OBJECTIVES: Immune thrombocytopenia (ITP), a rare autoimmune platelet disorder, presents varying unmet needs based on 2 key factors: (1) whether presenting as primary (idiopathic) or secondary (comorbid/underlying conditions), and (2) disease phase (newly diagnosed, persistent, or chronic). The objective of this study was to characterize adults with primary chronic ITP using a United States (US) claims database.

METHODS: Adults aged ≥18 years with primary chronic ITP were identified using a US claims database (Komodo Health closed claims, January 2015-March 2023) as follows: (1) ≥2 outpatient (30-365 days apart) or ≥1 inpatient claim(s) associated with primary ITP between Jan 2016 and Mar 2021, (2) ≥3 years continuous enrollment with no ITP diagnoses 1 year pre-first primary ITP claim, (3) absence of diagnostic/treatment codes associated with secondary ITP, and (4) ≥1 primary ITP claim during the chronic phase (365-730 days following first diagnosis). Baseline characteristics were assessed at first primary ITP diagnosis, and Charlson Comorbidity Index (CCI) was assessed prior to chronic phase.

RESULTS: Overall, 7576 patients with primary chronic ITP were identified. Mean (SD) age at diagnosis was 52.5 (17.9) years (18-40 years: 28%; 41-65 years: 46%; >65 years: 26%), with a predominance in females (sex rate ratio: 1.43), and mean (SD) CCI of 1.58 (2.07). Over half of patients (54%, n=4077) were untreated in the chronic phase, whereas 46% (n=3499) received ≥1 ITP treatment. Patients untreated in the chronic phase had a significantly lower CCI compared with patients receiving ITP treatment (mean [SD] CCI: 1.41 [1.95] vs. 1.79 [2.19], t[7574] = 7.98, p <0 .001).

CONCLUSIONS: Characteristics of overall patients with primary chronic ITP were largely consistent with existing literature. Further studies are required to better understand burden and unmet needs in both the treated and untreated patient populations.