Treatment Review; August 1995
The drug cidofovir, also known as HPMPC, is now in clinical
trials. In earlier studies, this drug caused kidney damage
(renal toxicity). It also demonstrated strong activity
against CMV, for an extended period of time. When the effect
of the first infusion wears off - in about 7 days - the
second infusion appears to have the same effect, and last the
same amount of time. At this point it is not known whether
the drug actually ever stops working against CMV. Both
foscarnet and ganciclovir eventually stop working, and CMV
progresses after about 6 months.
The first studies of cidofovir indicate that the best way to
give the drug is once a week. The new study that is described
below will give the drug once a week for the first two weeks,
then once every two weeks. If this turns out to be an
effective way to give this drug, it would certainly be more
convenient and less invasive than the usual once or twice a
day infusions of the already approved drugs.
To participate in this trial you must have failed previous
treatment. Requirements for failing previous treatment vary
according to the location of the CMV infection in your eye.
All participants are treated with cidofovir. After the two
week induction period, participants are randomized to 2
different doses. Treatment is once a week for 2 weeks and
once every other week after that. Clinic visits may require
two days of visits, all outpatient. All participants receive
probenicid and saline hydration at the same time. Probenicid
helps protect the liver from possible side effects due to
treatment with cidofovir. Probenicid is a pill. Cidofovir is
given by intravenous infusion.
To participate, you must be 18 years or older with CMV
retinitis that has progressed while on foscarnet or
ganciclovir for at least a 4 week period. You may not have
been treated with ganciclovir or foscarnet within 2 days of
starting the study. You may not have ever been treated with
cidofovir. You must do a one week washout from anti-CMV
investigational agents. If you have an intravitrial implant
with ganciclovir, the implant will have to be taken out
before starting the study. For more information about this
study, or the treatment or prevention of CMV, call The
Network at (800) 734-7104.
Although there is no guarantee that the drug cidofovir will
not cause side effects, researchers and some people with AIDS
support the continued testing of this drug because it holds
great promise. By adding the drug probenicid to the study,
researchers hope that the kidneys will not be damaged. This
drug has been used for this purpose with other drugs.