First-Ever Peptide-Based Drugs Could Both Prevent and Treat COVID-19

Scientists have developed two new drugs to both prevent SARS-CoV-2 infection, and also treat people who have been exposed to the virus so they do not develop severe disease.

The peptide-based drugs developed by scientists from QIMR Berghofer Medical Research Institute (Queensland, Australia) are now being tested in hamsters, with promising early results showing they are not toxic and have few side effects. The drugs are also stable and can be stored at room temperature - which would make them easy to distribute.

The discovery of the peptide-based drugs was made possible after the researchers uncovered a previously unknown mode of entry that SARS-CoV-2 exploits to invade cells and cause COVID-19 disease. The researchers were able to develop the drugs after discovering that some people have a chemical tag which acts like a padlock on the ACE2 receptor. The researchers also discovered that if the virus invaded the cells it would unlock the tag from the inside - allowing more efficient virus replication. The two early intervention drugs target how human cells respond to the SARS-CoV-2 virus, instead of the virus itself. The first peptide-based drug would be given pre-exposure to the virus and help boost the efficacy of vaccines, while the second drug would stop the spread of the virus in already infected cells.

Laboratory tests show the first peptide-based drug reduces infection by cloaking the ACE2 receptor protein on human cells. The SARS-CoV-2 spike protein uses the ACE2 receptor to bind to and invade cells. The virus then latches onto the cloaking peptides, which they mistake for human cells - preventing infection. The lab tests have also shown that if the virus finds its way into cells, the second peptide-drug can block how the virus hijacks the host cell and replicates. It also boosts the immune system’s ability to recognize the virus. The research was conducted on COVID-19 patient blood and human cells.

“These are the first drugs we are aware of that can operate on dual fronts. We hope, if the clinical trials are successful, that the first drug could be given as a therapy alongside vaccination to prevent the virus binding to cells and taking hold, while the second peptide could be used to stop the virus replicating in already-infected patients,” said Professor Sudha Rao, senior researcher and head of QIMR Berghofer’s Gene Regulation and Translational Medicine Group.

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QIMR Berghofer Medical Research Institute