Low-dose Rituximab in Adults with Autoimmune Haematological Disorders: A Review

Rituximab, a monoclonal anti-CD20 antibody, has proven to be an excellent therapeutic agent for haematological diseases. Low-dose rituximab (LDR; 100 mg weekly for 4 weeks) has emerged as a promising alternative to the standard dosing (375 mg/m²) for autoimmune haematological disorders, offering comparable efficacy with reduced adverse events and costs. In this review, the authors examine LDR’s role in immune thrombocytopenia, thrombotic thrombocytopenic purpura, and autoimmune haemolytic anaemia (AIHA) in the adult population. For immune thrombocytopenia, studies demonstrate that LDR achieves high overall response rates in both patients with relapsed/refractory disease and those who are newly diagnosed, confirming its non-inferiority to standard dosing. Combination therapies including thrombopoietin agonists further enhance efficacy. Single-dose rituximab shows comparable efficacy to LDR, but reduces indirect costs derived from hospital visits. In thrombotic thrombocytopenic purpura, LDR combined with plasma exchange plus steroids reduces relapse rates, in-hospital stays, and procedures, though prospective data remains limited. For AIHA, LDR combined with steroids or other agents (such as the immunomodulatory drug, bortezomib) induces high response rates, particularly in warm AIHA. Overall, LDR exhibits favourable safety (with minimal infectious complications) and cost-effectiveness across these disorders. While current evidence supports LDR as a front-line or salvage therapy, further research is needed to optimise dosing, identify ideal candidates, and validate combination strategies in randomised trials.