R1626 belongs to a class of antivirals called polymerase inhibitors which are being investigated in combination with the current standard of care, pegylated interferon and ribavirin. The hope is that this potent combination will increase the number of patients who manage to clear the hepatitis C virus from their system and become cured of this insidious and deadly disease.
High barrier to resistance
R1626 has also demonstrated a high barrier to the development of resistance, according to a second abstract being presented at the conference2. Resistance to R1626 was not identified following intensive testing for either two weeks of treatment with R1626 as monotherapy or in patients treated with R1626 for 4 weeks in combination with the standard of care.
“The results from this phase IIa study show that R1626 has a profound effect when used in combination with PEGASYS plus COPEGUS,” said Dr. Paul Pockros (Scripps Clinic, San Diego, California), the lead investigator of the study. “The synergistic antiviral effect of R1626 along with the lack of resistance means that R1626 could be an exciting antiviral drug for the treatment options for patients with hepatitis C if a safe and acceptable dosage regimen can be determined in future studies.”
The study found: 
· Up to 81% of those patients treated with R1626 1500 mg BID + PEGASYS + ribavirin had an undetectable HCV viral load by week 4 (mean reduction of 5.2 log10 IU/mL)
· ALT, a liver enzyme, normalised in approximately 50% of patients in R1626 treatment groups
· Most reported adverse events were mild to moderate. A higher incidence of grade 4 neutropenia was reported in R1626 treatment arms (39-48% in the 1500 mg arms) and was the main reason for dose reductions and discontinuation
Further phase II studies are underway to investigate R1626 in combination with PEGASYS and COPEGUS.
Start of the phase IIb trial
As a result of the robust antiviral effect seen in this phase IIa study, R1626 is being progressed into phase IIb study to further investigate the new treatment regimens of R1626, in combination with standard or lower dose of PEGASYS® (peginterferon alfa-2a (40KD)) and standard dose of COPEGUS® (ribavirin).
“The strong synergistic antiviral effect seen among R1626, PEGASYS and COPEGUS in the Phase IIa study together with the design of the phase IIb study makes me confident that we will find the right balance between the safety and efficacy,” said Dr. Stefan Zeuzem, Professor of J.W. Goethe University Hospital, Frankfurt, Germany, the lead investigator in this Phase IIb study.
About Hepatitis C in the UK
Hepatitis C, one of the most common chronic blood-borne infections, is transmitted primarily through blood or blood products. Estimates of prevalence for hepatitis C in England and Wales vary considerably from 200,000 to 500,000. It is a leading cause of cirrhosis, liver cancer and liver failure, despite being potentially curable. The future of hepatitis C therapy is likely to involve combinations of new small-molecule antiviral drugs and pegylated interferon-based treatment, like PEGASYS.
About Roche in the UK
Roche aims to improve people's health and quality of life with innovative products and services for the early detection, prevention, diagnosis and treatment of disease. Part of one of the world’s leading healthcare groups, Roche in the UK employs nearly 2,000 people in pharmaceuticals and diagnostics. Globally Roche is the leader in diagnostics, and a major supplier of medicines for the treatment of cancer, transplantation, virology, bone and rheumatology, obesity and renal anaemia. Find out more at www.rocheuk.com
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Olivia Garbutt, Roche UK
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