OBJECTIVES:

Advanced systemic mastocytosis (AdvSM) is a group of rare disorders characterized by abnormal growth and accumulation of mast cells in one or several organs which lead to mediator release and/or organ dysfunction/damage with therefore reduced life expectancy. The study objective was to describe the distribution of systemic therapy prescriptions and prevalence of adult AdvSM patients in Germany based on claims data from 2015 to 2020. Avapritinib received EMA approval in March 2022 and was therefore not included in the analysis.

METHODS:

A retrospective claims data analysis using German statutory health insurance data from the Institute for Applied Health Research Berlin (InGef) database was performed. The analyzed sample of the InGef database (~5% of the German population) is adjusted by age and gender to represent the German population and shows good overall accordance with the German population in terms of morbidity, mortality and drug use. Adult AdvSM patients were identified by ICD-10-GM codes C94.3 and C96.2 in the most recent available year in the database, 2020. Systemic therapies in the timeframe between 2015 and 2020 were identified (by ATC/OPS codes) including antineoplastic agents, midostaurin, cladribine, imatinib, hydroxyurea, interferon, and allogeneic stem cell transplant.

RESULTS:

A total of 22 adult patients had at least one recorded inpatient (primary or secondary diagnosis) ICD-10-GM diagnosis code for AdvSM and/or at least two outpatient recorded diagnosis codes for AdvSM (verified diagnosis) in 2020 as well as at least one systemic treatment with pre-defined agents between 2015 and 2020. This corresponds to the prevalence of 0.51 per 100.000 individuals. About 90.9% of identified patients had a prescription for antineoplastic agents. Midostaurin was prescribed to 27.3% of these patients. None of the patients underwent allogeneic stem cell transplantation in the study timeframe.

CONCLUSIONS:

The results were consistent with the medical guidelines and recently published prevalence data.