ibritumomab tiuxetan

Action and Spectrum

Actions and spectrum: 

ibritumomab tiuxetan is a monoclonal antibody that is used the treat certain types of non-Hodgkin’s lymphoma. It is a chimeric antibody that targets the CD20 antigen on the surface of B-cells and delivers a radioactive isotope, yttrium-90 or iodine-131, to destroy the cancer cells.

Once administered, ibritumomab tiuxetan binds to CD20 on the surface of B-cells, which are cancerous cells in non-Hodgkin’s lymphoma. The radioactive isotope attached to the antibody emits beta radiation that damages the DNA in the B-cells and causes cell death. 

Ibritumomab tiuxetan is effective against both indolent and aggressive forms of non-Hodgkin’s lymphoma and has been shown to improve. Overall, ibritumomab tiuxetan is a targeted therapy that selectively destroys cancer cells while minimizing damage to healthy cells, providing a valuable treatment option for patients with non-Hodgkin’s lymphoma. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

HA (12%) 

Vomiting (12%) 

Pain (13%) 

Abdominal pain (16%) 

Fever (17%) 

Chills (24%) 

Infections (29%) 

Nausea (31%) 

Asthenia (43%) 

Anemia (61%) 

Neutropenia (77%) 

Thrombocytopenia (95%) 

1-10% 

Secondary malignancy (2%) 

Urticaria (4%) 

Dyspepsia (4%) 

Anxiety (4%) 

Constipation (5%) 

Flushing (6%) 

Hypotension (6%) 

Myalgia (7%) 

Arthralgia (7%) 

Edema (8%) 

Anorexia (8%) 

Rash (8%) 

Back pain (8%) 

Pruritus (9%) 

Diarrhea (9%) 

Dizziness (10%) 

Cough (10%) 

Black Box Warning

Black Box Warning: 

ibritumomab tiuxetan has a black box warning for the risk of severe and prolonged myelosuppression, which can lead to life-threatening infections and bleeding. Myelosuppression is a reduction in the production of blood cells, including red blood cells, platelets, and white blood cells, which can increase the risk of infections and bleeding. 

The black box warning also highlights the risk of infusion reactions, including anaphylaxis, which can be severe or fatal. Infusion reactions can occur during or after the infusion of ibritumomab tiuxetan and may include symptoms such as fever, chills, rash, itching, difficulty breathing, and low blood pressure. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

ibritumomab tiuxetan is contraindicated in patients with known hypersensitivity to murine proteins, which are components of the ibritumomab tiuxetan drug product. It is also contraindicated in patients with a history of severe hypersensitivity reactions to murine proteins or to any component of the ibritumomab tiuxetan drug product. 

Additionally, ibritumomab tiuxetan is contraindicated in patients with a history of severe thrombocytopenia or other bleeding disorders, as it may exacerbate these conditions. 

Because ibritumomab tiuxetan contains a radioactive isotope, it is also contraindicated in patients who are pregnant or breastfeeding, as exposure to radiation can harm the developing fetus or infant.  

Caution: 

ibritumomab tiuxetan should be used with caution in patients with a history of bone marrow depression, including thrombocytopenia, leukopenia, and anaemia, as it may exacerbate these conditions. Close monitoring of blood counts is recommended during and after treatment with ibritumomab tiuxetan. 

ibritumomab tiuxetan may also cause immunosuppression, which can increase the risk of infection. Patients should be monitored for signs of infection, and prophylactic antibiotics or antiviral agents may be necessary. 

Patients with a history of cardiac disease should be monitored closely during treatment with ibritumomab tiuxetan, as it may cause or exacerbate heart failure, arrhythmias, or other cardiovascular complications. 

Because ibritumomab tiuxetan contains a radioactive isotope, precautions should be taken to reduce radiation exposure to healthcare workers and others who meet the patient or their bodily fluids.  

Comorbidities: 

ibritumomab tiuxetan is primarily used in the treatment of non-Hodgkin’s lymphoma (NHL) and is generally reserved for patients who have failed prior therapies or who are not candidates for other treatments. As such, patients receiving ibritumomab tiuxetan may have a range of comorbidities associated with NHL or other underlying medical conditions. 

Patients with NHL often have compromised immune systems and may be more susceptible to infections and other complications. They may also have pre-existing cardiac or pulmonary disease, as well as bone marrow depression and other hematologic abnormalities. 

In addition to the potential risks associated with the underlying medical condition, patients receiving ibritumomab tiuxetan are also at risk for infusion reactions, immunosuppression, and other adverse effects related to the treatment itself. 

Pregnancy / Lactation

Pregnancy consideration: US FDA pregnancy category: not assigned 

Lactation: It is also not known whether Ibritumomab tiuxetan is excreted in human milk.  

