Cidara Therapeutics Announces Expanded and Accelerated Phase 3 Plan for CD388, a Non-Vaccine Preventative of Seasonal Influenza
Cidara Therapeutics (Nasdaq: CDTX) announced significant updates to its Phase 3 trial plans for CD388, a non-vaccine flu preventative, following FDA End-of-Phase 2 meeting. The company will accelerate the Phase 3 study by six months, starting in September 2025 for the Northern Hemisphere.
Key developments include: expansion of the study population to include adults over 65 years alongside high-risk patients aged 12+, increasing eligible U.S. patients from 50 million to over 100 million; potential for BLA approval based on a single Phase 3 trial; and a target enrollment of 6,000 subjects. The study will evaluate a single 450mg dose of CD388 administered subcutaneously at the start of flu season.
Cidara Therapeutics (Nasdaq: CDTX) ha pubblicato aggiornamenti significativi sui piani dello studio di fase 3 per CD388, un agente profilattico antinfluenzale non vaccinico, dopo l'incontro End-of-Phase 2 con la FDA. L'azienda accelererà lo studio di fase 3 di sei mesi, con inizio previsto a settembre 2025 nell'emisfero settentrionale.
Tra gli sviluppi principali: l'espansione della popolazione studiata per includere adulti oltre i 65 anni insieme ai pazienti ad alto rischio dai 12 anni in su, aumentando da 50 milioni a oltre 100 milioni i pazienti idonei negli Stati Uniti; la possibilità di un'approvazione BLA basata su un singolo trial di fase 3; e un target di reclutamento di 6.000 partecipanti. Lo studio valuterà una singola dose di 450 mg di CD388 somministrata per sottocute all'inizio della stagione influenzale.
Cidara Therapeutics (Nasdaq: CDTX) anunció importantes actualizaciones a sus planes de ensayo de fase 3 para CD388, un preventivo de gripe no vacunado, tras la reunión End-of-Phase 2 de la FDA. La empresa acelerará el estudio de fase 3 en seis meses, con inicio previsto en septiembre de 2025 en el hemisferio norte.
Entre los desarrollos clave: ampliación de la población del estudio para incluir a adultos mayores de 65 años junto con pacientes de alto riesgo a partir de los 12 años, aumentando el número de pacientes elegibles en EE. UU. de 50 millones a más de 100 millones; la posibilidad de aprobación de BLA basada en un único ensayo de fase 3; y un reclutamiento objetivo de 6.000 sujetos. El estudio evaluará una dosis única de 450 mg de CD388 administrada por vía subcutánea al inicio de la temporada de gripe.
Cidara Therapeutics (나스닥: CDTX)는 FDA의 End-of-Phase 2 회의 후 CD388, 비백신성 독감 예방제에 대한 3상 시험 계획에 중요한 업데이트를 발표했습니다. 회사는 3상 연구를 6개월 단축하여 북반구에서 2025년 9월부터 시작합니다.
주요 개발 내용으로는 연구 대상 확장으로 12세 이상 고위험 환자와 함께 65세 이상 성인을 포함하고, 미국의 자격 환자 수를 5천만 명에서 1억 명 이상으로 확대하는 것; 단일 3상 시험에 기반한 BLA 승인 가능성; 그리고 목표 모집은 6,000명입니다. 연구는 독감 시즌 시작 시점에 피하주사로 투여되는 단일 450 mg CD388 용량을 평가합니다.
Cidara Therapeutics (Nasdaq : CDTX) a annoncé des mises à jour importantes de ses plans d’essai de phase 3 pour le CD388, préventif anti-grippe non vaccinant, suite à une réunion End-of-Phase 2 avec la FDA. L’entreprise accélérera l’essai de phase 3 de six mois, son démarrage étant prévu en septembre 2025 dans l’hémisphère nord.
