Common brand names

• Riabni
• Rituxan
• Ruxience
• Truxima

How it is administered

Rituximab is administered as an intravenous (IV) infusion by a healthcare professional. It is available in single-dose vials for IV use, and the dose is calculated based on body surface area (mg/m²). The medication is diluted and infused slowly, with the first infusion typically given at a slower rate to monitor for reactions. Subsequent infusions may be given more quickly if the first is well tolerated.

There are also subcutaneous formulations (such as rituximab and hyaluronidase) for certain indications, but the standard for blood cancers is IV infusion.

How it works

Rituximab is a monoclonal antibody that targets the CD20 antigen found on the surface of pre-B and mature B-lymphocytes (a type of white blood cell). By binding to CD20, rituximab causes the destruction of these B-cells through several mechanisms, including complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC).

This targeted action helps reduce the number of abnormal B-cells that are characteristic of certain blood cancers, such as B-cell prolymphocytic leukemia (B-PLL), non-Hodgkin’s lymphoma, and chronic lymphocytic leukemia (CLL). After treatment, B-cell levels in the blood typically drop significantly, and recovery of normal B-cells may take several months to a year.

Who should take it

Rituximab is indicated for adults with certain blood cancers, including:

• Relapsed or refractory, low-grade or follicular, CD20-positive B-cell non-Hodgkin’s lymphoma (NHL)
• Previously untreated follicular, CD20-positive, B-cell NHL in combination with chemotherapy and as maintenance therapy
• Diffuse large B-cell lymphoma (DLBCL) in combination with chemotherapy
• Chronic lymphocytic leukemia (CLL), in combination with fludarabine and cyclophosphamide

While rituximab is not specifically FDA-approved for B-cell prolymphocytic leukemia (B-PLL), it may be used off-label for this rare disease, as B-PLL cells often express CD20. Your doctor will determine if rituximab is appropriate for your specific situation based on your diagnosis and overall health.

Who should not take it

Rituximab should not be used in patients with a known severe allergic reaction (hypersensitivity) to rituximab or any of its components.

It is not recommended for patients with severe, active infections. Patients with active hepatitis B infection should not start rituximab until the infection is managed, as rituximab can cause hepatitis B reactivation. Caution is also advised in patients with significant heart or lung problems, as infusion reactions can be more dangerous in these groups.

Rituximab can cause harm to unborn babies, so it should not be used during pregnancy unless absolutely necessary. Women of childbearing potential should use effective contraception during treatment and for 12 months after the last dose.

Commonly used with

Rituximab is often used in combination with chemotherapy agents, such as:

• Cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)
• Fludarabine and cyclophosphamide (FC)
• Bendamustine

For maintenance therapy in follicular lymphoma, rituximab may be used alone after initial combination therapy. In CLL, it is commonly combined with fludarabine and cyclophosphamide.

Commonly tested with

Rituximab has been tested in combination with various chemotherapy regimens in clinical trials for blood cancers, including:

• CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)
• CVP (cyclophosphamide, vincristine, prednisone)
• Fludarabine and cyclophosphamide (FC)
• Bendamustine

It has also been studied with other targeted therapies and immunotherapies in clinical research settings.