Hepatitis C Drug Telaprevir Raises Cure Rate
Study: 75% Viral Cure Rate With Telaprevir Plus Standard Therapy
May 26, 2010 -- Adding the experimental hepatitis C drug telaprevir to standard interferon/ribavirin therapy cured 75% of newly treated patients, drug maker Vertex announced.
Moreover, most patients taking a 12-week course of telaprevir combination therapy were able to shorten the total length of their grueling treatment from 48 weeks to 24 weeks.
Because hepatitis C virus (HCV) rapidly becomes resistant to telaprevir, the drug must be given in combination with other antiviral treatments, and these treatments are continued for weeks after completion of telaprevir therapy.
All of the patients in the clinical trial were infected with HCV genotype 1 -- the most common U.S. strain, and the hardest to cure. Without telaprevir, less than half of patients with genotype 1 HCV achieve a cure.
In the world of hepatitis C treatment, "cure" is a relative term. Treatment does not necessarily eradicate the virus from the body. Successful treatment results in "sustained viral response (SVR)" or "viral cure," meaning that treatment has brought the virus to undetectable levels. Usually, the immune system is able to keep any remaining HCV under control after a viral cure.
About 9% of telaprevir-treated patients who achieved SVR relapsed -- that is, their HCV levels once again became detectable during post-treatment follow-up.
Testing Telaprevir's Effects
In the study, two groups received either eight- or 12-week courses of the telaprevir/interferon/ribavirin combination, followed by 12 or 36 more weeks of treatment with interferon/ribavirin. Those whose HCV became undetectable at weeks 4 and 12 got the shorter treatment course. A third group of patients got 48 weeks of standard interferon/ribavirin treatment.
Standard interferon/ribavirin usually causes flu-like side effects. Adding telaprevir doesn't make this easier, increasing the risk of anemia, rash, itching, and nausea.
Telaprevir increased the number of patients who dropped out of the trial because of side effects: from 3.6% in the control group receiving only standard therapy to 6.9% in those who took telaprevir for 12 weeks and to 7.7% of those who took telaprevir for eight weeks.
Telaprevir Not FDA Approved
Overall, researchers consider the study a huge success.