Modified version of growth hormone that blocks its receptor. Used in acromegaly when surgery or somatostatin analogs are not enough.
Regulatory status
Approved (FDA / EMA)
Family
Growth hormone receptor antagonist
Scientific evidence
High
Number of findings
3
Where it acts
Hormones and metabolism
Also known as
Somavert, B2036-PEG
Regulatory status
FDA (US): Approved (2003, Somavert) for acromegaly with an inadequate response to surgery, radiotherapy, or other treatments.
EMA (EU): Approved (2002, Somavert) for acromegaly with an inadequate response to surgery, radiotherapy, or somatostatin analogs.
Dose
Loading dose of 40 mg subcutaneously; then 10 mg daily, adjusting in 5 mg steps according to IGF-1, up to a maximum of 30 mg daily (FDA Somavert label).
Safety
Elevated transaminases (monitor liver function), injection-site reactions, lipohypertrophy, flu-like symptoms. Tumor size must be monitored with MRI because the drug does not control it. May improve glucose and cause hypoglycemia in people with diabetes. Only with endocrinology follow-up.
Interactions
May require reducing insulin or other antidiabetic drugs because it increases insulin sensitivity. Opioids may require higher doses of pegvisomant.
Differences between women and men
Women need on average higher doses than men to normalize IGF-1 (about 19.2 versus 14.5 mg/day weight-adjusted, in 118 trial patients). View the study →
Effect by goal · level of evidence
IGF-1 normalization in acromegaly
improvesHighRCT (AA)in people
89% normalize IGF-1 (20 mg)
12-week RCT with 112 patients: IGF-1 normalized in 54%, 81%, and 89% with 10, 15, and 20 mg/day, versus 10% with placebo. Adverse effects were similar between groups.
Registry of 2,221 patients followed for a median of 7.4 years: IGF-1 was normal in 53.7% at one year and in 75.4% at 10 years. Tumor growth in 7.1% and abnormal transaminases in 3.2%.
It is a growth hormone with mutations and attached to polyethylene glycol. It binds to the receptor but does not activate it, so it blocks the action of the body's own growth hormone. The liver produces less IGF-1, which is responsible for most of the symptoms of acromegaly. It does not act on the tumor or lower growth hormone in the blood.
What the evidence says
In people
Normalization of IGF-1 in acromegaly. 12-week RCT with 112 patients: IGF-1 normalized in 54%, 81%, and 89% with 10, 15, and 20 mg/day, versus 10% with placebo. Adverse effects were similar between groups. PubMed 10770982
Long-term real-world experience (ACROSTUDY). Registry of 2,221 patients followed for a median of 7.4 years: IGF-1 was normal in 53.7% at one year and in 75.4% at 10 years. Tumor growth occurred in 7.1% and abnormal transaminases in 3.2%. PubMed 34342594
Women require higher doses. Analysis of 118 patients (69 men, 49 women): women needed on average 0.04 mg/kg more to normalize IGF-1. PubMed 17077131