FLICKR, NIAIDWith the death toll from Middle Eastern respiratory syndrome (MERS) rising in Saudi Arabia, the United Arab Emirates, and, most recently, South Korea, researchers are scrambling to develop a treatment that can slow the coronavirus. This week (June 29), researchers at Regeneron Pharmaceuticals and the University of Maryland announced progress on this front: antibody-based technology, which has been used to design experimental treatments against Ebola, has yielded a treatment that can tackle MERS in mice. The group published their results in the PNAS.
“Instead of just trying to invent new drugs, we also invent new technologies that enable us to make new drugs more reliably and more rapidly,” Neil Stahl, Regeneron’s executive vice president of research and development, told MIT Technology Review.
First, the researchers had to establish a mouse model of MERS by genetically engineering the animals to express human immune receptors. “Mice are typically not susceptible to MERS,” coauthor Matthew Frieman, an assistant professor of microbiology and immunology at the University of the Maryland School of Medicine, said in a press release. “This new mouse model will significantly boost our ability to study potential treatments and help scientists to understand how the virus causes disease in people.”
The team then screened some 1,000 antibodies that bind to the MERS coronavirus (MERS-CoV), and tested the most-promising ones in humanized mice just before and just after they were infected with the virus. Two antibodies, dubbed REGN3051 and REGN3048, were able to neutralize the virus, making them the first treatments to successfully protect and treat an animal model of MERS, according to the press release. “While early, this is very exciting, and has real potential to help MERS patients,” Frieman said.
The researchers are now working to move the two antibodies into human trials. “There’s no reason why it shouldn’t be successful, but it’s very hard to predict until it’s actually in clinical trials [in people].” Columbia University’s Stephen Morse told MIT Technology Review.
Meanwhile, an experimental MERS vaccine, called MVA-MERS-S, is moving into a Phase 1 trial, MNT reported. The vaccine, which uses a viral vector called Modified Vaccinia virus Ankara (MVA) and carries an MERS-CoV antigen called the spike glycoprotein (protein S), proved effective in preclinical testing, according to a report published May 27 in the Journal of Virology. Researchers in Germany the Netherlands found that the vaccine successfully elicited high levels of MERS-CoV–neutralizing antibodies in cell cultures, and that the virus failed to replicate in MERS-susceptible mice treated with the vaccine.
“We have now shown for the first time that MVA-MERS-S effectively induces protective immunity against MERS-CoV in a mouse model,” coauthor Asisa Volz of Ludwig-Maximilians-Universitaet Muenchen in Germany said in a press release.