Regeneron Pharmaceuticals, Inc.
Anti-STEAP2 Antibodies, Antibody-Drug Conjugates, and Bispecific Antigen-Binding Molecules that Bind STEAP2 and CD3, and Uses Thereof

Abstract:

The protein known as six-transmembrane epithelial antigen of prostate 2 (STEAP2) is highly expressed in prostate cancer and is associated with the expression of other prostate cancer-associated genes. The present invention provides novel full-length human IgG antibodies that bind to human STEAP2 (monospecific antibodies). The present invention also provides novel bispecific antibodies (bsAbs) that bind to both STEAP2 and CD3 and activate T cells via the CD3 complex in the presence of STEAP2-expressing tumors. According to certain embodiments, the present invention provides bispecific antigen-binding molecules comprising a first antigen-binding domain that specifically binds human and monkey CD3, and a second antigen-binding molecule that specifically binds humanSTEAP2. In certain embodiments, the bispecific antigen-binding molecules of the present invention are capable of inhibiting the growth of tumors expressing STEAP2. The bispecific antigen-binding molecules of the invention are useful for the treatment of prostate diseases and disorders in which an upregulated or induced STEAP2-targeted immune response is desired and/or therapeutically beneficial. For example, the bispecific antibodies of the invention are useful for the treatment of prostate cancers, including castrate-resistant prostate cancer. The present invention also includes anti-STEAP2 antibody drug conjugates which inhibit tumor growth in vivo.