First Hepatitis C Treatment Data Demonstrating Proof of Principle with Direct-Acting Antiviral-only

March 22, 2012 - PRLog -- (Mumbai, March 22, 2012) – Bristol-Myers Squibb Company  today announced the full results, published in the New England Journal of Medicine, from a Phase II clinical trial in patients with hepatitis C virus (HCV) genotype 1 who had not responded to prior therapy with PEG-interferon alfa and ribavirin (‘null responders’*). The study demonstrated that its primary endpoint of the achievement of sustained virologic response 12-weeks post-treatment (SVR12) is possible with a direct-acting antiviral (DAA)-only combination containing daclatasvir and asunaprevir (4/11 patients, including two of two patients infected with HCV genotype 1b). This study was the first study to demonstrate the possibility that hepatitis C can be cured (defined as sustained virologic response 48 weeks post-treatment or SVR48) without the use of interferon. The study also demonstrated that 100 percent (10/10) of these difficult-to-treat patients dosed with quadruple therapy containing daclatasvir and asunaprevir in combination with PEG-Interferon alfa and ribavirin achieved SVR12.

In this study there were no serious adverse events on treatment or discontinuations due to adverse events. Diarrhea was the most common adverse event in both groups (73% and 70%).

“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. Because of this high unmet medical need, there is a necessity for new combination regimens that can increase response rates in null responders,” said lead investigator Anna Lok, MD, FRCP, director of clinical hepatology and professor in the department of internal medicine at the University of Michigan Medical School in Ann Arbor. “The data seen in this study with Bristol-Myers Squibb’s investigational DAAs daclatasvir and asunaprevir, either as DAA-only therapy or as part of quadruple therapy, are encouraging as we work to advance hepatitis C therapy for  this difficult-to-treat patient population. This study also shows for the very first time that sustained viral responses can be achieved without the use of interferon and ribavirin.”

Daclatasvir is the first NS5A replication complex inhibitor to be investigated in HCV clinical trials and is currently in Phase III development. Asunaprevir is an investigational, oral, selective NS3 protease inhibitor.

* Null responders – patients whose virus did not respond to prior treatment with PEG-interferon alfa and ribavirin
(HCV RNA decrease 3x upper limit of normal (ULN)] which did not require treatment discontinuation or dose interruptions, and all patients stabilized or improved with continued therapy. Six patients, all of whom received PEG-interferon alfa and ribavirin, experienced Grade 3 or 4 neutropenia, a blood disorder characterized by an abnormally low number of white blood cells.

About the Study
This open-label, phase IIa study evaluated the antiviral activity and safety of the combination of daclatasvir and asunaprevir with and without PEG-Interferon alfa and ribavirin in 21 HCV genotype 1 null responders. Patients in the study were randomized to receive one of two treatment regimens for 24 weeks. The 11 patients in Group A received dual-DAA therapy with daclatasvir 60 mg once daily and asunaprevir 600 mg twice daily, both taken orally. The 10 patients in Group B received quadruple therapy with daclatasvir 60 mg once daily, asunaprevir 600 mg twice daily, PEG-interferon alfa 180 μg once weekly, and ribavirin 1000-1200 mg daily (according to body weight) in two divided doses. The primary study objective was to determine the proportion of patients achieving undetectable viral load (HCV RNA