Rituxan Approved for Rheumatoid Arthritis
Rituxan, one of the world's best-selling cancer drugs, has been approved by the U.S. Food and Drug Administration to be used in combination with methotrexate as a treatment for rheumatoid arthritis. The goal of Rituxan treatment is to reduce the signs and symptoms of rheumatoid arthritis in adult patients who have moderately-to-severely active disease and who have failed one or more TNF blockers, which may include Enbrel (etanercept), Remicade (infliximab), or Humira (adalimumab).
The Mechanism of Rituxan Treatment
Rituxan selectively targets CD20-positive B-cells (b-lymphocytes). Rituxan is the first treatment for rheumatoid arthritis which selectively targets the CD20-positive B-cells. Though rheumatoid arthritis has previously been considered a T-cell-mediated disease, other research has revealed that B-cells play roles in the initiation and development of rheumatoid arthritis.
Three Controlled Studies Were Basis for Rituxan Approval
The decision to approve Rituxan for rheumatoid arthritis was based on results from three randomized, double-blind, placebo-controlled studies of patients with active rheumatoid arthritis.
In REFLEX, the phase III trial, a significantly higher number of patients who received a single treatment (two infusions) of Rituxan along with methotrexate achieved clinical endpoints (ACR20, ACR50, ACR70) compared to patients taking placebo and methotrexate.
At 24 weeks, Rituxan patients had significant improvement in signs and symptoms associated with rheumatoid arthritis, including pain and disability.
How Is Rituxan Administered?
Rituxan is given to the patient as two 1000 mg. I.V. infusions separated by two weeks. It is given in combination with methotrexate. Thirty minutes prior to each infusion, it has been recommended that the steroid methylprednisolone 200 mg. I.V. be given.
The course of treatment is repeated every 6 to 9 months, according to Genentech and Biogen, the makers of Rituxan.
What Is The Cost of Rituxan Treatment?
The cost of a course of treatment with Rituxan costs about $9,088, said to be equivalent to the TNF blocker drugs on an annual basis.
How Is Rituxan Different from Other Biologic Drugs?
The currently available biologic DMARDs used to treat rheumatoid arthritis are classified as:
- Enbrel (etanercept) - anti-tumor necrosis factor (TNF blocker)
- Remicade (infliximab) - TNF blocker
- Humira (adalimumab) - TNF blocker
- Simponi (golimumab) - TNF blocker
- Cimzia (certolizumab pegol) - TNF blocker
- Orencia (abatacept) - T-cell co-stimulation modulator
- Actemra (tocilizumab) - targets interleukin-6 (IL-6)
- Kineret (anakinra) - targets interleukin-1 (IL-1)
- Rituxan (rituximab) - targets CD20-positive B-cells
What's Next for Rituxan?
What comes next for the best-selling cancer drug which is now approved for rheumatoid arthritis as well? Rituxan is being studied for other autoimmune diseases and disorders such as:
FDA Approves Rituxan - The First Targeted B-Cell Therapy for Treatment of Moderate-to-Severe Rheumatoid Arthritis. Genentech. 2/28/06.
Rheumatoid Arthritis Drug Approved. New York Times. 3/1/06.