- Repurposing drugs that are designed to treat other conditions is our best near-term hope for finding a COVID-19 treatment.
- There are dozens of trials right now on a slew of drugs that were originally tested against diseases like Ebola, malaria, HIV, and arthritis.
- The early clinical results have shown a mix of promising and disappointing data.
- The studies have all been limited by small patient populations and other constraints. But a lot more information is coming as soon as April.
- Here are the six leading repurposed drugs being tested, and everything you need to know about each of them.
- Visit Business Insider's homepage for more stories.
Repurposed drugs are the most promising options for finding a way to treat COVID-19, the disease caused by the novel coronavirus, in the near term.
Dozens of clinical trials are enrolling patients and administering a range of drugs originally designed for other ailments such as Ebola, HIV, malaria, and arthritis. In the coming weeks, clinical results will begin to trickle in.
These repurposed drugs are largely not expected to amount to anything close to a panacea for the virus. The gold standard for halting infectious diseases remains vaccines, which can protect healthy people from getting infected in the first place.
Vaccine research typically takes years. Even under the urgency of this pandemic, US health officials have said it will take at least a year to know if any vaccine is safe and effective.
Other biotech and pharma companies are scrambling to craft new therapeutics. Even with the most aggressive timetables for clinical testing, those won't be widely available to patients until at least the fall.
That leaves repurposed drugs as the near-term hope. If they work against the disease - which remains a big open question - they could bring major relief to healthcare systems feeling the weight of a pandemic and save lives. A treatment option could shorten hospital stays, free up scarce ventilators, and ultimately improve outcomes for COVID-19 patients.
Here's an overview of the six leading repurposed drug candidates - along with what's driving optimism, reasons to be skeptical, and the latest updates on clinical testing.
Remdesivir is largely seen as the leading candidate among repurposed drugs for COVID-19
What is it: Remdesivir is an experimental antiviral drug developed by Gilead Sciences, a massive biotech company that has developed leading medicines for HIV and hepatitis C. It was first developed in 2009 and was tested in more than 100 Ebola patients. It's currently being tested in hundreds of patients in countries including the US and China.
Why it might work: Research in test tubes has shown the drug is active against this coronavirus, called SARS-CoV-2. It also blocked virus replication in monkeys for a different coronavirus.
Remdesivir has drawn attention given some one-off reports of patient recoveries, though anecdotal reports are unreliable as scientific evidence. For instance, the antiviral was used in the first COVID-19 case in the US, with doctors noting the patient's condition improved starting the day after receiving remdesivir.
Why it might not: We have no hard clinical evidence it works in humans who have COVID-19. While the drug showed it was safe for people to take when it was tested against Ebola, it wasn't particularly effective against that virus.
Even if it winds up working against COVID-19, the drug has some significant limitations. It is given as a 10-day intravenous infusion. Gilead has also noted to several Wall Street analysts it is difficult to manufacture. The drug has also reportedly caused some liver issues and stomach problems.
What to watch for: Remdesivir should have a litany of clinical trial readouts in the coming weeks. Gilead has said it's expecting data from two Chinese studies in mid-April. Both of those studies are testing remdesivir against a placebo in several hundred patients, providing the randomized controlled trial data that is the gold standard of medical research.
More high-quality trials are underway. Gilead is running two studies that are recruiting globally. While the biotech's study in moderate COVID-19 cases will test 5-day and 10-day IVs of remdesivir against a placebo group, the second study in very sick patients will not have a control arm.
Finally, the National Institutes of Health's infectious disease unit has been running a remdesivir trial for more than a month now, enrolling COVID-19 patients in hospitals in Washington, Nebraska, and Georgia with plans to expand to up to 50 sites globally.
Hydroxychloroquine is an old, generic drug with large COVID-19 trials now gearing up
What is it: First approved in 1955, hydroxychloroquine is the most commonly used version of chloroquine, a longtime anti-malaria drug. The old generic medication is also approved to treat arthritis and lupus.
Why it might work: Laboratory testing showed hydroxychloroquine had slightly better potency against SARS-CoV-2 than chloroquine. Hydroxychloroquine also appeared to be widely used in China and South Korea in fighting COVID-19, with both countries adding the drug to their treatment guidelines.
Didier Raoult, a French infectious disease researcher, ran a clinical trial in a few dozen COVID-19 patients that yielded intriguing results. Among the positives, it suggests taking hydroxychloroquine in combination with azithromycin, an antibacterial, appeared to speed up the time it took for patients to beat the virus.
The compound is particularly intriguing because it's a simple, generic medication that's taken as a pill. If it works, it would be comparatively easy to scale up production to reach a mass market.
