Drugs are being developed to alleviate symptoms in the most severe cases of coronavirus.
Although they are not vaccines or a cure against Covid-19, some drugs have shown “very promising” early results to help treat coronavirus patients.
US scientists have been trialling a drug used to treat Ebola patients, on people admitted to hospital with the virus.
Patients given the anti-inflammatory, anti-viral drug - remdesivir - had a recovery time that was almost a third faster than those given a placebo, the first results from an international clinical trial showed.
Abdel Babiker, professor of epidemiology and medical statistics at UCL, told BBC Radio 4’s Today programme: “These are very encouraging results from the first large-scale randomised trial to report on any treatment of Covid-19.”
Preliminary results also suggested a survival benefit, with a lower mortality rate of 8% for the group receiving the drug, compared with 11.6% for the placebo group, the National Institute of Allergy and Infectious Diseases (NIAD) said.
Dr. Anthony Fauci, the head of the NIAD and a leading member of the White House’s coronavirus task force said the drug had a “clear-cut, significant positive effect.”
“We think it’s really opening the door to the fact that we now have the capability of treating [Covid-19],” Dr Fauci said on Wednesday.
More than 1,000 patients have been recruited across the world for the trial, including 46 from the UK, for the Adaptive Covid-19 Treatment Trial, which began at the start of April.
Scientists involved in the study defined recovery as a patient being well enough to come off oxygen, being discharged from hospital or even returning to normal activity levels.
During the trial, which involved more than 70 hospitals across the globe, patients were given the anti-viral drug every day for 10 days while they remained in hospital.
Professor Mahesh Parmar, director of the Medical Research Council Clinical Trials Unit at UCL, who oversaw the EU portion of the trial, said scientists will continue to gather further data while the early results are reviewed by regulators.
Prof Parmar said: “These results are very promising indeed. They show that this drug can clearly improve time to recovery.”
But he said before the drug can become widely available, the data and results need to be reviewed by regulators to assess whether the drug can be licensed, and they need assessment by the relevant health authorities in various countries.
“While this is happening, we will obtain more and longer term data from this trial, and other ones, on whether the drug also prevents deaths from Covid-19,” Prof Parmar added.
Sarah Pett, professor of infectious diseases at the UCL trials unit, paid tribute to the co-operation between teams as they worked to deliver results quickly.
She said: “Delivering the results of the first stage of the ACTT study in such a short time is down to the dedication and hard work of the teams in the USA, at UCL, all of the hospitals who participated in this trial, and of course most importantly, the patients who agreed to participate.
“The spirit of collaboration has never been stronger, in this time of urgent global need. The reward for all of us has been to provide data which suggests remdesivir helped the patients in the ACTT study recover more quickly.
“This is a foundation on which to build, and these findings will help other patients with Covid-19.”
What other drugs are being trialled to treat coronavirus patients?
Remdesivir, which was originally developed to treat Ebola, is one of a handful of experimental drugs undergoing clinical trials worldwide to treat coronavirus.
A trial found a HIV drug was “beneficial” to Covid-19 patients, after doctors in Wuhan treated severe Covid-19 patients with the HIV drug Kaletra.
Patients were prescribed Kaletra, an off-patent version of lopinavir/ritonavir produced by AbbVie, as well as a second drug, bismuth potassium citrate, said Zhang Dingyu, the president of the Jinyintan Hospital in Wuhan, where the disease originated late last year.
A study published last month in the New England Journal of Medicine, based on a test in Chinese patients with severe COVID-19 at Jinyintan, said that Kaletra, also known as Aluvia, was not effective as a potential treatment.
But Zhang said three medical workers had started taking Kaletra 2-3 days after symptoms of the virus surfaced.
"Towards the end of taking the drug, the changes their lungs experienced were really great," he added.
Meanwhile, Yale University in the US has launched a trial to test the effectiveness of an asthma drug in treating coronavirus patients.
The drug - ibudilast – showed promise in improving lung health in mouse models as it blocks a gene that drives inflammation.
Scientists from Yale University's New Haven Hospital, says it hopes the drug will reduce inflammation and slow down the progression of a threatening lung condition seen in the most severely ill coronavirus patients.
Coronavirus: Everything you need to know: