John Libbey Eurotext

Bulletin du Cancer


Immunotargeting of tumors: state of the art and prospects in 2000 Volume 87, issue 11, Novembre 2000


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JE2176 Université Montpellier I, coordinateur du groupe de travail, Immunociblage des tumeurs et ingénierie des anticorps, centre de recherche en cancérologie, CRLC Val-d'Aurelle-Paul-Lamarque, 34298 Montpellier Cedex 5.
  • Key words: immunotargeting, monoclonal antibody.
  • Page(s) : 777-91
  • Published in: 2000

Following 15 years of experimental studies, tumor immunotargeting using monoclonal antibodies directed against tumor associated antigens shows now important clinical developments. This is mainly due to encouraging therapeutic results which have been obtained using humanized antibodies such as the anti-CD20 rituximab in follicular B lymphomas and the anti-ErbB2 herceptin in breast carcinomas. Thanks to genetic engineering, it is possible to graft variable or hypervariable regions from murine antibodies to human IgG, and even to obtain fully human antibodies by using either transgenic mice containing a large part of the human repertoire of human IgG, or selection of human antiboby fragments expressed by phages. Radiolabeling of antibodies played a major role to demonstrate the tumor immunotargeting specificity and remains attractive for the diagnosis by immunoscintigraphy as well as for the treatment by radioimmunotherapy of some cancers. In this review, the current results and the prospects of diagnostic and therapeutic uses of anti-tumor antibodies and their fragments will be described. Concerning diagnosis, 123-iodine or 99m-technetium labeled Fab fragments allowed very demonstrative tumor images but this technique has a limited effect upon the therapeutic attitude. Immuno-PET (positron emission tomography) could enhance the sensitivity of this imaging method. Radio-immunoguided surgery and immunophotodetection are attractive techniques still under evaluation. Concerning therapy, 131-iodine labeled anti-CD20 antibodies gave spectacular results in non-Hodgkin's B lymphomas. In solid tumors which are less radiosensitive, radioimmunotherapy could concern small tumors and need the use of two-steps targeting and/or alpha emitters radioisotopes. Some other strategies will be described such as bispecific antibodies directed against tumors and immune effector cells, some antibody fragments expressed on T cells called T-bodies or some biological studies using intrabodies. Published data and works in progress demonstrate that immunotargeting of tumors will have a growing place in the treatment of cancer patients.