PI Perspective #46

September 2008     View PDF     En español

TRIO study’s novel combination shows promise

by Paul Dalton

With well over 20 drugs from 6 classes available to treat HIV, there’s growing interest in using novel drug combinations. Studies of class-sparing regimens are particularly important. While many new drugs have been developed over the past decade, the basic model of HAART — 2 NRTIs plus a potent drug from another class — has remained largely unchallenged. Results from a study presented at the International AIDS Conference may provide a boost for people seeking to investigate different ways of using HIV drugs.

The TRIO study is following around 100 people with extensive HIV treatment experience who were given a novel drug combination: the integrase inhibitor Isentress (raltegravir), the NNRTI Intelence (etravirine) and the protease inhibitor Prezista (darunavir). To enroll, people had to be on a failing drug regimen, with HIV levels above 1,000 copies/mL. All participants had extensive HIV drug resistance and limited treatment options. None had ever taken the drugs used in the study.

After 24 weeks, around 90% of people in the study had HIV levels below 50 copies. Of the 10 who had detectable HIV levels, only 3 had viral loads above 400 copies. On average their CD4 counts increased by 99 cells.

As good as these results are, there are two important caveats. First, there’s no control group to draw comparisons to — which always weakens a study’s observations. Second, these are early results from a planned 96-week study, so it’s crucial to follow the study through to its conclusion.

Nonetheless these results hold promise. The drugs used in this study are among the newest developed. Most study to date of these drugs has been as part of traditional HAART regimens. This study suggests that at least these three HIV drugs (and possibly other) can be effectively combined in new ways.

A number of doctors have told Project Inform that they have been using this combination (sometimes called DUET-MRK after the DUET and BENCHMRK studies) in their clinics. While we support creative thinking and innovative approaches to HIV treatment, we also know that there’s no substitute for solid scientific evaluation.