Boceprevir Ups Hepatitis C Treatment Success
Boceprevir Ups Hepatitis C Treatment Success
Aug. 9, 2010 -- Adding Merck's boceprevir to standard hepatitis C therapy increases the viral cure rate up to 75% -- a success rate similar to that of Vertex's telaprevir.
Standard hepatitis C treatment results in a "cure" less than half the time. It combines alpha interferon with ribavirin, a drug with general antiviral effects. In contrast, boceprevir and telaprevir directly attack the hepatitis C virus (HCV).
Boceprevir and telaprevir each inhibit the HCV protease molecule. Like HIV protease inhibitors, these HCV protease inhibitors are extremely effective at suppressing the virus they target.
Unfortunately, there's another similarity. Like the AIDS virus, the hepatitis virus quickly develops resistance to protease inhibitors. Neither boceprevir nor telaprevir can be given alone -- each must be added to standard combination treatment with alpha interferon and ribavirin.
That standard combination causes a lot of hard-to-tolerate side effects. Both boceprevir and telaprevir add to the side effect burden. Very preliminary evidence suggests that boceprevir may be somewhat easier to take.
Nevertheless, the boceprevir findings are very good news for people with hepatitis C infection. They show the drug greatly increases the odds that treatment will result in a cure -- that is, in HCV dropping to undetectable levels. Patients who achieve such a "sustained viral response" (SVR) or "viral cure" usually don't see the virus come back to harmful levels.
The boceprevir studies tested the drug in patients with genotype 1 HCV infection. Genotype 1 is the most common HCV strain in the U.S. and is generally considered the most resistant to treatment.
In a phase III clinical trial reported by Merck, among never-before-treated patients:
In another phase III clinical trial reported by Merck, among patients for whom previous treatment failed:
Standard hepatitis C treatment results in a "cure" less than half the time. It combines alpha interferon with ribavirin, a drug with general antiviral effects. In contrast, boceprevir and telaprevir directly attack the hepatitis C virus (HCV).
Boceprevir and telaprevir each inhibit the HCV protease molecule. Like HIV protease inhibitors, these HCV protease inhibitors are extremely effective at suppressing the virus they target.
Unfortunately, there's another similarity. Like the AIDS virus, the hepatitis virus quickly develops resistance to protease inhibitors. Neither boceprevir nor telaprevir can be given alone -- each must be added to standard combination treatment with alpha interferon and ribavirin.
That standard combination causes a lot of hard-to-tolerate side effects. Both boceprevir and telaprevir add to the side effect burden. Very preliminary evidence suggests that boceprevir may be somewhat easier to take.
Nevertheless, the boceprevir findings are very good news for people with hepatitis C infection. They show the drug greatly increases the odds that treatment will result in a cure -- that is, in HCV dropping to undetectable levels. Patients who achieve such a "sustained viral response" (SVR) or "viral cure" usually don't see the virus come back to harmful levels.
Boceprevir Clinical Trial Results
The boceprevir studies tested the drug in patients with genotype 1 HCV infection. Genotype 1 is the most common HCV strain in the U.S. and is generally considered the most resistant to treatment.
In a phase III clinical trial reported by Merck, among never-before-treated patients:
- 66% had an SVR with boceprevir plus standard treatment for 48 weeks.
- 63% had an SVR after four weeks of standard therapy and 44 weeks of boceprevir plus standard therapy.
- 38% on standard treatment had an SVR.
In another phase III clinical trial reported by Merck, among patients for whom previous treatment failed:
- 66% had an SVR with boceprevir plus standard treatment for 48 weeks.
- 59% had an SVR after four weeks of standard therapy and 44 weeks of boceprevir plus standard therapy.
- 21% on standard treatment had an SVR.
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