Discontinuation of Thrombopoietin Receptor Agonists: A 10 Year Real-World Experience from an Academic Hospital in Madrid

Background: Thrombopoietin receptor agonists (TPO-RAs) have become the second line treatment for patients with immune thrombocytopenia (ITP). Despite TPO-RAs are currently indicated for continuous treatment, some patients can achieve a sustained response that allows tapering and discontinuation. Predictors of responses and relapses after discontinuation are unknown factors that are being under investigation.

Methods: This is a retrospective study approved by Hospital Universitario La Paz Ethical Committee. We describe our experience during 10 years in discontinuation of TPO-RAs and relapses in the ITP patient cohort from Hospital Universitario La Paz in Madrid.We included all ITP patients treated with TPO-RAs between 1^st January 2011 and 31^st December 2020. We analyzed response, discontinuation, and relapses after TPO-RAs treatments, with a follow-up period until 31^st December 2021.

This research was funded by ISCIII-Fondos FEDER PI19/00772 and Platelet Disorder Support Association.

Results:One-hundred-fifty-one ITP patients were treated with TPO-RAs between 1^st January 2011 and 31^st December 2020. We excluded those without complete information about response, discontinuation, and relapses after TPO-RAs, analyzing a total of 133 patients. Thirteen received Romiplostim, 7 men and 6 women, with a median age of 66y (range 3-98). All of them achieved a clinical response according to standard criteria and in 4 it was possible to discontinue TPO-AR, with no need of retreatment with a median follow-up of 17,4 months (13,6-39,5).

Seventy-five patients were treated with Eltrombopag, 33 men and 42 women, with a median age of 49y (range 1-98). Seventy-one patients get a clinical response, which allows discontinuation of TPO-AR in 43 of them, with 25 sustained responses and a median follow-up of 40,5 months (9,9-60,3).

We also included 45 ITP patients, 21 men and 24 women, median age of 53y (range 2-93), who received both TPO-AR because of lack of response or intolerance with the first (4 Romiplostim and 41 Eltrombopag). Among the 34 patients who achieved a response, 17 were able to discontinue TPO-ARs and 7 needed retreatments. The follow-up period for this cohort was 23,4 months (1,9-75).

Globally, 39 patients discontinue TPO-RAs with no need of further ITP treatment with a median follow-up of 28,4months (1,9-75) since discontinuation until the end of the study.Results are summarized in Table 1.

Conclusion: In conclusion, 29% (39/113) of ITP patients who were treated with TPO-RAs could discontinue this treatment without relapses with a median follow-up of 28,4months (1,9-75) since discontinuation.