B cell depletion with rituximab in patients with diffuse cutaneous systemic sclerosis

Area of Science:

• Immunology
• Rheumatology
• Dermatology

Background:

• Diffuse cutaneous systemic sclerosis (dcSSc) is an autoimmune condition characterized by fibrosis and potential organ involvement.
• Current treatments for dcSSc have limitations, necessitating exploration of novel therapeutic strategies.
• B cells are implicated in the pathogenesis of systemic sclerosis.

Purpose of the Study:

• To evaluate the safety and tolerability of rituximab in patients with dcSSc.
• To assess the preliminary efficacy of rituximab on skin manifestations and autoimmunity in dcSSc.
• To investigate the impact of rituximab on B cell populations in dcSSc patients.

Main Methods:

• A pilot study involving fifteen patients with dcSSc receiving two doses of rituximab (1,000 mg each) intravenously, two weeks apart.
• Safety, clinical outcomes, and exploratory markers were assessed at baseline and six months post-treatment.
• The primary efficacy endpoint was the change in the modified Rodnan skin thickness score (MRSS) at six months.

Main Results:

• Rituximab was generally safe and well-tolerated, with infusion reactions and rare infections as primary adverse events.
• No significant change in MRSS was observed at six months, indicating limited impact on skin thickness.
• B cell depletion in circulation and skin was achieved, but autoantibody titers showed minimal changes. Pulmonary function remained stable.

Conclusions:

• Rituximab demonstrated a favorable safety profile in this cohort of dcSSc patients.
• While rituximab effectively depleted B cells, it did not yield significant clinical benefits for skin manifestations or autoantibody levels.
• Further investigation is warranted to explore rituximab's potential in other organ systems affected by dcSSc.