A dual-targeting PDGFRbeta/VEGF-A molecule assembled from stable antibody fragments demonstrates anti-angiogenic activity in vitro and in vivo.
Targeting angiogenesis is a promising approach to the treatment of solid tumors and age-related macular degeneration (AMD). Inhibition of vascularization has been validated by the successful marketing of monoclonal antibodies (mAbs) that target specific growth factors or their receptors, but there is considerable room for improvement in existing therapies. Combination of mAbs targeting both the VEGF and PDGF pathways has the potential to increase the efficacy of anti-angiogenic therapy without the accompanying toxicities of tyrosine kinase inhibitors and the inability to combine efficiently with traditional chemotherapeutics. However, development costs and regulatory issues have limited the use of combinatorial approaches for the generation of more efficacious treatments. The concept of mediating disease pathology by targeting two antigens with one therapeutic was proposed over two decades ago. While mAbs are particularly suitable candidates for a dual-targeting approach, engineering bispecificity into one molecule can be difficult due to issues with expression and stability, which play a significant role in manufacturability. Here, we address these issues upstream in the process of developing a bispecific antibody (bsAb). Single-chain antibody fragments (scFvs) targeting PDGFRbeta and VEGF-A were selected for superior stability. The scFvs were fused to both termini of human Fc to generate a bispecific, tetravalent molecule. The resulting molecule displays potent activity, binds both targets simultaneously, and is stable in serum. The assembly of a bsAb using stable monomeric units allowed development of an anti-PDGFRB/VEGF-A antibody capable of attenuating angiogenesis through two distinct pathways and represents an efficient method for rapid engineering of dual-targeting molecules.
Mabry
Robert
R
Antibody Discovery and Assay Technology, ZymoGenetics, Inc., Seattle, WA, USA. mabryr@zgi.com
Gilbertson
Debra G
DG
Frank
Amanda
A
Vu
Tuyen
T
Ardourel
Dan
D
Ostrander
Craig
C
Stevens
Brenda
B
Julien
Susan
S
Franke
Secil
S
Meengs
Brent
B
Brody
Jennifer
J
Presnell
Scott
S
Hamacher
Nels B
NB
Lantry
Megan
M
Wolf
Anitra
A
Bukowski
Tom
T
Rosler
Robert
R
Yen
Cindy
C
Anderson-Haley
Monica
M
Brasel
Kenneth
K
Pan
Qi
Q
Franklin
Hank
H
Thompson
Penny
P
Dodds
Mike
M
Underwood
Sara
S
Peterson
Scott
S
Sivakumar
Pallavur V
PV
Snavely
Mark
M
D000595:Amino Acid Sequence; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D018033:Antibodies, Bispecific / Q000008:administration & dosage / Q000494:pharmacology*; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology; D005260:Female; D006801:Humans; D007167:Immunotherapy; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000276:immunology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D011485:Protein Binding; D015202:Protein Engineering; D055550:Protein Stability; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D047368:Tumor Burden / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology
D020533:Angiogenesis Inhibitors; D018033:Antibodies, Bispecific; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D042461:Vascular Endothelial Growth Factor A; D020797:Receptor, Platelet-Derived Growth Factor beta