TMC125 Showed Significant Virologic Response at Week 24 in Treatment-Experienced HIV Patients with NNRTI Resistance in Phase 3 Trials

Yardley, PA - Data from two ongoing Phase 3 studies (DUET-1 and DUET-2) showed significantly more HIV-1 adult patients with documented non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI) resistance reached an undetectable viral load (defined as achieving confirmed undetectable level 50 HIV-1 RNA copies/mL) with TMC125 (etravirine), Tibotec’s investigational next-generation NNRTI, plus background regimen compared to placebo plus background regimen at week 24. These findings were published in the July 7, 2007, issue of The Lancet.

TMC125 is the first NNRTI to show significant antiviral activity in patients with documented NNRTI resistance. Tibotec, Inc. plans to file these findings with the Food and Drug Administration as part of a New Drug Application.

DUET-1 and DUET-2 examined the use of TMC125 in combination with other anti-retroviral medications in treatment-experienced adult HIV-1 patients with documented resistance to NNRTIs and protease inhibitors. These data will be presented at the 4th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2007), in Sydney, Australia, on July 25, 2007.

A total of 612 patients were randomized and treated in DUET-1 – 304 in the TMC125 plus background regimen (BR) group and 308 in the placebo plus BR group. In DUET-2, a total of 591 patients were randomized and treated – 295 in the TMC125 plus BR group and 296 in the placebo plus BR group. For all patients, the background regimen included 600 mg darunavir, co-administered with 100 mg ritonavir, twice-daily, plus investigator-selected nucleoside reverse transcriptase inhibitors (NRTIs) and optional use of enfuvirtide.

Results from the DUET-1 study showed that significantly more patients (56 percent; n=170) in the TMC125 arm achieved a confirmed undetectable viral load (less than 50 copies/mL), compared with those in the placebo arm (39 percent; n=119) [p=0.005]. Similarly, in DUET-2, significantly more patients (62 percent; n=183) in the TMC125 arm achieved a confirmed undetectable viral load compared with those in the placebo arm (44 percent; n=129) [p=0.0003].

“The NNRTI class has been one of the cornerstones of antiretroviral therapy for more than a decade. However, NNRTI resistance limits the use of this class in treatment-experienced patients,” said Tony Mills, MD, HIV specialist in private practice, Los Angeles, and Assistant Professor of Clinical Medicine, UCLA. “The results that we saw in DUET-1 and -2 in patients with documented NNRTI resistance are very exciting and suggest that in the future, we may have the ability to sequence NNRTIs in HIV treatment.”

24-Week Safety Findings

In DUET-1, the most commonly reported adverse events (=10%), regardless of causality, among patients in the TMC125 arm vs. placebo arm were rash (20 percent vs. 10 percent), nausea (14 percent vs. 12 percent), diarrhea (12 percent vs. 20 percent), headache (10 percent vs. 13 percent), nervous system disorders including headache, somnolence, dizziness, and memory impairment (15 percent vs. 20 percent), and psychiatric disorders including insomnia, anxiety, depression and nightmare (10 percent vs. 14 percent). In the TMC125 arm, 42 patients discontinued treatment for any reason vs. 56 patients in the placebo arm.

In DUET-2, the most commonly reported adverse events (=10%), regardless of causality, among patients receiving TMC125 vs. placebo were rash (14 percent vs. 9 percent), diarrhea (18 percent vs. 20 percent), nausea (14 percent vs. 10 percent), injection site reaction (13 percent vs. 15 percent), headache (9 percent vs. 11 percent), fatigue (9 percent vs. 10 percent), nervous system disorders (15 percent vs. 17 percent) and psychiatric disorders (16 percent vs. 17 percent). In the TMC125 arm, 51 patients discontinued treatment for any reason vs. 73 in the placebo arm.

Most of the rashes seen with TMC125 were mild to moderate in severity, occurred within the first few weeks of treatment and resolved with continued TMC125 treatment. Grade 3 or 4 rash occurred in 1 percent of patients in the TMC125 arm and no patients in the placebo arm.

DUET-1 and -2 Study Design

The DUET studies are double-blind, placebo-controlled, international Phase 3 trials designed to assess the efficacy and safety of TMC125 in treatment-experienced adult HIV-1 patients with documented evidence of NNRTI and PI resistance. Participants were randomized to receive TMC125 200 mg twice daily or placebo, each given in addition to a background regimen (BR).

In both studies, patient randomization was stratified for enfuvirtide use in the background regimen (no use, re-use, or first time use), previous darunavir use (used or not), and screening plasma viral load.

Patients with HIV-1 who were eligible for the DUET trials had a viral load of greater than 5,000 copies/mL, were on a stable antiretroviral therapy regimen, and had evidence of at least one NNRTI-resistance-associated mutation, either at screening or from historical resistance tests as well as evidence of three or more primary PI mutations at screening.

TMC125 Expanded Access Program

The expanded access program (EAP) for TMC125 is now open in a number of European countries, Canada and the United States. TMC125 is available to HIV-1 infected adults, at least 18 years old, who have limited treatment options either due to virological failure or intolerance to multiple ARV regimens. Patients must be three-class experienced, having received licensed treatment from each of the three major oral classes of anti-HIV drugs (NRTIs, NNRTIs, and PIs), unable to use currently approved NNRTIs due to resistance and/or intolerance and have received at least two PI-based regimens.

For more about the program, healthcare professionals and people living with HIV/AIDS may obtain information by visiting www.clinicaltrials.gov.