Rituximab and Cyclophosphamide in anti-synthetase syndrome (ASyS)-related ILD: an observational retrospective study
Abstract
Objective Anti-synthetase syndrome (ASyS)-related interstitial lung disease (ILD) has a poor prognosis. Intravenous cyclophosphamide (CYC) and rituximab (RTX) are the main treatments currently used for moderate to severe ILD. We compare the efficacy of CYC followed by standard immunosuppressive treatment (IST) vs. RTX in ASyS-related ILD.
Methods This observational retrospective study was conducted between 2003 and 2016 in three tertiary care centers. All patients with ASyS-related ILD and treated with CYC or RTX with at least six months of follow-up were included. Pulmonary progression-free survival (PFS) - defined according to the American Thoracic Society guidelines - was assessed at 6 months and 2 years. All severe adverse events were recorded.
Results Sixty-two patients were included. Thirty-four received 2-12 monthly intravenous CYC pulse, followed by standard IST in 30 cases (88%). RTX-group included 28 patients. Following initial day 1-day 15 infusions, RTX was repeated every 6 months in 26 cases (93%) and 15 patients (54%) received concomitantly another IST. Median steroid dose was similar between both groups. Although RTX and CYC demonstrated similar PFS at 6 months (92% vs. 81%, respectively), RTX was superior at 2-years (Hazard Ratio = 0,263 [0,094 - 0,732], p=0.011). Interestingly, lower DLCO at baseline was independently predictive of poor 2-year PFS (0.965 [0.936-0.995], p=0.023). FVC and DLCO improved in both groups without significant difference. Serious adverse events were similar in both groups.
Conclusion Despite similar PFS at 6 months, RTX was associated with a better 2-year PFS compared to CYC in patients with ASyS-related ILD.