Niclosamide is a prescription small molecule drug listed as an essential medicine by the World Health Organization (WHO) which has been safely used on millions of patients. In the U.S., niclosamide was approved by the FDA in 1982 for the treatment of intestinal tapeworm infections. In addition to its antihelminthic activity, niclosamide has novel anti-inflammatory and anti-viral properties.
Niclosamide may be used for multiple inflammation-mediated GI indications, such as inflammatory bowel disease (IBD) and immune checkpoint inhibitor-associated colitis (ICI-AC) while avoiding systemic complications related to immunosuppressant steroids, since it is not systemically absorbed.
There remains an urgent need to develop new medicines that can be manufactured at large scale quickly to treat COVID-19. Niclosamide was recently identified by the Institut Pasteur Korea as a potent inhibitor of SARS-CoV-2, the virus causing COVID-19, with potency 40X greater than remdesivir. Additionally, emerging evidence confirms the severe GI-related complications of COVID and potential fecal spread of the virus. Patients treated with an oral and non-systemic, niclosamide formulation that delivers high local GI concentrations may have decreased viral load and GI-associated symptoms of COVID. Importantly, the manufacturing process for niclosamide can be scaled up to supply large populations quickly.