Arcitumomab

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Arcitumomab is a drug based on a fragment of a murine monoclonal antibody linked to the radioisotope technetium ( 99m Tc). Arcitumomab is an immunoconjugate that is used as a diagnostic agent in oncology .

The antibody is a Fab fragment of IMMU-4, a murine IgG1 monoclonal antibody which is obtained from the ascites of mice by purification. To this end, pepsin is added to the ascites in order to produce the F (ab ') 2 fragments from the IMMU-4 and then ultimately the 50  kDa arctumomab.

Arcitumomab was sold under the trademark CEA-Scan by Immunomedics; the marketing authorization was withdrawn by the EMA in 2005.

Mechanism of action

The carcinoembryonic antigen (CEA) is a protein that is overexpressed on the surface of many tumor cells. In particular, over 95% of all colorectal cancers express CEA. Arcitumomab can be used as an in vivo diagnostic agent for such tumors in order to obtain a prognosis about the absorption of the active substance and the course of the disease. Combined with single-photon emission computed tomography (SPECT), it delivers specific high-resolution functional images that make the localization, extent of remission and / or metastasis development visible in colon cancer .

dosage

The ampoules with Arcitumomab do not contain technetium in the delivery form. Immediately before intravenous administration, sodium pertechnetate solution is eluted from a technetium generator , reconstituted and diluted with physiological saline injection solution. For adults, a single injection of 1 mg, Fab 'fragment labeled with 750 to 1000  MBq 99m Tc, is recommended. The radiolabelled solution (5 to 10 ml) should be given as an intravenous injection over a period of approximately 30 seconds.

The half-life of 99m Tc is 6.02 hours. During the decay, gamma quanta with 140.5  keV are generated, which are detected and evaluated by SPECT.

See also

literature

  • Hans J. Hansen et al .: Preclinical Evaluation of an “Instant” 99m Tc-labeling Kit for Antibody Imaging . In: Cancer Research . tape 50 , 3 Supplement, 1990, pp. 794s-798s , PMID 2297726 .
  • Thomas Behr, Wolfgang Becker, Ewald Hannappel, David M. Goldenberg, Friedrich Wolf: Targeting of Liver Metastases of Colorectal Cancer with IgG, F (ab ′) 2, and Fab ′ Anti-Carcinoembryonic Antigen Antibodies Labeled with 99mTc: The Role of Metabolism and Kinetics . In: Cancer Research . tape 55 , 23 Supplement, 1995, pp. 5777s-5785s , PMID 7493346 .
  • K. Hughes, C. Pinsky, N. Petrelli, YZ Patt, LD Hammershaimb, DM Goldenberg: Use of radioimmunodetection with CEAScan® in planning for resection of recurrent colorectal cancer . In: Proc Amer Soc Clin Oncol . tape 14 , 1995, pp. 544 .
  • FL Moffat et al .: Clinical utility of external immunoscintigraphy with the IMMU-4 technetium-99m Fab 'antibody fragment in patients undergoing surgery for carcinoma of the colon and rectum: results of a pivotal, phase III trial. The Immunomedics Study Group. In: Journal of Clinical Oncology . tape 14 , no. 8 , 1996, pp. 2295-2305 , PMID 8708720 .
  • F. James Primus, Keith D. Newell, Annelle Blue, David M. Goldenberg: Immunological Heterogeneity of Carcinoembryonic Antigen: Antigenic Determinants on Carcinoembryonic Antigen Distinguished by Monoclonal Antibodies . In: Cancer Research . tape 43 , no. 2 , 1983, p. 686-692 , PMID 6184152 .

Web links

Individual evidence

  1. ↑ Page on the active ingredient at EMA
  2. ↑ MJ Goldstein, EP Mitchell: Carcinoembryonic antigen in the staging and follow-up of patients with colorectal cancer. In: Cancer investigation. Volume 23, Number 4, 2005, pp. 338-351, PMID 16100946 (review).