COVID-19 News

BARDA partner plans human trials of COVID-19 drug derived from cow plasma

A South Dakota company expects to start human trials next month for a COVID-19 antibody treatment derived from the plasma of cows. But these aren't just any cows. Scientists genetically engineered the animals to give them an immune system that's part human. That way, the animals produce disease-fighting human antibodies to Covid-19, which are then turned into a drug to attack the virus.

The company, SAB Biotherapeutics, received initial funding to develop the treatment from the Biomedical Advanced Research Development Authority (BARDA) through an existing Rapid Response contract with the Department of Defense (DoD) Joint Program Executive Office for Chemical, Biological, Radiological, and Nuclear Defense (JPEO - CBRND) Joint Project Lead for Enabling Biotechnologies (JPL-EB).

"These animals are producing neutralizing antibodies that kill [the novel coronavirus] in the laboratory," Eddie Sullivan, CEO of SAB Biotherapeutics said in a statement to CNN. "We are eager to advance to the clinic as we move forward in the regulatory process with the hopes of bringing this potential COVID-19 therapeutic to patients in need of a solution."

The company did not say how many people would be studied in the clinical trials or how long they would take.

To make its drug, SAB took skin cells from a cow and knocked out the genes that are responsible for creating cow antibodies, and instead inserted an engineered artificial human chromosome that produces human antibodies. They put the DNA from those cells into a cow egg and turned it into an embryo. They then implanted that embryo into a cow to start a pregnancy, and over the past two decades, have produced several hundred genetically identical cows, all of them with partly human immune systems. 

The scientists then injected some of the cows with a non-infectious part of the virus that causes COVID-19. The cows are now producing human antibodies to the coronavirus.

SAB has manufactured hundreds of doses of the medicine, called SAB-185, to use in its clinical trials. The company has not yet announced whether it will study the drug as prevention or treatment for Covid-19, or both.

The principle behind the drug is similar to the longstanding practice of convalescent plasma treatment, which is still being used today to treat COVID-19. But cows have several advantages over human plasma donors. One, SAB says, is that cows naturally have a more robust immune response than humans, and repeated injections with the coronavirus make that response even stronger. Two, cows are large and have more plasma to give. Three, they can give plasma three times a month, instead of once a month, like humans.  

According to SAB, their drug made from cow plasma has levels of neutralizing antibodies four times higher than the most potent antibodies in human samples they studied. This research, conducted at the University of Pittsburgh, was shared in a press release by the company, and has not been published or peer reviewed.

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Read the press release regarding the antibody levels in SAB-185: