BMS drugs may alleviate hepatitis C without interferon

Bristol-Myers Squibb (BMS) has published trial data which suggest that combination therapy with its hepatitis C drugs daclatasvir and asunaprevir has the potential to cure patients who have previously failed interferon-based therapy.

The phase II study, published in the New England Journal of Medicine (January 19), showed that the two directly-acting antiviral compounds achieved a sustained virologic response over 12 weeks of treatment.

If further results shows that these responses can be sustained for 48 weeks, then the regimen will be deemed curative.

Daclatasvir is the first NS5A replication complex inhibitor to be investigated in clinical trials and is currently in phase III development, said BMS, while asunaprevir is an NS3 protease inhibitor in phase II.

Combined use of directly-acting antivirals could provide patients with an all-oral alternative to the current standard of injectable therapy with interferon alpha, say the researchers.

Meanwhile, the study also showed that quadruple therapy with the two BMS compounds, pegylated interferon alpha and ribavirin achieved a sustained virologic response at week 12.

"Even with the recent approval of two protease inhibitors, treatment of hepatitis C patients who have not responded to PEG-interferon alfa and ribavirin has limited success," said the lead investigator in the trial, Anna Lok of the University of Michigan Medical School in Ann Arbor.

"Because of this high unmet medical need, there is a necessity for new combination regimens that can increase response rates in null responders," she added.

Currently, combination therapy with pegylated interferon alpha and ribavirin achieves sustained responses in just 50 to 80 per cent of patients - depending on the hepatitis C virus strain.

However, the availability of oral protease inhibitors - namely Vertex' Incivek (telaprevir) and Merck & Co's Victrelis (boceprevir) - has pushed response rates up.

In an editorial accompanying the NEJM study, Dr Raymond Chung, director of hepatology at Massachusetts General Hospital in Boston, described the findings as a "watershed moment" in treatment for chronic hepatitis C.

"We are on the threshold of a treatment revolution," he said.