Open-label pilot trial reveals B cell depletion without significant skin score improvement in diffuse cutaneous systemic sclerosis, suggesting limited short-term clinical benefit.
Key Points
To evaluate the safety, preliminary clinical efficacy, and biological effects of rituximab on autoimmunity and fibrosis in patients with diffuse cutaneous systemic sclerosis.
Enrolled 15 patients with early diffuse cutaneous systemic sclerosis (first non-Raynaud's symptom within 18 months) in an open-label pilot trial.
Administered two 1,000 mg intravenous infusions of rituximab spaced two weeks apart, evaluating outcomes at baseline and 6 months.
Measured the primary endpoint of change in the modified Rodnan skin thickness score (MRSS) along with pulmonary function and skin biopsy infiltrates.
The mean change in the modified Rodnan skin thickness score between baseline and 6 months was not statistically significant, and pulmonary function measures remained stable.
Rituximab achieved complete depletion of dermal B cell infiltrates in most skin biopsies at 6 months alongside peripheral B cell clearance, with only modest, variable changes in autoantibody titers.
Adverse events were marked by frequent infusion reactions and rare infectious complications, specifically one urinary tract infection and one dental abscess.