Sirolimus is effective for primary relapsed/refractory autoimmune cytopenia: a multicenter study

Area of Science:

• Hematology
• Immunology
• Pharmacology

Background:

• Autoimmune cytopenias, such as autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), and Evans syndrome (ES), present significant challenges due to high refractory and relapse rates.
• Current treatment options for these conditions often have limitations, necessitating the exploration of novel therapeutic strategies.

Purpose of the Study:

• To evaluate the efficacy and toxicity of sirolimus in patients with primary relapsed or refractory autoimmune cytopenias.
• To determine the response rates, duration of response, and adverse events associated with sirolimus treatment.

Main Methods:

• A retrospective study collected data from 45 patients (3 pediatric, 42 adult) with relapsed/refractory AIHA, ITP, or ES treated with sirolimus between October 2016 and January 2019.
• Patients were treated for a median of 14 months and followed up for a median of 18 months.
• Response was assessed based on complete responses (CRs) and overall response rates, with adverse events meticulously recorded.

Main Results:

• Sirolimus treatment led to a response in 38 out of 45 patients, with 28 achieving complete responses (CRs) at a median of 2 months.
• The CR rate was 46.7% and the overall response rate was 75.6% at the end of follow-up.
• The most common adverse event was mucositis (5 patients); other adverse events occurred in less than 5% of patients, indicating good tolerance. AIHA patients showed better response and lower relapse rates.

Conclusions:

• Sirolimus demonstrates significant efficacy in treating primary relapsed/refractory autoimmune cytopenias.
• The drug is well-tolerated, with a low incidence of severe adverse events and a low relapse rate.
• Sirolimus represents a promising therapeutic option for patients with difficult-to-treat autoimmune cytopenias.