Rituxan is a CD20-directed cytolytic antibody.
Rituxan is specifically indicated for the treatment of adult patients with moderate to severe pemphigus vulgaris.
Rituxan is supplied as an injection for intravenous administration. The recommended dose is as follows:
Administer Rituxan as two-1000 mg intravenous infusions separated by 2 weeks in combination with a tapering course of glucocorticoids.
Maintenance treatment: Administer Rituxan as a 500 mg intravenous infusion at Month 12 and every 6 months thereafter or based on clinical evaluation. Treatment of relapse: Administer Rituxan as a 1000 mg intravenous infusion on relapse, and consider resuming or increasing the glucocorticoid dose based on clinical evaluation.
Subsequent infusions of Rituxan may be administered no sooner than 16 weeks following the previous infusion.
The FDA approval of Rituxan for PV was based on the Ritux 3 trial, a Roche-supported, randomized, controlled trial conducted in France that used Roche-manufactured, European Union (EU)-approved rituximab product as the clinical trial material. The study compared the Ritux 3 regimen (EU-approved rituximab product plus short-term corticosteroids [CS]) to CS alone as a first-line treatment in patients with newly diagnosed, moderate to severe pemphigus. The primary endpoint of the study was complete remission at month 24 without the use of steroids for two or more months. (Complete remission defined as complete epithelialization and absence of new and/or established lesions.) Results of the study showed that 90 percent of PV patients treated with the Ritux 3 regimen met the endpoint, compared to 28 percent of PV patients treated with CS alone.
Adverse effects associated with the use of Rituxan for PV may include, but are not limited to, the following:
The Rituxan drug label comes with the following Black Box Warning:
Infusion-Related Reactions: Rituxan administration can result in serious, including fatal, infusion-related reactions. Deaths within 24 hours of Rituxan infusion have occurred. Approximately 80% of fatal infusion reactions occurred in association with the first infusion. Monitor patients closely. Discontinue Rituxan infusion for severe reactions and provide medical treatment for Grade 3 or 4 infusion-related reactions. Severe Mucocutaneous Reactions Severe, including fatal, mucocutaneous reactions can occur in patients receiving Rituxan. Hepatitis B Virus (HBV) Reactivation: HBV reactivation can occur in patients treated with Rituxan, in some cases resulting in fulminant hepatitis, hepatic failure, and death. Screen all patients for HBV infection before treatment initiation, and monitor patients during and after treatment with Rituxan. Discontinue Rituxan and concomitant medications in the event of HBV reactivation. Progressive Multifocal Leukoencephalopathy (PML), including fatal PML, can occur in patients receiving Rituxan.
Rituxan (rituximab) is a monoclonal antibody that targets the CD20 antigen expressed on the surface of pre-B and mature B-lymphocytes. Upon binding to CD20, rituximab mediates B-cell lysis. Possible mechanisms of cell lysis include complement dependent cytotoxicity (CDC) and antibody dependent cell mediated cytotoxicity (ADCC). B cells are believed to play a role in the pathogenesis of rheumatoid arthritis (RA) and associated chronic synovitis. In this setting, B cells may be acting at multiple sites in the autoimmune/inflammatory process, including through production of rheumatoid factor (RF) and other autoantibodies, antigen presentation, T-cell activation, and/or proinflammatory cytokine production.
For additional information regarding Rituxan or pemphigus vulgaris, please visit https://www.rituxan.com/