Co-Administration of Vadimezan and Recombinant Coagulase-NGR Inhibits Growth of Melanoma Tumor in Mice.

Tumor vascular targeting appeared as an appealing approach to fight cancer, though, the results from the clinical trials and drugs in the market were proved otherwise. The promise of anti-angiogenic therapy as the leading tumor vascular targeting strategy was negatively affected with the discovery that tumor vascularization can occur non-angiogenic mechanisms such as co-option. An additional strategy is induction of tumor vascular infarction and ischemia.

NGR (Asn-Gly-Arg)-targeted delivery of coagulase to tumor vasculature arrests cancer cell growth.

Induction of selective thrombosis and infarction in tumor-feeding vessels represents an attractive strategy to combat cancer. Here we took advantage of the unique coagulation properties of staphylocoagulase and genetically engineered it to generate a new fusion protein with novel anti-cancer properties. This novel bi-functional protein consists of truncated coagulase (tCoa) and an NGR (GNGRAHA) motif that recognizes CD13 and αβ integrin receptors, targeting it to tumor endothelial cells.

An overview on Vadimezan (DMXAA): The vascular disrupting agent.

Vascular disrupting agents (VDAs), a group of cancer remedies, can cause a specific and irreversible destruction of established tumor vessels, and the complete halt of blood flow in the tumor. DMXAA (ASA404) or Vadimezan, a flavone-acetic acid-based drug, is the most promising VDAs that induces a rapid shutdown of blood flow in tumors but not in normal tissue. The exact mechanism of vascular disruption is unknown; however, proposed direct and indirect mechanisms of action for DMXAA comprises (i) inducing apoptosis in endothelial cells; (ii) hemorrhagic necrosis and ischemia in tumor; (iii) release of serotonin (5-HT); (vi) stimulation of innate immune system; (v) production of inflammatory cytokines, for example TNF, IL-6, GCSF, KC, IP-10, and MCP-1; (vi) activation of NFκB and p38 (MAPK); (vii) production of nitric oxide; and (viii) reducing tumor energetics and membrane turnover.

RGD delivery of truncated coagulase to tumor vasculature affords local thrombotic activity to induce infarction of tumors in mice.

Induction of thrombosis in tumor vasculature represents an appealing strategy for combating cancer. Herein, we combined unique intrinsic coagulation properties of staphylocoagulase with new acquired functional potentials introduced by genetic engineering, to generate a novel bi-functional fusion protein consisting of truncated coagulase (tCoa) bearing an RGD motif on its C-terminus for cancer therapy. We demonstrated that free coagulase failed to elicit any significant thrombotic activity.