Posology : מינונים

4.2    Posology and method of administration

Treatment should be initiated and monitored by physicians who are qualified and experienced in the diagnosis and management of paediatric patients with growth hormone deficiency (GHD).

Posology

The recommended dose is 0.66 mg/kg body weight administered once weekly by subcutaneous injection.

Each pre-filled pen is capable of setting and delivering the dose prescribed by the physician. Dose may be rounded up or down based on the physician’s expert knowledge of the individual patient needs.
When doses higher than 30 mg are needed (i.e. bodyweight > 45 kg), two injections have to be administered.
Starting dose for patients switching from daily growth hormone medicinal products For patients switching from daily growth hormone medicinal products, the weekly therapy with somatrogon may be initiated at a dose of 0.66 mg/kg/week on the day following their last daily injection.

Dose titration
Somatrogon dose may be adjusted as necessary, based on growth velocity, adverse reactions, body weight and serum insulin-like growth factor 1 (IGF-1) concentrations.

When monitoring for IGF-1, samples should always be drawn 4 days after the prior dose. Dose adjustments should be targeted to achieve average IGF-1 standard deviation score (SDS) levels in the normal range, i.e. between -2 and +2 (preferably close to 0 SDS).

In patients whose serum IGF-1 concentrations exceed the mean reference value for their age and sex by more than 2 SDS, the dose of somatrogon should be reduced by 15%. More than one dose reduction may be required in some patients.

Treatment evaluation and discontinuation
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-1, hormones, glucose levels) and pubertal status. Routine monitoring of serum IGF-1 SDS levels throughout the course of treatment is recommended. More frequent evaluations should be considered during puberty.

Treatment should be discontinued when there is evidence of closure of the epiphyseal growth plates (see section 4.3). Treatment should also be discontinued in patients having achieved final height or near final height, i.e. an annualised height velocity < 2 cm/year or a bone age > 14 years in girls or > 16 years in boys.

Missed dose
Patients should maintain their regular dosing day. If a dose is missed, somatrogon should be administered as soon as possible within 3 days after the missed dose, and then the usual once weekly dosing schedule should be resumed. If more than 3 days have passed, the missed dose should be skipped and the next dose should be administered on the regularly scheduled day. In each case, patients can then resume their regular once weekly dosing schedule.

Changing the dosing day
The day of weekly administration can be changed if necessary as long as the time between two doses is at least 3 days. After selecting a new dosing day, the once weekly dosing should be continued.

Special populations

Elderly
The safety and efficacy of somatrogon in patients over the age of 65 years have not been established.
No data are available.
Renal impairment
Somatrogon has not been studied in patients with renal impairment. No dose recommendation can be made.

Hepatic impairment
Somatrogon has not been studied in patients with hepatic impairment. No dose recommendation can be made.


Paediatric population
The safety and efficacy of somatrogon in neonates, infants and children less than 3 years of age have not yet been established. No data are available.

Method of administration

Somatrogon is administered by subcutaneous injection.
Somatrogon is to be injected in the abdomen, thighs, buttocks or upper arms. The site of injection should be rotated at each administration. Injections to the upper arms and buttocks should be given by the caregiver.

The patient and caregiver should receive training to ensure understanding of the administration procedure to support self-administration.

If more than one injection is required to deliver a complete dose, each injection should be administered at a different injection site.

Somatrogon is to be administered once weekly, on the same day each week, at any time of the day.

Ngenla 24 mg solution for injection in pre-filled pen
The pre-filled pen delivers doses from 0.2 mg to 12 mg of somatrogon in increments of 0.2 mg (0.01 mL).

Ngenla 60 mg solution for injection in pre-filled pen
The pre-filled pen delivers doses from 0.5 mg to 30 mg of somatrogon in increments of 0.5 mg (0.01 mL).

For instructions on the medicinal product before administration, see section 6.6 and at the end of the package leaflet.