In vitro activity of cysteamine against SARS-CoV-2 variants

• Published in: Molecular genetics and metabolism Vol. 137; no. 1-2; pp. 192 - 200
• Main Authors: Thoene, Jess, Gavin, Robert F., Towne, Aaron, Wattay, Lauren, Ferrari, Maria Grazia, Navarrete, Jennifer, Pal, Ranajit
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2022
• Subjects: Antiviral Agents - pharmacology; COVID-19 Drug Treatment; Cysteamine; Cysteamine - pharmacology; Disulfides; Humans; Nasal spray; Ophthalmic Solutions; Orphan drug; Pandemics; SARS-CoV-2; Viral inhibition; Cysteamine; SARS-CoV-2; Orphan drug; Disulfides; Viral inhibition; Nasal spray
• ISSN: 1096-7192; 1096-7206
• DOI: 10.1016/j.ymgme.2022.08.009

Global COVID-19 pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Continuous emergence of new variants and their rapid spread are jeopardizing vaccine countermeasures to a significant extent. While currently available vaccines are effective at preventing illness associated with SARS-CoV-2 infection, these have been shown to be less effective at preventing breakthrough infection and transmission from a vaccinated individual to others. Here we demonstrate broad antiviral activity of cysteamine HCl in vitro against major emergent infectious variants of SARS-CoV-2 in a highly permissible Vero cell line. Cysteamine HCl inhibited infection of wild type, alpha, beta, gamma, delta, lambda, and omicron variants effectively. Cysteamine is a very well-tolerated US FDA-approved drug used chronically as a topical ophthalmic solution to treat ocular cystinosis in patients who receive it hourly or QID lifelong at concentrations 6 times higher than that required to inhibit SARS CoV-2 in tissue culture. Application of cysteamine as a topical nasal treatment can potentially1) mitigate existing infection 2) prevent infection in exposed individuals, and 3) limit the contagion in vulnerable populations.