WASHINGTON--Studies of two new protease inhibitors, used in combination
with currently available anti-HIV agents, show good results in
reducing viral load. Furthermore, studies of a new test for determining
viral load indicate a significant relationship between high viral
load and faster disease progression.
All three studies were presented at the Third Conference on Retroviruses
and Opportunistic Infections, sponsored by the Infectious Diseases
Society of America, the NIH, and the CDC.
The three-drug combination of indinavir (Merck's investigational
protease inhibitor, Crixivan), AZT (Retro-vir), and 3TC (Epivir)
reduced the amount of HIV in the blood by 99%, to undetectable
levels, in 24 of 26 patients, with effects lasting for up to 6
months, said Dr. Roy Gulick of New York University. The study
was conducted at NYU and three other US hospitals.
In another study, which combined indinavir with AZT and ddI (Videx),
HIV was reduced to undetectable amounts in 13 of 22 patients (59%)
for 5 months. The most serious side effect was kidney stones,
seen in 2% to 3% of patients.
In a large, 7-month international study, 13% of patients receiving
the protease inhibitor ritonavir had progressive HIV disease (ie,
developed an AIDS-related disease or died) vs 27% of placebo patients,
said Dr. John M. Leonard of Abbott Laboratories.
Mortality was 4.8% among 543 patients given ritonavir vs 8.4%
among the 547 controls, a reduction of more than 50%. The study
involved many different drug combinations, since patients continued
to receive the anti-HIV drugs they were taking prior to entry
into the study.
Side effects associated with ritonavir use were predominantly
nausea and other gastrointestinal problems.