At least 10 different drug compounds ranging from cancer therapies to antipsychotics and antihistamines may be effective at preventing the new coronavirus from multiplying in the body, according to a multidisciplinary study conducted by a team of scientists in the United States and France. The researchers mapped the human proteins the virus interacts with inside the body when it infects cells and makes copies of itself, then looked for compounds that could block the virus from using those proteins. The result showed that 47 compounds in cell cultures had the desired effect, at least 10 of which are already in approved drugs or being studied for diverse conditions, but could be repurposed against COVID-19, the illness caused by the new coronavirus. Researchers have been rushing to develop experimental therapies as well as to repurpose existing drugs to treat patients with COVID-19 and communities are pinning high hopes on Gilead Sciences Inc's experimental antiviral drug, remdesivir. In the new study, published in the journal Nature on Thursday, candidates for repurposing included allergy medicine ingredients including clemastine, the antipsychotic haloperidol, and malaria drug hydroxychloroquine. The study also revealed why hydroxychloroquine is often found to have toxic effects on the heart. The malaria drug, which has been repeatedly touted by US President Donald Trump, binds to a receptor on human cells, which the virus needs to infect the cell. But hydroxychloroquine also hits a particular protein in the heart tissue, which could explain the drug's effect on heart rhythms—side effect recently flagged by US and EU health regulators. The team also found that an experimental chemical, PB28, was 20-times more potent than hydroxychloroquine in targeting the receptor, but had far less affinity for the heart protein. The hormone progesterone was also found to act against the virus, which might shed some light on the reasons that men appear to be more susceptible to COVID-19 and more often suffer severe complications. Another compound found to have antiviral activity was plitidepsin, used in Madrid-based PharmaMar's experimental cancer therapy Aplidin that is currently being tested in COVID-19 trials in Spain. "Some of our drugs and compounds are many times more potent than remdesivir, at least in a laboratory setting," study author Nevan Krogan of the University of California San Francisco, said in a media briefing. Gilead's remdesivir could be the closest to regulatory approval after initial trial results on Wednesday found that the drug helped patients recover more quickly. The team said it would continue testing the candidates they have identified and use the same methods to further study the biology of the disease for more insights. —Saumya Joseph Source