GigaGen jumps into COVID-19 arena with polyclonal antibodies

Mining the blood of recovered patients for treatments during a pandemic isn’t a new idea. Takeda and Grifols are already doing it, working on antibody-rich drugs made from the plasma of patients who have fought off COVID-19 infection. But a small South San Francisco startup thinks its approach could be even better.

“These drugs right now are made by taking plasma from human donors or animals, purifying antibodies from it, which then become a drug. It’s like a cocktail of antibodies,” GigaGen CEO David Johnson, Ph.D., told FierceBiotech. Problem is, that approach is hard to scale.

“You need many, many hundreds of donors to make a fairly small batch of product, and then you have to go out and find more donors—it’s not a very scalable approach,” he said. What’s more, this blanket approach doesn’t pick out specific antibodies against COVID-19: “In your serum, you have antibodies against all kinds of diseases, and those diseases might have been ones you saw months ago and not necessarily coronavirus,” he said.

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Enter GigaGen’s Surge technology, which uses single-cell sequencing to “capture and recreate” whole libraries of antibodies from recovered COVID-19 patients. The company can then choose which of those antibodies to turn into recombinant polyclonal antibody treatments in a method that does not rely on collecting vast amounts of plasma from many donors.

It’s developing a treatment called rCIG (recombinant anti-coronavirus 19 hyperimmune gammaglobulin) that will contain antibodies to shut down replication of the SARS-CoV-2 virus. Although rCIG could be given as a prophylactic, Johnson sees it more as a therapeutic as it must be given to patients intravenously.

“This method is much more scalable than plasma-based methods, since one person’s B cell repertoire can be used to generate a drug that treats millions of patients,” the company said in a statement Monday. “Additionally, due to their recombinant nature, GigaGen’s recombinant polyclonal therapies have a decreased risk of contamination and are consistent from batch to batch, enabling a controlled dosing protocol.”

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GigaGen is recruiting patients who have survived COVID-19 to donate blood for the development of rCIG. It’s building up its manufacturing capabilities and hopes to be in human trials in 2021. Johnson isn’t worried about trailing other players to the clinic, because “we don’t know what’s going to work, so we want to have many different efforts from many different groups, public and private. We need to throw everything we can against this virus.”

Aside from rCIG, GigaGen is working on recombinant monoclonal antibody treatments for cancer as well as polyclonals for primary immune deficiency and, in partnership with Grifols, for infectious diseases. But some supply chain uncertainty around necessities for preclinical studies has led GigaGen to put much of its work on hold.

“For example, if I need reagents for our COVID-19 work, we don’t want to use them for some other project because who knows if I can get those reagents again … We had to ask ourselves, is this program worth that struggle or extra cost right now, or should we put it on hold and just work on COVID-19?” Johnson said.

“The one good thing is we, as a small company, can respond fast. It may take a lot of bigger companies to make decisions about what to do,” he added. “We sat down and changed our portfolio in a week, because we had to.”

Editor's note: This story was updated to clarify that GigaGen is developing recombinant monoclonal antibodies for cancer and recombinant polyclonal antibody treatments for primary immune deficiency and infectious diseases.