(AIDSmeds.com)—During a December 19 conference call with investors, Montreal-based Theratechnologies announced encouraging preliminary results from its Phase III clinical trial of TH9507, an experimental drug for the treatment of HIV-associated lipodystrophy. According to company officials, the growth hormone promoter was well tolerated and reduced visceral adipose tissue (VAT) by a modest 15% in those who received the drug for 26 weeks, compared to a 5% VAT increase among those receiving placebo.

To date, no treatments have been approved for the management of VAT increases – a buildup of fat around the gut, deep within the body – seen in many HIV-positive people. However, studies have shown that administration of recombinant human growth hormone (rhGH) reduces VAT – an average 20% drop in VAT after 12 weeks was seen in one recent study – and may also have a therapeutic effect on lipid levels.

Unfortunately, rhGH therapy is associated with some notable side effects, including fluid retention and an increased risk of blood glucose elevations.

Theratechnologies has been experimenting with the use of a synthetic growth hormone release factor (GRF) dubbed TH9507. It acts on pituitary cells in the brain, triggering growth hormone production and secretion. This more natural release of growth hormone by the pituitary gland, company researchers suggest, may result in treatment benefits similar to those seen in rhGH lipodystrophy studies, but with fewer side effects.

The preliminary data reported by Theratechnologies comes from one of two Phase III clinical trials planned by the company. The first study enrolled 412 U.S. and Canadian HIV-positive patients with evidence of lipodystrophy-associated VAT increases. Patients received either daily subcutaneous injections of TH9507 (2 mg) or placebo injections for 26 weeks.

The primary goal of the study was a reduction in VAT. Compared to pre-treatment measurements, patients treated with TH9507 saw their VAT decrease by 15% after 26 weeks. In the placebo group, there was an average 5% increase in VAT after 26 weeks. This 20% difference between the two groups was statistically significant, meaning that it wasn’t due to chance.

A central question surrounding the fat-busting effects of growth hormone therapy is the fact that it doesn’t differentiate between VAT and subcutaneous adipose tissue (SAT). Because many HIV-positive people with VAT increases also suffer from lipoatrophy, there has been some concern that the manipulation of growth hormone levels may worsen, or increase the risk of developing, fat loss in the face, arms, or legs. However, according to Theratechnologies, no significant changes in SAT or limb fat were observed in the TH9507 study.

The company also reported that cholesterol and triglyceride profiles among those receiving TH9507 improved during the 26-week treatment period. Details, however, were not provided.

As for safety, Theratechnologies reported that TH9507 was generally well tolerated by study participants. Encouragingly, there were no significant differences between the TH9507-treated group and the placebo group in terms of glucose elevations. No patients discontinued the study as a result of glucose problems.

Theratechnologies says that it will be releasing additional, more detailed data from this study through scientific meetings and journals in the coming months.

A second Phase III trial to confirm the results of the first trial is set to get underway in North America and Europe during the first quarter of 2007.

Source:

Theratechnologies, Inc .