Sustained Remission of ITP with Thrombopoietin Receptor Agonists Treatment
Thrombopoietin receptor agonists (TPO-RAs) are highly effective drugs administered in chronic immune thrombocytopenia (ITP). Several studies have shown that they can induce remission and long-term response, even after prolonged discontinuation.
Findings from Studies
Monitoring Patients After Therapy Discontinuation with Ongoing Response
A team from Brno published a retrospective data analysis in the International Journal of Hematology in 2015 of patients with ITP treated with TPO-RAs, for whom therapy was discontinued due to sustained response. At the time, 46 patients were being treated for relapsed or refractory ITP. Treatment was stopped in 11 patients, of whom 7 received romiplostim and 4 eltrombopag, after achieving a response. No adverse effects were observed in any of them. All patients had previously been treated with 1−3 lines of other therapies, and 6 had undergone splenectomy. None of these 11 patients experienced disease relapse after discontinuation of TPO-RAs during a median follow-up of 33 months (range 16−54 months).
Experience with Newly Diagnosed and Non-Splenectomized Patients
Japanese authors in a recent publication also confirm the possibility of discontinuing treatment in some treated patients. The authors focused on newly diagnosed and non-splenectomized patients who achieved sustained complete remission with a platelet count of ≥ 100 × 109/l with TPO-RAs treatment. Between 2011 and 2018, 77 individuals were treated at the authors’ institution; 27 of them achieved total remission, and TPO-RAs treatment was discontinued. The overall response rate among all patients was 79.2%, and the TPO-RAs discontinuation rate was 41.6%. For newly diagnosed patients with ITP who had discontinued TPO-RAs treatment, the response rate without further treatment (TFR) within 2 years of follow-up was 66.4%, with a cumulative incidence of loss of complete remission at 46.7%. Patients who responded within 14 days of initiating TPO-RAs had a higher TFR rate (87.5% vs. 48.5%; p = 0.0106).
Multicentric Experience with Patients with Worse Prognosis
A Spanish group published an experience showing a decrease in disease activity and achievement of sustained TFR in patients with a rather worse prognosis. Multicentric monitoring in 19 Spanish hospitals involved 82 patients who started TPO-RAs treatment between 2012 and 2014; data were collected until 2018. The median time from ITP diagnosis to the start of TPO-RAs treatment was 5.5 years (range 1.1−50.3 years). In all patients, TPO-RAs administration was initiated with the vision of long-term therapy.
During the follow-up, 47.6% of patients discontinued TPO-RAs treatment. With a median prior duration of TPO-RAs therapy of 1.4 years (range 0.1−3.3 years), 19 patients (23.2%) achieved a long-term sustained platelet count of ≥ 50 × 109/l without any additional therapy to increase platelet counts. Worse achievement of TFR seemed to be associated with switching between TPO-RAs. Better chances of achieving TFR were also observed in patients treated with romiplostim. The median time to reduce and discontinue TPO-RAs and achieve a sustained platelet response was 3.3 years (95% confidence interval [CI] 2.7−4.0 years).
Conclusion
A significant group of patients with ITP, whether newly diagnosed or long-term and chronic, can achieve a treatment response lasting even after discontinuation of TPO-RAs. A more favorable prognostic group appears to be patients who were primarily treated with romiplostim and did not switch between TPO-RAs.
(eza)
Sources:
1. Červinek L., Mayer J., Doubek M. Sustained remission of chronic immune thrombocytopenia after discontinuation of treatment with thrombopoietin-receptor agonists in adults. Int J Hematol 2015; 102 (1): 7−11, doi: 10.1007/s12185-015-1793-1.
2. Iino M., Sakamoto Y., Sato T. Treatment-free remission after thrombopoietin receptor agonist discontinuation in patients with newly diagnosed immune thrombocytopenia: an observational retrospective analysis in real-world clinical practice. Int J Hematol 2020 Aug; 112 (2): 159−168, doi: 10.1007/s12185-020-02893-y.
3. Lozano M. L., Mingot-Castellano M. E., Perera M. et al. Predictive factors for thrombopoietin receptor agonist free responses in chronic ITP patients: a multicenter retrospective study with long-term follow-up. Blood 2019; 134 (Suppl_1): 2370.
Did you like this article? Would you like to comment on it? Write to us. We are interested in your opinion. We will not publish it, but we will gladly answer you.