Nasal spray treats Delta variant infection in mice

Researchers have shown a new compound delivered in a nasal spray is highly effective in preventing and treating COVID-19 caused by the Delta variant in mice. The researchers, including at UBC, Université de Sherbrooke, and Cornell University, believe this is the first treatment of its kind proven to be effective against all COVID-19 variants of concern reported to date, including alpha, beta, gamma and delta. Published today in Nature, the research opens the door to developing a therapeutic spray for humans.

Variants of concern, including the recent Omicron variants, have reduced vaccine effectiveness, but senior author Dr. François Jean, associate professor in the UBC department of microbiology and immunology, says early, still unpublished results from his team show promise that N-0385 is also effective at blocking Omicron variant infections in human lung cells. “Our unpublished results represent encouraging findings with the current rapid propagation of Omicron BA.2 around the world.”

The specially designed compound, named N-0385, blocks a particular human enzyme’s activity, used by the virus to infect a host cell. The small molecule was developed by Drs. Richard Leduc, Éric Marsault, Pierre-Luc Boudreault and their team at Université de Sherbrooke. UBC researchers tested four variants, including Delta, in human lung cells and organoids, tissue cultures that can mimic the organ they’re taken from, and found that N-0385 inhibits infection, with no evidence of toxicity. “The compound is unique because it blocks entry at the cell surface, without having to get into the cell, which prevents it from causing any detectable cell damage. As well, it’s highly potent, in that it needs only a tiny amount to work very effectively,” says co-author Dr. Andrea Olmstead (she/her), research associate in the department of microbiology and immunology.

The project teams are working with Ebvia, a private company, to secure funding for clinical trials. Future avenues of research at UBC and Université de Sherbrooke include optimizing N-0385 when used in combination with recently approved drugs to treat COVID-19.