Mycophenolate mofetil is an effective and safe option for the management of systemic sclerosis-associated interstitial lung disease: Results from the Australian Scleroderma Cohort Study

Objective. To report the efficacy and tolerability of mycophenolate mofetil (MMF) and azathioprine (AZA) in the management of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Methods. Patients in the Australian Scleroderma Cohort Study treated with at least 3 months of MMF or AZA for SSc-ILD confirmed on high resolution computed tomography (HRCT) chest were identified and their pulmonary function tests (PFTs) retrieved. Individuals with available results for T-1 (12 months prior to treatment commencement), T0 (date of treatment commencement) and at least one subsequent time point were included in the drug efficacy analysis. The Wilcoxon signed-rank test was used to compare absolute FVC at T-1, T0, 12 months (T1), 24 months (T2) and 36 months (T3). Analysis of drug tolerability included all identified patients treated with MMF or AZA. Results. 18/22 patients treated with MMF and 29/49 treated with AZA had adequate PFTs for inclusion in the drug efficacy analysis. Median absolute FVC at T-1 for MMF treatment was 2.50L, declining to 2.12L at T0 (p=0.02). Following MMF therapy, FVC results were stable at T1 (2.13L, p=0.86), T2 (2.17L, p=0.65) and T3 (2.25L, p=0.78). In the AZA group, a statistically significant decline did not occur prior to treatment, however FVC results remained stable at T1, T2 and T3. Adverse events leading to early discontinuation ( < 12 months treatment) were less common in the MMF group (4/22 vs. 13/49). Gastrointestinal complications were the main cause of discontinuation in both groups. Conclusion. In patients with SSc-ILD with declining pulmonary function, MMF therapy was associated with stability for up to 36 months. Early adverse events leading to discontinuation occurred less frequently in patients treated with MMF than in AZA treated patients.