The technology

Macimorelin (Aeterna Zentaris) is a medicine that stimulates the release of growth hormone into the blood. It is used to test the body's ability to produce growth hormone and therefore diagnose growth hormone deficiency (GHD). It is not used as a treatment for GHD. It is available as granules (60 mg) that are dissolved in water and taken orally. It should be taken once, and the recommended dose is 0.5 mg per kg body weight. Blood samples are then taken at 45 minutes, 60 minutes and 90 minutes to see how much growth hormone the body produced.

Innovations

The company claims that macimorelin is the only oral growth hormone stimulation test for diagnosing adult growth hormone deficiency (AGHD). It claims that its mode of action is innovative because it works directly at the pituitary gland and, unlike the insulin tolerance and glucagon tests, it does not rely on inducing hypoglycaemia to provide a growth hormone response. The company also claims that macimorelin is quick and easy to administer. It takes about 90 minutes with 3 blood draws compared with 120 to 180 minutes and 7 blood draws for the insulin tolerance test and 240 to 300 minutes and 7 to 9 blood draws for the glucagon test. The company claims it has fewer contraindications than the insulin tolerance test, which has significant contraindications, so it could potentially reduce barriers to testing and improve access to treatment.

Current care pathway

Several tests are available to diagnose GHD. The gold standard is the insulin tolerance test. A general definition of severe GHD in adults is a peak concentration of less than 9 mU/litre (3 ng/mL) in response to insulin-induced hypoglycaemia. When the insulin tolerance test is contraindicated, other tests can be used, such as response to growth hormone-releasing hormone (GHRH), arginine or glucagon.

The following publication has been identified as relevant to this care pathway:

Population, setting and intended user

Macimorelin is used for adults with GHD. The Society for Endocrinology estimates that the prevalence of adult-onset GHD is about 1 in 10,000 of the adult UK population (see NICE's technology appraisal guidance TA64 [2003]). This equates to about 5,600 adults with adult-onset GHD in England.

The technology is intended for use in secondary or tertiary care. Macimorelin will likely be used by endocrinology clinicians with experience in diagnosing GHD. Usually, the test will be administered by an endocrinology nurse specialist.

The company states that the test is easy to administer and staff do not need additional training, but, if needed, self-directed training is available online and consists of web access to a summary of product characteristics, a 'how to use' leaflet, a simple video explaining the steps and a 'how to use' protocol developed by UK endocrinology clinicians. This is included in the cost of the technology.

Costs

Technology costs

The NHS list price for macimorelin is £300. The company states that the full procedural cost, including clinician time to administer and supervise the test (2 hours of nurse time), is £421.30 per test (excluding VAT).

Costs of standard care

The insulin used in the insulin tolerance test costs £3.96. The full procedural costs are £438.91 per test (including 4 hours of nurse and 1 hour of doctor time). The alternative test, the GHRH-arginine test, has a cost of £89.48 for both tests and a total procedure cost (including 4 hours of nurse and 1 hour of doctor time) of £469.60 per test (excluding VAT).

Resource consequences

The company states that macimorelin was launched for use in the NHS in May 2022 but is currently not used. The company is engaging with key secondary and tertiary units to add macimorelin to their formulary list.

The company claims that the testing procedure time with macimorelin is considerably shorter, lasting 90 minutes compared with 2 to 4 hours or more for other GHD tests. It claims this will reduce medical resource costs and save clinician time. The company also claims that macimorelin has fewer contraindications and a more favourable safety profile compared with the insulin tolerance test and does not involve inducing hypoglycaemia. It claims that the total budget impact of macimorelin is substantially lower than standard care. This is supported by a budget impact analysis published as a conference abstract, but limited detail is available (English et al. 2022).

The company states that adopting macimorelin in clinical practice does not need any changes to facilities or infrastructure.