Les évolutions clés incluent : l’extension de la population étudiée pour inclure les adultes de plus de 65 ans ainsi que les patients à haut risque âgés de 12 ans et plus, portant le nombre de patients américains éligibles de 50 millions à plus de 100 millions ; la possibilité d’une approbation BLA basée sur un seul essai de phase 3 ; et un recrutement cible de 6 000 sujets. L’étude évaluera une dose unique de 450 mg de CD388 administrée par voie sous-cutanée au début de la saison grippale.
Cidara Therapeutics (Nasdaq: CDTX) hat nach dem End-of-Phase-2-Treffen der FDA bedeutende Updates zu den Phase-3-Studienplänen für CD388 veröffentlicht, einen nicht-vakzinierenden Grippepräventionsstoff. Das Unternehmen wird die Phase-3-Studie um sechs Monate beschleunigen und im September 2025 für die Nordhalbkugel beginnen.
Zu den wichtigsten Entwicklungen gehören: Ausweitung der Studienpopulation auf Erwachsene über 65 Jahre sowie Hochrisikopatienten ab 12 Jahren, wodurch sich die berechtigten US-Patienten von 50 Millionen auf über 100 Millionen erhöhen; Potenzial für eine BLA-Zulassung basierend auf einer einzigen Phase-3-Studie; und eine angestrebte Rekrutierung von 6.000 Probanden. Die Studie wird eine einzelne Dosis von 450 mg CD388, subkutan verabreicht, zu Beginn der Grippesaison evaluieren.
Cidara Therapeutics (ناسداك: CDTX) أعلنت عن تحديثات مهمة في خطط تجربة المرحلة الثالثة لـ CD388، وقاية الإنفلونزا غير التطعيمية، عقب اجتماع End-of-Phase 2 مع FDA. ستعجل الشركة الدراسة في المرحلة 3 بمقدار sechs أشهر، مع بدء في سبتمبر 2025 للنصف الشمالي من العالم.
تشمل التطورات الرئيسية: توسيع عينة الدراسة لتشمل البالغين فوق 65 عامًا إلى جانب مرضى عاليي المخاطر الذين عمرهم 12 عامًا فأكثر، مما يزيد عدد المرضى المؤهلين في الولايات المتحدة من 50 مليون إلى أكثر من 100 مليون؛ احتمال موافقة BLA بناءً على تجربة مرحلة 3 واحدة؛ وهدف تسجيل من 6,000 مشارك. ستقيّم الدراسة جرعة واحده 450 mg من CD388 تُعطى تحت الجلد في بداية موسم الإنفلونزا.
Cidara Therapeutics (纳斯达克: CDTX) 在与 FDA 的 End-of-Phase 2 会议之后，宣布了其 CD388 的三期试验计划的重要更新——CD388 是一种非疫苗性流感预防药物。公司将 把三期研究提前六个月完成，北半球预计于 2025 年 9 月开始。
要点包括：扩大研究人群，不仅包含 65 岁以上的成人，还包括 12 岁及以上的高风险患者，将美国的合格患者数量从 5000 万增加到超过 1 亿；在< b>单一的三期试验基础上实现 BLA 批准的潜力；以及一个目标入组人数为 6,000 名受试者。研究将评估在流感季初以皮下给药的单次 450 mg CD388剂量。
- Potential for BLA approval with single Phase 3 trial, streamlining the approval process
- Study population expanded from 50M to over 100M potential U.S. patients
- Phase 3 timeline accelerated by 6 months
- Phase 3 program fully funded through completion
- Large-scale Phase 3 trial with 6,000 subjects may present recruitment challenges
- Success dependent on sufficient flu cases during study period for statistical significance
Insights
Cidara's CD388 flu preventative advances to Phase 3 with expanded population and accelerated timeline, significantly increasing commercial potential.
Cidara's CD388 is moving forward with a substantially accelerated and expanded Phase 3 trial following positive FDA feedback. The trial will now begin six months earlier than planned in September 2025 instead of spring 2026, allowing data collection during the Northern Hemisphere's flu season. Crucially, the FDA has indicated that a single successful Phase 3 trial may be sufficient for BLA approval, streamlining the path to market.
