Bristol-Myers Squibb’s experimental hepatitis C therapies achieve primary endpoint in Phase II trial

Bristol-Myers Squibb announced Wednesday that in a small mid-stage trial, two of the company’s experimental drugs cleared the hepatitis C virus in 36 percent of patients who failed to respond to existing therapies. Lead researcher Anna Lok noted that the study, which was published in the NEJM, is the first of its kind to demonstrate efficacy without interferon in null-responders.

The study randomised 21 patients with hepatitis C genotype 1 who had not responded to previous treatment with interferon and ribavirin to receive Bristol-Myers Squibb’s daclatasvir and asunaprevir, either alone or in combination with interferon and ribavirin. Results showed that five of 11 patients in the dual therapy arm achieved a sustained virologic response (SVR) with undetectable virus at the end of 24 weeks of treatment, a response that was sustained by four of 11 patients 12 weeks post-treatment. However, all 10 patients in the quadruple therapy arm had undetectable virus levels after 24 weeks of therapy and nine of 10 had a SVR at 12 weeks post-treatment.

Commenting on the results, Lok noted that “the four-drug arm was very impressive. These patients had not shown a response before and now we get a 90 to 100 percent rate of sustained response.” However, she noted that even though only four patients in the two-drug group reached a SVR, the data suggest it may be possible to treat hepatitis C infection with two direct-acting antiviral (DAA) agents only.

“Clearly, this is the biggest development in hepatitis C research in a very long time,” remarked Raymond Chung in an accompanying editorial, adding that “we are on the threshold of a treatment revolution that will greatly improve the effectiveness of hepatitis C virus therapy by dramatically increasing the number of persons treated.” He further noted that while the drugs are still experimental, an interferon-sparing regimen is only a few years away. “It is not beyond belief that we’ll have an all-oral therapy available as early as 2015. That’s the pace it’s going right now,” he added.