What is the indication, dosage, and duration of rituximab (Rituxan) in patients with systemic sclerosis?

From the Guidelines

Rituximab should be considered for the treatment of skin fibrosis in systemic sclerosis, with a recommended dosage of 375 mg/m² weekly for four consecutive weeks, as supported by a double-blind RCT 1. The indication for rituximab in systemic sclerosis is for the treatment of skin fibrosis, particularly in patients with severe, progressive disease that has not responded to standard therapies.

• The dosage of rituximab used in the study was 375 mg/m² weekly for four consecutive weeks, which is not the usual dose used for other rheumatic diseases.
• The treatment duration is individualized, but the study suggests that four intravenous doses of rituximab given once per week for 4 weeks can lead to significant improvement in skin fibrosis.
• The study found that rituximab was well-tolerated, with no difference in adverse events compared to the placebo group 1.
• The decision to use rituximab should be made by specialists experienced in managing systemic sclerosis after careful consideration of the risk-benefit profile for each patient.
• Patients should be monitored for infections, progressive multifocal leukoencephalopathy, and hypogammaglobulinemia during treatment.
• Rituximab works by depleting CD20+ B cells, which are implicated in the pathogenesis of systemic sclerosis through autoantibody production, cytokine secretion, and fibroblast stimulation.
• Before initiating treatment, patients should undergo screening for hepatitis B, tuberculosis, and immunoglobulin levels.
• Premedication with acetaminophen, antihistamines, and sometimes corticosteroids is recommended to reduce infusion reactions.
• Another study also supported the use of rituximab for the treatment of SSc-ILD, with a significant improvement in FVC at 24 weeks compared to baseline 1.

From the Research

Indication of Rituximab in Systemic Sclerosis

• Rituximab is indicated for the treatment of systemic sclerosis (SSc) associated with interstitial lung disease (ILD) 2, 3, 4, 5, 6.
• The main indications for rituximab in SSc are interstitial lung fibrosis, cutaneous, and/or articular manifestations unresponsive to previous therapies 2.
• Rituximab may be used to treat patients with SSc who have failed standard immunomodulatory therapies 6.

Dosage of Rituximab in Systemic Sclerosis

• The dosage of rituximab used in the treatment of SSc is typically 4 weekly infusions of 375mg/m(2) 2.
• Some studies have used rituximab in combination with other immunosuppressive therapies, such as mycophenolate mofetil 6.

Duration of Rituximab Treatment in Systemic Sclerosis

• The duration of rituximab treatment in SSc can vary, but some studies have reported treatment durations of up to 2 years or more 2, 3, 5.
• Long-term treatment with rituximab may be necessary to achieve and maintain clinical benefits in patients with SSc 5.
• The optimal duration of rituximab treatment in SSc is not well established and may depend on individual patient factors and response to treatment 4.

Efficacy of Rituximab in Systemic Sclerosis

• Rituximab has been shown to improve lung function and skin fibrosis in patients with SSc 2, 3, 4, 5.
• Rituximab may also improve other clinical manifestations of SSc, such as arthritis and cutaneous sclerosis 2.
• The efficacy of rituximab in SSc may depend on individual patient factors, such as the presence of anti-topoisomerase antibodies (ATA) and gender 6.