Doxorubicin immunoconjugates containing bivalent, lysosomally-cleavable dipeptide linkages

Bioorg Med Chem Lett. 2002 Jun 3;12(11):1529-32. doi: 10.1016/s0960-894x(02)00194-4.

Abstract

Bivalent doxorubicin (DOX)-dipeptides (16a-c) were prepared and conjugated to the monoclonal antibody BR96. The dipeptides are cleaved by lysosomal proteases following internalization of the resulting immunoconjugates. Conjugate 18b demonstrated antigen-specific in vitro tumor cell killing activity (IC(50)=0.2 microM) that was equipotent to DOX with a near doubling of drug molecules/MAb. Size exclusion chromatography showed 18b to be a noncovalent dimer that was formed immediately upon conjugation.

MeSH terms

  • Antibodies, Monoclonal / chemistry*
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / pharmacology
  • Binding Sites
  • Cathepsin B / blood
  • Cathepsin B / metabolism
  • Chromatography, Gel
  • Dimerization
  • Dipeptides / chemistry*
  • Dipeptides / pharmacology
  • Doxorubicin / analogs & derivatives*
  • Doxorubicin / chemical synthesis
  • Doxorubicin / chemistry*
  • Doxorubicin / immunology
  • Doxorubicin / pharmacology
  • Half-Life
  • Humans
  • Immunoconjugates / chemistry
  • Immunoconjugates / immunology
  • Immunoconjugates / pharmacology
  • Inhibitory Concentration 50
  • Lung Neoplasms / drug therapy
  • Lysosomes / enzymology
  • Stereoisomerism
  • Sulfhydryl Compounds / chemistry
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / immunology

Substances

  • Antibodies, Monoclonal
  • BR96-doxorubicin immunoconjugate
  • Dipeptides
  • Immunoconjugates
  • Sulfhydryl Compounds
  • Doxorubicin
  • Cathepsin B