Avatrombopag for the treatment of thrombocytopenia post hematopoietic stem-cell transplantation

Abstract

Background: Thrombocytopenia post hematopoietic stem-cell transplantation (HCT) usually contributes to poor outcomes with no standardized treatment. Eltrombopag and romiplostim can be feasible for post-HCT thrombocytopenia, but the use of avatrombopag has not yet been evaluated. Objectives: We aimed to evaluate the efficacy and safety of avatrombopag treatment in patients diagnosed with post-HCT thrombocytopenia. Design: In this retrospective study, we evaluated the efficacy and safety of avatrombopag treatment in a cohort of 61 patients diagnosed with thrombocytopenia post HCT in our clinical center. Methods: Avatrombopag was initiated at 20 mg daily, with a dosage adjustment to achieve platelet recovery to >20 × 109/l independent from transfusion for 7 consecutive days (overall response, OR) or to >50 × 109/l free from transfusion for 7 consecutive days (complete response, CR). Factors influencing OR and CR were studied in univariate and multivariate analyses, respectively. Within the follow-up, adverse events like myelofibrosis, thrombosis, and organ toxicities were monitored carefully. Results: The overall response rate (ORR) to avatrombopag was 68.9% and the cumulative incidence (CI) of OR was 69.1%. The complete response rate (CRR) and the CI of CR were both 39.3%. The median days from avatrombopag initiation to OR and CR were 21 and 25 days, respectively. An adequate number of megakaryocytes before the initiation of avatrombopag was an independent protective factor of avatrombopag treatment for OR (hazard ratio, HR = 4.628, 95% confidence interval 1.92–11.15, p = 0.0006) and CR (HR = 4.892, 95% confidence interval 1.58–15.18, p = 0.006). Avatrombopag was well tolerated in all patients with no severe adverse events. Conclusion: Our findings suggested that avatrombopag can be optional for thrombocytopenia post HCT.

Avatrombopag for the treatment of thrombocytopenia in children's patients following allogeneic hematopoietic stem-cell transplantation: A pilot study

“…Moreover, the CRR was in a range of 50%–72% among PIT, SFPR, and PGF in adults ( 6 ). Regarding avatrombopag for post-HSCT thrombocytopenia, there were only a few studies published to date, and all of these studies were performed in only the adult population ( 18 , 21 ). Zhou et al reported that the ORR was 68.9% while CRR was 39.3% using avatrombopag for the treatment of delayed platelet engraftment and SFPR ( 18 ).…”

“…Regarding avatrombopag for post-HSCT thrombocytopenia, there were only a few studies published to date, and all of these studies were performed in only the adult population ( 18 , 21 ). Zhou et al reported that the ORR was 68.9% while CRR was 39.3% using avatrombopag for the treatment of delayed platelet engraftment and SFPR ( 18 ). Zhu et al further investigated the effects of avatrombopag combined with MSC for post-HSCT thrombocytopenia.…”

“…Meanwhile, the promotion of platelet engraftment was proposed to facilitate platelets ≥20 × 10 9 /L without transfusion for 7 days post-HSCT. The number of megakaryocytes in bone marrow (BM) smear less than 7 in 1.5 cm × 3.5 cm area was considered as inadequate megakaryocyte status ( 18 , 19 ).…”

“…The overall response (OR) was defined as the platelet ≥20 × 10 9 /L for at least 7 consecutive days without transfusion. Meanwhile, the complete response (CR) was defined as the platelet ≥50 × 10 9 /L for at least 7 consecutive days without transfusion ( 18 ). Adverse events and severe adverse events were evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 5.0.…”

Novel Perspectives on Thrombopoietin Receptor Agonists Applications

“…71 Platelet transfusions remain the backbone of therapy, while boost doses of CD34 þ cells have been used in PGF. 68 Some retrospective studies, as seen in ►Table 2, examined TPO-RA's role in this context, with reported response rates varying from 39.3 to 83.3%, [72][73][74][75][76][77][78][79][80][81][82][83] whereas results from few prospective studies are mostly conflicting. 84,85 Both ROMI and EP, and recently avatrombopag, proved to be as safe and effective and possibly cost-effective in comparison to transfusions in thrombocytopenia after allo-HSCT and PGF.…”