The expanded patient population represents a significant commercial opportunity. By including adults over 65 years without specific comorbidities (in addition to the original target of high-risk and immunocompromised patients), Cidara has more than doubled the potential eligible patient pool from approximately
The trial design is robust: a global, multicenter, randomized, double-blind, placebo-controlled study with 6,000 subjects receiving either a single 450-milligram subcutaneous injection of CD388 or placebo at the start of flu season. An interim analysis after the Northern Hemisphere season will guide Southern Hemisphere enrollment. The primary endpoint combines laboratory-confirmed influenza with objective symptoms, a standard approach for demonstrating efficacy.
Following their recent financing, Cidara believes the Phase 3 program is fully funded through completion, eliminating near-term capital concerns. The company is positioning CD388 as a potentially first-in-class, universal, non-vaccine, long-acting preventative for seasonal influenza – addressing limitations of current vaccines, particularly in vulnerable populations.
- Update based on FDA End-of- Phase 2 meeting outcome
- Phase 3 study start accelerated by six months, in time for the fall 2025 Northern Hemisphere flu season
- A single Phase 3 trial of CD388, if successful, may be sufficient for BLA approval
- Phase 3 study population expanded to include adults over 65 years of age in addition to subjects with high-risk co-morbidities and immune compromised status
SAN DIEGO, Sept. 24, 2025 (GLOBE NEWSWIRE) -- Cidara Therapeutics, Inc. (Nasdaq: CDTX), a biotechnology company applying its proprietary Cloudbreak® platform to develop drug-Fc conjugate (DFC) therapeutics, today announced updates to its planned Phase 3 registrational trial of CD388 following its End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA). Cidara is proceeding with an expanded and accelerated development plan seeking biologics license application (BLA) approval based on a single Phase 3 study. Based on FDA feedback the study population will be expanded to include adults over 65 years of age with no specific co-morbidities in addition to subjects over 12 years of age with high-risk comorbidities or immune compromised status, substantially increasing the initial number of patients potentially eligible to receive CD388 from approximately 50 million to well over 100 million people in the U.S.
The planned Phase 3 study will be a global, multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of a single 450-milligram dose of CD388 administered via subcutaneous injection at the beginning of the flu season. The company intends to begin enrollment by the end of September 2025 in the Northern Hemisphere with continuation into the spring of 2026 in the Southern Hemisphere, with a target enrollment of 6,000 subjects. This represents a six-month acceleration from the prior plan to initiate the Phase 3 study in the spring of 2026 in the Southern Hemisphere. 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.
“The FDA’s input on our Phase 3 study design was invaluable and we welcome the opportunity to expand the trial to include adults over 65 years of age who are among the most vulnerable to serious complications from influenza,” said Jeffrey Stein, Ph.D., president and chief executive officer of Cidara. “Older adults receive less protection from vaccines because the immune system naturally declines with age. Including them in our trial not only addresses a critical unmet need but will also accelerate enrollment. With the success of our financing earlier this summer, we believe that our planned Phase 3 development program will be fully funded through completion, and we look forward to building on the strong Phase 2b NAVIGATE results as we advance CD388 toward becoming a universal, non-vaccine, long-acting option for flu prevention.”
In Cidara’s planned Phase 3 study, participants will be randomized in a 1:1 ratio to receive either a 450-milligram dose of CD388 or placebo. The primary endpoint will be based on laboratory-confirmed influenza, body temperature ≥ 37.2°C (99°F), and new or worsening of either two respiratory symptoms (cough, sore throat, nasal congestion) or one respiratory symptom and one new systemic symptom (headache, fatigue, feeling feverish, or body aches).
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. Additional DFCs have been developed for oncology and in July 2024 Cidara received investigational new drug application clearance for CBO421 which is intended to target CD73 in solid tumors. 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 planned Phase 3 registrational trial of CD388, the potential to obtain BLA approval based on a single Phase 3 clinical trial, the accelerated impact on enrollment of the expanded study design, 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 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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