SARS-CoV-2, the new coronavirus that causes COVID-19, is transmitted primarily through infectious airborne droplets and tiny particles. For this reason the respiratory tract, the entry point of the virus, could be a good target for drugs aimed at protecting us from the disease.
This is the rationale behind the development of Invisimask, a human monoclonal antibody by Eureka Therapeutics. An anti Covid nasal spray formulation that in recent months has also been explored by the University of San Francisco (AeroNabs) and from that of Pittsburgh (Q-Griffithsin) Now, the anti Covid nasal spray has reported promising results in mice.
Invisimask, spray and protect
A single administration of Eureka's drug into the nose protected the mice against SARS-CoV-2 for at least 10 hours, even at the lowest concentrations tested.
Company researchers described in a paper on the bioRxiv preprint site.
Eureka's team calculates that the Invisimask anti-Covid nasal spray could work as a daily preventative measure, and is preparing a clinical trial application with the FDA.
An invisible mask
"We foresee a daily nasal spray that works as an invisible mask in slowing the spread of Covid", explains the CEO of Eureka in a note. Cheng Liu, Ph.D .. “The use of antibodies in a preventive nasal spray adds to the arsenal of tools we have to fight the spread of the virus. The concept can also be applied to other airborne diseases. We are thrilled with the results and are working to advance the product for human use. "
Like the many other COVID-19 antibody products available, Eureka's targets the SARS-CoV-2 spike protein to prevent the virus from entering and infecting healthy host cells. The Invisimask prototype showed a high ability to bind to the spike protein and efficiently inhibit several mutated forms, including the most common and infectious one today, D614G.
Invisimask, Eureka Therapeutics anti Covid nasal spray
Eureka's team further modified its drug to also increase its ability to bind to mucin, a protein produced by surface cells that produce mucus. The goal was to extend the retention time of the antibody in the respiratory tract, and this appears to have been achieved.
Eureka's team has indeed shown that the modified antibodies enhanced the neutralization of the virus.
InvisiMask currently remains stable in an anti Covid nasal spray formulation for up to two weeks at 37 degrees Celsius.
In mice, a single spray of the antibody at the lowest dose of 25 μg provided at least 10 hours of protection against virus infection at its highest viral load tested.
Nasal spray treatments under study
Eureka is one of the many companies that have focused their research on Covid treatment. However, the formula of the nasal spray is being studied, as mentioned, also by other companies.
In addition to those mentioned, Iowa State University is collaborating with Zeteo Biomedical to design a vaccine in the form of a nasal spray. Twist Bioscience evaluates the possibility of turning its single domain antibodies, or nanobodies, into a preventive daily nasal spray after also receiving promising results in mice.
Regeneron's Covid Antibody Cocktail has obtained FDA clearance for emergency use for outpatient treatment. The company works to provide the cocktail in the form of an anti Covid nasal spray.
Nasal sprays containing antibody therapy require a about 10.000 times lower dosage to that needed for systemic infusions, according to Eureka.
"This will significantly reduce the cost and make it accessible for wider use," the researchers write in the study.