Università Vita-Salute San Raffaele, All at IRCCS San Raffaele Scientific Institute, Milan, Italy; Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR), All at IRCCS San Raffaele Scientific Institute, Milan, Italy.
Università Vita-Salute San Raffaele, All at IRCCS San Raffaele Scientific Institute, Milan, Italy; Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR), All at IRCCS San Raffaele Scientific Institute, Milan, Italy.
Eur J Intern Med. 2021 Feb;84:63-67. doi: 10.1016/j.ejim.2020.12.006. Epub 2020 Dec 29.
Rituximab is increasingly used in IgG4-related disease (IgG4-RD) but high costs limit its wide off-label administration. European and US regulatory agencies have recently approved rituximab biosimilars for the treatment of different rheumatologic and hematological conditions. No data are available, yet, on the efficacy and safety of rituximab biosimilars for the treatment of IgG4-RD. Scope of the present work is to evaluate the efficacy and safety of the rituximab biosimilar CT-P10 (RTX-B) in patients with IgG4-RD.
Patients with active IgG4-RD, naïve to rituximab or switched from the originator (RTX-O) to the biosimilar were treated with RTX-B and prospectively followed-up for 18 months. Safety and efficacy were assessed at six months. Relapse rate was assessed at 18 months. Disease activity was assessed by means of the IgG4-RD Responder Index (IgG4-RD RI).
Thirty-eight patients were included in this study. Thirty-three patients (87%) were naïve to RTX. Five patients (13%) relapsed after RTX-O and were switched to RTX-B. After six months, 21 patients (60%) achieved disease remission. The median serum IgG4 concentration decreased from 1344 to 575 mg/L (p < 0.01), and the median IgG4-RD RI decreased from 7.5 to 0 (p < 0.01). B-cell depletion was observed in all patients. Eight patients (36%) relapsed within 18 months. Side effects related to RTX-B administration were observed in 14 patients (37%). These results are in line with our previous experience with RTX-O.
The (Truxima) rituximab biosimilar CT-P10 represents a safe and effective alternative to rituximab originator for the treatment of IgG4-RD.
利妥昔单抗（RTX）在 IgG4 相关疾病（IgG4-RD）中的应用日益增多，但高昂的费用限制了其在适应证外的广泛应用。欧洲和美国的监管机构最近批准了利妥昔单抗生物类似药，用于治疗不同的风湿免疫性和血液系统疾病。然而，目前尚无关于利妥昔单抗生物类似药治疗 IgG4-RD 的疗效和安全性的数据。本研究旨在评估 IgG4-RD 患者使用利妥昔单抗生物类似药 CT-P10（RTX-B）的疗效和安全性。
本研究前瞻性纳入了接受利妥昔单抗治疗且随访时间至少 18 个月的 IgG4-RD 患者。患者先前未使用过利妥昔单抗（RTX 初治）或由原研药（RTX-O）转换为生物类似药（RTX-B）。在治疗 6 个月和 18 个月时分别评估疗效和安全性，在 18 个月时评估复发率。采用 IgG4-RD 应答指数（IgG4-RD RI）评估疾病活动度。
本研究共纳入 38 例患者，其中 33 例（87%）为 RTX 初治，5 例（13%）为 RTX-O 治疗后复发而转换为 RTX-B。治疗 6 个月后，21 例（60%）患者达到疾病缓解。治疗后 6 个月时，患者的血清 IgG4 浓度中位数从 1344 降至 575mg/L（p<0.01），IgG4-RD RI 中位数从 7.5 降至 0（p<0.01）。所有患者均出现 B 细胞耗竭。18 个月时 8 例（36%）患者复发。14 例（37%）患者出现与 RTX-B 治疗相关的不良反应。这些结果与我们先前使用 RTX-O 的经验一致。
RTX-B（Truxima）是治疗 IgG4-RD 的一种安全有效的利妥昔单抗原研药替代药物。
