Placental infection may be more likely early in pregnancy; COVID-19 may cause heart failure in some patients

By Nancy Lapid

(Reuters) – The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

Placental infection may be more likely in early pregnancy

The coronavirus that causes COVID-19 rarely infects the placenta, but new research suggests that when such an infection does occur it is more likely to happen early in pregnancy. Analyzing 12 placentas from healthy women, ranging in gestational age from 5 weeks to 36 weeks, researchers found that the cells in the placenta that become infected with the coronavirus have the surface protein ACE2, which the virus uses as a gateway for entry. Late in pregnancy, the ACE2 proteins are positioned on cells in a way that does not expose them to the virus circulating in the mother’s blood, possibly protecting the placenta from infection, said study coauthor Dr. Drucilla Roberts of the Massachusetts General Hospital in Boston. This “protective” positioning pattern was less often seen in early gestation placentas, when ACE2 was typically present over the entire cell circumference, the study found. That suggests “increased vulnerability of the early placenta to infection,” Roberts said. “As more pregnant women recover from first trimester SARS-CoV-2 infection, it is important to remain vigilant to possible placental infection” and transmission from mother to fetus, the researchers said in a report published in Journal of Infectious Diseases. How often that happens, and effects on the fetus and newborn remain unknown, they added.

COVID-19 patients face low risk of new heart failure

Patients hospitalized with COVID-19 may develop heart failure even if they do not have a previous history of heart disease or cardiovascular risk factors, although the risk is low, according to a study published on Monday in the Journal of the American College of Cardiology. Among 6,439 hospitalized COVID-19 patients, doctors found 37 patients (0.6%) with no history of heart failure who developed new cases during their hospitalization – including eight in their 40’s, on average, who had no previous cardiovascular disease or risk factors. It is not clear yet whether new-onset heart failure in these patients is an indirect effect of critical illness or a direct effect of the virus invading the heart, said study coauthor Dr. Anu Lala of the Icahn School of Medicine at Mount Sinai in New York, in a statement. “Importantly,” she added, “though symptoms of heart failure – particularly shortness of breath – can mimic symptoms associated with COVID-19, being alerted to the findings of this study may prompt clinicians to monitor for signs of congestion more consistent with heart failure than COVID-19 alone.”

Hepatitis C drugs work synergistically with remdesivir

Combining Gilead Sciences’ antiviral drug remdesivir – the current standard of care for hospitalized COVID-19 patients – with oral drugs used to treat hepatitis C virus (HCV) might be more effective than remdesivir alone, laboratory experiments suggest. Four HCV drugs that work synergistically with remdesivir “are especially interesting,” said Gaetano Montelione of Rensselaer Polytechnic Institute in Troy, New York. In test tube experiments, these HCV drugs increased remdesivir’s antiviral activity as much as 10-fold, his team reported on Monday in Cell Reports. The drugs – simeprevir, grazoprevir, paritaprevir, and vaniprevir – inhibit a protein in the coronavirus called PLpro, while remdesivir, which is given intravenously, targets viral polymerase proteins. Drug companies are developing oral drugs that target the same viral proteins as remdesivir. If those become available, Montelione said, it may be possible to offer them in combination with a hepatitis C drug for use at home, before COVID-19 patients become so ill that they need to be hospitalized. “So far all of the research has been performed in cells,” he noted, “and this approach must undergo further testing, perhaps first in animals, and then in clinical trials.”

(Reporting by Nancy Lapid; Editing by Bill Berkrot)

Remdesivir appears safe for seriously ill children; patients may not pose highest risk to hospital staff

By Nancy Lapid

(Reuters) – The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

Antiviral remdesivir appears safe for children

The antiviral drug remdesivir appears to be as safe and effective for use in children with COVID-19 as in adults, according to the largest study to date of children with severe COVID-19 who received the drug. Remdesivir, sold by Gilead Sciences Inc under the brand name Veklury, shortens time to recovery in adults with COVID-19. It is not yet approved for children under age 12. In March 2020, Gilead began accepting doctors’ requests for compassionate use of remdesivir in critically ill children with COVID-19. In the new study of 77 children in the United States, UK, Italy and Spain, “remdesivir was well tolerated, with a low incidence of serious adverse events,” related to the drug, researchers reported on Wednesday in Pediatrics. Within four weeks of starting treatment, 88% of the children had decreased need for oxygen support, 83% had recovered and 73% were discharged. Among those requiring mechanical ventilation, 90% were able to be taken off the ventilators. A randomized controlled trial is underway to confirm that the high level of recovery was due to the effects of remdesivir, the researchers said. An editorial published with the study said: “Although morbidity and mortality rates differ, children hospitalized with acute COVID-19 often have a similar disease course as adults. Children are also likely to have a similar response to remdesivir as adults.”

