Tibotec Discontinues Exploratory Trial With TMC125

Phase III Registration Studies Continue

01-Dec-2005

Tibotec Pharmaceuticals Ltd. announced the discontinuation of a single exploratory open-label phase II study involving TMC125, a non-nucleoside reverse transcriptase inhibitor (NNRTI). Discontinuation of this study has no impact on the phase III registration studies of TMC125, which are currently enrolling in highly treatment-experienced patients. The trial design, the patient population, the formulation of TMC125 and the background regimen of these trials are substantially different from that of the discontinued study.

The discontinued study, TMC125-C227, involved protease inhibitor (PI)-naive patients failing a first line non-nucleoside reverse transcriptase inhibitor (NNRTI)-containing regimen. Patients were randomized to receive either TMC125 or a protease inhibitor and the background regimen was limited to two nucleoside reverse transcriptase inhibitors (NRTIs).

Data collected after 12 weeks of therapy show that there is a difference in the proportion of patients achieving or maintaining an undetectable viral load in favor of the control group, which received PI-based therapy. In contrast to data recently presented at the European AIDS Conference (EACS) in Dublin, the virologic response of some patients receiving TMC125 was suboptimal. In this trial, undetectable viral load is defined as less than 50 copies/ml. No safety concerns were identified. The company decided to stop the trial based on these data; the study's Data Safety Monitoring Board endorsed that decision.

Further analyses will be conducted to investigate potential explanations for and causes of the lower response in patients receiving TMC125 in this study, including resistance at baseline, activity of the supporting dual nucleoside analogue backbone, and plasma levels of TMC125.

To minimize the chances of compromising future treatment options, Tibotec researchers believe that it is in the best interest of patients involved in the study, including those presently responding to TMC125 therapy, to be switched to a regimen based on approved antiretrovirals as soon as possible. The Company will be providing patients, investigators, ethics committees and regulatory authorities with currently available information.

Given the antiviral activity demonstrated with TMC125 thus far in studies involving patients with NNRTI-resistant virus, Tibotec researchers are confident in the design and conduct of the phase III trials, TMC125-C206 and TMC125-C216 (DUET 1 and DUET 2), which are currently enrolling patients.

https://www.bionity.com/en/news/50587/tibotec-discontinues-exploratory-trial-with-tmc125.html