Somapacitan-induced reversible lipoatrophy in an adult woman with hypopituitarism.

Background: Lipoatrophy is rare adverse event (AE) in daily recombinant human growth hormone (rhGH). Data on lipoatrophy in newly developed long-acting GH (LAGH) are scarce. We report the first case of lipoatrophy in adult patient treated with LAGH somapacitan.

Case presentation: A 38-year-old woman with congenital panhypopituitarism was transitioned from daily rhGH 0.4 mg QD to somapacitan dose 4 mg QW due to non-adherence to daily rhGH. Despite adequate education and regular changing of injection sites, the patient reported reduced subcutaneous tissue at all four injection sites, after the 4th application of somapacitan. Somapacitan was discontinued at patient preference and lipoatrophy completely reversed after 3 months.

Conclusions: Lipoatrophy caused by somapacitan was completely reversible. We speculate that high initial dose and volume of somapacitan caused delayed diffusion and a direct local lipolytic effect in our patient. Although, titration of somapacitan was initiated as previously reported in REAL2 study protocol, recent clinical guidelines advise more gradual increase of somapacitan dose also in women on oral estogens that are switched from daily rhGH. Importantly, our case and the two previously described cases in children in the REAL 3 study showed that lipoatrophy caused by somapacitan was transient and completely reversible, and that discontinuation of the drug is not always mandatory.