How it is administered

Ibritumomab tiuxetan is given as an intravenous (IV) infusion. The treatment involves a specific schedule:

• Day 1: Rituximab 250 mg/m² is given as an IV infusion.
• Day 7, 8, or 9: Rituximab 250 mg/m² is given again, followed within 4 hours by the ibritumomab tiuxetan (Y-90 Zevalin) infusion. The dose of Y-90 Zevalin depends on your platelet count and is administered over 10 minutes through a free-flowing IV line.

Premedication with acetaminophen and diphenhydramine is recommended before each rituximab infusion to reduce the risk of infusion reactions. The medication is prepared by a specialized team and must be used within 8 hours of preparation.

How it works

Ibritumomab tiuxetan is a targeted therapy that combines a monoclonal antibody (ibritumomab) with a radioactive substance (yttrium-90). The antibody part specifically binds to the CD20 antigen, a protein found on the surface of most B cells, including those in follicular lymphoma and other B-cell non-Hodgkin’s lymphomas.

Once attached to the cancerous B cells, the radioactive yttrium-90 delivers localized radiation, which damages and kills the targeted cells and nearby lymphoma cells. This dual action—targeted antibody therapy and radiation—helps to destroy lymphoma cells more effectively while limiting damage to surrounding healthy tissue. After treatment, B cells are depleted but typically recover within months. The medication does not affect all immune cells, so some immune function remains intact.

Who Should take it

Ibritumomab tiuxetan is indicated for adults with:

• Relapsed or refractory, low-grade or follicular B-cell non-Hodgkin’s lymphoma (NHL), including follicular lymphoma that has not responded to other treatments or has returned after previous therapy.
• Previously untreated follicular NHL who have achieved a partial or complete response to first-line chemotherapy.

This medication is used as part of a specific regimen and is usually considered when other treatments have not worked or as a consolidation therapy after initial chemotherapy. Your doctor will determine if this is the right option based on your type of lymphoma, previous treatments, and overall health.

Who should not take it

Ibritumomab tiuxetan should not be used in:

• Patients with 25% or more lymphoma involvement in the bone marrow or those with impaired bone marrow reserve, as the risk of severe, prolonged low blood counts is higher.
• Pregnant women, due to the risk of harm to the unborn baby from the radioactive component.
• Patients who have recently received live viral vaccines, as their immune response may be weakened.

Caution is also needed in people with a history of severe infusion reactions, severe skin or mucous membrane reactions, or those at risk for infections or bleeding. Always discuss your full medical history with your healthcare provider before starting this medication.

Commonly used with

Ibritumomab tiuxetan is always used in combination with rituximab as part of its therapeutic regimen. Rituximab is given before each ibritumomab tiuxetan infusion to help target the lymphoma cells more effectively.

Other supportive medications, such as acetaminophen and diphenhydramine, are used to reduce the risk of infusion reactions. Your doctor may also recommend medications to support blood counts or prevent infections, depending on your individual risk.

Commonly tested with

Ibritumomab tiuxetan has been tested in clinical studies alongside rituximab and following various chemotherapy regimens, including CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), CVP (cyclophosphamide, vincristine, prednisone), and fludarabine-containing regimens.

It has also been studied as a consolidation therapy after first-line chemotherapy in follicular lymphoma, compared to observation (no further therapy).