Cidara Therapeutics Announces First Participants Dosed in Phase 3 ANCHOR Trial Evaluating CD388 for the Prevention of Seasonal Influenza in High-Risk Populations

- Phase 3 study expected to enroll 6,000 participants starting in the Northern Hemisphere

- Participants will include adults over 65 years of age in addition to individuals with high-risk co-morbidities and immune compromised status

Cidara Therapeutics, Inc. (Nasdaq: CDTX), a biotechnology company using its proprietary Cloudbreak ® platform to develop drug-Fc conjugate (DFC) therapeutics, today announced that the first participants have been dosed in its Phase 3 trial to evaluate the safety and efficacy of CD388, a non-vaccine preventative of seasonal influenza, in populations at high-risk for complications of influenza. Based on feedback from the FDA the study population has been expanded to also include generally healthy adults over 65 years old with no specific co-morbidities in addition to other high-risk populations with certain comorbidities and immune compromised status.

"Dosing of the first participants in our Phase 3 trial marks an important milestone in the development of CD388, a potentially transformational preventative for those at high-risk of complications from influenza," said Jeffrey Stein, Ph.D., president and chief executive officer of Cidara. "The positive results from our recent Phase 2b NAVIGATE trial show that CD388 can be an important new option for preventing influenza illness in healthy, unvaccinated adults. As CD388 is not a vaccine, its activity does not rely on an immune response and has the potential to be an effective season-long flu preventative for those at risk from complications from influenza, those who do not respond to vaccines or those who prefer not to receive a vaccine. We look forward to enrolling the Phase 3 study, beginning today with the 2025 Northern Hemisphere influenza season."

The Phase 3 trial, named ANCHOR, is a global, multicenter, randomized, double-blind, placebo-controlled trial to evaluate the safety and efficacy of CD388 administered as a one-time 450-milligram subcutaneous dose in adults and adolescents. The company plans to enroll a minimum of 10% of participants with immune-compromised status and equally balance the remaining enrollment between high-risk participants with comorbidities and healthy adults over 65 years of age. The study will include an interim analysis following the Northern Hemisphere flu season to assess the trial size and powering assumptions and determine enrollment for the Southern Hemisphere flu season. Results from this single Phase 3 trial, if successful, are expected to be sufficient for potential BLA approval in the high-risk populations represented in the Phase 3 trial. The company had cash of over $500 million as of the end of Q2, which is expected to fund the Phase 3 program through completion.

Further information on the ANCHOR trial can be found at https://clinicaltrials.gov/study/NCT07159763 .

About Cidara Therapeutics
Cidara Therapeutics is using its proprietary Cloudbreak® platform to develop novel DFCs comprising targeted small molecules or peptides coupled to a proprietary human antibody fragment. Cidara's lead DFC candidate, CD388, is a long-acting antiviral designed to achieve universal prevention of seasonal and pandemic influenza with a single dose by directly inhibiting viral proliferation. In June 2023, CD388 was granted Fast Track Designation by the FDA. Cidara announced positive top-line results from its Phase 2b NAVIGATE trial in June 2025. Cidara is headquartered in San Diego, California. For more information, please visit www.cidara.com .

Forward-Looking Statements
This release contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and such forward-looking statements are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. "Forward-looking statements" describe future expectations, plans, results, or strategies and are generally preceded by words such as "anticipates," "expect," "intends," "believes," "may," "plan" or "will". Forward-looking statements in this release include, but are not limited to, statements related to the potential benefits of and future plans for CD388, the expected timing, study design and target enrollment for the Phase 3 registrational trial of CD388, the potential to obtain BLA approval based on a single Phase 3 clinical trial and Cidara's ability to fully fund the planned Phase 3 development program through completion. Such statements are subject to a multitude of risks and uncertainties that could cause future circumstances, events, or results to differ materially from those projected in the forward-looking statements, such as unanticipated delays in or negative results from Cidara's clinical trials and other risks related to clinical development, delays in action by regulatory authorities, other obstacles associated with the enrollment of participants or other aspects of CD388 or other DFC development, having to use cash in ways other than as expected and other risks and uncertainties associated with Cidara's business in general. These and other risks are identified under the caption "Risk Factors" in Cidara's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025 and other filings subsequently made with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management's assumptions and estimates as of such date. Cidara does not undertake any obligation to publicly update any forward-looking statements, whether as a result of the receipt of new information, the occurrence of future events or otherwise.

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