Patients may not pose highest COVID-19 risk for hospital staff

U.S. healthcare workers on the frontlines of the pandemic who become sick with COVID-19 are more likely to have acquired the infection in the community than through patient care, new research suggests. At a major Wisconsin medical center, researchers investigated likely sources of infections by analyzing the gene sequences of the virus obtained on swab samples from 95 healthcare workers and their patients. Only 11% of participants’ infections could be traced to a coworker and only 4% to a patient, the researchers reported in Clinical Infectious Diseases. They said their observations align with recent studies evaluating healthcare-associated infections in the Netherlands and in the UK, and with another recent study that found the most important risk factor for COVID-19 was the rate of the disease in surrounding communities, not workplace factors. “It appears that healthcare personnel most commonly become infected with SARS-CoV-2 via community exposure,” the researchers conclude. “This emphasizes the ongoing importance of mask-wearing, physical distancing, robust testing programs, and rapid distribution of vaccines.”

(Reporting by Nancy Lapid; Editing by Bill Berkrot)

U.S. infectious disease group backs Gilead’s remdesivir for COVID-19 treatment

By Rebecca Spalding

(Reuters) – The top U.S. infectious disease medical association said on Monday that Gilead Sciences Inc’s antiviral drug remdesivir should be used for hospitalized COVID-19 patients despite a World Health Organization (WHO) recommendation last week against its use.

The Infectious Diseases Society of America (IDSA) in updated guidelines said its experts back the drug for use in severe COVID-19 patients based on a clinical trial showing it reduced hospital stays. The WHO study that led to its recommendation against the drug suggested it had no benefit in saving lives or reducing the need for mechanical breathing assistance.

“As hospitals around the United States fill up, the IDSA panel views the effect of remdesivir speeding up time to recovery to be an important benefit,” Dr. Rajesh Gandhi, co-chair of the society’s COVID-19 treatment and management guidelines expert panel, said on a call with reporters. “Better medicines that improve survival are clearly needed.”

Unlike the trial that led to its U.S. regulatory approval, the WHO’s study was not placebo-controlled. Studies with a placebo comparison are generally considered more scientifically rigorous than those without a control group.

The IDSA also has advised against the routine use of Eli Lilly and Co’s COVID-19 antibody treatment bamlanivimab, which received U.S. emergency use authorization. The IDSA panel said it recommended against its routine use for ambulatory patients, but that it may still be appropriate for patients with increased risks after a discussion with their doctor.

“Antibodies may end up having a role. I think we just need more definitive data,” Dr. Gandhi said. “I want to keep our eye on what benefit they may end up having as well as which patients are most likely to benefit.”

It said Roche Holdings Ag’s rheumatoid arthritis drug Actemra, known chemically as tocilizumab, is not recommended for routine use in hospitalized COVID-19 patients, saying there was still not enough evidence supporting its benefits.

(Reporting by Rebecca Spalding; Editing by Bill Berkrot)

Exclusive: WHO-led COVID drug scheme doubles down on antibodies, steroids and shuns remdesivir

By Francesco Guarascio

BRUSSELS (Reuters) – A World Health Organization-led scheme to supply COVID-19 drugs to poor countries is betting on experimental monoclonal antibody treatments and steroids but is shunning Gilead’s remdesivir blockbuster therapy, an internal document shows.

The WHO draft document, seen by Reuters and dated Oct. 30, says the priorities are to secure monoclonal antibodies in a tight market and to boost purchases and distribution of cheap steroid dexamethasone, of which it has already booked nearly 3 million courses of treatment for poorer countries.

Monoclonal antibodies are manufactured copies of antibodies created by the body to fight an infection.

The paper, which for the first time outlines how the scheme would spend donors’ money, does not cite remdesivir among priority drugs – a significant omission as the antiviral is the only other medication alongside dexamethasone approved across the world for treating COVID-19.

Gilead Science, the U.S. company that developed remdesivir, said the WHO scheme had not funded its COVID-19 trials and had never approached the firm for the possible inclusion of the drug in its portfolio.

