treatment, including 151 with genotype 1 of the virus, two with genotype 2, 26 with genotype 3 and 11 with genotype 4.

Among those with genotype 1, 44 had been treated with Sovaldi (sofosbuvir) and Olysio (simeprevir), with or without ribavirin; 28 had been treated with Sovaldi and Daklinza (daclatasvir), with or without ribavirin; 60 had been treated with Harvoni (ledipasvir/sofosbuvir), with or without ribavirin; and 19 were treated with Viekira Pak (ombitasvir/paritaprevir/ritonavir; dasabuvir), with or without ribavirin. Among those with genotype 3, 16 were treated with Sovaldi and Daklinza, with or without ribavirin; nine were treated with Harvoni, with or without ribavirin; and one was treated with Sovaldi and ribavirin.

Among those with genotype 1, 59 percent had cirrhosis, and 69 percent had failed previous treatment with interferon, ribavirin and a protease inhibitor.

Eighty-three percent of the individuals who failed treatment showed genetic resistance to hep C treatments at one to three key points in the viral genome.

Only three people who failed Harvoni had none of the three main predictors of treatment failure: cirrhosis, a previous treatment failure or genetic resistance variants.

Twenty-three percent of those with genotype 1 (34 people) and 15 percent of those with genotype 3 (four people) restarted treatment. The majority of those with genotype 1 had failed Sovaldi and Olysio and took Viekira Pak or Harvoni for retreatment. Those with genotype 3 were retreated with 24 weeks of Sovaldi and Daklinza plus ribavirin.

Among the 14 people with available data on their treatment outcome, 93 percent of those with genotype 1 and 100 percent of those with genotype 3 were cured after retreatment.

The researchers are cautious about their findings given the incompleteness of the data at this time. However, the rate of those who achieved a sustained virologic response four weeks after completing treatment (SVR4) was 90 percent. An SVR 4 indicates an excellent chance that an individual will maintain an undetectable hep C viral load for another eight weeks and achieve an SVR12, which is considered a cure.