Cheap FDA-Approved Drug May Be an Ideal COVID-19 Treatment

Scientists at Sanford Burnham Prebys Medical Discovery Institute and the University of Hong Kong have found that the drug clofazimine exhibits potent antiviral activities against SARS-CoV-2. Clofazimine is typically used to treat leprosy. SARS-CoV-2 is the virus that causes COVID-19.

Clofazimine is FDA-approved and on the World Health Organization's list of essential medicines. Scientists found that the drug also prevents the exaggerated inflammatory response associated with severe COVID-19.

A study is published in Nature. It reports that scientists tested clofazimine in hamsters that were infected with SARS-CoV-2.

The scientists found that clofazimine lowered the amount of virus in the lungs, including when given to healthy animals prior to infection. The drug also reduced lung damage and prevented cytokine storm. Cytokine storm is an overwhelming inflammatory response to SARS-CoV-2 that can be deadly.

The scientists are persuaded that clofazimine is an ideal candidate for a COVID-19 treatment. It is safe, affordable, easy to make, taken as a pill, and can be made globally available. Based on these findings, a phase 2 study could begin immediately. It will evaluate clofazimine as an at-home treatment for COVID-19.

"We hope to test clofazimine in a Phase 2 clinical trial as soon as possible for people who test positive for COVID-19 but are not hospitalized," says Sumit Chanda, one of the senior authors of the study.

"Since there is currently no outpatient treatment available for these individuals, clofazimine may help reduce the impact of the disease, which is particularly important now as we see new variants of the virus emerge and against which the current vaccines appear less efficacious."

"Our data suggests that clofazimine should also be tested as a monotherapy for people with COVID-19, which would lower many barriers to treatment," adds Chanda. "People with COVID-19 would be able to simply receive a regime of low-cost pills, instead of traveling to a hospital to receive an injection."

Clofazimine was previously identified as a promising drug candidate against SARS-CoV-2. This was done by screening known drugs in the ReFRAME library for their ability to block the replication of the virus. The ReFRAME library was created by Scripps Research, with a goal of repurposing existing drugs to meet unmet clinical needs.

"The animals that received clofazimine had less lung damage and lower viral load, especially when receiving the drug before infection," says Ren Sun, one of the senior authors of the study. "Besides inhibiting the virus, there are indications that the drug also regulates the host response to the virus, which provides better control of the infection and inflammation."

"Potentially most importantly, clofazimine appears to have pan-coronavirus activity, indicating it could be an important weapon against future pandemics," says Kwok-Yung Yuen, another senior author of the study. Yuen discovered the coronavirus that causes severe acute respiratory syndrome (SARS).

"Our study suggests that we should consider creating a stockpile of ready-made clofazimine that could be deployed immediately if another novel coronavirus emerges."