technetium Tc-99m arcitumomab

Action and Spectrum

Actions and Spectrum: 

Actions: 

Carcinoembryonic antigen (CEA), which is overexpressed in 95% of colorectal tumors, is recognized by arcitumomab. As a result, the radioisotope, which releases photons, and the antibody build up in these cancers. High-resolution pictures displaying the tumor’s location, state of remission or progression, and metastases can be acquired using SPECT (single photon emission computed tomography). 

Spectrum:  

This is a medication utilized in the diagnosis for colorectal cancers. Comprising the fragment (Fab) of the arcitumomab (monoclonal antibody) (CEA-Scan) and the technetium-99m (radionuclide) (immunoconjugate). Monoclonal antibody (arcitumomab), derived from the IgG1 murine monoclonal antibody NP-4, undergoes enzymatic cleavage by pepsin to produce the fragment of F(ab)2. The fragment is then prepared through reduction (mild).

Prior to administration, reconstitution of arcitumomab (monoclonal antibody) with a (99mTc) sodium pertechnetate (radioactive agent)solution obtained from a generator (technetium). FDA-approved in 1999, it serves as a aid in diagnosis, along with diagnostic (standard) assessments, to detect the location, presence, and risk of metastatic and/or recurrent colorectal carcinoma involving the extrahepatic abdomen,  pelvis, and liver in colorectal carcinoma patients with a confirmed histological diagnosis. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Itching 

Fever 

Eosinophilia 

Radiation poisoning 

Black Box Warning

Black Box Warning: 

Patients may experience anaphylactic responses and other allergic reactions after receiving mouse protein. Drugs for the treatment of reactions to hypersensitivity, such as adrenaline, antihistamines, and corticosteroids, should be on hand for quick use in the event of an allergic reaction during CEA-Scan® administration, even though severe reactions of this kind have not been seen in clinical trials following this agent’s administration. 

Contraindication / Caution

Contraindication/Caution: 

Contraindications 

• Hypersensitivity 
• Pregnancy 

Cautions 

• Renal impairment 
• Hepatic impairment 
• Drug interactions 
• Pregnancy  
• Breastfeeding 

Pregnancy / Lactation

Pregnancy consideration:  

Pregnancy category: C 

Breastfeeding warnings:  

No data is available regarding the excretion of drug in breast milk. 

Pregnancy category: C 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

Selective binding occurs with the CEA (carcinoembryonic antigen) expressed on the cell surface of colorectal tumors. 

Pharmacodynamics: 

Binds to CEA (carcinoembryonic antigen), a cell surface protein frequently elevated in malignancies beyond colorectal cancer. The covalently attached radioactive Tc99 to the antibody enables the radiodiagnostic detection of CEA-expressing cells and tumors. Pharmacokinetics: 

Absorption 

The time to achieve peak effect is 30 minutes 

Distribution 

Protein-bound is 70-80% 

The volume of distribution is 20 L 

Metabolism 

Most likely eliminated via the reticuloendothelial system’s opsonization or by the generation of human antimurine antibodies. 

Elimination and Excretion 

The half-life is 1 hour 

The drug is excreted 60% in feces and 25-30% in urine. 

Adminstartion

Administration: 

Technetium Tc-99m arcitumomab is administered intravenously for radiodiagnosis. This monoclonal antibody selectively binds to the carcinoembryonic antigen (CEA) expressed on colorectal tumor cells. The antibody is covalently linked to the radioactive isotope Tc-99m, enabling the visualization of CEA-expressing cells and tumors through gamma imaging.

This diagnostic tool assists in the identification and localization of malignancies beyond the colon where CEA is overexpressed. The administration is a targeted approach, aiding in the detection and assessment of specific cancerous cells, contributing to improved diagnostic accuracy in oncology. Regular follow-ups and adjustments to the management plan are common to ensure optimal health outcomes. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: technetium Tc-99m arcitumomab 

Pronounced: tek-NEE-shee-um tee-see-NIN-ahyn ark-i-TOO-mo-mab 

Why do we use technetium Tc-99m arcitumomab? 

Immunomedics is the manufacturer of technetium (99mTc) arcitumomab, a medication used for colorectal cancer diagnostic imaging. Technetium-99m, a radionuclide, and the Fab’ fragment of a monoclonal antibody (arcitumomab, brand name CEA-Scan) make up this combination.