Sirolimus is effective and safe in childhood relapsed-refractory autoimmune cytopenias: A multicentre study

Autoimmune cytopenias are a heterogeneous group of disorders characterized by immune-mediated destruction of haematopoietic cell lines. Effective and well-tolerated treatment options for relapsed-refractory immune cytopenias are limited. In this study, the aim was to evaluate the efficacy and safety of sirolimus in this disease group within the paediatric age group. The study enrolled patients in the paediatric age group who used sirolimus with a diagnosis of immune cytopenia between December 2010 and December 2020, followed at six centres in Turkey. Of the 17 patients, five (29.4%) were treated for autoimmune haemolytic anaemia (AIHA), six (35.2%) for immune thrombocytopenic purpura (ITP) and six (35.2%) for Evans syndrome (ES). The mean response time was 2.7 months (range, 0-9 months). Complete response (CR) and partial response (PR) were obtained in 13 of 17 patients (76.4%) and nonresponse (NR) in four patients (23.5%). Among the 13 patients who achieved CR, three of them were NR in the follow-up and two of them had remission with low-dose steroid and sirolimus. Thus, overall response rate (ORR) was achieved in 12 of 17 patients (70.5%). In conclusion, sirolimus may be an effective and safe option in paediatric patients with relapsed-refractory immune cytopenia.