Military Close to Human Ebola ‘Cocktail’ Treatment

FREDERICK, MD — Military researchers have moved a step closer to protecting humans against the deadly effects of Ebola virus.

A new Ebola virus study has shown promising preliminary results, preventing disease in infected nonhuman primates using monoclonal antibodies. The report recently available in the online edition of the Proceedings of the National Academy of Sciences (PNAS), describes the use of a “cocktail” of monoclonal antibodies, or mAbs, to prevent lethal disease in rhesus macaques.1

All animals survived when the compound, known as MB-003, was administered one hour after infection, and two-thirds of them were protected, even when the treatment was administered 48 hours after infection.

Ebola virus causes hemorrhagic fever and kills as many of 90% of human patients. In addition to being a global health concern, especially in central Africa, the virus also is considered a potential biological threat agent. No available vaccines or treatments currently are approved for use in humans.

Lead investigator Gene Olinger, Ph.D., a virologist at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), said a consortium of investigators has taken very distinct technologies and combined them to develop a cutting-edge medical countermeasure against a lethal viral disease.

“It is rare that an antiviral compound prevents Ebola virus infection with limited to no morbidity in treated animals at any point of treatment following infection by this lethal virus," Olinger said. "Until recently, attempts to utilize antibodies to provide protection against Ebola virus have been met with failure. The level of protection against disease that we saw with MB-003 was impressive.”

Initially developed as a monoclonal antibody cocktail in the mouse model, MB-003 was successfully humanized, then produced in the tobacco plant-based production system, making it a more economical counter-measure.

“We were pleased to see how well the humanized mAbs of MB-003 performed,” said Larry Zeitlin, PhD, president of Mapp Biopharmaceutical and senior author on the study. “We also were pleasantly surprised by the superiority of the plant-derived mAbs compared to the same mAbs produced in traditional mammalian cell culture.”

The process is both cost- and time-efficient, according to the report.

“Our GMP facility can generate a new antibody lot in two weeks to rapidly address new threats and new outbreaks,” said Barry Bratcher, chief operating officer of Kentucky BioProcessing and co-author on the PNAS study.

Funding for the study and related investigations came from the National Institutes of Health, the Defense Advanced Research Projects Agency, the Transformational Medical Technologies Initiative and the Defense Threat Reduction Agency.

1. Olinger GG Jr, Pettitt J, Kim D, et. al. Delayed treatment of Ebola virus infection with plant-derived monoclonal antibodies provides protection in rhesus macaques. Proc Natl Acad Sci U S A. 2012 Oct 30;109(44):18030-5. doi: 10.1073/pnas.1213709109. Epub 2012 Oct 15. PubMed PMID: 23071322.