Paclitaxel immunoconjugate for the specific treatment of ovarian cancer in vitro.

A paclitaxel derivative was used for the preparation of a drug immunoconjugate for the specific targeting to ovarian cancer cells by the BCM43/2E5 monoclonal antibody. To determine the efficiency of conjugation we developed two reproducible immunoassays. Paclitaxel was detected on the conjugate by a paclitaxel immunoassay and the activity of the antibody was determined by a competition assay with BCM43/2E5 antibody. Paclitaxel-BCM43/2E5 immunoconjugate was tested on five human cell lines. This conjugate was cytotoxic for ovarian teratocarcinoma cells, ovarian adenocarcinoma and breast cancer cells, while the activity was negligible for normal cells. These results describe, for the first time, the synthesis of a soluble tumor specific- paclitaxel immunoconjugate which may establish a new mode for the use of this drug in cancer therapy for limiting side effects.