EHA2023 Hybrid Congress hosted by The European Hematology Association will be held in the form of online and offline, in Frankfurt, Germany from June 8-11, 2023. Every year, it attracts nearly 10,000 people from all over the world to participate in, which is an important and influential international conference in the field of hematology.This year, the results of phase III study of Avatrombopag for the treatment of Chinese adults with chronic primary immune thrombocytopenia(ITP) were selected as poster to exchange in EHA2023 Hybrid Congress (Abstract No.: P1611).Avatrombopag is a second-generation oral thrombopoietin receptor agonist (TPO-RA), licensed in by Fosun Pharma.

Session:32.Platelet disorders   Time: 18:00-19:00, June 8, 2023

Avatrombopag was granted the priority evaluation qualification by the National Medical Products Administration (NMPA) in May 2019, and was approved for the treatment of thrombocytopenia in adult patients with chronic liver disease (CLD) undergoing diagnostic procedures or surgery in April 2020. Its indication for the treatment of chronic ITP in adults who not respond well to previous treatments is currently approved in the United States and Europe. ITP is the most common hemorrhagic disease, which is caused by increased platelet destruction and decreased production mediated by immune disorders. When the platelet count of ITP patients is lower than 30×109/L, therapeutic intervention is recommended by the guidelines1. The results published in EHA2023 Hybrid Congress are from the first randomized, double-blind, placebo-controlled clinical study of Avatrombopag in Chinese adults with ITP, providing important evidence for the application of Avatrombopag in Chinese ITP population.

Method:

This multicenter, randomized (2:1), double-blind, parallel-group Phase 3 study enrolled Chinese adults with ITP of ≥12 months and a platelet count <30×109/L to once-daily oral Avatrombopag (initial dose 20 mg) or matching placebo. After a 6-week double-blind core treatment phase, eligible subjects entered the open-label extension phase and received avatrombopag treatment for 20 weeks. The primary endpoint was the proportion of responders with a platelet count of ≥ 50 × 109/L at week 6 of core treatment phase in absence of rescue treatment.

Results:

A total of 74 subjects were randomized into the study, 48 into the Avatrombopag group and 26 into the placebo group. At Week 6, 77.08%（95% CI：62.69%, 87.97%) of subjects treated with Avatrombopag achieved a platelet count of ≥ 50 × 109/L without receiving rescue treatment, vs 7.69% (95% CI：0.95%, 25.13%) in the placebo group, with a treatment difference of 69.39% (95% CI：56.15%, 86.26%). The primary efficacy endpoint was met with statistically significant results favoring avatrombopag compared with placebo.

1. In the core treatment phase，the proportion of responders at Day 8 in the Avatrombopag group was 72.92%，compared with 3.85% in the placebo group.

2.In the Avatrombopag group, the median cumulative number of weeks of platelet response was numerically higher than placebo (4.1 vs 0 weeks, respectively).

3.In the core treatment phase, Avatrombopag-treated subjects had a lower incidence of ITP-related bleeding symptoms than placebo-treated subjects (70.83% vs. 88.46%).

4.Treatment-emergent adverse events (TEAEs) were reported in 85.4% and 76.9% subjects treated with Avatrombopag and placebo, respectively.

5.Across the core and extension phases (whole study), the median cumulative number of weeks of platelet response in Avatrombopag-treated subjects was 17.6 weeks.

Conclusion:

This study supports the superior efficacy of Avatrombopag over placebo in the treatment of Chinese adults with chronic ITP. Avatrombopag is well tolerated, with no interruption of treatment due to treaty-related adverse events during the core treatment phase and no serious adverse events reported.

审批号：NP-MA-2023-05-06-CN-AVA-097

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