NGENLA

What it is

NGENLA (somatrogon) is a solution for injection. Somatrogon is a glycoprotein produced in Chinese Hamster Ovary cells by recombinant DNA technology, comprised of the amino acid sequence of human growth hormone with one copy of the C-terminal peptide from the beta chain of human chorionic gonadotropin at the N-terminus and two copies of this peptide in tandem at the C-terminus. NGENLA is available as a clear and colourless to slightly light-yellow solution for injection in single-patient-use disposable pre-filled pens containing either 24 mg or 60 mg, with the 24 mg pen delivering doses in 0.2 mg increments and the 60 mg pen delivering doses in 0.5 mg increments. The pre-filled pen is capable of setting and delivering a dose that is variable and determined based on patient body weight.

Approved indications

— Long-term treatment of paediatric patients with growth disturbance due to insufficient secretion of growth hormone.

Dosing overview

The recommended dose is 0.66 mg/kg body weight administered once weekly by subcutaneous injection. NGENLA is administered once weekly, on the same day each week, at any time of the day. Regular monitoring of insulin-like growth factor-1 concentrations is recommended during treatment, with samples always drawn 4 days after the prior dose. NGENLA dosage may be adjusted based on growth velocity, body weight and serum insulin-like growth factor 1 concentration, with a 15% dose reduction required if blood IGF-1 concentrations exceed the mean reference value for age and sex by more than 2 standard deviation scores.

Key safety warnings

NGENLA is contraindicated in patients with active tumours and/or malignancy. There is no clinical experience with NGENLA in patients with acute critical illness; treatment with daily growth hormone products has been associated with increased mortality in such patients, and if patients receiving NGENLA therapy become acutely critically ill, the potential benefit of continued treatment should be weighed against the potential risk. Serious systemic hypersensitivity reactions including anaphylaxis and angioedema have been reported with daily growth hormone products; if a serious hypersensitivity reaction occurs, NGENLA should be immediately discontinued and treated promptly per standard of care. Patients with or at risk for pituitary hormone deficiency may be at risk for reduced serum cortisol levels and unmasking of central hypoadrenalism, and those treated with glucocorticoid replacement may require increased maintenance or stress doses; patients should be monitored for reduced serum cortisol levels and need for glucocorticoid dose increases. Intracranial hypertension with papilledema, visual changes, headache, nausea and vomiting has been reported in a small number of patients treated with daily growth hormone products, usually occurring within the first 8 weeks, with signs and symptoms rapidly resolving after cessation of therapy or dose reduction. NGENLA should be temporarily discontinued in patients with clinical or fundoscopic evidence of intracranial hypertension, with monitoring for signs and symptoms recommended if treatment is restarted. Treatment with daily growth hormone products may induce insulin resistance and hyperglycaemia; additional monitoring should be considered in patients treated with NGENLA who have glucose intolerance or additional risk factors for diabetes, and anti-diabetic therapy might require adjustment in patients with diabetes mellitus. Because NGENLA increases growth rate, signs of development or progression of scoliosis should be monitored during treatment.

Contraindications

NGENLA is contraindicated in patients with active tumours and/or malignancy. NGENLA is contraindicated in patients with acute critical illness due to complications following open heart or abdominal surgery, multiple accidental trauma, or acute respiratory failure. NGENLA is contraindicated in patients with known hypersensitivity to somatrogon or any of its excipients.

PBS listing

NGENLA injection 60 mg in 1.2 mL single use pre-filled pen is listed on the PBS as 2 items with authority required restriction, at an ex-manufacturer price of A$901.25. NGENLA injection 24 mg in 1.2 mL single use pre-filled pen is listed on the PBS as 2 items with authority required restriction, at an ex-manufacturer price of A$360.50.

Regulatory history

The TGA approved NGENLA (somatrogon) on 23 November 2021 for the long-term treatment of paediatric patients with growth disturbance due to insufficient secretion of growth hormone. This approval allows for the marketing of a new biological entity designed for once-weekly administration. The PBAC recommended NGENLA in March 2022 for paediatric growth hormone deficiency.