posted on 2021-02-24, 01:04authored byPaul S. Marinec, Kyle E. Landgraf, Maruti Uppalapati, Gang Chen, Daniel Xie, Qiyang Jiang, Yanlong Zhao, Annalise Petriello, Kurt Deshayes, Stephen B. H. Kent, Dana Ault-Riche, Sachdev S. Sidhu
We
report a general approach to engineering multivalent d-proteins
with antibody-like activities in vivo.
Mirror-image phage display and structure-guided design were utilized
to create a d-protein that uses receptor mimicry to antagonize
vascular endothelial growth factor A (VEGF-A). Selections against
the d-protein form of VEGF-A using phage-displayed libraries
of two different domain scaffolds yielded two proteins that bound
distinct receptor interaction sites on VEGF-A. X-ray crystal structures
of the d-protein/VEGF-A complexes were used to guide affinity
maturation and to construct a heterodimeric d-protein VEGF-A
antagonist with picomolar activity. The d-protein VEGF-A
antagonist prevented vascular leakage in a rabbit eye model of wet
age-related macular degeneration and slowed tumor growth in the MC38
syngeneic mouse tumor model with efficacies comparable to those of
approved antibody drugs, and in contrast with antibodies, the d-protein was non-immunogenic during treatment and following
subcutaneous immunizations.