The drug-supply scheme is one of the four pillars of the so-called ACT Accelerator, a WHO-led project which also seeks to secure COVID-19 vaccines, diagnostics and protective gear for poorer countries by raising more than $38 billion by the beginning of 2022.

“Immediate priorities for the (therapeutics) pillar are intensifying efforts on monoclonal antibodies while scaling up dexamethasone use,” says the WHO document, still subject to changes and expected to be published on Friday or next week.

The drug-supply scheme, co-led by the Wellcome Trust, a charity, and Unitaid, a health partnership hosted by the WHO, urgently needs $6.1 billion, $750 million of which by February, out of a total ask of $7.2 billion.

More than half the money needed urgently would be used to procure and distribute monoclonal antibodies, the document shows, saying these therapeutics could have a “game-changing” impact but are in short supply.

No drug based on monoclonal antibodies has yet been approved against COVID-19, but the WHO scheme has already invested in research on the new technology and has secured production capacity at a plant of Fujifilm Diosynth Biotechnologies in Denmark.

Fujifilm was not immediately available for a comment.

The scheme wants to spend $320 million to produce antibodies in that facility, the document says, estimating that would be enough to secure at least 4 million antibody courses assuming upper-range procurement costs of $80 per course.

A spokeswoman for Unitaid, speaking on behalf of the co-leaders of the scheme, confirmed that it wanted to raise and invest $320 million in securing monoclonal antibodies but declined to comment on potential commercial deals citing confidential agreements.

Another $110 million would be used for regulatory approval and other market preparation procedures for monoclonal antibodies in poorer countries, the document shows, while $220 million would fund clinical trials of monoclonal antibodies and COVID-19 drugs projects in poorer countries.

Among companies developing monoclonal antibodies against COVID-19 are U.S. pharmaceutical giant Eli Lilly, Switzerland’s Novartis and U.S. firm Regeneron, whose antibodies were administered together with remdesivir to U.S. President Donald Trump in October when he tested positive for the coronavirus.

Eli Lilly has already agreed to produce antibodies at the Fujifilm plant from April and make them available at “an affordable price” to poorer countries, a company spokeswoman said.

Lilly’s drug is being trialed and is seeking emergency authorization in the United States.

A U.S. government-run trial of the drug was paused in mid-October over safety concerns, but other trials continue. In spite of the suspension, the U.S. administration said last week it had sealed a $375-million supply deal.

It is unclear how and whether the WHO scheme will raise the money needed for the supply of antibodies and other projects.

Regeneron was not immediately available for comment.

Novartis, which expects results soon from a trial of its arthritis treatment canakinumab against COVID-19, said on Thursday that it received a request several days ago from the WHO scheme seeking information about medicines to tackle the coronavirus. Novartis also makes dexamethasone.

REMDESIVIR? NO, THANKS

Despite being short of funds, the WHO drugs-supply scheme wants to “transform the treatment landscape”, the document says, and distribute hundreds of millions of courses of COVID-19 drugs to poorer countries by 2022.

Apart from monoclonal antibodies and dexamethasone, it is also planning to develop and secure experimental drugs, including new antivirals and repurposed drugs.

The scheme wants to spend another $100 million to seal deals with unspecified drugmakers from mid-2021, the document says, and next year plans to invest another $4.4 billion to secure drugs showing positive results in clinical trials.

The Unitaid spokeswoman said that among repurposed therapeutics, dexamethasone and its alternative, hydrocortisone, were the most promising.

Remdesivir, alternatively known as Veklury, is also a repurposed antiviral which was initially trialed against Ebola.

Unitaid confirmed the scheme had not procured or funded remdesivir. It did not comment on whether it may buy the drug in future or on why remdesivir did not appear among priority treatments in the document.

Remdesivir has been authorized in dozens of countries around the world to treat COVID-19. However, preliminary findings of a major WHO-sponsored trial revealed in October the antiviral had little or no benefit for COVID-19 patients, contradicting previous positive trials.

Governments however continue to buy it, with Germany this week announcing the purchase of more than 150,000 doses for the next six months.

(Reporting by Francesco Guarascio @fraguarascio; additional reporting by John Miller in Zurich and Caroline Humer; editing by Nick Macfie)

EU urged to review remdesivir supply deal after COVID trial results

By Francesco Guarascio

BRUSSELS (Reuters) – The European Union should renegotiate a 1 billion euro ($1.17 billion) contract it sealed last week with Gilead for a six-month supply of the COVID-19 drug remdesivir after it showed poor results in a large trial, experts said on Friday.

In a blow to one of the few drugs being used to treat people with COVID-19, the Solidarity Trial conducted by the World Health Organization showed on Friday that remdesivir appeared to have little or no effect on mortality or length of hospital stays among patients with the respiratory disease.

The trial results were disclosed a week after the EU’s executive Commission announced its largest contract to date with Gilead for the supply of 500,000 courses of the antiviral drug at a price of 2,070 euro per treatment, which Gilead said was the standard for wealthy nations.

The Commission “needs to present the reasons behind the rush to conclude the latest contract with Gilead and move to review it in light of the Solidarity Trial findings,” said Yannis Natsis, who represents patients’ organizations on the board of the European Medicines Agency (EMA), the EU drug regulator.

The EU announced on Oct. 8 that it had signed the supply contract with the U.S. company on behalf of its 27 member states and 10 partner countries, including Britain.

Gilead had known about the results of Solidarity since Oct. 6, the WHO said, citing disclosure rules under the Solidarity Trial.

Gilead told Reuters it had received in late September an “heavily redacted manuscript” from the WHO which contained different information from the final document published on Friday.

“TIME IS OF THE ESSENCE”

The Commission’s decision was made after EU countries warned of shortages of remdesivir in their hospitals amid a new surge of COVID-19 infections across Europe.

The contract does not oblige countries to buy remdesivir, although it ties them to the agreed price.

Gilead did not comment on whether remdesivir’s price for wealthy countries could change after the WHO trial, and the company questioned its results.

“As time is of the essence – we are in a situation of a public health emergency – we have to not only invest up-front in vaccine development but also in access to therapeutics,” a spokesman for the European Commission said.

He added the EMA would look into the Solidarity results and data available from other studies on COVID treatments “to see if any changes are needed to the way these medicines are used”.

But the spokesman did not comment on whether the EU was aware of the Solidarity results before it signed the contract with Gilead. He also did not reply to questions on whether the price agreed with Gilead could be renegotiated.

“The EU should revisit the prices to be paid for Remdesivir. Why pay 1 billion euros for a drug with no effects on survival?” said Andrew Hill, a senior visiting research fellow in the Department of Pharmacology at the University of Liverpool.

He said generic versions of the drug manufactured in India were sold at 200 euros per course.

(Reporting by Francesco Guarascio @fraguarascio; additional reporting by John Miller; Editing by Gareth Jones)

NIH starts clinical trial testing antibody treatments in COVID-19 patients

(Reuters) – The U.S. National Institutes of Health (NIH) said on Tuesday it has started a study to evaluate two antibody treatments in COVID-19 patients as part of the agency’s program to identify promising drugs to help tackle the new coronavirus.

The trial will test AbbVie Inc’s psoriasis drug risankizumab along with Gilead Sciences’ antiviral remdesivir, compared to a placebo and remdesivir.

The study will also test Humanigen’s experimental drug lenzilumab with remdesivir, compared to placebo and remdesivir.

“The goal here is to identify as quickly as possible the experimental therapeutics that demonstrate the most clinical promise as COVID-19 treatments and move them into larger-scale testing,” said NIAID Director and U.S. infectious diseases expert Anthony Fauci.

Gilead’s remdesivir, which was among the first to be used to treat COVID-19 and received emergency use authorization from the U.S. Food and Drug Administration in May, has since been authorized for use in several other countries.

Risankizumab and lenzilumab belong to a class of drugs known as monoclonal antibodies that are laboratory-made versions of proteins naturally produced by the immune system in response to invading viruses or other pathogens.

The treatment has come under the spotlight after U.S. President Donald Trump was treated with Regeneron Pharmaceuticals’ antibody drug earlier this month.

Regeneron and Eli Lilly have both applied to the U.S. FDA for emergency use of their antibody treatments.

(Reporting by Amruta Khandekar; editing by Ankur Banerjee and Ramakrishnan M.)