Why it might not: Raoult's study is rife with caveats. The patient population was tiny and not randomly assigned to a treatment arm. There was no long-term follow up, and the study didn't directly measure whether patients got better. Plus, six patients dropped out early for various reasons and were excluded from the main analysis.
Adding to that skepticism, another small trial of 30 COVID-19 patients in China published on March 24 showed no difference between hydroxychloroquine and placebo.
Hydroxychloroquine isn't a benign drug either. It can cause severe side effects if not taken properly, including vision loss, low blood sugar, and heart problems. A 2018 review article also cautioned hydroxychloroquine can cause neurological side effects for some, with the frequency unknown of serious complications like psychosis and suicidal tendencies.
What to watch for: Bigger and better trials are coming to see if hydroxychloroquine actually works.
Columbia University researchers are planning to test 1,600 people who live with someone diagnosed with COVID-19, to see if hydroxychloroquine works in people at high risk of infection to prevent the virus. This NYC-based trial will randomly assign participants to either the drug or placebo.
There's also randomized controlled trials in Mexico testing both 500 COVID-19 patients with severe respiratory disease as well as 400 healthcare workers as a treatment to prevent the disease.
Kevzara and Actemra are arthritis drugs that could alleviate the disease's symptoms, instead of fighting the virus itself
What are they: Kevzara and Actemra are both in the same therapeutic class, called IL-6 inhibitors. The Swiss pharma giant Roche sells Actemra. Kevzara is sold in the US by Regeneron and internationally by Sanofi.
Why they might work: While antivirals are more directly targeting the virus, these IL-6 inhibitors could alleviate some of COVID-19's severe symptoms.
Interleukin-6 is a signaling mechanism that human bodies make as an immune response to an infection. In cases of a runaway immune system, this can lead to severe disease. Some early data from China suggests that blocking this mechanism could help COVID-19 patients, though it didn't come from a randomized controlled trial.
In particular, it may help alleviate the inflammatory response happening in patients' lungs that makes it difficult to breathe.
Why they might not:The early data from China needs to be confirmed on a larger, more robust scale, particularly given the potential for side effects.
IL-6 inhibitors can harm patients by weakening their immune system, increasing the risk of other infections, researchers wrote in a March 24 JAMA article.
What to watch for: Both drugs are now being tested in large studies in the US that compare them with a placebo.
The Japanese flu drug Avigan has brought some early, encouraging results
What is it: Fujifilm Toyama Chemical's Avigan is an influenza treatment and a broad-spectrum antiviral drug. It's not approved in the US.
Why it might work: Avigan outperformed another antiviral called arbidol in a trial conducted in China, according to a recent report of those findings. The flu drug helped COVID-19 patients recover seven days faster than the patients on arbidol, and also reduced the frequency of symptoms like coughing and fever.
Why it might not: Like all the coronavirus studies released so far, conclusions are limited by the study's design. RBC Capital Markets' analysts noted it was open-label, meaning patients and doctors know which treatment they were given, and it compared Avigan to arbidol instead of a placebo.
RBC also noted the drug may have the potential to cause kidney damage, a notable side effect. Fourteen percent of patients on Avigan registered elevated uric acid levels, which can occur when your kidneys don't eliminate uric acid properly.
What to watch for: A couple ongoing studies in China are projected to be finished in late April or May. One is combining Avigan with chloroquine, and testing that combination against of just Avigan and placebo. The other trial is testing Avigan in combination with Actemra, Roche's IL-6 inhibitor described above.
Kaletra is an HIV drug that has seen discouraging early results
What is it: An HIV drug sold by AbbVie that was approved in 2000. It's a combination of two drugs: lopinavir and ritonavir.
Why it might work: As a general antiviral treatment, Kaletra may theoretically help reduce the viral load of the disease in patients.
The World Health Organization has enough belief in the drug's potential to include Kaletra in two of the four arms to be tested in a global trial. (One arm will combine Kaletra with interferon-beta, a drug that aims to reduce inflammation caused by an immune response.)
Why it might not: The first clinical results for any coronavirus treatment have come for Kaletra and were disappointing.
In roughly 200 patients split between Kaletra and placebo in Wuhan, China, the HIV drug was not show benefits in keeping patients alive, reducing the amount of virus in patients, or shortening their hospital stays. Those results were published on March 18 in The New England Journal of Medicine.
An additional Chinese trial of 44 patients found Kaletra brought "little benefit for improving the clinical outcome," researchers concluded in an advanced publication on March 24.
What to watch for: The WHO's trial should bring definitive results on Kaletra, if the organization decides to move forward with it given the early negative findings.
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