RT Journal Article
SR Electronic
T1 Specifically Targeting Angiopoietin-2 Inhibits Angiogenesis, Tie2-Expressing Monocyte Infiltration, and Tumor Growth
JF Clinical Cancer Research
JO Clin Cancer Res
FD American Association for Cancer Research
SP 1001
OP 1011
DO 10.1158/1078-0432.CCR-10-2317
VO 17
IS 5
A1 Huang, Hanhua
A1 Lai, Jing-Yu
A1 Do, Janet
A1 Liu, Dingguo
A1 Li, Lingna
A1 Del Rosario, Joselyn
A1 Doppalapudi, Venkata R.
A1 Pirie-Shepherd, Steven
A1 Levin, Nancy
A1 Bradshaw, Curt
A1 Woodnutt, Gary
A1 Lappe, Rodney
A1 Bhat, Abhijit
YR 2011
UL http://clincancerres.aacrjournals.org/content/17/5/1001.abstract
AB Purpose: Angiopoietin-1 (Ang1) plays a key role in maintaining stable vasculature, whereas in a tumor Ang2 antagonizes Ang1's function and promotes the initiation of the angiogenic switch. Specifically targeting Ang2 is a promising anticancer strategy. Here we describe the development and characterization of a new class of biotherapeutics referred to as CovX-Bodies, which are created by chemical fusion of a peptide and a carrier antibody scaffold. Experimental Design: Various linker tethering sites on peptides were examined for their effect on CovX-Body in vitro potency and pharmacokinetics. Ang2 CovX-Bodies with low nmol/L IC50s and significantly improved pharmacokinetics were tested in tumor xenograft studies alone or in combination with standard of care agents. Tumor samples were analyzed for target engagement, via Ang2 protein level, CD31-positive tumor vasculature, and Tie2 expressing monocyte penetration. Results: Bivalent Ang2 CovX-Bodies selectively block the Ang2–Tie2 interaction (IC50 < 1 nmol/L) with dramatically improved pharmacokinetics (T½ > 100 hours). Using a staged Colo-205 xenograft model, significant tumor growth inhibition (TGI) was observed (40%–63%, P < 0.01). Ang2 protein levels were reduced by approximately 50% inside tumors (P < 0.01), whereas tumor microvessel density (P < 0.01) and intratumor proangiogenic Tie2+CD11b+ cells (P < 0.05) were significantly reduced. When combined with sunitinib, sorafenib, bevacizumab, irinotecan, or docetaxel, Ang2 CovX-Bodies produced even greater efficacy (∼80% TGI, P < 0.01). Conclusion: CovX-Bodies provide an elegant solution to overcome the pharmacokinetic–pharmacodynamic problems of peptides. Long-acting Ang2 specific CovX-Bodies will be useful as single agents and in combination with standard-of-care agents. Clin Cancer Res; 17(5); 1001–11. ©2011 AACR.