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Mec3.5
Mecasermin (IGF-1) Research
Mostly mechanism / observationalLimited safety
6 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most Mecasermin (IGF-1) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality studies published 1999–2023 with a typical study size of 76 participants.
Based on 6 studies · 349 total participants
Confidence
Low
By outcome
Growth & anabolism
Mostly mechanism / observational6 studies
Glucose & insulin-like activity
Mostly mechanism / observational5 studies
Safety profile
Mostly mechanism / observational3 studies
Active research area
2 studies in the last 5 years
199920112023
1Open-Labeln=76 · small study2007
Height velocity increased from 2.8 cm/yr on average at baseline to 8.0 cm/yr during the first year of treatment (P < 0.0001)... The most common adverse event was hypoglycemia... reported by 49% of treated subjects.
Pivotal long-term trial: 76 children with severe IGF-1 deficiency due to GH insensitivity treated with rhIGF-I (mecasermin) 60–120 µg/kg twice daily for up to 12 years
First-year height velocity roughly tripled (2.8 → 8.0 cm/yr), dose-dependently — the trial-proven benefit in the approved indication
Hypoglycemia was the most common adverse event (49% of subjects); injection-site lipohypertrophy (32%) and tonsillar/adenoidal hypertrophy (22%) followed
The observed mean gain in height was 13.4 cm more than had been expected without treatment... Long-term therapy with IGF-I improves adult height of patients with severe IGFD. Most patients did not bring their heights into the normal adult range.
In most NPP children with SPIGFD, with or without LS, rhIGF1 therapy promotes linear growth... Treatment-emergent AEs were experienced by 65.3% of patients; hypoglycaemia was most common.
Bang P, Woelfle J, Perrot V, Sert C, Polak M. · Eur J Endocrinol (2021)
Large real-world registry (European Increlex Growth Forum Database, n=242) of rhIGF-1 (mecasermin) in severe primary IGF-1 deficiency, including Laron syndrome
Confirmed linear-growth benefit across patients with and without Laron syndrome; younger age at baseline predicted better response
Treatment-emergent adverse events affected 65.3% of patients, with hypoglycaemia the most common — reinforcing the hypoglycemia signal at scale
In practice, the limited clinical benefits of mecasermin do not justify exposure to its potential risks.
Prescrire International (no authors listed). · Prescrire Int (2009)
Independent drug-bulletin appraisal — the best counter-evidence: judged that even in the approved indication the height benefit was modest (mean −6.7 SD at baseline improved only to −5.2 SD after 8 years; growth failure remained very severe)
Catalogues the main short-term harms: hypoglycaemia, headache, and intracranial hypertension; nearly 1 in 5 children developed tonsillar hypertrophy causing otitis and hearing loss
Flags animal findings of organ hypertrophy (kidney, spleen, heart) and carcinogenic effects, with the human risk unknown
5Pilotn=10 · very small study1999
Leg protein balance improved with rhIGF-1/IGFBP-3, which was associated with an increase in muscle protein fractional synthetic rate... All patients were euglycemic without electrolyte imbalances.
Debroy MA, Wolf SE, Zhang XJ, Chinkes DL, Ferrando AA, Wolfe RR, Herndon DN. · J Trauma (1999)
Closest thing to a 'muscle' study: a 5-day rhIGF-1/IGFBP-3 infusion in 10 severely burned adults improved leg muscle protein balance and fractional synthetic rate
The anabolic signal was real — and notably occurred WITHOUT glucose abnormalities in this monitored setting
Critical caveat: this is a small, short study in a catabolic clinical state (severe burns), not muscle building in healthy adults
rhIGF-1 was shown to efficiently induce development of Laron patients achieving at least proper rate of growth (compared to healthy group) in 80% of subjects.
Grubczak K, Stożek K, Starosz A, Bossowski F, Pasławska M, Bossowski A, Moniuszko M. · Stem Cell Rev Rep (2023)
Mechanistic human study tracking very-small-embryonic-like (VSEL) and hematopoietic stem cells over 4–5 years of mecasermin therapy in IGF-1-deficient children
IGF-1-deficient patients had initially elevated stem-cell populations that gradually normalized with rhIGF-1 therapy, correlating with SDF-1 and growth parameters
Reconfirms the growth efficacy (≥80% reaching proper growth rate) while probing IGF-1's broader proliferative/developmental biology