With HCV compounds telaprevir and boceprevir now in the homestretch, much of the focus at the American Association for the Study of Liver Diseases meeting was on new details from previously reported Phase III trials. Shorter treatment duration and new subgroup analyses further solidified the case for telaprevir from Vertex Pharmaceuticals Inc., while Merck & Co. Inc. is hoping a different lead-in regimen for boceprevir will offer doctors more flexibility, particularly with patients who have failed standard therapy.
Vertex and Merck both plan to submit NDAs by year end, and physicians told BioCentury they want the choice of both of the first-generation HCV protease inhibitors.
According to these physicians, the available data suggest telaprevir has a leg up for treating treatment-naïve patients, based on its higher SVR rates and a shorter course of therapy vs. boceprevir when added to standard of care (SOC), which is pegylated interferon and ribavirin.
Raymond Chung, director of hepatology at Harvard Medical School, told BioCentury telaprevir appears to be slightly more effective in treatment-naïve patients, but what really sets it apart from boceprevir is its potential to shorten the amount of time a patient must remain on therapy.
"For reasons related to the combined cumulative exposure to potential side effects of standard interferon therapy plus a protease inhibitor, the fact of the matter is that the ability to truncate the regimen becomes a very important issue," he noted.
Sustained viral response (SVR), defined as an undetectable viral load 24 weeks after the completion of treatment, is the goal of treatment. On SOC alone, about 60% of patients with chronic HCV genotype 1 infection who undergo a 48-week course of treatment will not achieve an SVR, including a substantial portion of patients who discontinue therapy due