Problems That Have Beset Antibody Therapeutics

Problems That Have Beset Antibody Therapeutics 

Many murine MAbs, depending upon their heavy chain isotype, are very inefficient in their ability to support ADCC and CDC. Effector functions are readily recruited into murine MAb by chimerization or humanization (Sec. IV). Indeed, 7 of 10 approved MAb drags utilize human IgGi constant domains and are thus potentially capable of mediating ADCC and CDC (Table 1). 

In the case of cell surface antigens, secretion or shedding into the circulation may abrogate their therapeutic benefit by either accelerating MAb clearance or by acting as sink for the MAb (22). This issue should be taken into account in the selection of a target antigen. 

A major difficulty with tumor immunotherapy is the meager quantity of MAb that localizes to a tumor—typically 0.01% of the injected dose per gram of tumor—combined with the often heterogeneous distribution of MAb within the 

Marcel Dekker, Inc. 270 Madison Avenue. New York, New York 10016 

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III. Problems That Have Beset Antibody Therapeutics... 

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