Multiple signaling pathways induced by hexvalent, monospecific and bispecific antibodies for enhanced toxicity to B-cell lymphomas and other diseases

摘要

Disclosed herein are compositions and methods of use comprising hexavalent DNL complexes. Preferably, the complexes comprise anti-CD20 and/or anti-CD22 antibodies or fragments thereof. More preferably, the anti-CD20 antibody is veltuzumab and the anti-CD22 antibody is epratuzumab. Administration of the subject hexavalent DNL complexes induces apoptosis and cell death of target cells in diseases such as B-cell lymphomas or leukemias, autoimmune disease or immune dysfunction disease. In most preferred embodiments, the DNL complexes increase levels of phosphorylated p38 and PTEN, decrease levels of phosphorylated Lyn, Akt, ERK, IKKα/β and IκBα, increase expression of RKIP and Bax and decrease expression of Mcl-1, Bcl-xL, Bcl-2, and phospho-BAD in target cells. The subject DNL complexes show EC50 values for inhibiting tumor cell growth in the low nanomolar or even sub-nanomolar concentration range.

主权项

1. A method of killing human cells that are CD20+ and CD22+, comprising exposing the cells to a hexavalent DNL complex comprising:
a. a first fusion protein comprising an AD moiety from the N-terminus of an AKAP protein attached to the C-terminal end of an IgG antibody; and b. four copies of a second fusion protein comprising a DDD (dimerization and docking domain) moiety, wherein the amino acid sequence of the DDD moiety is selected from the group consisting of residues 1-44 of human protein kinase A (PKA) RIIα and residues 1-44 of human PKA RIIβ, attached to the C-terminal end of an antigen-binding antibody fragment;wherein pairs of the DDD sequence form dimers that bind to the AD moiety to form the DNL complex; and wherein the complex binds to human CD20 and human CD22.