Prophylactic but not therapeutic activity of a monoclonal antibody that neutralizes the binding of VEGF-B to VEGFR-1 in a murine collagen-induced arthritis model.

OBJECTIVE: To assess the therapeutic potential of a mAb that neutralizes the binding of VEGF-B to VEGFR-1, to inhibit the pathogenesis of CIA in mice. METHODS: CIA was induced in C57BL6/J and DBA-1 mice by intradermal injection of chick collagen type II (CII) in adjuvant. A neutralizing VEGF-B mAb or an isotype control mAb was then administered by intraperitoneal injection twice weekly beginning either post CII booster injection but prior to or immediately following clinical disease diagnosis. RESULTS: Neutralizing VEGF-B mAb inhibited the development of CIA in C57BL6/J mice in a dose-dependent manner when administered following the CII booster injection, but prior to clinical disease diagnosis. This result was also confirmed in DBA-1 strain mice. In contrast, the neutralizing VEGF-B mAb had no measurable effect on disease severity or progression when treatment commenced from the day of clinical disease diagnosis. CONCLUSIONS: Treatment with an mAb that neutralizes the binding of VEGF-B to VEGFR-1 exhibits prophylactic but not therapeutic actions in a mouse model of RA. These data indicate that while VEGF-B/VEGFR-1 signalling is involved in the early development of arthritis it may not be required for maintenance or progression of established disease.