Tapering Eltrombopag in Patients with Chronic ITP: How Successful Is This and in Whom Does It Work?

• Published in: Blood 2015-12, Vol.126 (23), p.1054-1054
• Main Authors: Bussel, James B., Mahmud, Shah N., Brigstocke, Sophie L, Torneten, Sarah M
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V126.23.1054.1054

▪ Background: Thrombopoietin receptor agonists (TPO-RA) eg eltrombopag (Epag), are highly effective treatments of ITP as demonstrated in multiple randomized studies. Studies have shown effective and safe long-term use; toxicity appears tolerable with thromboembolism the most common serious adverse event. An important question is if there will be an indefinite long-term need for treatment with these agents once initiated. The aim of this study is to taper eltrombopag in a single arm study to determine how many and which patients will be able to discontinue treatment over time. It specifically targets patients with adequate counts ie 50-100,000/uL, not waiting for patients whose counts spontaneously increase to high levels and thus indicate that they are being over-dosed. Methods: All patients on eltrombopag at doses of 75 mg daily or less for at least 4 months were offered study entry; only one refused. Initially the study tapered Epag rapidly but then changed to slow tapering over up to 2 years. Patients whose platelet counts were >50,000/uL were tapered at 4 week intervals in 10-20% dose increments. Tapering could be postponed for clinical reasons ie impending procedure or trip, infection skewing count, sports or other physical activity, etc. Analysis was descriptive and t test comparisons used to assess variables associated with successful tapering. Results: Patients were divided into 3 groups: 10 responders (those able to discontinue eltrombopag completely within 2 years, fig 1A), 10 tapering (those still tapering who have reduced their medication but not discontinued it, fig 1B), and 12 non-responders (those who tried and failed to discontinue within 2 years). To complete being a responder required >12 weeks without any ITP treatment, platelet count > 30,000/uL and 20,000/uL more than baseline after the last dose of eltrombopag. Eight of the 10 responders have remained off therapy for more than 1 year with platelet counts consistently > 50,000/uL. No medication was provided in the study. No serious AEs occurred and no serious bleeding events were seen. Fig 1a illustrates the discontinuation of eltrombopag treatment in responders: 4 discontinued within 8 weeks while the longest discontinuation required a full 2 years. Fig 1b shows patients who are tapering eltrombopag but have not reached 2 years by indicating how many are on