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The Food and Drug
Administration (FDA) today, October 12, 2007,
granted
accelerated approval
for raltegravir tablets (400 mg) for treatment of Human
Immunodeficiency Virus (HIV)-1 infection in combination with
other antiretroviral agents. Raltegravir, sold under the trade
name Isentress, is the first agent of the pharmacological class
of antiretroviral agents known as HIV integrase strand transfer
inhibitors, commonly referred to as integrase inhibitors. They
are designed to slow the advancement of HIV-1 infection
by blocking the HIV integrase enzyme that the virus needs in
order to multiply.
When
used with other anti-HIV medicines, raltegravir may reduce the
amount of HIV in the blood and may increase white blood cells,
called CD4+ (T) cells, that help fight other infections.
Raltegravir received
a priority review by the FDA. The review and approval of the
New Drug Application
was completed in within six months.
FDA’s approval of raltegravir is based on efficacy and safety
data from two double-blind, placebo-controlled studies (BENCHMRK 1
and BENCHMRK 2) in 699 highly antiretroviral
treatment-experienced HIV-1 infected adult patients (16 years or
older, with documented resistance to at least 1 drug in each of
3 Classes (NNRTIs, NRTIs, PIs) of antiretroviral therapies).
462 patients used the recommended 400 mg dose twice daily in
combination with other currently available HIV medications; 237
patients received a placebo in combination with other currently
available HIV medications. The mean changes in plasma HIV-1
RNA from baseline were -1.85 log10
copies/mL in the ISENTRESS 400 mg twice daily arm and -0.84 log10
copies/mL for the control arm. The mean increase from baseline
in CD4+ cell counts was higher in the arm receiving ISENTRESS
400 mg twice daily (89 cells/mm3)
than in the control arm (35 cells/mm3).
The
most common adverse events reported with raltegravir were
diarrhea, nausea, and headache. Blood tests showed abnormal
elevated levels of a muscle enzyme in some patients receiving
raltegravir. Caution is advised when using raltegravir in
patients at increased risk for certain types of muscle problems,
such as patients taking other medications that can cause muscle
problems.
Raltegravir has not been studied in pregnant women. Women who
are taking HIV medications when they get pregnant are advised to
ask their physician about registering with the
Antiretroviral Pregnancy Registry.
As
with other treatments for HIV, patients taking raltegravir may
still develop infections, including opportunistic infections or
other conditions that may develop in patients living with HIV-1
infection, and can still pass the virus on to others through
sexual contact, sharing needles, or being exposed to blood.
The
long-term effects of raltegravir are not known at this time, and
its safety and effectiveness in children less than 16 years of
age has not been studied.
Raltegravir is
distributed by New Jersey-based Merck & Co., Inc.
Please refer to the attached
product labeling
and
patient
information sheet for
additional information about raltegravir.
Richard Klein
Office of Special Health Issues
Food and Drug Administration
Kimberly Struble
Division of Antiviral Drug Products
Food and Drug Administration |
