"We have to realise that these are interim results, and we have to wait to see if this rapid viral response does indeed become a sustained viral response," said lead author John McHutchison, MD, professor, division of medicine, Duke University Medical Center, Durham, North Carolina, United States.

In the interim analyses of the ongoing clinical trial, 138 of 175 patients given the 3-drug treatment had achieved undetectable viral levels, using the sensitive 10 IU/mL assay compared with 8 of 75 patients treated with peginterferon plus ribavirin (P < .0001). All patients had genotype 1 hepatitis C virus, which is the strain that is most difficult to treat because of difficulty in achieving a sustained virological response.

When the 30 IU/mL assay was used, 88% of patients on triple therapy compared with 16% of patients on standard treatment had achieved an undetectable viral load (P < .0001), Dr. McHutchison said.

In a second arm of the study, 20 patients were selected to test proof- of- principle that the length of treatment with the hepatitis C medications could be radically curtailed from the present 48-week regimen of weekly injections of peginterferon and twice daily oral ribavirin. Telaprevir is also taken daily by mouth.

Dr. McHutchison said three patients in that group dropped out prior to treatment, leaving 17 patients in the study. Eventually nine patients in this group achieved undetectable levels of virus at 12 weeks and discontinued all medication. They were followed for 20 weeks. Three patients relapsed.

"We believe that we have established proof that some patients can achieve undetectable virus and remain free of virus without any treatment," Dr. McHutchison said. However, the gold standard for treatment is to maintain that level for 24 weeks -- achieving a sustained viral response. "Obviously, we have to wait a bit longer to determine if we have achieved that," he added.

In the trial, presented on April 14^th, 80 patients were randomised to receive pegylated interferon and ribavirin for 48 weeks – the present standard of care in hepatitis C infection eradication therapy.

The remainder of patients were randomised to one of three treatment arms: 80 patients were treated with telaprevir for 12 weeks in addition to the other drugs, and peginterferon plus ribavirin continued for another 36 weeks; 80 patients received the three drugs for 12 weeks and then 12 additional weeks of just peginterferon and ribavirin; 20 patients took the three drugs for 12 weeks and then discontinued all medication.

Adverse effects associated with telaprevir included rash, nausea, pruritus, diarrhoea, anaemia and vomiting. Dr. McHutchison noted that these are the same side effects seen with ribavirin, suggesting that there may be some interaction between the two medications.

The study is sponsored by Vertex of Cambridge, Massachusetts, U.S. and Tibotec, Cork, Ireland.


[Presentation Title: Results of an Interim Analysis of a Phase 2 Study of Telaprevir (VX-950) With Peginterferon alfa-2a and Ribavirin in Previously Untreated Subjects With Hepatitis C. Abstract Number 786]

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