- Several coronavirus treatment options based on antibodies are currently in testing, and the latest addition comes from a company that used cow blood to grow potent antibodies capable of neutralizing the novel virus.
- SAB-185 is the name of the polyclonal antibody therapeutic that will be tested in clinical trials this summer.
- Harvested from the plasma of genetically altered cows, the drug candidate has powerful antibodies in much higher quantities than the most potent human antibodies retrieved from COVID-19 survivors’ plasma.
Remdesivir and dexamethasone are so far the only drugs that were proven to work as COVID-19 therapies. The former is an experimental drug created to treat Ebola, and it turned out to speed up the recovery of patients with mild and moderate coronavirus infections. Dexamethasone is a cheap steroid that’s widely available, but it’s only useful in severe COVID-19 cases. Neither one offers the perfect cure for the novel coronavirus, but they’re steps in the right direction for a disease that’s not expected to disappear anytime soon. These drugs could buy doctors even more time so that research is completed for a few promising vaccine candidates that can prevent COVID-19 as well as brand new antibody drugs that have both the potential of helping with COVID-19 recovery and offering temporary immunity.
The latest antibody therapy to approach human trials comes from a company that has been growing powerful COVID-19 antibodies in the blood of cows.
“These animals are producing neutralizing antibodies that kill [the novel coronavirus] in the laboratory,” SAB Biotherapeutics CEO Eddie Sullivan told 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.”
SAB used skin cells from a cow and replaced the cells that create cow antibodies with an artificial human chromosome that produces human antibodies. The DNA from those cells was inserted into a cow egg two decades ago, and the embryo was grown in a cow. Since then, the company has produced hundreds of genetically identical cows featuring partly human immune systems.
This year, the scientists injected some of the cows with a non-infectious version of the SARS-CoV-2 virus, and they generated potent antibodies that can be used in humans to fight off the infection. SAB manufactured hundreds of doses of the drug, which is called SAB-185. This will be used in the upcoming trials, although it’s unclear how many people will be included in the test.
SAB explained that cows have a few significant advantages over humans when it comes to plasma antibodies. They produce a more robust immune response and repeated injections with the novel coronavirus further boost that response. The animals can then give plasma three times a month, not just once, which is the case with humans.
What’s even better is that the plasma from these genetically altered cows has levels of COVID-19 neutralizing antibodies four times higher than the most potent antibodies found in human plasma samples. The company already announced its discovery via a press release, although the lab research wasn’t published in a medical journal. ”In just seven weeks, we’ve accelerated development of a specifically targeted natural human polyclonal therapeutic, without the need for human serum, and generated large volumes of highly-potent neutralizing antibodies to SARS-CoV-2, to produce clinical lots of our COVID-19 therapeutic candidate, SAB-185,” Sullivan said in a statement.
“Consistent with data across SAB’s platform in other indications, these data suggest that our potential COVID-19 therapeutic may remain effective even as SARS-CoV-2 continues to evolve,” he said. “SAB-185, which was developed from the original Wuhan strain sequences, demonstrated highly-potent neutralizing titers to the mutated Munich strain of the virus, believed to be most prevalent strain in the U.S. These data give us great confidence as we begin manufacturing clinical product and prepare to move forward in the regulatory pathway to provide a potential solution to combat COVID-19.”
SAB isn’t the only biopharmaceutical company developing COVID-19 antibodies using animals. Regeneron does it with genetically altered mice, while researchers from Japan and a Belgium-American team have been working with antibodies obtained from llamas. If any of these drugs prove to be effective and safe in human testing, we could soon have better COVID-19 therapy options than remdesivir and dexamethasone.