Approved & therapeutic
Mecasermin
Increlex
Mecasermin is recombinant human insulin-like growth factor 1, approved for growth failure in children aged 2 years and older with severe primary IGF-1 deficiency, or with growth hormone gene deletion who have developed neutralising antibodies to growth hormone. Severe primary IGF-1 deficiency is defined on the label as height standard deviation score at or below -3.0, basal IGF-1 standard deviation score at or below -3.0, and normal or elevated growth hormone. It replaces IGF-1 directly rather than acting through growth hormone, and it is not a substitute for growth hormone in approved growth hormone indications or for secondary forms of IGF-1 deficiency.
- Status
- Mecasermin is approved by the U.S. FDA and has official prescribing information.
- Evidence
- Approved labeling. Official prescribing information exists, based on clinical trials in people.
- Half-life
- Mean terminal half-life approximately 5.8 hours after a single subcutaneous dose in subjects with severe primary IGF-1 deficiency (label pharmacokinetics; terminal half-life derived from 3 subjects aged 12 to 22 years). No healthy-subject half-life is given in the label.
- How it's taken
- Subcutaneous injection only. Do not administer intravenously. Rotate injection sites between upper arm, thigh, buttock and abdomen to help prevent lipohypertrophy.
- Mechanism
- Anabolic (IGF-1 / myostatin)
- Pathways
- IGF-1, GH axis, Insulin Signalling
How Mecasermin works
Mecasermin is structurally identical to endogenous insulin-like growth factor 1 and activates the type 1 IGF-1 receptor in target tissues, stimulating the signalling that drives statural growth. Because it bypasses the growth hormone receptor, it works in children whose growth hormone signalling is absent or blocked. Its structural similarity to insulin also gives it insulin-like hypoglycemic effects.
What research has looked at
- In the pooled registration analysis of five studies (four open-label and one double-blind placebo-controlled) in 71 pediatric patients with severe primary IGF-1 deficiency, mean height velocity rose from 2.8 cm/yr before treatment to 8.0 cm/yr in year 1 (p<0.0001). Comparisons were paired against each subject's own pre-treatment height velocity rather than a concurrent control group.
- Height gains continued but attenuated with time: the mean increase in height velocity over pre-treatment was +5.2 cm/yr in year 1, +2.3 in year 3, +1.5 in year 4, and was no longer statistically significant by year 7 (+1.0 cm/yr, p=0.0897) or year 8 (+0.7 cm/yr, p=0.3059).
- Mean height standard deviation score improved by roughly 1.4 to 1.5 points over up to 8 years of treatment, though treated patients remained profoundly short (mean height standard deviation score about -5.2 at year 8, from -6.7 at baseline). Bone age advanced slightly faster than chronological age over the treatment period, which is relevant to final adult height.
Evidence level: Approved labeling. Official prescribing information exists, based on clinical trials in people. These are areas studied or reported, not promised effects.
Reported side effects and risks
- Severe hypoglycemia leading to hypoglycemic seizures has been observed. Hypoglycemia was reported by 42 percent of trial subjects, 5 had severe episodes requiring assistance, and 4 had hypoglycemic seizures or loss of consciousness; frequency was highest in the first month and in younger children. The drug has insulin-like effects and must be given within about 20 minutes before or after a meal or snack. The dose must be withheld if the patient is unable to eat, must never be increased to make up for an omitted dose, and high-risk activities such as driving or exercise should be avoided for 2 to 3 hours after dosing, particularly at initiation. Preprandial glucose monitoring is recommended at initiation and until a well-tolerated dose is established.
- Contraindicated in pediatric patients with malignant neoplasia or a history of malignancy, in patients with closed epiphyses, and in known hypersensitivity to mecasermin or any inactive ingredient. Postmarketing reports of malignant neoplasms have occurred, mostly in patients with rare genetic short-stature conditions carrying increased cancer risk, and more frequently at higher-than-recommended doses or doses producing IGF-1 above the normal range for age and sex; therapy is discontinued if malignant neoplasia develops.
- Hypersensitivity and allergic reactions ranging from injection-site reactions to systemic reactions including anaphylaxis requiring hospitalisation; postmarketing frequency of anaphylaxis-indicative cases is estimated at about 0.3 percent. Treatment is interrupted and urgent medical attention sought if a systemic allergic reaction occurs.
- Intracranial hypertension with papilledema, visual changes, headache, nausea and vomiting; signs resolved after interruption of dosing. Funduscopic examination is recommended at initiation and periodically during therapy.
- Lymphoid tissue hypertrophy, including tonsillar and adenoidal hypertrophy, which can cause snoring, sleep apnea or chronic middle-ear effusion. Tonsillar hypertrophy occurred in 15 percent of trial subjects and 7 of 71 underwent tonsillectomy or tonsilloadenoidectomy. Periodic examination is recommended.
- Slipped capital femoral epiphysis, which may lead to osteonecrosis, can occur with rapid growth. Any child developing a limp or hip or knee pain during therapy must be evaluated for it. Progression of preexisting scoliosis may also occur and should be monitored.
- Contains benzyl alcohol as a preservative, which has been associated with serious and fatal adverse reactions including gasping syndrome in neonates and infants; use in infants is not recommended.
- Other reactions reported in 5 percent or more of trial subjects include injection-site lipohypertrophy and bruising, otitis media and serous otitis media, snoring, headache, dizziness, convulsions, vomiting, hypoacusis and middle-ear fluid, cardiac murmur, arthralgia and limb pain, and thymus hypertrophy. Rapid early increases in renal and splenic length, echocardiographic cardiomegaly or valvulopathy without symptoms, facial soft-tissue thickening, and elevations in AST, LDH, cholesterol and triglycerides were also observed; causality is uncertain given the absence of a control group.
- Efficacy in the growth hormone gene deletion and neutralising-antibody population is effectively extrapolated: of the 61 subjects with at least one year of treatment, 7 had growth hormone gene deletion and 1 had neutralising antibodies to growth hormone, and no separate subgroup analysis is reported. The current label carries no boxed warning.
Sources
- PubMed research on Mecasermin · NIH · National Library of Medicine
- DrugBank record for Mecasermin · DrugBank
- Active clinical trials for Mecasermin · U.S. National Library of Medicine
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Mecasermin FAQ
What is Mecasermin?
Mecasermin is recombinant human insulin-like growth factor 1, approved for growth failure in children aged 2 years and older with severe primary IGF-1 deficiency, or with growth hormone gene deletion who have developed neutralising antibodies to growth hormone. Severe primary IGF-1 deficiency is defined on the label as height standard deviation score at or below -3.0, basal IGF-1 standard deviation score at or below -3.0, and normal or elevated growth hormone. It replaces IGF-1 directly rather than acting through growth hormone, and it is not a substitute for growth hormone in approved growth hormone indications or for secondary forms of IGF-1 deficiency.
How does Mecasermin work?
Mecasermin is structurally identical to endogenous insulin-like growth factor 1 and activates the type 1 IGF-1 receptor in target tissues, stimulating the signalling that drives statural growth. Because it bypasses the growth hormone receptor, it works in children whose growth hormone signalling is absent or blocked. Its structural similarity to insulin also gives it insulin-like hypoglycemic effects.
Is Mecasermin FDA approved?
Yes. Mecasermin is approved by the U.S. FDA and has official prescribing information. Evidence level: approved labeling. Official prescribing information exists, based on clinical trials in people.
What is the half-life of Mecasermin?
Reported half-life: Mean terminal half-life approximately 5.8 hours after a single subcutaneous dose in subjects with severe primary IGF-1 deficiency (label pharmacokinetics; terminal half-life derived from 3 subjects aged 12 to 22 years). No healthy-subject half-life is given in the label.
How is Mecasermin taken?
Subcutaneous injection only. Do not administer intravenously. Rotate injection sites between upper arm, thigh, buttock and abdomen to help prevent lipohypertrophy.
What side effects have been reported with Mecasermin?
Reported in the sources: Severe hypoglycemia leading to hypoglycemic seizures has been observed. Hypoglycemia was reported by 42 percent of trial subjects, 5 had severe episodes requiring assistance, and 4 had hypoglycemic seizures or loss of consciousness; frequency was highest in the first month and in younger children. The drug has insulin-like effects and must be given within about 20 minutes before or after a meal or snack. The dose must be withheld if the patient is unable to eat, must never be increased to make up for an omitted dose, and high-risk activities such as driving or exercise should be avoided for 2 to 3 hours after dosing, particularly at initiation. Preprandial glucose monitoring is recommended at initiation and until a well-tolerated dose is established; Contraindicated in pediatric patients with malignant neoplasia or a history of malignancy, in patients with closed epiphyses, and in known hypersensitivity to mecasermin or any inactive ingredient. Postmarketing reports of malignant neoplasms have occurred, mostly in patients with rare genetic short-stature conditions carrying increased cancer risk, and more frequently at higher-than-recommended doses or doses producing IGF-1 above the normal range for age and sex; therapy is discontinued if malignant neoplasia develops; Hypersensitivity and allergic reactions ranging from injection-site reactions to systemic reactions including anaphylaxis requiring hospitalisation; postmarketing frequency of anaphylaxis-indicative cases is estimated at about 0.3 percent. Treatment is interrupted and urgent medical attention sought if a systemic allergic reaction occurs; Intracranial hypertension with papilledema, visual changes, headache, nausea and vomiting; signs resolved after interruption of dosing. Funduscopic examination is recommended at initiation and periodically during therapy; Lymphoid tissue hypertrophy, including tonsillar and adenoidal hypertrophy, which can cause snoring, sleep apnea or chronic middle-ear effusion. Tonsillar hypertrophy occurred in 15 percent of trial subjects and 7 of 71 underwent tonsillectomy or tonsilloadenoidectomy. Periodic examination is recommended; Slipped capital femoral epiphysis, which may lead to osteonecrosis, can occur with rapid growth. Any child developing a limp or hip or knee pain during therapy must be evaluated for it. Progression of preexisting scoliosis may also occur and should be monitored; Contains benzyl alcohol as a preservative, which has been associated with serious and fatal adverse reactions including gasping syndrome in neonates and infants; use in infants is not recommended; Other reactions reported in 5 percent or more of trial subjects include injection-site lipohypertrophy and bruising, otitis media and serous otitis media, snoring, headache, dizziness, convulsions, vomiting, hypoacusis and middle-ear fluid, cardiac murmur, arthralgia and limb pain, and thymus hypertrophy. Rapid early increases in renal and splenic length, echocardiographic cardiomegaly or valvulopathy without symptoms, facial soft-tissue thickening, and elevations in AST, LDH, cholesterol and triglycerides were also observed; causality is uncertain given the absence of a control group; Efficacy in the growth hormone gene deletion and neutralising-antibody population is effectively extrapolated: of the 61 subjects with at least one year of treatment, 7 had growth hormone gene deletion and 1 had neutralising antibodies to growth hormone, and no separate subgroup analysis is reported. The current label carries no boxed warning.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.