Abstract
BACKGROUND: Clinical data on hetrombopag, a novel thrombopoietin receptor agonist (TPO-RA) developed in China, remain limited for the treatment of immune thrombocytopenia (ITP). This retrospective study aimed to investigate the efficacy and safety of hetrombopag for ITP patients in the real-world setting. METHODS: Patients with ITP received hetrombopag monotherapy at an initial dose of 2.5 mg or 5.0 mg once daily. The primary endpoint was the proportion of responders whose platelet count ≥ 50 × 10(9) /L, which were assessed at week 4, 8 and 12 after treatment. The secondary endpoint was the safety profile of hetrombopag. RESULTS: A total of 50 ITP patients were enrolled. The median time to response was 7 days; the mean platelet count increased from 16 × 10⁹/L at baseline to 104 × 10⁹/L at week 12; the response rate was 71% at week 12. The 5 mg/d group showed significantly better efficacy as early as week 2 compared with the 2.5 mg/d group (P < 0.05). Among 15 nonresponders in the 2.5 mg group, 11 patients were switched to the 5 mg group, and 6 of them then achieved response. The clinical response was reached in 7 of 8 ITP patients switching from eltrombopag to hetrombopag. There was no difference in the overall response rate between patients receiving hetrombopag as a second-line therapy and later-line therapies (P = 0.951). No serious adverse events were observed. In addition, the total number of megakaryocytes in the bone marrow was positively associated with treatment efficacy at week 4 (P = 0.001). CONCLUSIONS: Hetrombopag was effective and safe in the real-world treatment of ITP. An initial dosage of hetrombopag 5 mg/d and a higher megakaryocyte count in bone marrow may predict better therapeutic efficacy.