Bioaffinity therapy with antibodies and drugs bound to soluble synthetic polymers.

Soluble synthetic copolymers based on N-(2-hydroxypropyl)methacrylamide (HPMA) containing different oligopeptide side-sequences were tested as transport molecules for drugs and anti-Thy 1.2 antibodies in affinity therapy. As target cells, T lymphocytes were studied. (1) HPMA copolymers containing targeting anti-Thy 1.2 antibodies are 70 times more cytotoxic against T lymphocytes than HPMA copolymers with non-specific immunoglobulin. (2) Daunomycin conjugated to a biodegradable side-sequence (Gly-Phe-Leu-Gly) is effective in a concentration 100 times lower than daunomycin conjugated to a non-cleavable sequence (Gly-Gly). (3) HPMA copolymers containing drug and targeting antibodies are effective both in vitro and in vivo.