Anti-EGFL7 antibodies enhance stress-induced endothelial cell death and anti-VEGF efficacy
Leisa Johnson, … , Weilan Ye, Priti S. Hegde
Leisa Johnson, … , Weilan Ye, Priti S. Hegde
Published August 15, 2013
Citation Information: J Clin Invest. 2013;123(9):3997-4009. https://doi.org/10.1172/JCI67892.
View: Text | PDF
Research Article Oncology

Anti-EGFL7 antibodies enhance stress-induced endothelial cell death and anti-VEGF efficacy

Abstract

Many oncology drugs are administered at their maximally tolerated dose without the knowledge of their optimal efficacious dose range. In this study, we describe a multifaceted approach that integrated preclinical and clinical data to identify the optimal dose for an antiangiogenesis agent, anti-EGFL7. EGFL7 is an extracellular matrix–associated protein expressed in activated endothelium. Recombinant EGFL7 protein supported EC adhesion and protected ECs from stress-induced apoptosis. Anti-EGFL7 antibodies inhibited both of these key processes and augmented anti-VEGF–mediated vascular damage in various murine tumor models. In a genetically engineered mouse model of advanced non–small cell lung cancer, we found that anti-EGFL7 enhanced both the progression-free and overall survival benefits derived from anti-VEGF therapy in a dose-dependent manner. In addition, we identified a circulating progenitor cell type that was regulated by EGFL7 and evaluated the response of these cells to anti-EGFL7 treatment in both tumor-bearing mice and cancer patients from a phase I clinical trial. Importantly, these preclinical efficacy and clinical biomarker results enabled rational selection of the anti-EGFL7 dose currently being tested in phase II clinical trials.

Authors

Leisa Johnson, Mahrukh Huseni, Tanya Smyczek, Anthony Lima, Stacey Yeung, Jason H. Cheng, Rafael Molina, David Kan, Ann De Mazière, Judith Klumperman, Ian Kasman, Yin Zhang, Mark S. Dennis, Jeffrey Eastham-Anderson, Adrian M. Jubb, Olivia Hwang, Rupal Desai, Maike Schmidt, Michelle A. Nannini, Kai H. Barck, Richard A.D. Carano, William F. Forrest, Qinghua Song, Daniel S. Chen, Louie Naumovski, Mallika Singh, Weilan Ye, Priti S. Hegde

×

Figure 7

CPCs express EGFL7 and serve as a biomarker of anti-EGFL7 activity.

Options: View larger image (or click on image) Download as PowerPoint
CPCs express EGFL7 and serve as a biomarker of anti-EGFL7 activity. (A) ...
(A) FACS-based expression of CD34 and CD31 was assessed in CD45dim cell population from human peripheral blood. Two distinct clusters of CEC (green) and CPC populations (blue) are shown. (B) Peripheral blood CECs, CPCs, and CD45+ cells were sorted from 3 donors and evaluated for EGFL7 transcripts. The mean ± SEM is depicted. (C) CPCs (2 × 105/well) were allowed to differentiate on fibronectin-coated plates for 21 days. Cells were fixed and incubated with anti-CD31 or isotype control and cell nuclei stained with DAPI. Original magnification, ×40. (D) CPCs were plated in quadruplicate on either fibronectin- or EGFL7-coated plates (3 × 104/well). Cells were then treated with either control IgG or h18F7 and proliferation assessed by counting the number of DAPI+ cells 48 hours later. The mean ± SD is depicted (n = 4 biological replicates). *P < 0.05; ***P < 0.0001. (E) Mice bearing MDA-MB231 xenografted tumors were treated with control anti-ragweed plus anti-gD, anti-VEGF plus control anti-gD, or control anti-ragweed plus anti-EGFL7 (mu; m18F7). Antibodies were dosed i.p. either 2 times per week (anti-ragweed and anti-VEGF) or 1 time per week (anti-gD and anti-EGFL7). (F) RIP-TβAg mice were treated with control anti-ragweed plus anti-gD, anti-VEGF, anti-EGFL7 (hu; h18F7), or anti-EGFL7 (mu; m18F7). Antibodies were dosed i.p., 1 time per week on days 1 and 8. (E and F) Whole blood was collected on day 19 (E) or 15 (F) for CPC enumeration. The mean ± SEM is depicted.