The COVID-19 pandemic made the public acutely aware of how vulnerable their noses are. The nose is a gateway to infection for respiratory pathogens like influenza and SARS-CoV-2, but options to shield nasal passageways from disease are limited.
A potential new defense may have appeared in the form of a commercially available nasal spray built from a collection of readily available and inactive chemical ingredients. According to results published in Advanced Materials on Sept. 25., the spray successfully neutralized numerous respiratory pathogens in the lab and protected mice from a potent flu strain for four hours after a single dose.
All the mice given the nasal spray, called PCANS and sold under the name Profi, survived exposure to a deadly flu virus and didn’t develop signs of illness, Nitin Joshi, Ph.D., a bioengineer at Brigham and Women’s Hospital and Harvard Medical College, told Fierce Biotech in an interview. Every mouse that did not receive the spray succumbed to the disease.
“That was really the pivotal moment when we thought this has great potential,” Joshi said.
Joshi and colleagues originally meant for PCANS to be a drug delivery system for a multiple sclerosis treatment that a neurologist at Brigham was developing. The team noticed in early studies that the spray could remain in the nose of mice for a long time, so, when COVID-19 hit, it pivoted to see whether the formula could be tweaked to prevent the spread of the virus and other infectious agents.
Because the team wanted its spray to hit the market as fast as possible, it decided to make it drug-free. This means that the researchers avoided ingredients that would interact chemically with either the nose or the virus and instead focused on inactive ingredients that would physically block the virus’s entry into cells.
The researchers combed through the FDA’s inactive ingredient database and list of substances that are generally recognized as safe for compounds that are already used in other nasal sprays. They mixed and matched ingredients, testing them on three key attributes: coating the nose’s skin cells in a protective film, binding to pathogens to prevent them from being able to enter cells and capturing the tiny pathogen-carrying droplets of water that enter the nose so that they don’t bounce their way deeper into the airway.
Some ingredients surprised them. Pectin, a thickener used in jams and jellies, was tested because of its stickiness but proved to be a potent antiviral, Joshi said. Another, called gellan, was used to make the hydrogel layer that coats the inside of the nose, but, when mixed with the mucous membrane, “the mechanical strength of the mucosa increased by 100-fold,” Joshi said.
When pitted against various pathogens, PCANS emerged victorious. In lab assays and tests using a 3D model of the human nose, it was able to block and neutralize SARS-CoV-2, influenza A, adenovirus and respiratory syncytial virus as well as the bacteria E. coli and Klebsiella pneumoniae. Mice given the spray before exposure to a highly lethal strain of H1N1 influenza all survived, while those who didn’t get PCANS died. Sprayed mice also had almost 100% lower virus levels in their lungs compared to non-sprayed mice.
“The authors also mentioned that the PCANS layer with the pathogens adhered to it is removed from the airways via mucociliary action and deposited in the gut, yet they did not support this with data from their mouse studies,” Sandra Leibel, M.D., a lung biologist at the University of California, San Diego, told Fierce in an email. “It would be important to show how these pathogens are removed from the nasopharynx.”
Because it’s drug-free, PCANS has already hit the market as Profi; it was launched in October 2023 by Akita Biosciences, a company founded by Joshi along with fellow co-author Jeffrey Karp, Ph.D., and Christopher Lee, Ph.D.
“We have seen that Profi has been exceptionally well received by our customers,” Joshi said. The spray right now is marketed as a personal care product for nasal hygiene, but Akita plans to put Profi through clinical trials for different pathogens so that they can make stronger claims about the product’s potency.
“I'm very interested in seeing this novel pre-exposure prophylactic nasal spray used in clinical trials in the future,” Leibel said.
Joshi sees a world where Profi is used as a regular prophylactic for respiratory diseases, complementing other protective measures like vaccines and face masks while avoiding their pitfalls. Vaccines need to be updated to tackle new variants of pathogens, for example, and masks can be ill-fitting.
“This is another armor, another layer of protection that people can really use to minimize the spread of infection,” Joshi said. “If there is an emerging threat like COVID, or new strains, we believe that Profi can be used in those circumstances as well because of its broad-spectrum activity.”