Real-world treatment patterns and outcomes among patients with immune thrombocytopenia (ITP) who switched treatment from eltrombopag or romiplostim to avatrombopag in the United States: Results from the REAL-AVA 3.5 study.

Real-world data on treatment response after switching between thrombopoietin receptor agonists are limited for patients with immune thrombocytopenia (ITP). The objective of this study is to describe treatment patterns and outcomes in patients with primary ITP who switched from eltrombopag (ELT) or romiplostim (ROMI) to avatrombopag (AVA). We conducted a retrospective chart review study of adults with primary ITP who initiated ELT or ROMI on or after 1 July 2019, switched to AVA within 30 days of ELT/ROMI discontinuation and had ≥6 months follow-up after AVA initiation. Patients were followed from AVA initiation until last contact, death or study end (21 March 2025), whichever occurred earliest. Response was defined as achieving ≥1 platelet count (PC) of ≥30 × 109/L, ≥50 × 109/L or ≥100 × 109/L in the absence of rescue therapy. Response durability was the percentage of time on AVA with PCs above the response threshold among responders. Patients (N = 201) most commonly discontinued ELT/ROMI due to lack of efficacy (59.2%). Among patients with baseline PCs <30 × 109/L (n = 79), 98.7% and 94.9% achieved PCs ≥30 × 109/L and ≥50 × 109/L on AVA respectively. Median response durability was 93.8%, 89.6% and 67.4% for ≥30 × 109/L, ≥50 × 109/L and ≥100 × 109/L respectively. Most patients who switched to AVA from ELT or ROMI achieved or maintained a clinically meaningful and durable platelet response throughout the study period.