rhMFG-E8 as an Effective Adjuvant Therapy for Hemorrhagic Shock

PROJECT DESCRIPTION: This SBIR Phase II project proposes to further develop recombinant human milk fat globule epidermal growth factor-factor 8 (rhMFG-E8) as a novel and effective adjuvant therapy for hemorrhagic shock, which kills 60,000 Americans every year. Hemorrhagic shock results in cell death, and dying cells release damage-associated molecular patterns (DAMPs). DAMPs promote inflammation, compounding organ injury to cause multiorgan failure, which is an important cause of morbidity and mortality after hemorrhage. MFG-E8 is a secreted glycoprotein that promotes the clearance of dying cells, thus abrogating the release of DAMPs. In our preliminary studies, we have shown that circulating levels of MFG-E8 are reduced in hemorrhaged mice, and that their adjuvant treatment with His-tagged rhMFG-E8 decreases inflammation and improves hemorrhagic shock survival. Since His-tagged biologics are not suitable for the use in human patients, we used a human cell expression system to produce pure tag-free rhMFG-E8, with superior biological activity. In a rat model of hemorrhagic shock, adjuvant treatment with tag-free rhMFG-E8 significantly reduced the number of apoptotic cells in the liver and lungs, circulating levels of proinflammatory cytokines and pulmonary infiltration by activated neutrophils. Tag-free rhMFG-E8 also attenuated renal and hepatic injury and improved hemorrhagic shock survival from 50% to 80%. Additionally, we determined rhMFG-E8’s distribution and elimination half-lifes and its non-carcinogenicity. Therefore, we hypothesize that tag-free rhMFG-E8 can be further developed as a new and effective adjuvant therapy for hemorrhagic shock. To advance the drug development, we will determine tag-free rhMFG-E8’s dose-dependent beneficial effects on organ injury and hemodynamic parameters, as well as its therapeutic window to improve survival after hemorrhage in the rat. We will also examine tag-free rhMFG- E8’s safety profile in the rat and verify its beneficial effects on organ injury, hemodynamic parameters, and survival in a pig model of hemorrhagic shock. These studies will provide critical dosing, time of administration, efficacy, and safety information to further develop tag-free rhMFG-E8 as an adjuvant therapy for hemorrhagic shock. Our future steps will include scaling up production of MFG-E8 and completing efficacy, ADME, and toxicokinetic preclinical studies. We will then file an investigative new drug (IND) application with the FDA to initiate clinical trials. Our ultimate goal is to obtain commercial utilization of tag- free rhMFG-E8 as a safe and effective resuscitation adjuvant for patients with hemorrhagic shock.PUBLIC HEALTH RELEVANCE STATEMENT: Severe bleeding is a major cause of death worldwide. In the United States, trauma is the single largest cause of death in people younger than 44 years of age. Prompt fluid administration can rescue severely bled patients, but patients then often develop multiorgan failure, leading to longer hospital stays, higher health costs, and increased death rates. Therefore, a treatment to prevent multiorgan failure after severe bleeding is badly needed. We have shown that a protein called rhMFG-E8 strongly protected severely bled mice and rats from organ failure and improved their survival. Therefore, we propose to further develop rhMFG-E8 as a new and powerful way to treat severe bleeding.