Fact Sheet Number 403
PROTEASE INHIBITORS
|
this Fact Sheet on a single page using: |
|
|
|
|
|
More information on Downloading & Printing Fact Sheets |
|
PrintNOTE: Fact Sheets 402 through 405 describe drugs that
are being tested against HIV. See Fact
Sheet 402 for reverse transcriptase inhibitors under development,
Fact Sheet 404 for information
on new classes of drugs, and Fact
Sheet 405 for information on immune stimulators. These drugs
have not been approved by the Food and Drug Administration (FDA)
for use against HIV.
These drugs block the protease enzyme. When new viral particles
break off from an infected cell, protease cuts long protein strands
into the parts needed to assemble a mature virus. When protease
is blocked, the new viral particles cannot mature. Protease inhibitors
being tested in humans include Atazanavir, GW433908, L-756,423,
Mozenavir (DMP-450), Tipranavir, and TMC114. Several firms are
trying to develop a new type of protease inhibitor that will not
be cross-resistant with existing drugs.
Atazanavir (BMS232632) by Bristol-Myers Squibb is as
strong as nelfinavir. It has few side effects and doesn’t raise
cholesterol like many PIs, but can cause high levels of bilirubin.
It is being tested as a once daily drug in Phase III trials.
GW433908 by GlaxoSmithKline is a “prodrug”
form of amprenavir. A prodrug
becomes active after it is broken down in the body. GW433908 will
be just 2 tablets instead of the current 8 capsules, twice daily,
and will not contain Vitamin E. See Fact Sheet 445 for more information
on amprenavir. GW433908 is in Phase III trials.
L-756,423 by Merck is chemically similar to indinavir.
However, it stays in the blood longer and should cause fewer kidney
problems. L-756,423 is being studied in combination with indinavir.
The dose being studied is 5 capsules once a day with food. There
have been no recent reports on its status.
Mozenavir (DMP450) by Triangle Pharmaceuticals is a
very potent protease inhibitor that appears to improve the activity
of several other antiviral drugs. Unfortunately, it is cross-resistant
with indinavir and ritonavir. It is not broken down by the same
liver enzyme as other protease inhibitors, so it is expected to
have fewer interactions with other drugs. Development is on hold
due to heart irregularities.
Tipranavir (PNU-140690) by Boehringer Ingelheim is a
new HIV protease inhibitor. It appears to work against HIV that
is already resistant to other protease inhibitors. It is being
studied in twice-daily dosing combined with ritonavir and is in
Phase II trials. It seems to have a high rate of side effects
including diarrhea, nausea and vomiting.
TMC114 by Tibotec Virco produces very rapid drops in
viral load. It is in Phase I studies.
Revised August 7, 2002
Goto InfoNet Main Page
Go toIndex of Fact Sheets
Clickhere if you have questions
New Mexico AIDS Education and Training Center
and the New Mexico Department of Health