Common brand names

• Zevalin

How it is administered

Ibritumomab tiuxetan is given as an intravenous (IV) infusion. It is administered in a medical facility by healthcare professionals trained in handling radioactive materials. The treatment is given as part of a regimen that also includes rituximab, another IV medication. The typical schedule involves:

• Day 1: Rituximab IV infusion
• Day 7, 8, or 9: Rituximab IV infusion followed by ibritumomab tiuxetan (radiolabeled with Yttrium-90) IV infusion within 4 hours

The dose of ibritumomab tiuxetan is based on body weight and platelet count, and the infusion usually takes about 10 minutes. Special precautions are taken to minimize radiation exposure to both patients and healthcare staff.

How it works

Ibritumomab tiuxetan is a targeted therapy that combines a monoclonal antibody (ibritumomab) with a radioactive substance (Yttrium-90). The antibody specifically binds to the CD20 antigen, which is found on the surface of most B-cells, including cancerous B-cells in non-Hodgkin’s lymphoma (NHL).

Once attached to the CD20 antigen, the radioactive Yttrium-90 delivers localized radiation directly to the cancerous B-cells and nearby cells. This radiation causes cellular damage and death, helping to reduce or eliminate the lymphoma cells. The targeted nature of this therapy allows for a focused attack on cancer cells while limiting damage to surrounding healthy tissues.

After treatment, there is a significant reduction in circulating B-cells, which gradually recover over several months. This approach is particularly effective in treating certain types of B-cell non-Hodgkin’s lymphoma, especially when other treatments have not worked or as a consolidation after initial chemotherapy.

Who should take it

Ibritumomab tiuxetan is indicated for adult patients with specific types of B-cell non-Hodgkin’s lymphoma (NHL):

• Patients with relapsed or refractory, low-grade or follicular B-cell NHL, meaning the disease has returned or not responded to previous treatments.
• Patients with previously untreated follicular NHL who have achieved a partial or complete response to first-line chemotherapy. In these cases, ibritumomab tiuxetan is used as a consolidation therapy to help maintain remission.

This medication is not used as a first-line treatment but rather after other therapies or in cases where the disease has not responded to standard treatments. Your doctor will determine if this medication is appropriate based on your specific diagnosis, treatment history, and overall health.

Who should not take it

Ibritumomab tiuxetan should not be used in certain situations:

• Patients with 25% or more lymphoma involvement in the bone marrow or those with impaired bone marrow reserve, as the risk of severe and prolonged low blood cell counts (cytopenias) is higher.
• Pregnant women should not receive this medication due to the risk of harm to the unborn baby from the radioactive component.
• Patients who have recently received live viral vaccines should avoid this medication, as their immune response may be weakened.

Caution is also advised for patients with a history of severe infusion reactions, severe skin or mucous membrane reactions, or those at risk for infections. Always inform your healthcare provider about your complete medical history before starting this treatment.

Commonly used with

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

Sometimes, supportive medications such as acetaminophen and diphenhydramine are given before infusions to reduce the risk of infusion reactions. Other supportive care, such as growth factors or transfusions, may be used to manage low blood counts.

Commonly tested with

Ibritumomab tiuxetan has been tested in combination with rituximab in clinical studies for B-cell non-Hodgkin’s lymphoma. It has also been studied as a consolidation therapy following various first-line chemotherapy regimens, including CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) and other combination chemotherapies.

It is not typically combined with other new targeted therapies or immunotherapies outside of clinical trials, but your doctor may recommend additional supportive medications as needed during your treatment.