Arcitumomab

At Arcitumomab is a preparation that is used for diagnosis in cancer medicine. About 95 percent of all colorectal cancers can be diagnosed by the intravenous administration of arcitumomab in an imaging procedure. This procedure is necessary, among other things, because any other diagnosis of colon cancer is usually very difficult. Because this type of cancer spreads in the body largely free of clear symptoms.

What is arcitumomab?

Arcitumomab is a so-called monoclonal antibody which is used in cancer medicine for diagnostic purposes. This antibody is a color fragment that can be obtained from the bellies of mice. To obtain arcitumomab, the mice are first injected with the digestive enzyme pepsin, which in the human digestive system has the task of processing the proteins ingested through food.

As soon as the peptin is administered, arcitumomab is obtained in two further intermediate steps. The active ingredient falls under the group of immunoconjugates because the antibody is linked to a second, functional molecule. This is the radioactive isotope technetium, which is assigned to the group of transition metals. The preparation was marketed by Immunomedics until 2005 under the trademark CEA-Scan.

Pharmacological effect

With the preparation Arcitumomab different types of colon cancer can be diagnosed with the help of an imaging procedure. The preparation is used in combination with single-photon emission computed tomography as an in vivo diagnostic tool to generate high-resolution images. This allows the tumor to be localized and to determine whether metastasis has already occurred.

However, it is necessary to enrich the active ingredient with the element technetium before intravenous administration, because this is not contained in the active ingredient in its pure form. The radioactive preparation is then diluted with a saline solution and injected. Because the element technetium has a half-life of around six hours, there is enough time to evaluate the gamma quanta that arise during the decay and to convert them into images.

This gives the treating physicians a relatively reliable result of the extent and progress of the cancer and can then order a suitable therapy for the treatment. Single-photon emission computed tomography is one of the imaging processes with which the most diverse metabolic processes within the human body can be examined. The method is not only used in the diagnosis of cancer.

Medical application & use

The preparation was used exclusively for diagnosis by imaging methods in cancer medicine. This is possible because the carcinomas in colon cancer in particular excrete the Carcionoembryonic antigen by applying pressure to the surface of the cell structures. Therefore, about 95 percent of colorectal cancers can be diagnosed with arcitumomab.

The vast majority of these are malignant tumors. Overall, colon cancer is the second most common cancer in Germany. About six percent of all adult men and women will develop colon cancer on average during their lifetime. Diagnosis is often difficult because colon cancer usually develops from benign colon polyps. These are mushroom-shaped growths that form on the mucous membrane of the large intestine. The polyps can range in size from a few millimeters to a few centimeters. Larger polyps in particular run the risk of developing colon cancer, which in the rarest of cases manifests itself through further symptoms.

The chances of a cure for colorectal cancer are between 40 and 60 percent, and treatment can be carried out through surgery or chemotherapy. The healing success depends very much on the stage at which the colon cancer is discovered. In order to discover the disease in good time, the health insurances in Germany have been covering the cost of a colonoscopy every ten years for insured persons aged 55 and over, provided that there is no suspicion of colon cancer after the first colonoscopy.

Risks & side effects

There are no known side effects from the administration of arcitumomab.