Mecasermin
Mecasermin is the active substance in Increlex. The EU has authorised Increlex to treat growth failure in patients aged 2 to 18 years with severe primary IGF-1 deficiency (current EMA product information; checked 2026-08-26). NCT00125164 enrolled 137 people. Ipsen sponsored the Phase 3 trial. At one year, mean height velocity was 7.7 cm/year in 49 people in one assigned treatment group. It was 6.9 cm/year in 42 people in the other analyzed treatment group. The 22 people who had no treatment averaged 5.2 cm/year.
What exactly is Mecasermin?
Mecasermin is recombinant human insulin-like growth factor 1. Increlex is the authorised medicine name.
| Identity field | Verified value, checked 2026-08-26 |
|---|---|
| Register name | Mecasermin |
| Register aliases | Increlex; Mekasermin; Insulin-like Growth Factor-1 |
| Register class | Recombinant human insulin-like growth factor 1 (rhIGF-1) |
| GSRS substance class | Protein |
| GSRS sequence length | 70 residues |
| Molecular formula | C331H517N94O101S7 |
| Sequence molecular weight | 7,651.7 Da |
| UNII | 7GR9I2683O, checked 2026-08-26 |
| Register CAS field | Not stored |
| CAS values in the GSRS record | 68562-41-4 is primary; 67763-96-6 is generic-family |
| Current U.S. application | BLA 021839, checked 2026-08-26 |
The register has no CAS field for this entry. GSRS lists two types of CAS value for it. GSRS stores Mecasermin rinfabate under the separate UNII NZ8M50KKRG. It is not an alias in this entry.
What did human studies measure?
| Primary record | Human sample | Measured finding | Funding and limit |
|---|---|---|---|
| NCT00125164 | The trial enrolled 137 people. The primary outcome used 22 untreated people. It used 42 people in one treatment group. It used 49 in the other. | Mean one-year height velocity was 5.2 cm/year untreated, 6.9 cm/year in one mecasermin group, and 7.7 cm/year in the other. The lower-result treatment group's adjusted difference from untreated was 1.79 cm/year (95% CI 1.19 to 2.39; p<0.0001). The higher-result treatment group's adjusted difference was 2.58 cm/year (95% CI 1.99 to 3.16; p<0.0001). Across all three treated groups, hypoglycaemia affected 14 of 111 participants. It affected 1 of 25 untreated participants. One treated participant had a hypoglycaemic seizure. | Ipsen is the industry lead sponsor. This was a randomized, open-label, observation-controlled Phase 3 trial. One treatment arm was excluded from the primary efficacy calculation after a protocol dose change. Checked 2026-08-26. |
| PMID 17192294 | 76 children treated for up to 12 years | Mean height velocity rose from 2.8 cm/year before treatment to 8.0 cm/year in year 1. It remained above baseline for up to 8 years. Hypoglycaemia was reported by 49%. Injection-site lipohypertrophy was reported by 32%. Tonsillar or adenoidal hypertrophy was reported by 22%. | PubMed lists two NCRR NIH grants. Crossref lists no funder. One author was affiliated with Tercica. The design was predominantly open-label. Checked 2026-08-26. |
| PMID 40626687 | 102 registry patients who reached near-adult height | Mean height standard-deviation-score gain was 0.9 overall. It was 1.4 in treatment-naive prepubertal patients. Almost half of that prepubertal subgroup reached near-adult height within the normal range. | Ipsen funded the paper. This analysis includes only registry patients who reached near-adult height by the cutoff. Checked 2026-08-26. |
What does the current EU product information record?
The current EMA file groups five studies (checked 2026-08-26). Ninety-two children with severe primary IGF-1 deficiency took Increlex. The efficacy review used data from 81 of them.
Mean height velocity rose from 2.6 cm/year before treatment to 8.0 cm/year in year 1. The year-8 mean was 4.4 cm/year in 19 patients. No one died in those studies. No one left a study due to an adverse event.
The same EMA file gives safety data for 413 trial patients with IGF-1 deficiency.
| Event in the current EMA product information | Reported frequency, checked 2026-08-26 |
|---|---|
| Headache | 44% |
| Hypoglycaemia | 28% |
| Vomiting | 26% |
| Injection-site hypertrophy | 17% |
| Otitis media | 17% |
| Intracranial hypertension or increased intracranial pressure | 4 of 413 patients |
The EMA file also records post-marketing reports of benign and malignant neoplasms in treated children and teens.
The EMA file does not name a trial funder for the pooled studies.
How strong is the evidence?
Evidence tier A reflects an authorised medicine with Phase 3 human results (checked 2026-08-26).
The EU granted the authorisation under exceptional circumstances. The condition is rare, so complete information could not be obtained. The EMA reviews new information each year.
What do current United States product records show?
| Current source checked August 26, 2026 | Result | Boundary |
|---|---|---|
DailyMed exact Mecasermin search | Two Increlex labels name mecasermin. A third match names mecasermin rinfabate. | DailyMed listing result only |
| openFDA Drugs@FDA | BLA 021839; Increlex; active ingredient MECASERMIN RECOMBINANT; prescription product | United States record only |
What do the EU and country fields show?
| Field | Current primary record |
|---|---|
Central EU status: authorised | The current EMA file lists Increlex under EMEA/H/C/000704. Its status is Authorised. Its active substance is Mecasermin. Its therapeutic area is Laron Syndrome. Its ATC code is H01AC03. Its marketing-authorisation holder is Esteve Pharmaceuticals, S.A. Checked 2026-08-26. |
Germany: doping_classified | The current German source names Mecasermin directly. It gives Insulin-like Growth Factor-1 as a synonym. This field is separate from the medicine's authorisation. Checked 2026-08-26. |
Sweden: authorised | The current product file lists INCRELEX. Its ATC code is H01AC03. Its active substance is mekasermin. Its status is Godkänd. Its sales status is Finns till försäljning. Its holder is Esteve Pharmaceuticals S.A. Its EU number is EU/1/07/402. The English spelling mecasermin returns zero in that file. Checked 2026-08-26. |
Authorization, evidence tier, and German classification answer different questions.
Is there a first submitted-product observation?
The register stores first_observed: null (checked 2026-08-26).
The register claims no date for a submitted vial. This empty field does not change the medicine status.