Rituximab is a genetically engineered human-mouse chimeric monoclonal antibody. It is produced using Chinese Hamster Ovary (CHO) cells in suspension and it is purified via several chromatographic steps. Rituximab is created from a fusion of the light and heavy chain variable domains of a murine monoclonal anti-CD20 antibody and human kappa light-chain and gamma 1 heavy-chain constant regions. The active component of this biosimilar rituximab consists of two heavy chains of 451 amino acids and two light chains of 213 amino acids, with an approximate molecular weight of 148 kDa.
Rituximab binds to the target CD20 antigen via the variable murine regions, while the remainder of the antibody interacts with human immune-effector mechanisms to kill the target cells. Rituximab has been shown to be an effective rheumatoid arthritis treatment in three randomised controlled trials and is now licensed for use in refractory rheumatoid disease. In the United States, it has been FDA-approved for use in combination with methotrexate (MTX) for reducing signs and symptoms in adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to one or more anti-TNF-alpha therapy.
This product is supplied as a sterile, clear, colorless, preservative-free liquid concentrate for intravenous (IV) infusion. It is provided in two dosages, 100 mg and 500 mg vials.