After reacquiring the rights to its non-vaccine flu preventative last year, Cidara Therapeutics has secured federal support to develop and produce the candidate, dubbed CD388, in the U.S.
The Department of Health and Human Services' (HHS’) Biomedical Advanced Research and Development Authority (BARDA) has graced Cidara and its flu asset with an award worth up to $339 million, Cidara said Thursday. The deal includes confirmed funding of $58 million over two years, which will be used to stand up domestic manufacturing for CD388 in the U.S. and help Cidara establish its “initial commercial supply chain,” the company explained in an Oct. 2 press release.
That initial tranche of cash will also fuel a clinical trial comparing a higher-concentration formulation and different presentations of CD388, help the company further characterize the asset’s activity against pandemic flu strains in nonclinical models and kick off development of trial protocols for expanded populations, Cidara said.
The remaining $281 million in options could be used to support additional studies of CD388 in specific populations, which Cidara said it would position as “a complement to the company’s plans” for an approval application to the FDA.
“Clinical and non-clinical data generated to date suggest that CD388 has the potential to be an effective non-vaccine preventative for both pandemic and seasonal influenza,” Jeffrey Stein, Ph.D., Cidara’s chief executive, said in a statement.
The BARDA tie-up will “both expand our commercial supply capacity, as well as ensure U.S. supply of CD388 in the event of an influenza pandemic,” he added.
CD388 is being developed as a non-vaccine alternative for flu prevention. The prophylactic is a member of the drug-Fc conjugate class, comprised of multiple copies of a potent small molecule neuraminidase inhibitor conjugated to a bespoke Fc fragment of a human antibody, according to Cidara.
The company stressed in its release that drug-Fc conjugates are not vaccines or monoclonal antibodies. Rather, they are low molecular weight biologics meant to function as “long-acting small molecule inhibitors,” Cidara said.
Cidara is developing CD388 to guard against all known strains of seasonal and pandemic influenza, and, because the candidate is not a vaccine, it’s expected to work in patients regardless of their immune status.
Cidara regained control of CD388 from Janssen last April following the Johnson & Johnson unit’s wind-down of all infectious disease and vaccine R&D. At the time of the strategy shift, Janssen had indicated that it planned to transfer rights to the drug to another entity, according to Cidara.
To recover its asset, Cidara handed Janssen $85 million upfront in a deal that also includes the potential for development, regulatory and commercial milestone payments.
The loss of a Big Pharma partner left Cidara with a funding gap, although the BARDA deal, a private stock placement led by RA Capital Management last year and other recent funding moves are likely helping bridge the gap for the San Diego company.
Cidara has announced a slew of CD388 updates over the past few months, starting with a phase 2b data readout on the asset in June. In the study, dubbed Navigate, the highest 450-mg dose of CD388 conferred 76% protection against seasonal influenza in unvaccinated adults versus placebo, while lower doses of 300 mg and 150 mg conferred 61% and 58% protection, respectively.
In late September, the company noted that it was moving forward with an “expanded and accelerated development plan” for the asset in which it will seek FDA approval using a single phase 3 study. The company said it aims to enroll 6,000 total subjects in the trial, which it had originally aimed to initiate next spring. Patients in the study will receive either the 450-mg dose of CD388 or placebo, Cidara said last month.
The company wasted no time getting started, announcing that it had dosed the first participants in the phase 3 program just one day after affirming its late-stage development strategy.
Meanwhile, BARDA's investment in Cidara's non-vaccine flu preventive comes amid a shift at the agency, which helps develop and stockpile medical countermeasures to ward off public health threats to the U.S.
Earlier this year, as the Trump administration took an ax to the U.S. federal health apparatus, Robert F. Kennedy Jr.'s HHS announced it was ending mRNA vaccine work funded by BARDA.
“BARDA is terminating 22 mRNA vaccine development investments because the data show these vaccines fail to protect effectively against upper respiratory infections like COVID and flu," RFK Jr. said in a statement addressing the decision. "We’re shifting that funding toward safer, broader vaccine platforms that remain effective even as viruses mutate.”