Idiotype switching of CD4‐specific monoclonal antibodies can prolong the therapeutic effectiveness in spite of host anti‐mouse IgG antibodies

Abstract
Immunotherapy using murine monoclonal antibodies (mAb) is limited by the host anti-mouse IgG response. Previous investigations demonstrated that a large proportion of the anti-mouse response was specific for idiotypic determinants of the mAb. This study demonstrates the feasibility of idiotype switching of therapeutic mAb to evade this anti-idiotype response. In this way prolongation of the therapeutic effectiveness of mAb treatment can be achieved. Using different CD4-specific mAb consecutively in rhesus monkeys it was possible to obtain therapeutic effectiveness in spite of host anti-mouse IgG antibodies, provided that no anti-idiotypic antibodies were present. Anti-constant part antibodies may even enhance therapeutic effectiveness.