Active Substance: pegvisomant
Common Name: pegvisomant
ATC Code: H01AX01
Marketing Authorisation Holder: Pfizer Limited
Active Substance: pegvisomant
Authorisation Date: 2002-11-13
Therapeutic Area: Acromegaly
Pharmacotherapeutic Group: Pituitary and hypothalamic hormones and analogues
Treatment of adult patients with acromegaly who have had an inadequate response to surgery and/or radiation therapy and in whom an appropriate medical treatment with somatostatin analogues did not normalize IGF-I concentrations or was not tolerate.
What is Somavert?
Somavert is a powder and solvent that are mixed together to make up a solution for injection. It contains the active substance pegvisomant (10, 15, 20, 25 and 30 mg).
What is Somavert used for?
Somavert is used to treat adults with acromegaly (a rare hormonal disorder that usually occurs in middle-aged adults, which is caused by the pituitary gland producing excess growth hormone).
Somavert is used in patients who did not respond well to surgery and/or radiation therapy, and to treatment with somatostatin analogues (another type of medicine used in acromegaly).
The medicine can only be obtained with a prescription.
How is Somavert used?
Treatment with Somavert should be initiated by a doctor who has experience in the treatment of acromegaly. Somavert is given by injection under the skin. The patient first receives a loading dose of 80 mg under medical supervision. Following this, Somavert is given as an injection under the skin of 10 mg once a day. The patient or caregiver can inject Somavert, after being trained by a doctor or a nurse. The doctor should check the response every four to six weeks and adjust the dose if needed. The maximum dose is 30 mg per day.
How does Somavert work?
Acromegaly occurs when the pituitary gland at the base of the brain makes too much growth hormone, generally because of a benign (non‑cancerous) tumour. Growth hormone promotes growth during childhood and adolescence. In acromegaly, this overproduction causes overgrowth of bone, swelling of soft tissue (such as the hands and feet), heart disease and other disorders. The active substance in Somavert, pegvisomant, is very similar to human growth hormone, but it has been designed so that it blocks the receptors to which growth hormone normally attaches itself. By blocking the receptors, Somavert prevents growth hormone from having an effect, thereby preventing the unwanted growth and other disorders seen in acromegaly.
How has Somavert been studied?
Somavert has been studied in 112 patients with acromegaly in a 12-week study. Three different doses of the medicine (10, 15 or 20 mg/day) were compared with placebo (a dummy treatment). The effectiveness was measured by comparing the levels of insulin-like growth factor‑I (IGF‑I) before and at the end of the study. IGF‑I is regulated by human growth hormone and causes growth in the body.
What benefit has Somavert shown during the studies?
Somavert lowered IGF-I levels at all of the doses tested. IGF-I was normal at the end of the study (week 12) in 38.5%, 75% and 82% of patients treated with 10, 15 or 20 mg/day Somavert, respectively, compared with 9.7% of the patients treated with placebo.
What is the risk associated with Somavert?
The most common side effects of Somavert during the clinical study were injection site reactions (seen in 11% of the patients), excessive sweating (7%), headache (6%) and asthenia (weakness, 6%). The majority of side effects were mild to moderate and of limited duration. Some patients who received Somavert developed anti-growth hormone antibodies (proteins that are produced in response to Somavert), but the clinical importance of this side effect is not known.
For the full list of all side effects and restrictions with Somavert, see the package leaflet.
Why has Somavert been approved?
The CHMP decided that the benefits of Somavert are greater than its risks and recommended that it be given marketing authorisation.
Other information about Somavert
The European Commission granted a marketing authorisation valid throughout the European Union for Somavert on 13 November 2002.
For more information about treatment with Somavert, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist.
Source: European Medicines Agency
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