Reuters (04.26.12) - Monday, April 30, 2012
The Food and Drug Administration (FDA) said Thursday it is
changing the label for Merck & Co.'s hepatitis C virus (HCV)
treatment Victrelis following studies indicating it should not
be taken with some common HIV drugs.
"Co-administration [of the two drugs] ... is not recommended
at this time because of the possibility of reducing the
effectiveness of the medicines, permitting the amount of HCV
or HIV ... in the blood to increase," FDA said.
Victrelis (boceprevir) was approved last May. FDA and Merck
first warned about the issue in February after results of a
drug interaction study of healthy patients who took Victrelis
and the widely used HIV drug Norvir (ritonavir) as part of a
combination protease inhibitor regimen. The study found
Victrelis reduced the concentrations of HIV drugs in the
A second, small clinical trial of 98 people presented last
month also contributed to FDA's labeling decision, though its
results were not as conclusive as the drug interaction study.
Some of the HCV/HIV co-infected patients were given Victrelis
plus peginterferon/ribavirin, while others received only
peginterferon/ribavirin; all patients were given a type of HIV
drug. Of 64 patients taking Victrelis, three had a rebound in
their HIV, compared to four of the 34 taking the older
combination HCV treatment.
Merck said it plans to conduct a larger drug interaction study
of Victrelis with other HIV drugs. FDA said it will report any
new information about Victrelis and those treatments when it
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