Treatment With Mycophenolate and Cyclophosphamide Leads to Clinically Meaningful Improvements in Patient‐Reported Outcomes in Scleroderma Lung Disease: Results of Scleroderma Lung Study II

Abstract

Objective Our objective was to determine if treatment with cyclophosphamide (CYC) and mycophenolate mofetil (MMF) improves patient‐reported outcomes (PROs) among patients with systemic sclerosis‐related interstitial lung disease (SSc‐ILD). Methods This study examined PROs in patients with SSc‐ILD (N = 142) who participated in the Scleroderma Lung Study II, a randomized controlled trial comparing MMF for 2 years with oral CYC for 1 year followed by 1 year of a placebo. Joint models were created to evaluate the course of PROs over 2 years. The difference in PRO scores from baseline to 24 months was measured, and the percentage of patients meeting the minimum clinically important difference (MCID) was calculated. Correlations between PROs and SSc‐ILD disease severity measures were also examined. Results Treatment with CYC and MMF led to improvements in several PROs with no between‐treatment differences. Scores for the Transitional Dyspnea Index (TDI) and St. George’s Respiratory Questionnaire (SGRQ) improved significantly over 2 years, and 29%/24% and 28%/25% of participants in the CYC/MMF groups met or exceeded the MCID estimates for TDI and SGRQ, respectively. At baseline, the forced vital capacity (FVC) percentage predicted (FVC%‐predicted) did not correlate with the Baseline Dyspnea Index or SGRQ. However, improvements in the FVC%‐predicted were weakly associated with improvements in dyspnea (assessed by the TDI) and SGRQ scores. Conclusion Treatment with CYC and MMF improved overall health‐related quality of life in patients with SSc‐ILD. The relationship between PRO measures and the FVC was relatively weak, suggesting that PROs provide complementary information about treatment efficacy not captured by changes in the FVC alone in this patient population.