March 10, 2011
From CROI, March 2011: In 2010, tesamorelin (Egrifta) was approved by the FDA for reducing excess gut fat in HIV-positive people. The drug is a human growth hormone releasing factor — a compound that encourages the pituitary gland to secrete growth hormone, which can reduce the visceral fat that lies around internal organs beneath the abdominal muscles. In a 52-week study that led to FDA approval, tesamorelin — which is injected into the stomach once a day — was shown to reduce visceral gut fat by 18%.
In another analysis from this study reported at CROI, 412 people on HIV treatment were followed for 26 weeks: 275 on tesamorelin and 137 on placebo. Participants averaged 48 years of age, and 85% were male. The researchers used one blood marker called osteocalcin to measure bone formation (increase of bone cells) and another called N to terminal telopeptide to measure bone resorption (decrease of bone cells).
These blood marker levels did not differ between the two groups at the start of the study. However, by week 26, the levels of both markers increased significantly in people on tesamorelin. The increased rate was higher in bone formation than what it was for bone resorption, which may mean that bone tissue may have increased for these individuals.
Although this is a prospective study, it only covered 26 weeks. Longer-term data may be forthcoming since the original tesamorelin study lasted 52 weeks. Also, this analysis was confined to using only blood markers for bone mass. Other bone measurement tools like DEXA scan were not used, which may shed light on the accuracy of these findings. More study needs to be done.
RESEARCH STUDY:
Effects of Tesamorelin, a Growth Hormone-releasing Factor Analogue, on Bone Turnover Markers in HIV+ Patients with Excess Abdominal Fat. Mamputu JC, et al. Poster #834.