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

ibritumomab tiuxetan is a chimeric monoclonal antibody that acts on CD20 antigen on the surface of B-cells. The antibody is conjugated to a radioactive isotope, yttrium-90 or lutetium-177, which emits high-energy beta particles that can selectively destroy cancerous B-cells. 

After binding to CD20, ibritumomab tiuxetan is rapidly internalized into the B-cell, where the radioactive isotope can deliver its cytotoxic effects. The beta particles emitted by the isotope have a short range (approximately 5 mm in tissue), which allows for targeted destruction of the cancerous cells while minimizing the damage to surrounding healthy tissue. 

ibritumomab tiuxetan is administered as an intravenous infusion, typically over the course of several hours. After infusion, the antibody is distributed throughout the body, where it selectively binds to CD20-expressing B-cells in lymphoid tissues and bone marrow. The radioactive isotope is then internalized by the B-cells, where it delivers its cytotoxic effects. 

Over time, the radioactive isotope decays and is eliminated from the body through normal metabolic pathways. The monoclonal antibody component of ibritumomab tiuxetan is eliminated more slowly, with a half-life of approximately 19 hours. The elimination of both components allows for a relatively short duration of radiation exposure while still providing a therapeutic effect.  

Pharmacodynamics: 

The pharmacodynamics of ibritumomab tiuxetan is primarily related to selectively targeting and destroying CD20-expressing B-cells. CD20 is a transmembrane protein that is expressed on the normal and malignant B-cells but not on other cells in the body. By targeting CD20, ibritumomab tiuxetan can selectively bind to and destroy B-cells while leaving other cells in the body relatively unaffected. 

The cytotoxic effects of ibritumomab tiuxetan are mediated by the radioactive isotope (yttrium-90 or lutetium-177) that is conjugated to the monoclonal antibody. The beta particles emitted by the isotope have a short range in tissue (approximately 5 mm), which allows for the targeted destruction of cancerous B-cells while minimizing damage to surrounding healthy tissue. 

The efficacy of ibritumomab tiuxetan in treating non-Hodgkin’s lymphoma (NHL) is related to its ability to selectively target and destroy cancerous B-cells. By destroying these cells, ibritumomab tiuxetan can help to reduce the size of lymphomas and improve symptoms associated with the disease.  

Pharmacokinetics: 

Absorption 

ibritumomab tiuxetan is administered intravenously and is immediately available in systemic circulation. 

Distribution 

The distribution of ibritumomab tiuxetan is primarily determined by the pharmacokinetics of the monoclonal antibody. It has a relatively long half-life of approximately 75 hours, which allows it to circulate in the body. The antibody is distributed throughout the body, including to lymphoid tissue and bone marrow, where it can target CD20-expressing B-cells. 

Metabolism 

ibritumomab tiuxetan is not metabolized in the body, as it is a monoclonal antibody. The radioactive isotope (yttrium-90 or lutetium-177) that is conjugated to the antibody undergoes radioactive decay and is eliminated from the body over time. 

Elimination and excretion 

The elimination of ibritumomab tiuxetan from the body is primarily determined by the pharmacokinetics of the monoclonal antibody. It is eliminated from the body through a combination of renal filtration and catabolism, with the majority of the drug being eliminated in the urine. 

Adminstartion

Administration: 

The administration of ibritumomab tiuxetan typically involves several steps, including: 

• Preparation: Prior to administering ibritumomab tiuxetan, the patient will usually undergo a series of tests to determine the appropriate dosage and to check for any potential contraindications. The patient may also receive pre-treatment medications to help manage side effects. 
• Injection of ibritumomab tiuxetan: The medication is typically administered intravenously (IV) over a period of several hours. The dosage and duration of the infusion will depend on the patient’s individual circumstances. 
• Imaging: After the infusion, the patient will undergo a series of imaging scans to determine the distribution of the medication throughout the body. 
• Radiation therapy: In some cases, the patient may receive additional radiation therapy following the infusion to further target the cancerous cells. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: ibritumomab tiuxetan 

Pronounced: [ ib-ri-TYOO-mo-mab-tye-UX-e-tan]  

Why do we use ibritumomab tiuxetan ? 

ibritumomab tiuxetan is a type of radioimmunotherapy that is primarily used in the treatment of certain types of non-Hodgkin lymphoma. Specifically, it is approved for use in patients with refractory or relapsed, low-grade, or follicular B-cell non-Hodgkin’s lymphoma who have previously received rituximab. 

ibritumomab tiuxetan works by binding to a protein called CD20 on the surface of cancer cells, delivering a radioactive substance directly to the cancerous cells to destroy them. This makes it a targeted therapy that can help to minimize damage to healthy cells and tissues. 

In addition to its use in non-Hodgkin’s lymphoma, ibritumomab tiuxetan has also been investigated for its potential use in other types of cancer, including chronic lymphocytic leukemia and multiple myeloma. However, more research is needed to determine its safety and effectiveness in these other types of cancer.