Researchers found it difficult to evaluate the therapy’s effectiveness in SSc due to the different organs involved and the lack of a well-assessed disease activity scale.
The study, “Efficacy and safety of rituximab in systemic sclerosis: French retrospective study and literature review,” published in Autoimmunity Reviews, aimed to investigate the long-term effects of rituximab use in SSc patients and to identify factors associated with treatment.
The study included medical data from 13 patients treated with rituximab and 26 SSc patients who were not treated with the therapy.
Researchers collected patient data from the Rodnan scale (mRSS, a measure of skin thickness used to assess disease outcomes in SSc clinical trials), dyspnea (shortness of breath), arthralgia (joint pain), and myalgia (muscle pain).
Several standard tests also assessed lung function, such as forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DCLO).
The 13 SSc patients had a median age of 44 and a median disease duration of 12 years. Rituximab was used to treat progressive interstitial lung disease in seven patients, joint involvement in six patients, heart disease in two participants, severe gastrointestinal involvement in three patients, and scleroderma kidney crisis and SSc-related myositis in one patient.
Although the 26 SSc patients who were not treated with rituximab (median age of 45) were matched to the treated group, they differed significantly in their disease duration, which was seven years (compared with 12 in the treated group).
Comparing the data from these two patient groups, the researchers found that rituximab treatment resulted in an improvement in DLCO in the 13 treated patients.
Lung function was also significantly improved in a subset of seven treated patients who had been diagnosed with diffuse SSc (dSSc), compared with 14 untreated dSSc patients.
Researchers also gathered information from previously published studies. This included data from 53 patients that indicated treatment with rituximab resulted in improvements in mRSS, lung function, and DLCO.
The researchers wrote that their own study data, combined with the published studies, confirms the effectiveness of rituximab in diffuse SSc, especially “in skin and interstitial disease involvements. The safety of rituximab seems to be reasonable and similar to previous data in other autoimmune diseases.”