FDA approves tesamorelin for reduction of central fat accumulation

On November 10, 2010, the Food and Drug Administration approved tesamorelin (Egrifta) to treat HIV patients with lipodystrophy, a condition in which excess fat develops in different areas of the body, most notably around the liver, stomach, and other abdominal organs (visceral body fat). Tesamorelin was approved to induce and maintain a reduction of excess visceral abdominal fat in HIV-infected patients with lipodystrophy.

Tesamorelin is the first FDA-approved treatment for lipodystrophy, and is a synthetic growth hormone releasing factor (GRF) that is administered in a once-daily injection.

Excess visceral fat accumulation may contribute to other health problems as well as reducing quality of life. The short-term results from the tesamorelin studies did not address the risk of cardiovascular disease.

Tesamorelin was evaluated in two clinical trials involving 816 HIV-positive adult men and women with lipodystrophy and excess abdominal fat. Of these, 543 patients received tesamorelin during a 26-week, placebo-controlled period. In both studies, patients treated with tesamorelin experienced greater reductions in abdominal fat (1517%) measured by CT scan, compared with patients receiving placebo injections.

The most commonly reported side effects in the studies included joint pain (arthralgia), skin redness and rash at the injection site (erythema and pruritis), stomach pain, swelling, and muscle pain (myalgia). Worsening blood sugar control occurred more often in patients treated with tesamorelin than with placebo.

Tesamorelin was developed by a Theratechnologies Inc and marketed in the US by EMD Serono.

comment

Although tesamorelin is now approved in the US, is has not been submitted to the European Medicine Agency (EMA).

The regulatory study design mandated that all patients discontinued treatment at the end of the 52-week study, with most patients using tesamorelin for only 26 weeks (either in the first or second half of the cross-over study). Patients who switched to the placebo injections in the second half of the study generally saw visceral fat return within a few months.

The decision to discontinue treatment, rather than switching to study exploratory maintenance doses, means that the FDA have approved a treatment that needs to be continued, but which only has 52-week safety data.

However, approval is conditional on further safety studies to be completed by 2015 that will assess longer-term efficacy and safety data.

Finally, as we went to press, a price for tesamorelin had not been set. With marketing by Serono (who also market recombinant Human Growth Hormone) it may not be an easily affordable option for most people.

Therapeutics have still not committed to providing compassionate access to tesamorelin for European patients who participated in these approval studies and who have seen optimistic results from treatment reverse back to baseline levels.