Novel immunoconjugates comprised of streptonigrin and 17-amino-geldanamycin attached via a dipeptide-p-aminobenzyl-amine linker system
作者:Patrick J. Burke、Brian E. Toki、David W. Meyer、Jamie B. Miyamoto、Kim M. Kissler、Martha Anderson、Peter D. Senter、Scott C. Jeffrey
DOI:10.1016/j.bmcl.2009.03.145
日期:2009.5
Cytotoxic agents streptonigrin and 17-amino-geldanamycin were linked to monoclonal antibodies (mAbs), forming antibody-drug conjugates (ADCs) for antigen-mediated targeting to cancer cells. The drugs were conjugated with a linker construct that is labile to lysosomal proteases and incorporates a valine-alanine-p-aminobenzyl (PAB)-amino linkage for direct attachment to the electron-deficient amine functional groups present in both drugs. The resulting ADCs release drug following internalization into antigen-positive cancer cells. The drug linkers were conjugated to mAbs cAC10 (anti-CD30) and h1F6 (anti-CD70) via alkylation of reduced interchain disulfides to give ADCs loaded with 4 drugs/mAb. The streptonigrin ADCs were potent and immunologically specific on a panel of cancer cell lines in vitro and in a Hodgkin lymphoma xenograft model. We conclude that streptonigrin ADCs are candidates for further research, and that the novel linker system used to make them is well-suited for the conjugation of cytotoxic agents containing electron-deficient amine functional groups. (C) 2009 Elsevier Ltd. All rights reserved.