Written By: Kaylee Zhou

Scientists from Sanford University and the University of Hong Kong recently published a study indicating that the drug clofazimine successfully defends and prevents severe inflammatory responses against SARS-CoV-2. These researchers emphasized that this is a step in the right direction towards detecting a possible treatment for patients with COVID-19 who are not hospitalized.

How Clofazimine Works

Discovered in 1954, clofazimine is FDA-approved and on the Essential Medicines list by the World Health Organization. This drug’s original use was to treat leprosy, and it wasn’t until a screening by the ReFRAME drug library that it was rediscovered as a possible treatment for COVID-19. ReFRAME is known to have over 12,000 drugs that the FDA has approved for human use, and its main goal is to reuse existing drugs to meet new medical needs. 

The researchers from Sanford and the University of Hong Kong set up their first study on the effects of Clofazimine by using hamsters that had been infected with COVID-19. Their experiment showed that the drug lowered the amount of virus present in the hamsters’ lungs and prevented possible overwhelming inflammatory responses. Ren Sun, a professor at the University of Hong Kong, even stated, “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” (Sanford Burnham Prebys Medical Discovery Institute, 2021). After further analysis, the researchers concluded that clofazimine was able to prohibit the virus’s replication behavior because it prevented the virus from using its spike proteins to bind to target entry cells (Liu, 2021). These hamsters also displayed lower levels of IL-6 in their blood, which is a chemical responsible for inflammation in the body, suggesting that the drug could also control and avert potentially deadly inflammatory responses. 

Why Clofazimine is Promising

The team of researchers has high confidence in clofazimine potential to be an ideal candidate for future COVID-19 treatments. In fact, Sumit Chanda, a professor and director of the Immunity and Pathogenesis Program at Sanford, said, “It is safe, affordable, easy to make, and can be taken as a pill and made globally available. People with COVID-19 would be able to receive a regime of low-cost pills, instead of traveling to the hospital to receive an injection” (Sanford Burnham Prebys Medical Discovery Institute, 2021). Chanda’s team further clarified that out of the 21 drugs they experimented with, clofazimine was the most effective in a lab dish, and that they are confident that the drug can be distributed in concentrations that are the safest for humans (Meara, 2021). These scientists also believe that the rediscovery of clofazimine has made a significant impact on the scientific community because this drug could be used as a defender and weapon for future pandemics. According to Kwok-Yung Yuen, chair of Infectious Diseases at the University of Hong Kong, “ We should consider creating a stockpile of ready-made clofazimine that could be deployed immediately if another novel coronavirus emerges” (Sanford Burnham Prebys Medical Discovery Institute, 2021). The team believes preparing this stockpile in advance, the team believes that the world will be able to better combat  a new coronavirus in the future. 

Future Testing Clofazimine

Based on the Phase 1 hamster experiment results, the scientists at the University of Hong Kong are now working on testing a Phase 2 clinical trial with clofazimine and interferon beta-1b on patients who are currently hospitalized. Interferon beta-1b is an immunoregulator currently given to patients with multiple sclerosis through injections (Sanford Burnham Prebys Medical Discovery Institute, 2021). The researchers are interested in discovering if clofazimine can reduce the amount of virus present and prevent inflammatory responses in infected humans, especially since new strains of the virus have been spreading. Chanda says that the purpose of the experiment is to “Collect data to see if it suggests that clofazimine should be tested as a monotherapy for people with COVID-19, which would lower many barriers to treatment” (Meara, 2021). 

Conclusion

The rediscovery of clofazimine has been a global effort since scientists from Sanford and the University of Hong Kong were able to work together and use each other’s results to improve upon their own experiments. The scientists involved were excited about the positive results from the phase 1 experiments, and they are now waiting to analyze the results from phase 2 on hospitalized patients. After they analyze the incoming results, they hope that they will be able to approve clofazimine as an at-home COVID-19 treatment in the near future. 

References and Sources

Liu, A. (2021, March 17). Could low-cost Leprosy drug clofazimine be repurposed for COVID-19? Retrieved March 20, 2021, from https://www.fiercebiotech.com/research/could-low-cost-leprosy-drug-clofazimine-be-repurposed-for-covid-19

Meara, K. (2021). Clofazimine shows promise for at-home covid-19 treatment. Retrieved March 20, 2021, from https://www.contagionlive.com/view/clofazimine-shows-promise-for-at-home-covid-19-treatment

Sanford Burnham Prebys Medical Discovery Institute. (2021, March 16). Leprosy drug holds promise as at-home treatment for covid-19. Retrieved March 20, 2021, from https://www.sciencedaily.com/releases/2021/03/210316083747.htm