Coverage of 2007 IAS
(International AIDS Society)
July 2007, Sydney, Australia
New Experimental NNRTI Starts Very Early Study
July 25, 2007
Preliminary data were presented on UK-453,061, an experimental
NNRTI, at the 4th IAS Conference on HIV Pathogenesis, Treatment
and Prevention in Sydney, Australia. The compound is being developed
by Pfizer and does not appear to be cross-resistant with the currently
available NNRTIs like Sustiva (efavirenz) and Viramune (nevirapine).
A short-term, dose-ranging monotherapy study followed 48 people
who were randomly assigned to take one of seven different doses
of UK-453,061 or a placebo for 7 days. HIV levels were checked daily
for the first week and 6 additional times within 40 days. Drug levels
were also measured one day after the last dose.
HIV levels dropped the most in people who received 500mg twice
a day or 750mg once a day arms—1.62 and 1.79 logs respectively.
HIV levels began to rise around three days after the last dose of
drug was given, returning to baseline after around 20 days. There
were few side effects reported in the study. Of particular note
was the lack of rash seen in the study—a side effect seen
with all other NNRTIs to date. More studies of these two doses are
planned.
These data are hopeful but very preliminary. The NNRTI class is
widely used, but all of the current drugs have significant drawbacks.
Alongside the Tibotec drugs etravirine (TMC-125) and rilpivarine
(TMC-278), Pfizer’s UK-453,061 offers a renewed sense of optimism
for this crucial class of anti-HIV drugs.
