Abstract
This longitudinal, descriptive study investigated the effect of the timing of thrombopoietin receptor agonist (TPO-RA) initiation on corticosteroid administration and related adverse events (AEs) in patients with immune thrombocytopenia (ITP) in Japan using real-world data from a health claim database. In total, 7696 patients were divided into 3 groups (early TPO-RA initiation, late TPO-RA initiation, and non-TPO-RA administration) by the presence and timing of TPO-RA administration. The early TPO-RA initiation group included patients first administered TPO-RA <60, <120, and <180 days after the index date. The late TPO-RA initiation group included patients first administered TPO-RA ≥60, ≥120, and ≥180 days after the index date. The early TPO-RA initiation group received the highest daily average prednisolone dose, followed by a rapid decrease in dose, similar to that in the non-TPO-RA administration group. In the early TPO-RA initiation group, there was a long-term trend toward daily average prednisolone doses of ≤5 mg, and by approximately 10 to 11 months, the median dose was 0 mg. Diabetes (insulin-dependent) and hypertension tended to occur more frequently in the late TPO-RA (8.4% and 19.9%, respectively) than in the early TPO-RA initiation group (6.9% and 14.4%, respectively). Incidence rates of infections in the late TPO-RA and early TPO-RA initiation groups were similar (7.2% vs 7.6%). The incidence of AEs was similar between male and female patients; a trend toward a higher incidence was observed in those aged ≥60 years. Early initiation of TPO-RA administration can contribute to reducing total prednisolone dosage, treatment duration, and AEs (eg, hypertension and insulin-dependent diabetes).