Background Systemic sclerosis (SSc) is a serious disease with high risk of interstitial lung disease (ILD); a feared complication with poor prognosis. The SLS 2¹ supported the clinical effectiveness of Mycophenolate Mofetil (MMF) and Cyclophosphamide (Cyc).

Objectives Evaluate the effect of MMF and Cyc on SSc-ILD in a population based cohort.

Methods All SSc patients at Oslo University Hospital (OUH) are included in an prospective, observational SSc cohort. All patients are followed annually by rheumatologists and data are recorded in the Norwegian systemic connective tissue disease registry (NOSVAR). Here, we assessed patients diagnosed after the year 2000 (n=433). Longitudinal pulmonary function tests (PFTs), HRCT lung image results, pulmonary hypertension (PH), clinical and demographic data, antibodies and vital status were obtained from NOSVAR. Outcome measures were vital status in December 2016, extent of fibrosis measured on HRCT, FVC and DLCO development.

Results Among 262 patients with complete data on treatment and ILD, 21 (8%) patients received treatment with Cyc, 14 (5.3%) with MMF and 17 (6.5%) with combination therapy of MMF and Cyc. 55.7% of patients did not receive any treatment for ILD. Baseline characteristics, lung fibrosis and function did not differ significantly between the MMF and Cyc (Table 1). Patients treated with Cyc show a trend of higher mortality. Treatment with Cyc resulted in a significant improvement of lung fibrosis; whereas treatment with MMF resulted in significant progression in lung fibrosis (-1.3% (SD 9.3) and 7.5% (SD 11.1), p=0.024) (Table 1). MMF treatment showed a significant improvement in the DLCO% (1.8% [SD 4.6]); whereas Cyc had a significant decline in the DLCO% (-2.1% [SD 3.5], p=0.14). Less patients treated with MMF developed PH compared with Cyc treatment (1[7.7%] compared to 8[42.1%], p=0.038) (Table 1).

Conclusions Preliminary data from our population based cohort indicate that in a real-life scenario treatment effects of Cyc and MMF appear comparable to randomized clinical trials, but there are some potentially important nuances. Cyc seems to halt fibrosis progression, but toxicity is a major concern, while MMF could have effects on DLCO decline and the development of PH.

References

1. Tashkin DP et al. Mycophenolate mofetil versus oral cyclophosphamide in SLS II. Lancet Respir Med. 2016.

References

Disclosure of Interest None declared