| 摘要 |
<p>Disclosed is a composition for enhancing delivery of a therapeutic agent to a solid tissue site, comprising: two single chain VH-VL bifunctional binding molecules which are joined together, having one specificity for a solid tissue antigen and the other for the therapeutic agent; a remover substance which binds circulating binding molecule; a therapeutic agent. The therapeutic agent is administered separately from the binding molecules and following the administration of a remover substance which aids in clearing free binding molecules in the circulation. In the preferred mode of the invention, the binding molecules have one specificity for antigens at the target site and one for the therapeutic agent. The binding molecules are adminstered and allowed time to approach a maximum concentration in the extravascular space. A remover substance, preferably a liposome conjugated with antibodies which are reactive with an antigenic epitope on the binding molecules, is then administered to remove excess binding molecules from the circulation and the extravascular space. A therapeutic agent, preferably a cytotoxic drug such as ricin A chain modified so as to enable it to enter the target cells once delivered to the target site, is then administered. <IMAGE></p> |
