Metabolic effects of a growth hormone-releasing factor in patients with HIV

This is the pivotal Phase III randomized controlled trial that earned tesamorelin its FDA approval and remains the single most-cited human study of a growth-hormone-releasing factor analog for body composition. Investigators randomized 412 patients with HIV-associated abdominal fat accumulation (86% male, on stable antiretroviral therapy) to receive 2 mg of tesamorelin or matching placebo by daily subcutaneous injection for 26 weeks. The primary endpoint was change in visceral adipose tissue measured by CT. At week 26, visceral adipose tissue decreased by 15.2% in the tesamorelin group versus a 5.0% increase in placebo (p<0.001). Triglycerides fell by ~50 mg/dL on tesamorelin and rose by ~9 mg/dL on placebo. IGF-1 increased by ~81% in the treatment group, consistent with the GHRH-axis mechanism, while glycemic measures showed no significant change over the trial period. The most common adverse events were mild injection-site reactions and arthralgia. The result framed tesamorelin as a uniquely visceral-fat-selective intervention rather than a general body-composition tool.

The studied population is narrow — adults with HIV-associated lipodystrophy on antiretroviral therapy — and that is the only indication the FDA approved. Generalizability to non-HIV populations seeking visceral-fat reduction or general body recomposition is not established by this trial; subsequent academic studies in non-HIV populations are smaller and less controlled. The primary endpoint is an imaging measure rather than a hard cardiovascular outcome, and follow-up was 26 weeks. Visceral-fat reduction reverses on discontinuation in extension data, which means the trial does not establish durable benefit off-treatment. The conflict-of-interest disclosures include sponsorship by Theratechnologies, the manufacturer; while this is standard for industry-funded pivotal trials, readers should weigh it alongside the primary-endpoint robustness rather than ignore it.