Eltrombopag for the treatment of refractory connective tissue disease-related thrombocytopenia: a pilot study of 52 cases

Abstract

The objective of this study was to investigate the therapeutic effectiveness and safety profile of Eltrombopag, a thrombopoietin receptor agonist, as prolonged therapy in refractory CTD-ITP patients. We conducted a pilot observational study of Eltrombopag in CTD-ITP patients who were unresponsive to or intolerant of conventional medications. Eltrombopag was administered orally at 25–75 mg/qd and adjusted on the basis of tolerance and efficacy until a minimum dosage of 25 mg/qd was reached. Clinical and laboratory data were collected and analysed monthly. The therapeutic response, relapse, and adverse events during the follow-up were also reviewed and evaluated. Fifty-two patients were enrolled and followed monthly for a median of 6 months. Thirty-six (90%) patients achieved durable overall remission. The remission rates were 67.5% at month 1, 87.5% at month 2, 97.5% at month 3, and 95% at month 6. The platelet count of the patients improved significantly, with the median reaching 50 × 109/L within 2 weeks (p = 0.003). Disease activity indices were reduced in SLE and pSS patients (p = 0.016), allowing glucocorticoid tapering (p = 0.004). One patient had no response, four relapsed, and fifteen (28.8%) experienced clinically relevant adverse events. In the analyses, protopathy, comorbidity, and prior treatment were associated with efficacy. For refractory CTD-ITP patients, Eltrombopag demonstrated significant clinical improvement, safety, and a steroid-sparing effect with prolonged use. Patient characteristics at baseline may affect treatment efficacy. First-line treatment with immunosuppressant therapy has a poor effect on ITP secondary to connective tissue disease and brings unignorable side effects on patients. Few studies have sufficiently elucidated the effects of Eltrombopag, a thrombopoietin receptor agonist, in refractory ITP secondary to CTD. Here, we report a series of refractory ITP-CTD patients treated with Eltrombopag. A 90% durable overall remission rate was observed at week 24, and remission rates promptly increased from 67.5% at month 1 to 89.5% at month 2. Eltrombopag had a rapid onset of action and permitted a steroid-sparing effect as the response was sustained. A 28.8% adverse event rate was observed. The baseline characteristics of patients may influence drug efficacy. This study may provide important supporting information for developing a treatment strategy for refractory CTD-ITP patients based on Eltrombopag.