Idiopathic inflammatory myopathies (IIM) represent a rare and heterogenous group diseases, and their treatment is not fully defined yet. According to previous small case series, the combination of mycophenolate mofetil (MMF) and rituximab (RTX) may be effective in controlling difficult-to-treat patients. Our aim was to further explore the efficacy and safety of this combined approach in patients with IIM. Patients with IIM treated with the RTX/MMF combination in our Center were retrospectively identified. After the start of combination therapy, the efficacy was evaluated at 12 months (T12) according the 2016 ACR/EULAR response criteria for IIM. Cardiac imaging and pulmonary function tests were used to monitor disease activity in patients with myocarditis and interstitial lung disease, respectively. Adverse events were recorded over the follow-up period. Among the 20 patients (median age 61 years; 70% female) included in the study, anti-synthetase syndrome was the most prevalent IIM subgroup (60%). At treatment start, muscle, heart, and lung were the most commonly actively affected organs. After 12 months, a moderate or major response was observed in all patients, and creatine kinase was significantly decreased (p-value = 0.012). Cardiac imaging and enzymes monitoring showed a reduction of heart inflammation, while pulmonary function tests improved in patients with lung involvement. No severe side effects were observed. Our data show that combination of RTX and MMF is effective and safe in patients with severe and refractory IIM. Therefore, this combined treatment might represent a feasible approach for difficult-to-treat IIM cases.

中文翻译：

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吗替麦考酚酯和利妥昔单抗联合治疗免疫特发性肌病的有效性和安全性

特发性炎症性肌病（IIM）是一种罕见且异质的疾病，其治疗方法尚未完全明确。根据之前的小病例系列研究，吗替麦考酚酯（MMF）和利妥昔单抗（RTX）的联合治疗可能能有效控制难治性患者。我们的目的是进一步探讨这种联合方法对 IIM 患者的疗效和安全性。对我们中心接受 RTX/MMF 联合治疗的 IIM 患者进行回顾性鉴定。联合治疗开始后，根据2016年ACR/EULAR IIM缓解标准在12个月（T12）评估疗效。心脏成像和肺功能测试分别用于监测心肌炎和间质性肺疾病患者的疾病活动性。在随访期间记录不良事件。在该研究纳入的 20 名患者（中位年龄 61 岁；70% 为女性）中，抗合成酶综合征是最常见的 IIM 亚组 (60%)。在治疗开始时，肌肉、心脏和肺是最常受影响的器官。 12 个月后，所有患者均观察到中度或主要反应，肌酸激酶显着下降（p 值 = 0.012）。心脏成像和酶监测显示心脏炎症减少，而肺部受累患者的肺功能测试有所改善。没有观察到严重的副作用。我们的数据表明，RTX 和 MMF 联合治疗对于严重难治性 IIM 患者是有效且安全的。因此，这种联合治疗可能是治疗难治性 IIM 病例的一种可行方法。