A U.S. Government-industry collaboration has resulted in the development of a monoclonal antibody (mAb)-based therapy for Ebola virus that protects rhesus macaque monkeys from developing lethal disease when administered up to two days after infection. The treatment, designated MB-003, is a mixture of three deimmunized and/or humanized mAbs that have been engineered from an original set of mouse mAbs directed against three non-overlapping Ebola virus glycoprotein epitopes.
The antibodies have been developed through a U.S. government-funded partnership between the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Mapp Biopharmaceuticals, and Kentucky BioProcessing. Importantly, Kentucky Bio has developed a cost-effective and fast GMP process to manufacture the antibodies in a rapid antibody manufacturing platform (RAMP) tobacco plant system, which would allow mass production for a national stockpile. The comparative in vivo tests in primates showed that the tobacco plant-derived antibodies were at least as effective as antibodies produced in a Chinese hamster ovary-based system.
The researchers report their development and initial primate trials in PNAS, in a paper titled “Delayed treatment of Ebola virus infection with plant-derived monoclonal antibodies provides protection in rhesus macaques.”
“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,” comments USAMRIID’s Gene Garrard Olinger Jr., Ph.D. “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.” Dr. Olinger says studies are continuing to progress MB-003 toward the clinic.