Immunotargeting of antitumor drugs

About forty years ago, immuno-targeting of antitumor drugs has been address ed as a way to improve their selectivity towards tumor cells. Despite the w ide display of researches to solve inherent problems within this approach, rare were the immuno-conjugates which reached the clinical level. In any ca se, none of them was introduced in chemotherapy. However, there was a renew al of activity for the last ten years, due, in part, to the access to very highly cytotoxic-containing immuno-conjugates such as those elaborated from maytansinoides, enediynes or intercalating agents CC1065. It was also due to the design of the Adept concept. This antibody-directed enzyme prodrug t herapy is based upon the use of monoclonal antibody to target an enzyme at the tumor cell surface which ultimately is expected to selectively deliver an antitumor drug from a suitable inactive prodrug. In both cases, clinical trials are in progress and one can expect that, at least, some immuno-conj ugates will be soon introduced in cancer chemotherapy.