Real-life use of mTOR inhibitor-based therapy in adults with autoimmune cytopenia highlights strong efficacy in relapsing/refractory multi-lineage autoimmune cytopenia.

Data on mTOR inhibitors (mTORi) in autoimmune cytopenia (AIC), in adults are scarce. We retrospectively analysed 30 cases of refractory or relapsing AIC treated with an mTORi-based therapy. Eleven warm autoimmune hemolytic anaemia, 10 autoimmune thrombocytopenia, 6 acquired pure red cell aplasia, 3 autoimmune neutropenia were included. Twenty were multilineage AIC (67%) and 21 were secondary AIC (70%). mTORi were associated with other therapies in 23 AIC (77%). Twenty-two AIC (73%) responded to mTORi-based therapy: 5 reached a partial response (17%) and 17 a complete response (57%). Survival without unfavourable outcome (failure, requirement of a new therapy, or death) was longer in multilineage AIC compared to single-lineage AIC (p = 0.049) with a median event-free survival of 48 versus 12 months. Median event-free survival was 48 months in secondary AIC and 33 months in primary AIC (p = 0.79). mTORi were discontinued in 4 patients (15%) for safety reasons and in 3 patients for patient's choice (12%). In conclusion, mTORi could be considered as an alternative or an add-on therapy in refractory or relapsing AIC in adult patients, especially in multilineage AIC.