COVID-19 antibodies last at least three months; so do symptoms for many

By Nancy Lapid

(Reuters) – The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

COVID-19 antibodies last at least three months

People infected with COVID-19 develop antibodies targeting the new coronavirus that last for at least three months, according to two reports published on Thursday in Science Immunology. The two studies, together involving nearly 750 patients, both point to immunoglobulin G (IgG) antibodies, which start showing up well after an infection begins, as the longest-lasting. Researchers found IgG antibodies with two targets – a spike protein on the virus that helps it infect cells, and a part of the spike called the receptor binding domain (RBD) – lasted more than 100 days. While the protective effect of COVID-19 antibodies is not completely clear, Jen Gommerman of the University of Toronto, coauthor of the study, said her team also found levels of so-called neutralizing antibodies, which inactivate the virus, “appeared to be very stable.” The other study, from Harvard Medical School, reported similar findings. This means that a properly designed vaccine “should elicit a durable antibody response that has the potential to neutralize the virus,” Gommerman said. Her group also found that antibodies in saliva correlated with antibodies in blood, but at this point the saliva tests are not sensitive enough to replace blood tests.

COVID-19 symptoms linger for months for many

Three months after becoming ill, many COVID-19 patients still have symptoms, two studies confirm, and the more severe the initial infections, the higher the odds of persistent problems. In Spain, doctors checked back with 108 patients, including 44 who had been severely ill. At 12 weeks after diagnosis, 76% still reported after-effects, with 40% reporting three or more coronavirus-related health issues, doctors said in a paper posted on Thursday on medRxiv ahead of peer review. The most common complaints were shortness of breath, physical weakness, cough, chest pain, palpitations, and psychological and cognitive disorders. In a similar study of 233 U.S. COVID-19 patients – eight of whom had been severely ill – one in four still had symptoms 90 days after first feeling ill. Rates were higher for patients who had been sicker: 59.4% at 30 days and 40.6% at 90 days. “But even for very mild and initially asymptomatic cases, 14.3% have complications persist for 30 days or longer,” the authors reported on Sunday on medRxiv. In the U.S. study, the most common persistent symptoms were impaired smell and taste, difficulty concentrating, shortness of breath, memory loss, confusion, headache, heart palpitations, chest pain, pain with deep breaths, dizziness, and rapid heartbeat.

Remdesivir cut COVID-19 recovery time by 5 days

Final data from a large study of Gilead Sciences Inc’s antiviral drug remdesivir showed the treatment cut COVID-19 recovery time by five days among hospitalized patients, one day faster than preliminary data had indicated, researchers reported on Thursday in The New England Journal of Medicine. The 1,062-patient study compared up to up to 10 days of therapy with remdesivir – now sold in some markets as Veklury – to a placebo. The average recovery time was 10 days among those who got the Gilead drug versus 15 days in the placebo group. Among patients requiring oxygen at the start, those taking remdesivir continued to need oxygen for an average of 13 days, compared to 21 days for patients who got a placebo. In a separate analysis looking just at patients who received oxygen, the drug appeared to reduce the risk of death over the next month by 70%. “We now have data suggesting that giving remdesivir to patients on oxygen may significantly reduce their chances of death compared to other subgroups,” Dr. Andre Kalil, an infectious disease expert at the University of Nebraska Medical Center and the study’s lead investigator, said in a news release.

Coronavirus rarely travels from mother to newborn

Transmission of the new coronavirus from mothers to newborns is rare, doctors from New York-Presbyterian/Columbia University Irving Medical Center reported on Monday in JAMA Pediatrics. They studied 101 babies born to 100 mothers with COVID-19, including 10 whose mothers had been severely ill. Almost all of the babies tested negative for the virus, while tests in two newborns had indeterminate results. If these two indeterminate results are considered positive, the overall incidence of transmission was 2.0%. Even with a 2% transmission rate, “none of our babies exhibited clinical symptoms of COVID-19, either during their newborn nursery stay or during … the first few weeks of life,” coauthor Dr. Dani Dumitriu told Reuters Health by email. Roughly 90% of the newborns were breastfed at least partially. “As the country heads into what looks like a second wave of the COVID-19 pandemic, it is important to know that separation of affected mothers from their newborns may not be warranted, and direct breastfeeding appears to be safe,” study coauthor Dr. Melissa Stockwell said.

(Reporting by Nancy Lapid, Julie Steenhuysen and Will Boggs; Editing by Bill Berkrot)

Trump says will leave hospital on Monday, ‘Don’t be afraid of Covid.’

WASHINGTON (Reuters) – U.S. President Donald Trump said he will leave the U.S. military hospital where he was being treated for COVID-19 later on Monday, adding that he felt “really good.”

“I will be leaving the great Walter Reed Medical Center today at 6:30 P.M. Feeling really good! Don’t be afraid of Covid. Don’t let it dominate your life. We have developed, under the Trump Administration, some really great drugs & knowledge. I feel better than I did 20 years ago!” he said on Twitter.

