This meeting provided an opportunity for both experts and newcomers to present and discuss their achievements as well as their difficulties in fundamental and applied areas of monoclonal antibodies in oncology. Detailed immunochemical studies are helping us to select new antibodies with more favourable characteristics for in vivo and in vitro use.
The desired size of antibody molecule may be critical for successful targeting and optimum biodistribution. The advantages and disadvantages of fragments over intact immunoglobulins have been outlined. A great deal of excitement and work have been shown in the applications of recombinant DNA technology both in "humanising" rodent antibodies and creating new molecules such as chimaeric human-mouse antibodies. Clinical studies are now awaited.
Detailed biodistribution studies in experimental animals xenografied with human tumours both at macroscopic and histological levels are an important step prior to clinical imaging and therapy. Improvements in radiochemistry and linker technology should allow for improved immunoconjugates.
Specific immunotherapy dates back to 1890, when Von Behring and Kitasato discovered antibodies against diphtheria. Little imagination was needed to translate that into a potential anticancer therapy but the limiting factor was the precise definition of tumour-associated markers. This meeting highlighted advances and limitations in the therapeutic application of both native as well as "armed" antibodies.
Many difficulties remain, especially in identifying appropriate antigens and epitopes, developing the optimal antibody species, attaching the most effective therapeutic or diagnostic agent, choosing the best method of administration and understanding the mechanisms such as physiological, catabolic or immunologic barriers responsible for less than optimal antibody targeting.
Much remains to be done, and meetings of this nature undoubtedly stimulate further investigation into this exciting concept of developing specific agents for the diagnosis and therapy of neoplasia.