Tibotec discontinues TMC125 study C227: phase III studies continue

On 29 November 2005, Tibotec issued a press release that announced the discontinuation of a single exploratory open-label phase II study of one TMC125, their NNRTI that is most developed. Phase III studies of TMC125, which are currently enrolling in highly treatment-experienced patients, have not been affected by this announcement.

The discontinued study, TMC125-C227, randomised PI-naive patients failing a first line NNRTI-containing regimen to receive either TMC125 or a PI, together with two RTIs.

After 12 weeks a difference in the proportion of patients achieving or maintaining an undetectable viral load (<50 copies/ml) in favor of the control group, indicted a sub-optimal virologic response of patients receiving TMC125. 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.

Tibotec researchers believed that it was in the best interest of trial participants, including those presently responding to TMC125 therapy, to be switched to a regimen based on approved antiretrovirals as soon as possible, in order to minimize the chances of compromising future treatment options.

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.


Until further analysis are performed and reported, or the exact details of this study are released, it is difficult to comment on this press release. We assume that the difference must have been significant for the study to have been closed.


Tibotec Press Release: Tibotec discontinues exploratory trial with TMC125: Phase III registration studies continue, (29 November, 2005).

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