Active Ingredient: Somapacitan
Somapacitan is indicated for the replacement of endogenous growth hormone (GH) in children aged 3 years and above, and adolescents with growth failure due to growth hormone deficiency (paediatric GHD), and in adults with growth hormone deficiency (adult GHD).
For this indication, competent medicine agencies globally authorize below treatments:
For:
Regimen A, in the case that patient age in years is < 60 :
Subcutaneous, 1.5 milligrams somapacitan, once weekly.
Regimen B, in the case that patient age in years is ≥ 60 :
Subcutaneous, 1 milligrams somapacitan, once weekly.
Regimen C, in the case that patient is female and there is estrogen receptor agonist :
Subcutaneous, 2 milligrams somapacitan, once weekly.
Table 1. Dose recommendation:
| Adult GHD | Recommended starting dose |
| Naïve patients Adults (≥18 to <60 years) Women on oral oestrogen therapy (irrespective of age) Elderly (60 years or older) | 1.5 mg/week 2 mg/week 1 mg/week |
| Patients switching from daily GH medicinal products Adults (≥18 to <60 years) Women on oral oestrogen therapy (irrespective of age) Elderly (60 years or older) | 2 mg/week 4 mg/week 1.5 mg/week |
The somapacitan dose must be individually adjusted for each patient. It is recommended to increase the dose gradually with 2-4 weeks intervals in steps from 0.5 mg to 1.5 mg based on the patients' clinical response and experience of adverse reactions up to a dose of 8 mg somapacitan per week. Serum insulin like growth factor-I (IGF-I) levels (drawn 3-4 days after dosing) can be used as guidance for the dose titration. The IGF-I standard deviation score (SDS) target should aim for the upper normal range not exceeding 2 SDS. IGF-I SDS levels in the target range are usually achieved within 8 weeks of dose titration. Longer dose titration may be necessary in some AGHD patients.
Generally, lower doses of somapacitan may be necessary in older patients.
Using IGF-I SDS as a biomarker for dose titration, the aim is to reach IGF-I SDS levels within the age-adjusted upper reference range (IGF-I SDS upper reference range: 0 and +2) within 12 months of titration. If this target range cannot be achieved within this period, or the patient does not obtain the desired clinical response, other treatment options should be considered.
During somapacitan maintenance treatment, evaluation of efficacy and safety should be considered at approximately 6- to 12-month intervals and may be assessed by evaluating biochemistry (IGF-I-, glucose-, and lipid levels), body composition, and body mass index.
Patients switching from a weekly growth hormone to somapacitan are recommended to continue administration at their once weekly dosing day.
Patients switching from daily human growth hormone to once-weekly somapacitan should choose the preferred day for the weekly dose and inject the final dose of daily treatment the day before (or at least 8 hours before) injecting the first dose of once-weekly somapacitan. Patients should follow the instructions for the dose presented in Table 1.
Females on oral oestrogen-containing therapy may have reduced IGF-I levels and may require dose adjustment of growth hormone to achieve the treatment goal. In paediatric GHD doses above 0.16 mg/kg/week have not been studied and are not recommended.
Patients who miss a dose are advised to inject once-weekly somapacitan upon discovery as soon as possible, within 3 days after the missed dose, and then resume their usual once-weekly dosing schedule. If more than 3 days have passed, the dose should be skipped and the next dose should be administered on the regularly scheduled day. If two or more doses have been missed, the dose should be resumed on the regularly scheduled day.
The day of weekly injection can be changed as long as the time between two doses is at least 4 days. After selecting a new dosing day, the once weekly dosing should be continued.
On occasions when injection at the scheduled dosing day is not possible, once-weekly somapacitan can be administered up to 2 days before or 3 days after the scheduled weekly dosing day as long as the time between two doses is at least 4 days (96 hours). Once-weekly dosing for the next dose could be resumed at the regularly scheduled dosing day.
Somapacitan is to be administered once-weekly at any time of the day.
Somapacitan is to be injected subcutaneously in the abdomen, thighs, buttocks or upper arms without dose adjustment.
The injection site should be rotated every week to prevent local lipoatrophy.
For:
In the case that patient age in years is ≥ 3 :
Subcutaneous, 0.16 milligrams somapacitan per kilogram of body weight, once weekly.
Table 1. Dose recommendation:
| Paediatric GHD | Recommended starting dose |
| Treatment-naïve paediatric patients and paediatric patients switching from other GH medicinal products | 0.16 mg/kg/week |
Somapacitan dose may be individualised and adjusted based on growth velocity, adverse reactions, body weight and serum insulin-like growth factor I (IGF-I) concentrations.
Average IGF-I standard deviation score (SDS) levels (drawn 4 days after dosing) can guide dose titration. Dose adjustments should be targeted to achieve average IGF-I SDS levels in the normal range, i.e. between -2 and +2 (preferably close to 0 SDS).
If the IGF-I (SDS) is >2, it should be reassessed after a subsequent somapacitan administration. If the value remains >2, reducing the dose by 0.04 mg/kg/week is recommended. More than one dose reduction may be required in some patients.
In patients who have had the dose reduced but are not growing well, the dose may be gradually increased as tolerated up to a maximum dose of 0.16 mg/kg/week. Dose increments should not exceed 0.02 mg/kg per week.
Evaluation of efficacy and safety should be considered at approximately 6- to 12-month intervals and may be assessed by evaluating auxological parameters, biochemistry (IGF-I, hormones, glucose, and lipid levels) and pubertal status. More frequent evaluations should be considered during puberty.
Treatment should be discontinued in patients having achieved final height or near final height, i.e. an annualised height velocity <2 cm/year and a bone age >14 years in girls or >16 years in boys which corresponds to the closure of the epiphyseal growth plates. Once the epiphyses are fused, patients should be clinically re-evaluated for the need for growth hormone treatment.
When GHD persists after growth completion, growth hormone treatment should be continued to achieve full somatic adult development including lean body mass and bone mineral accrual (for guidance on dosing see recommended dose for adults (Table 1)).
Patients switching from a weekly growth hormone to somapacitan are recommended to continue administration at their once weekly dosing day.
Patients switching from daily human growth hormone to once-weekly somapacitan should choose the preferred day for the weekly dose and inject the final dose of daily treatment the day before (or at least 8 hours before) injecting the first dose of once-weekly somapacitan. Patients should follow the instructions for the dose presented in Table 1.
Females on oral oestrogen-containing therapy may have reduced IGF-I levels and may require dose adjustment of growth hormone to achieve the treatment goal. In paediatric GHD doses above 0.16 mg/kg/week have not been studied and are not recommended.
Patients who miss a dose are advised to inject once-weekly somapacitan upon discovery as soon as possible, within 3 days after the missed dose, and then resume their usual once-weekly dosing schedule. If more than 3 days have passed, the dose should be skipped and the next dose should be administered on the regularly scheduled day. If two or more doses have been missed, the dose should be resumed on the regularly scheduled day.
The day of weekly injection can be changed as long as the time between two doses is at least 4 days. After selecting a new dosing day, the once weekly dosing should be continued.
On occasions when injection at the scheduled dosing day is not possible, once-weekly somapacitan can be administered up to 2 days before or 3 days after the scheduled weekly dosing day as long as the time between two doses is at least 4 days (96 hours). Once-weekly dosing for the next dose could be resumed at the regularly scheduled dosing day.
Somapacitan is to be administered once-weekly at any time of the day.
Somapacitan is to be injected subcutaneously in the abdomen, thighs, buttocks or upper arms without dose adjustment.
The injection site should be rotated every week to prevent local lipoatrophy.
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