Endocrine Abstracts

Introduction: Somapacitan is 23.3-kDa human GH derivate linked to small noncovalent albumin binding moiety that facilitates reversible endogenous albumin binding to delay somapacitan elimination. The longer half-life and improved pharmacodynamics allow injections once per week. Some patients find a daily regimen with established treatment difficult, especially because treatment may be lifelong or at least for several years. Poor adherence with medication can lead to poorer clinical outcomes. In studies somapacitane was well tolerated and no safety issues were identified.

Case report: We report a case of 38 years old women with congenital panhypopituitarism with pituitary dysplasia, posterior pituitary ectopy and disconnected pituitary stalk. Diagnosis of hypopituitarism was established when she was 8 years old. In the past PROP1 and LHX3 mutations were excluded. Patient received treatment with hydrocortisone 20 mg QD in divided doses, levothyroxine 100 µg QD, somatotropine 0.4 mg sc. QD, norgestrel/estrogen. Because she was not adherent to somatotropine treatment we started treatment with somapacitan 4 mg sc. QW. At the start of treatment, she was educated from nurse educator about correct handling and application of medication. She followed the recommendation to administer somapacitan by subcutaneous injection to the abdomen or thigh with regular rotation of injection sites. Before switch from somatotropine to somapacitan IGF-1 was 72 µg/l (69.0 – 227.0 µg/l), IGF-1 SDS was -1.825. Three days post second injection IGF-1 was 140 µg/l, IGF-1 SDS was 0.143. Approximately 4 weeks after start of treatment, she reported reduced subcutaneous tissue on the site of application. On evaluation lipoatrophy of diameter of about 10 cm were present at two sides of lower abdomen and in left and right tight. The reduction of fat tissue was confirmed with DXA. Otherwise, she reported more energy, improved quality of life and treatment satisfaction. IGF-1 SDS was in target range. We discontinued treatment with somapacitan and re-started treatment with somatropine. On follow-up visit 1 month after discontinuation of somapacitan partial improvement in lipoatrophy was noted.

Discussion and conclusion: To our knowledge this is the first case of lipoatrophy in adult during treatment with somapacitan. Until today, lipoatrophy, which was reversable with change of application site, was described in 2 children in randomised control trial REAL 3.