New treatment for Covid-19 shows promise, but scientists urge caution

Scientists have found that the coronavirus attacks the body in part by blocking its natural interferon response. PHOTO: EPA-EFE

LONDON (NYTIMES)- A British drug company said on Monday (July 20) that an inhaled form of a commonly used medicine could slash the odds of Covid-19 patients becoming severely ill, a sliver of good news in the race to find treatments that was met by scientists with equal measures of caution and cheer.

The drug, based on interferon beta, a protein naturally produced by the body to orchestrate its response to viruses, has become the focus of intensifying efforts in Britain, China and the United States to treat Covid-19 patients.

Scientists have found that the coronavirus attacks the body in part by blocking its natural interferon response, disarming cells that would otherwise be alerting neighbouring cells to activate their own genes and fortify themselves against the invading virus. In theory, administering interferon to patients could invigorate its defences in the early stages of illness.

But giving patients interferon without eliciting serious side effects has proved challenging. The symptoms of a seasonal flu, for example, are largely produced by the mobilisation of the body's interferon response, scientists said.

The British drug company Synairgen tried to circumvent that problem by developing an inhaled form of interferon that directly targets cells in the lungs, rather than an injection, which can produce more intense side effects. It conducted a small, double-blind trial on patients hospitalised with Covid-19, the illness caused by the coronavirus, in nine British hospitals.

The initial results, announced in a brief news release but not yet peer reviewed or published, were promising: The inhaled form of interferon beta tested by Synairgen was shown to reduce the odds of hospitalised patients becoming severely ill - needing ventilation, for example - by 79 per cent compared with patients who received a placebo.

But the significance of the findings was seriously limited - and, in the view of some scientists, undercut - by the small size of the trial. It involved only 101 patients, Synairgen said, making it difficult to know for certain how beneficial the drug was.

Still, the results were tantalising.

"If there is the material to distribute it to the population, and you could keep the price down, this could absolutely be a game changer," said Benjamin tenOever, a professor of microbiology at the Icahn School of Medicine at Mount Sinai in New York. "I don't doubt it will work. I just don't know how feasible it is."

The professor was a co-author of a study in May in Cell, a scientific journal, about how the virus blocks the body's interferon response. He said evidence was piling up that administering interferon could help limit the replication of the virus, especially in the early stages of illness, fending the virus off for long enough that a second set of genes could successfully eradicate it.

In hamsters, tenOever said, there were signs that interferon cleared the virus and blocked onward transmission.

In China, the early results of a study among medical workers also showed promise, concluding that interferon nasal drops "may effectively prevent Covid-19 in medical staff."

The study found that the drops "have potential promise for protecting susceptible healthy people during the coronavirus pandemic".

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