Although vaccine efforts against COVID-19 are moving at breakneck speed, experts caution that the 12- to 18-month time frame suggested by government officials is "overly optimistic." Therapeutics from antivirals and antibody cocktails to drugs focused on specific symptoms will act as a “bridge” while the world waits for a vaccine.
One of those approaches could fight the coronavirus in more ways than one. Suppressing cough in COVID-19 patients not only addresses a symptom that can be “traumatic and debilitating,” but it can tamp down on the spread of the disease from patients to hospital staff, family or housemates.
While most patients with COVID-19 suffer a dry, unproductive cough when they’re sick, some of them continue to cough even after they’ve recovered from the infection.
“The data show about 40% of patients who recover from COVID-19 in hospital get sent home with a postviral cough that lasts three to eight weeks,” said Nocion Therapeutics CEO Rick Batycky, Ph.D., referring to a cough that can linger long after a respiratory tract infection goes away.
Containing those coughs, or stopping them altogether, could play a role in curbing the spread of the virus. We’re all familiar with the first line of defense: staying home and wearing masks. But masks that aren’t N95 don’t work well at sealing people off. Nocion, a biotech already working on treatments for cough and itch, thought it could go upstream.
It’s doing so because the medicines that doctors usually prescribe to suppress cough—including over-the-counter cough syrups, an expectorant called guaifenesin and narcotic cough suppressant codeine—typically don’t work. They’re still in use because they’ve been “grandfathered in from back in the day,” but they haven’t gone through randomized, controlled studies.
“It’s not surprising, especially since the compounds we’re talking about are already available over the counter. They don’t have what we would consider today to be valid, objective data to support those claims [that they work,]” Batycky said.
Nocion had been chugging along with its lead program in chronic cough when “COVID hit and shut everything down,” Batycky said. The delay turned out to be an opportunity. Nocion had planned to start a phase 1 study a few years down the line, but the pandemic meant the company could—and should—go into patients now.
The company scored priority status as a potential COVID-19 treatment from the U.K.’s Medicines and Healthcare products Regulatory Agency as well as expedited approval for its phase 1 study of the drug. That study will kick off any day now.
“We are doing exactly the same phase 1 study we planned, not just in refractory chronic cough, but also in viral or postviral cough. Part of that is COVID-19,” Batycky said.
Unlike other cough treatments in development, which target specific receptors, Nocion’s approach aims more broadly at nociceptors, the neurons that send pain or itch signals when they are inflamed. Its drugs get into those nociceptors through ion channels called large-pore channels that open up when they are inflamed—that is, when something causes the cells to send a pain or itch signal.
It’s like using a Trojan horse to deliver drug molecules into the cells, Bruce Bean, Ph.D., one of Nocion’s co-founders, said when the company launched last year.
This sneaky approach means that Nocion can target cough more broadly than, say, a P2X3 antagonist like Merck’s gefapixant. That drug beat placebo at cutting the number of times patients coughed per hour in two phase 3 trials involving about 2,000 patients. But it may not work as well in patients whose cough is driven by a different receptor channel than P2X3, or by other channels in addition to P2X3. For Nocion, it doesn’t matter which channel is responsible.
“It’s likely that different viruses maybe upregulate or affect different pore channels … As long as there is a cough occurring that is triggered from things happening in the lung, we can sneak in through whichever channel is open,” Batycky said.
Nocion’s treatment could potentially be used beyond COVID-19 for people with chronic cough or postviral cough after recovering from a different respiratory illness, like the flu. And, of course, it would come in handy if another pandemic like COVID-19 hits.
Batycky hopes that other COVID-19 treatments in the pipeline turn out to be “pathogen-agnostic.”
“Those are the things we should be thinking about because this will happen again. We are a fuller world, living in closer contact,” he said. “Masks and compounds like this could reduce a key vector in terms of transmission. Anything that takes that R0 value down while a vaccine is being developed—I would think those are critical.”