Training its novel treatment and preventative for flu and other viral infections on COVID-19
Cidara Therapeutics’ lead drug, rezafungin, now in Phase 3 development, is a broad-spectrum antifungal in a known class, the echinocandins, but the COVID-19 pandemic has moved the spotlight to the antiviral Fc-conjugate (AVC) drugs in the company’s novel antiviral platform that offer both prevention and treatment. Its AVCs are designed to attack viruses directly and also activate the immune system against them. In Cidara’s pipeline, the lead antiviral drug, coded CD377, targets influenza, but other potential targets are RSV (respiratory syncytial virus), HIV, and COVID-19.
WHAT’S AT STAKE
In the absence of a COVID-19 vaccine, could a better option exist? Cidara believes it has an affirmative answer — and one that may apply to other targets, such as influenza. Many companies are developing new antivirals and vaccines aimed at the COVID-19 pandemic, but Cidara is herding along a fresh flock of agents that could do double duty by both preventing and treating serious viral infections.
Cidara’s CEO, Jeff Stein, says CD377 could be “transformational” as a long-acting treatment and preventative. For starters, Stein says the drug could take the place of the long-sought but elusive universal flu vaccine. “When we tell people our drug could be administered once every flu season, they often confuse it with a vaccine, but it is not one,” he says. “It is a disease-specific therapy, a potent antiviral drug conjugated to a fragment of human antibody that attracts a localized immune response at the site of infection and confers a remarkable half-life.” Stein explains the AVCs would allow fast and potent treatment of existing infections at relatively low doses, along with universal prevention. “Even if you have a robust immune system when you get vaccinated, it takes about three weeks to build the immune response,” he says.
In the COVID-19 pandemic, flu vaccinations have fallen because of patients’ reluctance to venture out of their homes. A potent antiviral could be a strong draw against their resistance. According to the Coalition to Stop Flu, of which Cidara is a member, the flu vaccination rate now hovers around 40 percent but must rise to at least 75 percent to ensure widespread protection.
“We pivoted to creating a COVID-19-targeting version after the flu program showed positive signs,” says Stein. “In January, we started with the first sequence information on the COVID-19 strain. We were able to design a potent inhibitor of the virus and we fused it to an antibody fragment. Now our in vitro testing has yielded some encouraging results. Most importantly, those results give us guidance on how to further improve potency.”
The full story on the activity of the candidate molecules will not be clear before in vivo testing reveals the immune response. Cidara scientists have learned many lessons that will guide them through selection and development of a COVID-19 drug. “We are designing these molecules to be effective not only against the SARS-CoV-2 virus, the causative agent of COVID-19, but against the full coronavirus family,” Stein says. “That would include SARS, MERS, and potentially Ebola. We’re looking at very highly conserved regions of the virus where we can prevent them from fusing to the human cells. Among our candidates are some that should be very broad-acting and others with more focused, potent activity against the SARS-CoV-2 strain.”
Cidara has large clinical development and research teams of biologists, medicinal chemists, and all the other experts needed to advance its preclinical programs. It aims to usher the influenza molecule, now in IND-enabling studies, into clinical studies in 2021. Its attraction for potential partnerships is running high, and a deal with Mundipharma with its antifungal program has boosted its overall growth. But now all eyes might be on its ambitious pivot to fighting the foe we’ve all come to despise: COVID-19.
Employees: 65 Headquarters: San Diego, CA
$76.8M IPO on NASDAQ in 2015
Research Partnership Funding
Received $30M upfront and a $9M equity investment from Mundipharma. Development, regulatory, and commercial milestone payments bring the total potential transaction value to $568M.agreement with Biocon.
Latest Updates May 2020: Began Phase 3 trial, rezafungin, prevention of invasive fungal disease in allogeneic blood and marrow transplantation. (Phase 3, invasive Candida infections, underway.)