Pharmacia's Somavert works in acromegaly

The growth hormone receptor antagonist Somavert (pegvisomant),originally developed by Sensus Drug Development which was acquired by Pharmacia earlier this year, has been shown to normalize concentrations of insulin-like growth factor-1 in 97% of patients with acromegaly, a debilitating and potentially life-threatening disorder also known as gigantism, according to a report in The Lancet (November 24). Pharmacia has filed for approval of Somavert in the USA and Europe.

Acromegaly is caused by prolonged overproduction of growth hormone by the pituitary gland, and is most commonly the result of a benign tumor affecting the gland. Overproduction of GH raises endogenous levels of IGF-1, which is used to measure the activity of the disease as its levels tend to be more stable that those of GH. As a result of this excess GH secretion, the skeleton, soft tissues and organs become enlarged, while the most serious health consequences are diabetes, hypertension and an elevated risk of cardiovascular disease.

Current treatment options include surgery and radiotherapy, as well as drug therapy with dopamine agonists such as bromocriptine and somatostatin analogs (eg octreotide). Both these drug classes can reduce GH levels, but while the former is orally-active it carries a significant side-effect burden and rarely normalizes IGF-1 levels, while the latter requires injections every eight hours. In contrast, Somavert, a GH analogue, requires once-daily injections and has shown an unprecedented activity in reducing IGF-1.