Indevus Pharmaceuticals Inc. said an independent data monitoring committee recommended the closure of the high-dose arm in the late-stage trial of PRO 2000, its experimental vaginal microbicide gel for HIV prevention.

The committee review found that there is no more than a small chance of the high dose showing protection against HIV infection compared to the placebo gel.

The committee, however, recommended that the low-dose arm continue to be tested for safety and effectiveness in the trial.

United Kingdom's Medical Research Council, which is sponsoring the trial, has decided to continue testing the low dose arm of PRO 2000, the company said in a statement.

The trial is being conducted in South Africa, Tanzania, Uganda and Zambia by the Microbicides Development Programme, an international partnership of researchers.

The trial is expected to be completed in late 2009, the specialty pharmaceutical company added.

Indevus shares closed at $6.13 Thursday on Nasdaq.