SOGROYA

What it is

Sogroya contains somapacitan, a long-acting recombinant human growth hormone derivative produced by recombinant DNA technology. It consists of 191 amino acids similar to endogenous human growth hormone, with a single substitution in the amino acid backbone (L101C) to which an albumin binding moiety has been attached. The albumin binding moiety consists of a fatty acid moiety and a hydrophilic spacer attached to position 101 of the protein. Sogroya is a solution for injection. Somapacitan is administered once weekly. This medicinal product is subject to additional monitoring in Australia to allow quick identification of new safety information.

Approved indications

— Replacement of endogenous growth hormone in paediatric patients aged 2 years and above with growth failure due to growth hormone deficiency. — Replacement of endogenous growth hormone in adults with growth hormone deficiency.

Dosing overview

For adult growth hormone deficiency, the somapacitan dose must be individually adjusted for each patient. It is recommended to increase the dose gradually with 2 to 4 week intervals in steps from 0.5 mg to 1.5 mg based on the patient's clinical response and experience of adverse reactions up to a dose of 8 mg somapacitan per week. The average somapacitan maintenance dose observed in the phase 3 clinical trials was 2.4 mg/week.

Key safety warnings

Introduction of growth hormone treatment may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations. In patients treated with growth hormone, previously undiagnosed central (secondary) hypoadrenalism may be unmasked and glucocorticoid replacement may be required. In addition, patients treated with glucocorticoid replacement for previously diagnosed hypoadrenalism may require an increase in their maintenance or stress doses following initiation of growth hormone treatment. Treatment with growth hormone may decrease insulin sensitivity, particularly at higher doses in susceptible patients, and consequently hyperglycaemia may occur in subjects with inadequate insulin secretory capacity. As a result, previously undiagnosed impaired glucose tolerance and overt diabetes mellitus may be unmasked during growth hormone treatment. Therefore, glucose levels should be monitored periodically in all patients treated with growth hormone, especially in those with risk factors for diabetes mellitus, such as obesity, or a family history of diabetes mellitus. Growth hormone increases the extrathyroidal conversion of T4 to T3 and may unmask incipient hypothyroidism. As hypothyroidism interferes with the response to growth hormone therapy, patients should have their thyroid function tested regularly and should receive replacement therapy with thyroid hormone when indicated. In the event of severe or recurrent headache, visual symptoms, nausea, and/or vomiting, a fundoscopy for papilloedema is recommended. If papilloedema is confirmed, a diagnosis of benign intracranial hypertension should be considered and if appropriate the growth hormone treatment should be discontinued. When somapacitan is administered at the same site over a long period of time, lipohypertrophy may occur. The injection site should be rotated to reduce the risk. The effect of growth hormone on recovery was studied in two placebo-controlled trials involving 522 critically ill adult patients suffering from complications following open heart surgery, abdominal surgery, multiple accidental trauma or acute respiratory failure. Mortality was higher in patients treated with 5.3 or 8 mg growth hormone daily compared to patients receiving placebo, 42% vs 19%. Based on this information, these types of patients should not be treated with somapacitan.

Contraindications

Somapacitan should not be used in patients with a known hypersensitivity to any of the ingredients. Somapacitan must not be used when there is any evidence of activity of a tumour. Intracranial tumours must be inactive and anti-tumour therapy must be completed prior to starting somapacitan therapy. Somapacitan should not be used for longitudinal growth promotion in children with closed epiphyses. Patients with acute critical illness suffering from complications following open heart surgery, abdominal surgery, multiple accidental trauma, acute respiratory failure or similar conditions should not be treated with somapacitan.

PBS listing

PBS listing information is not provided in the available source documents.

Regulatory history

The TGA approved Sogroya (somapacitan) for the replacement of endogenous growth hormone in adults with growth hormone deficiency on 14 February 2022, with the product subsequently entered onto the ARTG on 21 February 2022. The 10 mg strength (6.7 mg/mL) was first listed on 21 February 2022, whilst the 5 mg (3.3 mg/mL) and 15 mg (10 mg/mL) strengths were first listed on 18 September 2023. In March 2022, the PBAC recommended Sogroya for adult-onset growth hormone deficiency. In July 2023, the PBAC recommended Sogroya for paediatric growth hormone deficiency.