(Reporting by Doina Chiacu; Editing by Chizu Nomiyama)

Exclusive: U.S. hospitals turn down remdesivir supplies, limit use to sickest COVID-19 patients

By Deena Beasley

(Reuters) – U.S. hospitals have turned down about a third of their allocated supplies of the COVID-19 drug remdesivir since July as need for the costly antiviral wanes, according to unpublished government statistics provided to Reuters by a U.S. pharmacists’ group.

Some hospitals said they are still buying the Gilead Sciences medicine to build inventory in case the pandemic accelerates over the winter. But they said current supplies are adequate, in part because they are limiting use to severely ill patients.

The Food and Drug Administration has allowed more liberal remdesivir use, but 6 out of 8 major hospital systems contacted by Reuters said they were not using it for moderate cases.

The slowdown suggests that a shortage of the drug is over and threatens Gilead’s efforts to expand use of remdesivir, which it sells under the brand name Veklury in some countries.

The U.S. Department of Health and Human Services (HHS) told hospitals and other healthcare organizations on Friday that between July 6 and September 8, state and territory public health systems accepted about 72% of the remdesivir they were offered, Michael Ganio, senior director of pharmacy practice and quality at the American Society of Health-System Pharmacists, told Reuters.

Hospitals in turn took only about two-thirds of what states and territories accepted, he added. It was not immediately clear what happened to the surplus supplies.

Neither Gilead nor HHS immediately responded to requests for comment.

A surplus of remdesivir – which costs $3,120 for a 6-vial intravenous course – marks a turnaround from earlier in the pandemic, when supplies of the drug had fallen short of demand in some regions.

Government-led distribution of remdesivir will expire at the end of September. Hospitals said they have little information on availability after that.

Remdesivir was first authorized by the FDA in May for emergency use in COVID-19 patients hospitalized and on oxygen support after data showed that it helped shorten hospital recovery time.

The agency last month expanded use to hospitalized patients who do not require oxygen support, based on data published in the JAMA medical journal showing that the drug provided a modest benefit for those patients.

The newer data has left many experts unconvinced.

Dr. Aneesh Mehta, chief of infectious diseases services at Atlanta’s Emory University Hospital, said Emory is focusing supplies on patients likely to benefit the most.

“I am not terribly impressed with the study,” said Dr. Adarsh Bhimraj, an infectious disease specialist at the Cleveland Clinic. He said he remains “skeptical” about using remdesivir in patients with moderate COVID, especially given the price.

(Reporting By Deena Beasley; editing by Peter Henderson and Bill Berkrot)

Gilead remdesivir study finds only marginal benefit for moderate COVID-19 patients

By Deena Beasley

(Reuters) – Moderately ill COVID-19 patients saw their condition improve after a 5-day course of Gilead Sciences Inc’s remdesivir, but the drug did not significantly shorten hospital stays and a 10-day course did not show a benefit, according to new data.

The drug, which was shown in a trial of severely ill COVID-19 patients to shorten their hospital recovery time, has been at the forefront of the battle against the pandemic.

The 600-patient analysis, published on Friday by the Journal of the American Medical Association, found that moderately ill patients treated with the antiviral drug for up to 5 days had significantly higher odds of improvement in certain areas, such as whether or not they needed supplemental oxygen, compared to patients given standard treatment.

Researchers said the clinical importance of the benefit for those patients was uncertain, however.

Remdesivir is currently sold under an emergency use authorization from the U.S. Food and Drug Administration for treating patients hospitalized with severe COVID-19, the disease caused by the new coronavirus. Gilead earlier this month filed an application seeking full FDA approval of the drug.

Differing trial results for remdesivir raise “the question of whether the discrepancies are artifacts of study design choices, including patient populations, or whether the drug is less efficacious than hoped,” according to a JAMA editorial accompanying the study.

The new study in moderately ill COVID-19 patients showed that 11 days after starting treatment, 65% of the 10-day remdesivir patients, 70% of the 5-day patients and 60% of the standard care patients had left the hospital.

Side effects seen more frequently in the remdesivir groups included nausea, low blood potassium levels, and headache.

The JAMA editorial said important questions remain regarding the efficacy of remdesivir, including which patients are most likely to benefit from the drug, the optimal duration of therapy, the drug’s impact on clinical outcomes, and its relative effect if combined with generic steroid treatments.

(Reporting by Deena Beasley; Editing by Nick Tattersall and Sonya Hepinstall)