Avatrombopag in immune thrombocytopenia: A real-world study of the Spanish ITP Group (GEPTI)

Abstract

Avatrombopag is the newest thrombopoietin receptor agonist (TPO-RA) approved to treat immune thrombocytopenia (ITP). Real-world evidence regarding effectiveness/safety is limited. The Spanish ITP Group (GEPTI) performed a retrospective study with patients starting avatrombopag for the first time. A total of 268 ITP patients were recruited. The median (interquartile range [IQR]) follow-up time was 47.5 (30.4-58.9) weeks. Among the 193 patients with baseline platelet counts <50 × 10⁹/L, 174 (90.1%) of them achieved response (PC ≥50 × 10⁹/L), and 113 (87.6%) of the 129 who persisted on avatrombopag at last visit had platelet levels above such threshold. Results were similar when only those patients switching to avatrombopag due to previous treatment failure were considered (n = 104). Patients reached response in 13 (7-21) days. Among patients with baseline levels ≥50 × 10⁹/L, 73/75 (97.3%) reported response, which was maintained by 53 (94.6%) of the 56 who continued on avatrombopag at the end of the study. Loss-of-response was always <10%. ITP duration did not influence response. Approximately 79% (34/43) of heavily pretreated (≥4 lines) patients with baseline platelet counts <50 × 10⁹/L switching after previous failure achieved PC ≥50 × 10⁹/L. Previous use of eltrombopag and/or romiplostim did not influence response, regardless of whether previous TPO-RA(s) succeeded or failed. Avatrombopag allowed dose-reduction/suspension of corticosteroids in 40/50 (80.0%) patients with baseline platelet counts <50 × 10⁹/L. Overall, 40/268 (14.9%) thrombocytosis and 12/268 (4.5%) thromboembolic events were reported. Our real-world cohort supports the use of avatrombopag to manage ITP, regardless of disease severity and treatment history.