Thrombopoietin receptor agonist discontinuation rates and reasons among patients with immune thrombocytopenia: a study of administrative claims linked with medical chart review.

Administrative claims provide a rich data source for retrospective studies of real-world clinical practice, yet some important data may be inconsistent or unavailable. This study explored factors influencing discontinuation of thrombopoietin receptor agonists (TPO-RAs) among patients with immune thrombocytopenia (ITP), by adding medical chart abstraction for additional details. Adult (≥ 18 years) patients with continuous commercial or Medicare Advantage with Part D health insurance coverage were included. Inclusion criteria were ≥ 1 claim for eltrombopag or romiplostim and ≥ 2 diagnoses of ITP between December 31, 2017, and January 1, 2020. Providers were asked to provide access to medical charts for abstraction. The analyses included only patients who discontinued TPO-RA and described patient characteristics, treatment patterns, platelet values, and reasons for discontinuation. Among 207 ITP patients treated with a TPO-RA, 137 (66%) discontinued treatment during the observation period. The mean TPO-RA treatment duration was 185 days. Mean platelet count at the time of discontinuation was 197 × 10/L. The most common reason for discontinuation was improvement of the patient's condition (42%). Other reasons included worsening of ITP/lack of response (12%), adverse events (12%), and cost-related or social reasons (23%). No reason was reported for 10%. Notably 26% of patients who discontinued remained off all ITP therapy for the remainder of the study, with a mean treatment-free period of 262 days. These results emphasize that some patients with ITP are able to discontinue TPO-RA therapy and achieve durable treatment-free periods.