A new nasal spray has been developed to treat the delta coronavirus variant responsible for COVID-19 infections. Success has been demonstrated against infection in mice, indicating broad spectrum results and the hope of developing a product suitable for use by humans.
The biological technology comes from the University of British Columbia, where researchers have also shown, with what is the first treatment of its kind, proven effectiveness against all SARS-CoV-2 variants of concern reported to date, including alpha, beta, and gamma (in addition to delta).
Furthermore, the product – N-0385 – also appears to be effective at blocking the Omicron BA.2 variant and consequential infections in human lung cells.
Nasal delivery devices are a drug delivery system designed to deliver a medical therapy. The nasal route is an alternative to invasive or oral drug administration and for respiratory illnesses it is an effective one, enabling the penetration of bioactive molecules through the nasal mucosa.
In terms of SARS-CoV-2 (the coronavirus responsible for COVID-19), it has been shown that the cells lining the nose function as a key entry point for the coronavirus. Based on this, a spray mechanism provides the means to circumvent the obstacles associated with other forms of treatment, such as injection or oral routes.
The drug is based on a specially designed compound that serves to block a particular human enzyme’s activity – one used by the virus to infect a host cell. The compound is also relatively safe given that the mechanism for blocking entry at the cell surface occurs without the compound needing to get into a cell. This reduces the risk of toxicity and avoids cell damage.
Studies show that genetically engineered mice infected with the virus causing COVID-19, when given a daily dose of the compound in a nasal spray across four days, survive infection provided that the spray is administered within twelve hours of the infection occurring. However, when commercialised for people the drug in nasal form will need to be used in combination with other treatments because the new drug acts as an entry inhibitor, blocking entry of the virus to cells. For those already infected, other drugs will need to be taken in order to reduce viral replication.

As well as being a treatment, the nasal spray also acts as a preventative agent when administered daily.
The Canadian research appears in the journal Nature, titled “A TMPRSS2 inhibitor acts as a pan-SARS-CoV-2 prophylactic and therapeutic.”
