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 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 or 20 mg/ml).
What is Somavert used for?
Somavert is used to treat patients 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 or radiation therapy, or to treatment with somatostatin analogues (another type of medicine used in acromegaly).
Because the number of patients with acromegaly is low, the disease is considered ‘rare’, and SOMAVERT was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 14 February 2001.
The medicine can only be obtained with a prescription.
How is Somavert used?
Somavert treatment should be initiated by a doctor who has experience in the treatment of acromegaly. Somavert is given by subcutaneous injection (under the skin). The patient first receives a loading dose of 80 mg under medical supervision. Following this, Somavert is given as a subcutaneous injection of 10 mg once a day. The patient or caregiver can inject Somavert, after training 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 happens because 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 fixes itself. By blocking the receptors, it prevents growth hormone from having an effect. This helps Somavert prevent the unwanted growth and other disorders seen in acromegaly. Pegvisomant is produced by a method known as ‘recombinant DNA technology’: it is made by a bacterium that has received a gene (DNA) that makes it able to produce the substance.
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), sweating (7%), headache (6%) and asthenia (loss of strength and energy, 6%). Some patients who received Somavert developed anti-growth hormone antibodies (proteins that are produced in response to Somavert). For the full list of all side effects reported with Somavert, see the Package Leaflet.
Somavert should not be used in people who may be hypersensitive (allergic) to pegvisomant or any of the other ingredients. Diabetic patients using the medicine have a risk of hypoglycaemia (low blood sugar), and their antidiabetes treatment may need to be adjusted.
Why has Somavert been approved?
The Committee for Medicinal products for Human Use (CHMP) decided that Somavert's benefits are greater than its risks for the treatment of 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 normalise IGF-I concentrations or was not tolerated. The Committee recommended that Somavert be given marketing authorisation.
Other information about Somavert:
The European Commission granted a marketing authorisation valid throughout the European Union for Somavert to Pfizer Limited on 13 November 2002. The marketing authorisation was renewed on 13 November 2007.
Source: European Medicines Agency
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