Immunoprotective therapy with targeted anticancer drugs

Doxorubicin or mitomycin C bonded to poly[N5‐(2‐hydroxyethyl)‐L‐glutamine]‐graft‐poly(ethylene glycol) or poly[N‐(2‐hydroxypropyl)methacrylamide], non‐targeted or targeted with monoclonal antibodies, do not induce expression of FasL on selected cancer cells (human colorectal cancer cell line SW 620) thus protecting effector cells of the immune system against Fas‐counterattack. The pre‐treatment with PHPMA‐bound DOX does not only protect but in fact mobilizes defense mechanisms of the tumor‐bearing hosts. The treatment with selected monoclonal antibody‐targeted PHPMA‐bound DOX causes a rapid and complete rejection of established tumors (mouse B cell leukemia BCL1, mouse B cell lymphoma 38C13 and mouse T cell lymphoma EL4) and generates prolonged systemic anti‐tumor immunity.