Tocilizumab in Refractory ASS-ILD

Hu Yinan111 enrolled

Overview

Refractory anti-synthetase syndrome-associated interstitial lung disease (ASyS-ILD) lacks targeted therapy. Interleukin-6 drives both inflammation and fibrosis. We evaluated the real-world efficacy and safety of tocilizumab, an IL-6 receptor antagonist. This single-center retrospective cohort study included patients with refractory ASyS-ILD treated between January 2020 and July 2025. Tocilizumab recipients were compared with those receiving standard of care (SOC) immunosuppressants. Overlap weighting based on propensity scores was used to balance 11 baseline variables. The primary outcome was improvement in symptoms and HRCT findings at ≥3 months. Secondary outcomes included changes in biomarkers and pulmonary function, progression-free survival (PFS), and adverse events. Cox regression identified independent predictors of symptom progression. Generalized additive models (GAM) explored nonlinear relationships, and XGBoost-SHAP machine learning assessed variable importance.

Study Type

OBSERVATIONAL

Enrollment

111

Conditions

Antisynthetase Syndrome Tocilizumab

Interventions

Tociliuzumab

Tocilizumab, a humanized monoclonal antibody against the IL-6 receptor, is approved for the treatment of rheumatoid arthritis, juvenile idiopathic arthritis, and giant cell arteritis. In patients with rheumatoid arthritis-associated ILD, tocilizumab has been shown to reduce KL-6 levels, a biomarker of alveolar epithelial injury. However, evidence for tocilizumab in ASyS-ILD is limited to isolated case reports, and no systematic evaluation of its efficacy and safety in this specific population has been published.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * age ≥18 years; * fulfillment of the 2017 EULAR/ACR classification criteria for ASyS; * HRCT-confirmed ILD; * refractory disease, defined as active disease despite prior treatment with glucocorticoids and at least one first-line immunosuppressant (including methotrexate, mycophenolate mofetil, azathioprine, cyclosporine, cyclophosphamide, baricitinib, or upadacitinib); * availability of baseline and follow-up clinical data at ≥3 months. Exclusion Criteria: * pregnancy or lactation; * pre-existing psychiatric disorders that would preclude study participation; * prior lung transplantation; * missing key outcome data; * Patients with Anti-MDA5 dermatomyositis.

Locations (1)

China-Japan Friendship Hospital

Beijing, Beijing Municipality, China

Outcomes

Primary Outcomes

Disease progression

Disease progression is classified data, which included the number of patients with symptoms progression（Symptom progression was defined as worsening of dyspnea, cough or rash requiring escalation of therapy or hospitalization） or with the worsening of pattern demonstrated on CT scans (defined as an increase in the extent of reticulation, traction bronchiectasis, or honeycombing on follow-up HRCT ) or the number of the patients with FVC% decline \>10% or with DLCO% decline \>15%.

Time frame: From the start of tocilizumab treatment or second-line treatment to disease progression, the longest possible duration is until October 31, 2025.