(Victrelis) Approved for Hepatitis C
The U.S. FDA on May 13 approved the HCV protease inhibitor
boceprevir (brand name Victrelis), the first direct-acting
hepatitis C drug.
advent of direct-acting antiviral agents that target different steps
of the hepatitis C virus (HCV) lifecycle is expected to revolutionize
hepatitis C treatment. Current standard therapy -- pegylated
interferon plus ribavirin -- works by stimulating the immune
response rather than targeting the virus directly.
The approval of Merck's boceprevir
comes just 2 weeks after its unanimous recommendation by the Food
and Drug Administration's Antiviral Drugs Advisory Committee.
Boceprevir, in combination with pegylated interferon plus ribavirin,
produced higher sustained virological response (SVR) rates than
standard therapy alone in the pivotal SPRINT-2 and RESPOND-2 studies.
The improvement was particularly notable for people with HCV genotype
1 and those who did not respond or relapsed with a prior course
of standard treatment.
The likelihood of SVR for genotype 1 prior non-responders was around
60% with boceprevir plus pegylated interferon/ribavirin compared
to about 20% with standard therapy alone. For treatment-naive patients,
cure rates approached 70% with boceprevir combination therapy versus
about 40% with standard treatment alone. People who achieve SVR
-- generally considered a cure -- reduce their risk of developing
liver cirrhosis and hepatocellular carcinoma.
Studies have shown that boceprevir is generally well-tolerated,
but it increases the risk of developing anemia; some recipients
also reported neutropenia (low neutrophil levels) and unusual taste
Boceprevir was approved for adults with HCV genotype 1 and compensated
liver disease. It is indicated for both treatment-naive patients
and prior non-responders or relapsers.
The standard dose of boceprevir is 800 mg 3-times-daily with food.
Patients should take pegylated interferon/ribavirin for a 4-week
lead-in period before starting boceprevir, then continue on all
Most people can use response-guided therapy -- adjusting duration
of therapy based on response at weeks 8, 12, and 24 -- but the maximum
48-week duration is recommended for some hard-to-treat patients.
Discontinuation due to likely treatment futility is recommended
for patients who still have HCV viral load of at least 100 IU/mL
at week 12 or detectable HCV RNA at week 24.
"This is an exciting day for physicians and patients because
Victrelis is the first major advancement for the treatment of chronic
hepatitis C approved in a decade," said clinical investigator
Bruce Bacon from Saint Louis University School of Medicine in a
Merck press release. "Compared to current standard therapy,
Victrelis can significantly increase a patient's chance of achieving
undetectable levels of the virus, thereby obtaining an SVR. For
many patients, Victrelis may allow for a shorter total duration
Merck has said that it will begin shipping boceprevir to pharmacies
within a week. The company also indicated that it is expanding its
support of public awareness and patient education efforts, as well
as a patient assistance program to help eligible patients obtain
access to the new drug.
"Victrelis is an important new advance for patients with hepatitis
C," said Edward Cox, director of the Office of Antimicrobial
Products in FDA's Center for Drug Evaluation and Research. "This
new medication provides an effective treatment for a serious disease,
and offers a greater chance of cure for some patients' hepatitis
C infection compared to currently available therapy."
The FDA is also expected to soon approve another HCV protease inhibitor,
telaprevir (Incivek), which also received unanimous approval
from the Antiviral Drugs Advisory Committee the day after boceprevir
in late April.
Merck's press release, including findings from the Phase 3 trials
and important safety information, is available online at http://www.merck.com/newsroom/news-release-archive/prescription-medicine-news/2011_0513.html.
Full Victrelis Prescribing Information is available at http://www.merck.com/product/usa/pi_circulars/v/victrelis/victrelis_pi.pdf.
The Victrelis Medication Guide is available at http://www.merck.com/product/usa/pi_circulars/v/victrelis/victrelis_mg.pdf.
Victrelis label information is also available from the FDA at http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/202258lbl.pdf.
Food and Drug Administration. FDA Approves Victrelis for Hepatitis
C. Press release. May 13, 2011.
R Klein and K Struble (FDA). Approval of Victrelis (boceprevir)
a direct acting antiviral drug to treat hepatitis C virus (HCV).
FDA Hepatitis Update. May 13, 2011.
FDA Approves Merck's Victrelis (boceprevir), First-in-Class Oral
Hepatitis C Virus (HCV) Protease Inhibitor. Press release. May 13,
Merck. Merck Announces Hope Against Hepatitis C Initiative to Support
Public Awareness, Education and Research in the Fight Against Hepatitis
C Virus. Press release. May 9, 2011.