OC 13.4 - Efficacy and safety of avatrombopag in Chinese children with persistent and chronic primary immune thrombocytopenia: A multicentre observational retrospective study in China

Sunday, June 23, 2024

10:15 – 10:30 ICT

Room: Ballroom B3

Presenting Author(s)

Zhifa Wang, PhD

Resident physician
Department II of Hematology Center, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, 100045, China
Beijing, Beijing, China (People's Republic)

Co-Author(s)

NW

Nan Wang, Master student

Department of Pharmacy
Beijing Children’s Hospital, Capital Medical University,
Beijing, Beijing, China (People's Republic)
JM

Jingyao Ma

Hemophilia Comprehensive Care Center, Hematology Center, Beijing Key Laboratory of Pediatric Hematol
Beijing Children’s Hospital, Capital Medical University,
Beijing, Beijing, China (People's Republic)
XC

Xiaoling Cheng

Department of Pharmacy
Beijing Children’s Hospital, Capital Medical University,
Beijing, Beijing, China (People's Republic)
Runhui Wu, PhD, MD

Professor
Department of Hematology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, 100045, China
Beijing, Beijing, China (People's Republic)

Background: Avatrombopag (AVA) is a novel thrombopoietin receptor agonist (TPO-RA) that has been recently approved as a second-line therapy for immune thrombocytopenia (ITP) in adults; however, its safety and efficacy data in children are lacking.

Aims: Here, we demonstrated the efficacy and safety of AVA as second-line therapy in children with ITP.

Methods: A multicenter, retrospective, observational study was conducted in children with persistent or chronic ITP who did not respond to or relapsed from previous treatment and were treated with AVA for at least 12 weeks between August 2020 and December 2022. The outcomes were the responses, including rapid response within 4 weeks, sustained response at weeks 12, bleeding control.

Results: Thirty-four (18 males) patients with a mean age of 6.3 (range: 1.9-15.3) years were enrolled. The median number of previous treatment types was four (range: 1-6), and 41.2% patients switched from other TPO-RAs. Within 4 weeks, overall response (OR) was achieved in 79.4% patients and complete response (CR, defined as a platelet count ≥100×109/L and the absence of bleeding) in 67.7% patients with a median response time of 7 (range: 1-27) days. At 12 weeks, OR was achieved in 88.2%, CR in 76.5%, and sustained response in 44% of patients. During AVA therapy, median platelet counts increased by week 1 and were maintained throughout the treatment period. The proportion of patients with grade 1 to 3 bleeding decreased from 52.95% at baseline to 2.94% at 12 weeks, while concomitant ITP medications decreased from 36.47% at baseline to 8.82% at 12 weeks, with only 9 (26.47%) patients receiving rescue therapy 23 times within 12 weeks.

Conclusion(s): These findings show that AVA could achieve a rapid and sustained response in children with persistent or chronic ITP as a second-line treatment, with good clinical bleeding control and reduction of concomitant ITP therapy, without significant AEs.