mAbs | Year: 2011
Bispecific antibodies based on full-length antibody structures are more optimal than fragment-based formats because they benefit from the favorable properties of the Fc region. However, the homodimeric nature of Fc effectively imposes bivalent binding on all current full-length bispecific antibodies, an attribute that can result in nonspecific activation of cross-linked receptors. We engineered a novel bispecific format, referred to as mAb-Fv, that utilizes a heterodimeric Fc region to enable monovalent co-engagement of a second target antigen in a full-length context. mAb-Fv constructs co-targeting CD16 and CD3 were expressed and purified as heterodimeric species, bound selectively to their co-target antigens, and mediated potent cytotoxic activity by NK cells and T cells, respectively. The capacity to co-engage distinct target antigens simultaneously with different valencies is an improved feature for bispecific antibodies with promising therapeutic implications. Source
Xencor | Date: 2014-03-13
The present invention discloses the generation of novel variants of Fc domains, including those found in antibodies, Fc fusions, and immuno-adhesions, which have an increased binding to the FcRn receptor and/or increased serum half-life.
Xencor | Date: 2014-03-07
The present invention describes novel immunoglobulin compositions that co-engage at least two antigens, e.g. a first and second antigen, or, as outlined herein, three or four antigens can be bound, in some of the scaffold formats described herein. First and second antigens of the invention are herein referred to as antigen-1 and antigen-2 respectively (or antigen-3 and antigen-4, if applicable. As outlined herein, a number of different formats can be used, with some scaffolds relying combinations of monovalent and bivalent bindings.
Xencor | Date: 2014-01-14
The invention provides heterodimeric antibodies comprising a first heavy chain comprising a first Fc domain and a single chain Fv region that binds a first antigen. The heterodimeric antibodies also comprise a second heavy chain comprising a second Fc domain, a first variable heavy chain and a first variable light chain, wherein the first and second Fc domains are different.
Xencor | Date: 2014-03-14
The present invention provides methods and compositions comprising a heterodimeric antibody comprising a first monomer comprising a first variant heavy chain constant region and an anti-CD4 binding moiety. The heterodimeric antibody also comprises a second monomer comprising: a second variant heavy chain constant region and an anti-CD25 binding moiety. In some cases, the pIs of the first and second variant heavy chain constant regions are at least 0.5 logs apart.