Rate of Prolonged Response After Stopping Thrombopoietin-receptor Agonists Treatment in ITP

Rate of Prolonged Response After Stopping Thrombopoietin-receptor Agonists Treatment in Immune Thrombocytopenia: a Prospective Multicenter Open Study

Thrombopoietin-receptor agonists (Tpo-RAs) have profoundly changed the management of ITP. However, today, there are no international recommendations concerning the long-term use of these costly, potentially pro-thrombotic agents, and that could induce bone marrow fibrosis in case of prolonged treatment. Tpo-RAs have been thought to play only a supporting role in ITP management. But our center along with many other research centers, have reported unexpected cases of durable remission after Tpo-RAs discontinuation in adult chronic ITP. In these retrospective studies, more than 20 % of patients were able to achieve prolonged remission.

The purpose of this study is to demonstrate that a substantial proportion of ITP patients may achieve a prolonged response after Tpo-RA discontinuation.

The investigators developed, in this study, a standardized procedure to discontinue Eltrombopag and Romiplostim, wherein the dose will be slowly tapered to limit the risk of bleeding. In case of relapse after Tpo-RA discontinuation, the decision to start a new therapy will be based on the clinician's judgment.

Inclusion Criteria:

1. Age >= 18 years
2. Diagnosis of ITP according to the standard definition
3. Disease duration of more than 3 months at Tpo-RA initiation
4. Platelet count > 100 x 109/L for more than 2 months on Tpo-RA Therapy, with at least 3 platelet counts > 100 x 109/L
5. Blood count lasting for less than 7 days
6. Normal marrow aspirate for patients aged of 60 and over
7. Informed signed consent
8. Treatment with Tpo-RA for at least 3 months

Exclusion Criteria:

1) Anticoagulation or anti-platelet treatment 2) Recent treatment with corticosteroids ± intravenous immunoglobulins (less than 2 months) 3) Rituximab or splenectomy within the 2 months preceding the Tpo-RA initiation 4) Rituximab or splenectomy after Tpo-RA initiation/RA initiation 5) Previous failure of Tpo-RA discontinuation 6) Pregnant or breastfeeding women 7) No affiliation to a social security scheme or other social protection scheme 8) Inability or refusal to understand or refusal to sign the informed consent from study participation 9) Patient deprived of freedom or under legal protection (guardianship, curatorship) 10) Hypersensitivity to Romiplostin or to any of the excipients or to E. coli derived proteins

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