Over 130 drugs under trail to treat Covid19, remdesivir leading contender: scientists

New Delhi: With a vaccine still a long distance away, efforts to repurpose old medications used for other ailments provide hope of an early counter to COVID-19, say scientists, placing the antiviral remdesivir on top of the list of possible contenders.

As COVID-19 continues its spread -- crossing 5.2 million cases and 3,38,000 fatalities on Saturday -- several categories of drugs are under clinical trial. Of them, remdesivir, which initially went into trials for treating the deadly Ebola virus five years ago, has shown promise by modestly speeding recovery from COVID-19, experts said.

More than 130 drugs are under experimentation to treat COVID-19, some may have the potential to stop the virus while others may help calm overactive immune responses that damage organs, according to a tracker maintained by the Milken Institute, an independent economic think tank in the US,

"Right now, there is only one effective approachÂ… which is to repurpose already approved drugs for other diseases if they can be used for COVID-19. One example is remdesivir," Ram Vishwakarma, director of the Indian Institute of Integrative Medicine, CSIR, Jammu, told PTI.

Remdesivir is helping people recover faster, and is lowering the death rate among critically ill patients, Vishwakarma said, adding that it can be life-saving.

We do not have time to develop new drugs. New drug development takes five-10 years so we are using existing drugs and conducting clinical trials to find if any of them are effective, Vishwakarma said.

Some molecules available for treating diseases like HIV or other viral infections can be quickly checked against the novel coronavirus, he explained. If found effective, they can be used against COVID-19 with the appropriate approval from drug control bodies.

When drug company Gilead Sciences sought to begin clinical trials for remdesivir to treat the novel coronavirus, it immediately got approval from the US FDA.

According to Vishwakarma, the other drug showing promise is favipiravir, a broad-spectrum antiviral approved in Japan, which is also under clinical trials for its effectiveness against COVID-19.

India is also playing its role.

The Indian Institute of Chemical Technology (IICT), Hyderabad, has developed the technology to make favipiravir, Council of Scientific and Industrial Research (CSIR) Director General Shekar Mande announced this month.

CSIR is conducting clinical trials for favipiravir, remdesivir and an anti-inflammatory drug called colchicine, which is commonly used to treat gout, said Vishwakarma.

"A number of drug trials are happening in India, which we are doing with pharmaceutical companies," Vishwakarma said.

Of the drugs under trial, remdesivir has shown the most promising results, agreed Subhabrata Sen, professor at the Department of Chemistry in Shiv Nadar University in Uttar Pradesh.

Last week, scientists from the Beijing Advanced Innovation Center for Genomics at Peking University in China, revealed a new method to identify multiple antibodies from recovered COVID-19 patients.

Using a single-cell genomics method, the researchers could rapidly identify antibodies from convalescent plasma, a component of patients' blood.

When the researchers tested these antibodies in mice, they found that some of them could neutralise the virus.

Another team from the University of Washington in the US found recently that a combination of antibodies, including those from a patient who had recovered from the 2002-03 SARS pandemic virus infection, can effectively block the novel coronavirus.

One of these molecules, named S309, showed particularly strong neutralising activity against SARS-CoV-2, they said, adding that it can act in combination with another, less potent antibody that targets a different site on the virus.

However, these results too are yet to be validated in human clinical trials.

Among other therapeutics currently under trial or in use, Sen said US President Donald Trump's "game changer" drug hydroxycholoroquine was promising "until it demonstrated serious side effects in the form of cardiovascular complications", rendering it ineffective.