Recombinant human thrombopoietin in combination with cyclosporin A as a novel therapy in corticosteroid-resistant primary immune thrombocytopenia.

Background: The management of patients with refractory immune thrombocytopenia (ITP) is challenging, as there is no standard treatment option. The aim of this study was to investigate the efficacy of recombinant human thrombopoietin (rhTPO) in combination with cyclosporin A (CsA) for the management of patients with corticosteroid-resistant primary ITP.

Methods: Thirty-six patients with corticosteroid-resistant ITP were randomly divided into an observation group and control group. In the observation group, 19 patients received subcutaneous injection of rhTPO at a dose of 1 µg/kg (300 U/kg) once daily up to day 14. Simultaneously they also received oral CsA at a dose of 1.5-2.0 mg/kg twice daily for three months. In the control group, rhTPO alone was administered subcutaneously at 1 µg/kg once daily in the other 17 ITP patients for 14 consecutive days and then the treatment was withdrawn.

Results: There was no significant difference in the response rate at the end of the first week after treatment initiation between the observation group and the control group (63.2% vs. 58.8%, P > 0.05), neither was there at the end of the second week (89.5% vs. 94.1%, P > 0.05). However, the relapse rate in the observation group was significantly lower than that in control group at the end of the first (17.7% vs. 50.0%, P < 0.05), second (29.4% vs. 68.8%, P < 0.05) and the third month (29.4% vs. 87.5%, P < 0.01). In addition, rhTPO plus CsA were well tolerated and adverse events recorded were mild.

Conclusions: Combination therapy with rhTPO and CsA was effective in the management of patients with corticosteroidresistant ITP, with a relatively short time to response and low recurrence rate. It might be considered as a potential secondline treatment regimen for ITP.