Cidara Therapeutics Presents Data on CD388 from its Phase 2b NAVIGATE Trial and Preclinical Studies Against H5N1 at ISRV’s 8th AVG and 3rd IMRP 2025 Meeting

- Efficacy and safety results from successful NAVIGATE Phase 2b trial of CD388 for prevention of influenza illness featured in late-breaking presentation

- Preclinical data demonstrating potential efficacy of CD388 to prevent H5N1 infection featured in oral presentation

SAN DIEGO, Sept. 17, 2025 (GLOBE NEWSWIRE) -- Cidara Therapeutics, Inc. (Nasdaq: CDTX), a biotechnology company using its proprietary Cloudbreak^® platform to develop drug-Fc conjugate (DFC) therapeutics, today announced two presentations during the . The conference is taking place September 17-20, 2025, in Singapore. The presentations highlight efficacy and safety data on CD388, Cidara’s non-vaccine influenza preventative, from the successful Phase 2b NAVIGATE study, as well as preclinical data on the efficacy of CD388 to prevent infection in H5N1 animal models.

“These two oral presentations further highlight the potential of CD388 to provide season long protection against influenza as well as activity against highly pathogenic pandemic strains like H5N1,” said Jeffrey Stein, Ph.D., president and chief executive officer of Cidara. “The Phase 2b presentation represents the first description of CD388 NAVIGATE study data in an academic setting. Importantly, the preclinical results of CD388 in a ferret model suggests that CD388 has the potential to provide prophylactic protection from this potentially deadly viral infection. We look forward to disclosing additional details on the safety, PK and virology data from our Phase 2b NAVIGATE study at upcoming conferences this fall.”

Late-Breaking Abstract Title: NAVIGATE: A Phase 2b, Randomized, Double-blind, Placebo-controlled, Multicenter Dose-ranging Trial to Evaluate the Efficacy and Safety of CD388 for Prevention of Influenza Illness in Healthy Adults

Presenter: Rick Bright, Ph.D. Bright Global Health, Cidara Therapeutics

Session: AVG Session 3

Session Date and Time: Wednesday, September 17, 2025, 3:50 p.m. – 4:05 p.m. SGT

Summary: The Phase 2b NAVIGATE study was conducted to evaluate the safety and efficacy of a single subcutaneous dose of CD388 for the prevention of laboratory-confirmed influenza in healthy, unvaccinated adults. Over 5,000 adults aged 18-64 years old without risk factors for complications from influenza were randomized to receive CD388 (150mg, 300mg, or 450mg) or placebo. The primary endpoint was preventative efficacy over 24 weeks against laboratory confirmed influenza. Overall, CD388 demonstrated it was well tolerated with statistically significant, single-dose protection against influenza illness over 24 weeks.

Abstract Title: A Single Prophylactic Dose of CD388 Provides Protection Against Highly Pathogenic Bovine-Origin Influenza A (H5N1) Virus in the Ferret Model

Presenter: Andreev Konstantin, Ph.D. St. Jude Children’s Research Hospital

Session: Parallel Session 2 (Track 1)

Session Date and Time: Friday, September 19, 2025, 10:30 a.m. – 12:30 p.m. SGT

Summary: The prophylactic efficacy of CD388 was evaluated against lethal A (H5N1) infection in ferrets. Ferrets untreated with CD388 displayed pronounced weight loss, neurological symptoms, and survival endpoints at 4-8 days post-inoculation. A single subcutaneous dose of CD388 at 3 mg/kg administered 24 hours before H5N1 virus inoculation protected 75% of ferrets from death. A 10 mg/kg dose of CD388 provided 100% survival in ferrets. CD388-treated animals exhibited reduced weight loss and clinical symptoms versus control. Overall, CD388 substantially reduced viral titers in the upper and lower respiratory tracts of ferrets and prevented viral neuroinvasion and systemic spread to other organs.

The abstracts from Cidara’s two presentations will be available on the Cidara corporate website under “publications” following the meeting.

Cidara will also be hosting a lunch symposium at the conference on Friday, September 19, 2025, from 1:00 – 1:45 p.m. SGT in the Grand Ballroom 1, Level 4, Waterfront Conference Centre. The symposium is titled “CD388: A New Modality for Broad Influenza Protection in Healthy and High-Risk Populations,” and will be co-chaired by Frederick G. Hayden, M.D., FACP and Rick Bright, Ph.D., along with Cidara’s SVP, clinical operations, Corrina Pavetto, and Cidara’s chief scientific officer, Les Tari, Ph.D. as speakers.

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 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 .

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, whether the Phase 2b NAVIGATE Trial results will be predictive of efficacy or safety in a Phase 3 trial, and whether the results of a preclinical trial in a ferret model may predict the activity of CD388 against the H5N1 strain or any strain of pandemic influenza in humans. 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 patients 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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