Department of Haematology, UCLH NHS Foundation Trust, London, UK.
Department of Haematology, UCLH and Cardiometabolic Programme-NIHR UCLH/UC BRC London, London, UK.
Br J Haematol. 2019 Jun;185(5):912-917. doi: 10.1111/bjh.15874. Epub 2019 Mar 28.
Immune thrombotic thrombocytopenic purpura (iTTP) is an acute, multisystem thrombotic microangiopathy mediated by ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) autoantibodies. Immunosuppression with anti-CD20 therapy is the mainstay of treatment. MabThera's patent has now expired and biosimilars have been approved. Eighty-four consecutive patient episodes over 2 years, prior to and following our switch to Truxima are presented. Day 1 (D1), Day 28 (D28) and 3-month platelet counts, ADAMTS13 activity, and CD19 levels, adverse reactions and infective complications were recorded. Platelet counts were not significantly different between acute MabThera and Truxima treatment (D1 P = 0.085, D28 P = 0.77, 3 months P = 0.71) and electively (D1 P = 0.79, D28 P = 0.68, 3 months P = 0.99). ADAMTS13 recovery also was not significantly different acutely (D1 P = 0.99, D28 P = 0.27, 3 months P = 0.26) and electively (D1 P = 0.59, D28 P = 0.61, 3 months P = 0.34). CD19% depletion at D1 and 3 months was not significantly different acutely (D1 P = 0.52, 3 months P = 0.56) and electively (D1 P = 0.22, 3 months P = 0.19). Infusion reactions and infective complications were comparable with both therapies. This is the first series of the Rituximab biosimilar Truxima to be reported in iTTP, demonstrating equivalence to MabThera in terms of ADAMTS13 recovery, CD19 depletion, and platelet count at D28 and 3 months post-administration, with comparable infusion and infective complications. The financial benefit of the biosimilar anti-CD20 is considerable.
免疫性血栓性血小板减少性紫癜（iTTP）是一种由 ADAMTS13（一种带有血栓反应蛋白 1 型基序的解整合素和金属蛋白酶，成员 13）自身抗体介导的急性、多系统血栓性微血管病。用抗 CD20 治疗抑制免疫是治疗的主要方法。MabThera 的专利现已过期，生物类似药已获得批准。本文介绍了我们在切换到 Truxima 前后 2 年连续 84 例患者的病例。记录了第 1 天（D1）、第 28 天（D28）和第 3 个月的血小板计数、ADAMTS13 活性和 CD19 水平、不良反应和感染性并发症。急性 MabThera 和 Truxima 治疗（D1 P=0.085，D28 P=0.77，3 个月 P=0.71）和择期治疗（D1 P=0.79，D28 P=0.68，3 个月 P=0.99）之间的血小板计数无显著差异。急性（D1 P=0.99，D28 P=0.27，3 个月 P=0.26）和择期（D1 P=0.59，D28 P=0.61，3 个月 P=0.34）ADAMTS13 恢复也无显著差异。D1 和 3 个月时 CD19%耗竭无显著差异，急性（D1 P=0.52，3 个月 P=0.56）和择期（D1 P=0.22，3 个月 P=0.19）。输注反应和感染性并发症与两种治疗方法相当。这是首例在 iTTP 中报道的利妥昔单抗生物类似药 Truxima，结果表明，在 ADAMTS13 恢复、CD19 耗竭和 D28 及 3 个月后的血小板计数方面，与 MabThera 相当，输注和感染性并发症也相当。生物类似物抗 CD20 的经济优势是相当可观的。
