Ab8, the drug constructed with the antibody fragment, has worked in mice and hamsters, and has the potential eventually to be used as COVID-19 therapy and COVID-19 prevention in humans, according to the news release.
The UPMC and Pitt researchers are collaborating with scientists at the University of North Carolina, University of Texas Medical Branch, the University of British Columbia and University of Saskatchewan.
They said the molecule doesn't bind to human cells, which they called "a good sign it won't have negative side-effects in people". Due to the smaller size, it can easily diffuse into the tissues and effectively neutralizes the virus.
He added that larger antibodies have been effective against other infectious diseases, giving the world a hope that they could also cure and prevent COVID-19 infections.
"The small size means that we can treat or prevent infection in more people with a set amount of protein, because we need less of it", Mellors said.
The tiny antibody component is the variable, heavy chain (VH) domain of an immunoglobulin, which is a type of antibody found in the blood. Next, to increase the VH ab8 avidity and extend its in vivo half-life, it was converted to a bivalent antibody domain by fusion to the human IgG1 Fc (VH-Fc ab8).
Researchers are also "thinking outside the box" for how the drug could be administered, stating it may be able to be inhaled or through a superficial injection, instead of an IV.
"Its small size might allow it to be given as an inhaled drug or intradermally, rather than intravenously through an IV drip, like most monoclonal antibodies now in development", the report says.
Abound Bio, a newly formed UPMC-backed company, has in-licensed the rights to Ab8 for global development.
Dimitrov's team has since discovered antibodies that battle a host of other infectious diseases including MERS, dengue, Hendra and Nipah viruses.
In February, Wei Li, assistant director of Pitt's Center for Therapeutic Antibodies and co-lead author of the research, began sifting through large libraries of antibody components made using human blood samples and found multiple therapeutic antibody candidates, including Ab8, in record time.
All noted how it appeared to stop the virus from entering cells.
"The new trial will tell us whether antibodies that attack the virus can be an effective treatment for COVID-19", she said. They found that ab8 significantly decreased infectious virus by 10-fold at two days post infection even at a very low dose of 2 mg/kg in mouse models, compared to untreated counterparts.
John Mellors, who co-authored the report with Xianglei Liu of Pitt, said Ab8 could be useful to prevent COVID-19 infection in humans.