Sirolimus as an Effective Agent in the Treatment of Immune Thrombocytopenia (ITP) and Evans Syndrome (ES): A Single Institution’s Experience

Background: Autoimmune cytopenias are characterized by immune-mediated destruction of hematopoietic cell lines with immune thrombocytopenia (ITP) affecting platelets and Evans syndrome (ES) affecting platelets and red blood cells. For patients with persistent disease, limited options for effective and well-tolerated therapies exist. Objectives: Our aim is to describe our institution’s experience with sirolimus as therapy for pediatric patients with persistent ITP and ES. Design/Method: A retrospective analysis was performed in patients with persistent ITP and ES treated with sirolimus. Responses were categorized as complete response (CR), partial response, modest response, or no response. Results: Of the 17 patients treated, 12 had ITP and 5 had ES. Seventy-three percent of ITP patients achieved a CR, 78% of them by 3 months. Only 2 patients did not achieve a durable response. Eighty percent of ES patients had a response, with 50% of them achieving CR and the other 50% an asymptomatic partial response. One patient with ES achieved modest response, but discontinued therapy due to an adverse effect. Of the patients that achieved CR, 90% remain off all therapy for a median of 2 years. Conclusions: Our data suggest that sirolimus is a safe and effective steroid-sparing agent in the treatment of persistent ITP and ES.