"The frequency of drug administration is an important factor in the treatment of growth hormone deficiency. The emergence of a once-weekly dosing option is significant in terms of treatment adherence.’

With the market for growth hormone injections rising rapidly, the diversified treatment options have been increasing market interest.

The introduction of once-weekly treatment options to the once-daily regimen has emphasized the importance of choosing the right treatment option for patients. 

Professor Masanobu Kawai (Osaka Women's and Children's Hospital( focused on the effect of the once-weekly growth hormone deficiency treatment.


Growth hormone deficiency is a condition in which the pituitary gland, which is responsible for the secretion of hormones in the body, does not produce enough growth hormone, and is defined as a serum peak growth hormone concentration of less than 10 ng/mL in two or more growth hormone provocation tests.

According to the Health Insurance Review and Assessment Service, the number of Korean patients under the age of 19 diagnosed with growth hormone deficiency has nearly doubled over the past 5 years, from 9,746 in 2019 to 19,363 in 2023.

The main treatment method is the administration of growth hormone therapy, and once-daily administration has been the main option. In September last year, Pfizer's once-weekly growth hormone deficiency treatment Ngenla (somatrogon) was approved for reimbursement, expanding the options available.

Professor Masanobu, who has more experience prescribing Angela as the drug was first released in Japan than in Korea, explained that Ngenla offers a big difference in terms of treatment adherence.

Professor Masanobu said, “As a once-daily growth hormone therapy, Ngenla’s approved dose is higher in Korea than in Japan. In Japan, we had concerns about the efficacy of the approved daily treatments due to their low dose, but the once-weekly treatments with higher doses have shown a clear effect.”

He added, “Ngenla has strengths in terms of treatment adherence, which is an important factor in growth hormone therapy. Patients with growth hormone deficiency are typically prescribed every 3 months, and patients who are prescribed daily growth hormone therapy have more injections left over at the time of their visit.’

This means that the convenience of a once-weekly treatment, compared to a daily treatment, leads to higher adherence. This convenience is expected to reduce the burden of administration on patients and caregivers.

In fact, according to a survey on growth hormone deficiency patients and their parents in Japan, 44% responded that the frequency of dosing was the most important aspect they consider when using growth hormone therapy.

“This finding, which was identified before the introduction of Ngenla, demonstrates the inconvenience patients felt due to the frequent administration of existing therapies. A once-weekly dosing regimen is convenient and could ease the burden of treatment for patients and their parents,” explained Professor Masanobu

The hurdle of the once-weekly dose is ‘pain’...‘Most patients would prefer less frequent dosing’

However, there is also a hurdle for once-weekly treatments. While they are less burdensome to administer than their competitors that require daily injections, there is still the issue of pain management that follows the use of injectables.

On this, Professor Masanobu said that the long-acting injectables may bring a higher pain burden due to the higher dose, but this can be addressed by adjusting the injection site.

“Once-daily treatments use thin, short needles, but Ngenla uses thicker, longer needles because of the higher dose. If the needle is injected deep enough to reach the subcutis, the injection pain can be absorbed by the surrounding tissues, reducing the burden.’

However, South Korea's approach to pain management differs from Japan's in that it uses a single injection.

Nevertheless, Professor Masanobu believed that Ngenla’s less frequent administration is likely to be preferred by most patients other than the younger patients for whom pain management is a priority.

In addition, Professor Masanobu believes that the emergence of a once-weekly dosing option for growth hormone deficiency treatment could lead to improvements in the patient and parents’ quality of life (QOL) beyond therapeutic effect.

Professor Masanobu said, “In terms of efficacy, the once-daily and once-weekly doses may have similar effects, however, the burden of daily dosing can affect a person's life in general. Considering the pressure felt by patients and parents, as well as treatment adherence, the ability to alleviate this burden is one of Ngenla’s greatest advantages.’