TUMOR-INHIBITION BY CHLORAMBUCIL COVALENTLY LINKED TO ANTI-TUMOR GLOBULIN

The alkylating agent chlorambucil has been covalently bound to antitumor globulins directed against cell surface antigen(s) of the mouse EL4 lymphoma. The resulting conjugates retained alkylating and antibody activities and were used to treat C57BL 6j mice after prior inoculation with the syngeneic EL4 lymphoma. Forty per cent of mice treated with the covalent conjugate, 78% of mice treated with non-covalent conjugate and 50% of mice treated with chlorambucil followed by antitumor globulin survived tumor-free for more than 100 days. Untreated mice had a mean survival of 18 ± 1.3 days and the groups that received chlorambucil or antitumor globulin only, or chlorambucil covalently bound to normal rabbit globulin died within 30 days of tumor inoculation. © 1979.