Long-Term Treatment With Mycophenolate Versus Cyclophosphamide For Systemic Sclerosis-Associated Pulmonary Fibrosis: A Case Control Retrospective Study

Background Evidence from uncontrolled studies suggests that mycophenolate mofetil (MMF), an immunomodulatory agent which inhibits lymphocyte proliferation is beneficial for the treatment of systemic sclerosis (SSc)-associated pulmonary fibrosis. Objectives We sought to determine the efficacy and safety profile of long term treatment with MMF or mycophenolate sodium (MS) in SSc patients with pulmonary fibrosis and compare these results to cyclophosphamide (CYC), the gold standard treatment. Methods We retrospectively identified our SSc patients with “active” pulmonary fibrosis confirmed by CT scan who were able to perform pulmonary function tests and received MMF or MS for at least one year. Treatment had been always initiated in symptomatic patients with either first-diagnosed pulmonary fibrosis or with a >10% decrease in forced vital capacity (FVC) over the past 12 months. These patients were carefully matched 1:1 for disease characteristics and baseline FVC (±3% of predicted) with patients fulfilling the same criteria but had received CYC. Patients’ course, including changes in FVC, total lung capacity (TLC), and diffusion capacity of the lung for carbon monoxide (DLCO) at one and two years of continuous treatment were compared between groups. Results Ten patients received MMF (n=3) or MS (n=7), either for first-diagnosed symptomatic pulmonary fibrosis (n=3) or for significant deterioration of FVC, whereas CYC was given in 4 and 6 first-diagnosed or deteriorating patients, respectively.Pulmonary function tests (mean±SD % of predicted) for the MMF/MS group at baseline, at one-year and two-years of treatment were as follows: FVC: 78±14, 80±12 and 82±16, respectively; TLC: 71±16, 74±11, and 72±13, respectively; DLCO: 57±12, 55±10, and 52±8, respectively. The respective values in the CYC group were as follows: FVC: 77±12, 80±12, and 80±11; TLC: 64±15, 69±16 and 71±11; DLCO: 53±15, 56±15 and 57±8. FVC, TLC or DLCO did not change significantly after one- or two years of MMF/MS or CYC therapy. After two years of continuous treatment 6 of 10 patients in each group fulfilled the definition of stable disease by the American Thoracic Society, 3 patients in each group improved (>10% in FVC) and the remaining patient in both groups failed to meet criteria for stability, as FVC decreased by more than 10%. Both drugs were well tolerated in these patients and no serious adverse events occurred in either group. Conclusions These results suggest that long term treatment with MMF or MS can be a safe therapeutic modality having a comparable to CYC effect in stabilising pulmonary function in a small cohort of patients with SSc-associated pulmonary fibrosis. Disclosure of Interest None Declared