Search

Summary: 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. Here, we demonstrated the efficacy and safety of AVA as second‐line therapy in children with ITP. A multicentre, 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 (defined as achieving a platelet count ≥30 × 109/L, twofold increase in platelet count from baseline and absence of bleeding), including rapid response within 4 weeks, sustained response at weeks 12 and 24, bleeding control and adverse events (AEs). 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. At 24 weeks, 22/34 (64.7%) patients who achieved a response and were followed up for 24 weeks were evaluated; 12/22 (54.55%) achieved a sustained response. During AVA therapy, median platelet counts increased by week 1 and were maintained throughout the treatment period. The proportion of patients with grade 1–3 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. There were 61.8% patients with 59 AEs: 29.8% with Common Terminology Criteria for Adverse Events grade 1 and the rest with grade 2. 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. [ABSTRACT FROM AUTHOR]

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia and a haemorrhagic risk. Thrombopoietin receptor agonists (TPO‐RAs) are highly effective for ITP and are widely used to treat patients with steroid treatment failure or dependency. However, although treatment response to TPO‐RAs may differ according to the type, the potential impact of switching from eltrombopag (ELT) to avatrombopag (AVA) with respect to efficacy or tolerance in children remains unknown. This study aimed to evaluate the outcomes of switching from ELT to AVA in paediatric patients with ITP. We retrospectively evaluated children with chronic immune thrombocytopenia (cITP) switched from ELT to AVA owing to treatment failure at the Hematology‐Oncology Center of Beijing Children's Hospital between July 2021 and May 2022. Overall, 11 children (seven and four boys and girls respectively) with a median age of 8.3 (range: 3.8–15.3) years were included. The overall response and complete response (platelet [PLT] count ≥100 × 109/L) rates during AVA treatment were 81.8% (9/11) and 54.6% (6/11) respectively. The median PLT count was significantly increased from ELT to AVA (7 [range: 2–33] × 109/L vs. 74 [15–387] × 109/L; p = 0.007). The median time to PLT count ≥30 × 109/L was 18 (range: 3–120) days. Overall, 7/11 patients (63.6%) used concomitant medications, and concomitant medication use was gradually discontinued within 3–6 months after AVA initiation. In conclusion, AVA after ELT is effective in the heavily pretreated paediatric cITP population, with high response rates even in those with an inadequate response to a prior TPO‐RA. [ABSTRACT FROM AUTHOR]