Coverage of 2006 International
Conference on AIDS
August 14–18, 2006, Toronto, Canada
Kaletra vs Sustiva vs a Combination of the Two
by Martin Delaney, August 17, 2006
In this study reported as a “late-breaker” in Toronto,
researchers compared the two regimens most highly recommended in
the US Federal Guidelines a Kaletra (lopinavir/ritonavir) regimen
and a Sustiva (efavirenz) regimen, both in combination with two
nucleoside analogue drugs [NRTIs, or “nukes”]). In addition,
the study included a group taking only a combination of the two
drugs, Kaletra + Sustiva, but without any NRTIs.
The study followed 753 volunteers for a median of 112 weeks. At
the conclusion, there was no statistically significant difference
among the three groups with respect to viral load. However, there
was a clear trend favoring the Sustiva + two nukes group and the
Sustiva + Kaletra group as compared to the Kaletra + two nukes group.
The Kaletra + two nukes arm showed a shorter time to rebounds in
HIV levels, which was something of a surprise to many observers.
However, since the finding was not statistically significant, it
is difficult to say just how important the observation is and whether
it should affect treatment decisions.
Perhaps the most important finding of the study was that the group
who took combined Sustiva and Kaletra performed at least as well
as the best conventional arm (Sustiva + two nukes). There is a growing
interest among patients, doctors and researchers in finding regimens
that do not require people to take two NRTIs. Since 1996, nearly
all regimens have included two nukes. However, findings over the
last several years have raised considerable concerns over the toxicity
of these drugs and many researchers believe people might fare better
without them. The combination of Sustiva plus Kaletra points the
way toward regimens that are highly potent and durable without using
NRTIs. We believe this kind of research will eventually lead to
widespread use of two-drug regimens and perhaps even single-drug
regimens that work as well as today’s three-drug combinations
but with less toxicity.
This study, along with others that are researching “induction
/ maintenance” approaches to therapy (starting with a higher
dose and three drugs then reducing the number of drugs), and the
imminent availability of drugs like integrase inhibitors, third
generation protease inhibitors, and entry inhibitors are collectively
on the verge of changing the entire paradigm of HIV treatment. We
believe this change will make taking therapy easier for people with
HIV and will produce more effective and longer lasting therapy.
