Tocilizumab and rituximab for systemic sclerosis interstitial lung disease: a real-world cohort analysis.

OBJECTIVES

Systemic sclerosis (SSc)-interstitial lung disease (ILD) is one of the leading causes of mortality in SSc. Data from randomised controlled trials (RCTs) supports rituximab and tocilizumab monotherapy but there is limited data regarding their use for those who fail standard immunomodulatory therapies.

METHODS

SSc patients treated with rituximab or tocilizumab were retrospectively identified in a single centre cohort. Linear mixed effect models were used to analyse before and after treatment lung function trajectory and identify patient characteristics associated with treatment response.

RESULTS

127 patients were included for analysis. 51 of 94 (51.4%) and 13 of 33 (39.4%) of the rituximab and tocilizumab cohorts respectively were receiving concurrent mycophenolate mofetil. Pre-treatment decline in absolute change %FVC/year and %DLCO/year respectively, was similar in both cohorts (-3.2% and -4.0% rituximab and -3.2% and -3.6% tocilizumab). Both treatments resulted in lung function stabilisation (%FVC/year and %DLCO/year: 1.2% and +0.2% rituximab cohort, 1.0% and 1.0% tocilizumab cohort). Anti-topoisomerase antibody (ATA) positive patients had a significant response on %FVC/year to tocilizumab compared with ATA negative patients. Gender had a significant impact on %FVC/year response to rituximab, with males responding to a greater degree than females. Age, ILD extent and skin subset had no impact on treatment response.

CONCLUSION

Combination rituximab or tocilizumab with background immunosuppressive therapy is associated with stabilisation in lung function trajectory among those who remain refractory to standard immunosuppressives. Specific patient characteristics have an impact on lung function response. Improved FVC response among ATA patients receiving tocilizumab validate data from RCTs.