What Cidara Therapeutics does

Cidara Therapeutics was a San Diego-based, clinical-stage biotechnology company founded in 2012 that developed long-acting therapeutics for serious diseases using its proprietary Cloudbreak drug-Fc conjugate platform. The company's core technology enabled the design of targeted immunotherapies with potential applications across oncology, viral infections, and autoimmune conditions. Its lead asset, CD388, was a non-vaccine, single-dose antiviral therapeutic designed for universal prevention of seasonal and pandemic influenza, demonstrated up to 76.1% efficacy against influenza A and B in Phase 2b trials in unvaccinated adults. The product received both FDA Fast Track and Breakthrough Therapy designations, and advanced into a Phase 3 ANCHOR trial that enrolled 6,000 participants across the US and UK. The company also had rezafungin, an antifungal candidate, in its pipeline.

Cidara operated as a pre-commercial biotech with no approved products on market, generating no product revenue. Capital was raised through a combination of federal grants (notably a $339M BARDA award in October 2025), public equity offerings (a $350M upsized offering in June 2025), and private placements (a $105M round led by Venrock Healthcare Capital Partners in November 2024). The company's primary customer-facing activity was scientific communication, investor relations, and regulatory engagement rather than commercial sales. Targeted customer segments included high-risk influenza populations (elderly, immunocompromised) and unvaccinated adults, with go-to-market planning dependent on FDA approval and pharmaceutical distribution channels.

In November 2025, Merck & Co. announced a definitive agreement to acquire Cidara for approximately $9.2 billion ($221.50 per share in cash), motivated by CD388's potential to expand Merck's respiratory pipeline and offset upcoming Keytruda patent expirations. The acquisition was completed on January 7, 2026, with approximately 85.96% of shares tendered, making Cidara a wholly owned subsidiary of Merck delisted from the Nasdaq Global Market.

Name

Cidara Therapeutics

Legal name

Merck & Co., Inc.

Website

https://cidara.com

Company type

Public

Founded year

2012

Operating status

Acquired

Headcount range

11–50 employees

Short description

Cidara Therapeutics was a San Diego-based clinical-stage biotech (founded 2012) that developed long-acting antivirals using its proprietary Cloudbreak drug-Fc conjugate platform. Its lead candidate CD388, a non-vaccine influenza preventative demonstrating 76.1% efficacy in Phase 2b, was acquired by Merck for $9.2 billion in January 2026.

Ownership category

akta.pro rank

Product category

Antiviral Pharmaceuticals

akta.pro primary industry

Lentiviral Vector Gene Therapy Developers (HLAAACAB)

Keywords

• Antiviral therapeutics
• Drug-Fc conjugates
• Influenza prevention
• Immunotherapy platform
• Antifungal drugs

Headquarters

HQ city

San Diego

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Supply Chain, Operations

Revenue model

1. Grant Funding: Federal funding from BARDA (Biomedical Advanced Research and Development Authority) awarded $339 million to support manufacturing and clinical development of CD388
2. Public Equity Offerings: Generated capital through public stock offerings - $350 million upsized public offering of common stock in June 2025
3. Private Placement: $105 million private placement led by Venrock Healthcare Capital Partners for R&D of product candidates
4. Public Offering: Approximately $17.5 million gross proceeds from public offerings of common stock and Series X Convertible Preferred Stock in March 2023
5. Acquisition Proceeds: Company was acquired by Merck & Co. for $9.2 billion in November 2025, representing value realization for shareholders

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

Cidara Therapeutics develops long-acting targeted immunotherapies for serious diseases using its proprietary Cloudbreak drug-Fc conjugate platform. Its lead asset, CD388, is a non-vaccine influenza preventative therapeutic that demonstrated up to 76.1% protection against influenza A and B in Phase 2b trials and is being evaluated in the Phase 3 ANCHOR trial. The pipeline also includes rezafungin, an antifungal candidate for serious invasive fungal infections.

Product overview

Cidara Therapeutics is a biotechnology company that developed long-acting therapeutics for serious diseases using its proprietary Cloudbreak drug-Fc conjugate platform. The company's primary product candidate was CD388, a non-vaccine influenza preventative therapeutic in Phase 3 trials, which demonstrated up to 76.1% efficacy in Phase 2b studies. The company also had rezafungin (antifungal) in its pipeline. In January 2026, Cidara was acquired by Merck & Co. for $9.2 billion.

Differentiator

Problem solved

Functional benefit

Products and services

• CD388 A long-acting antiviral drug-Fc conjugate therapeutic designed for universal prevention of seasonal and pandemic influenza. Administered as a single dose for season-long protection. Phase 2b data showed up to 76.1% prevention efficacy against influenza A and B in unvaccinated adults. Holds FDA Fast Track and Breakthrough Therapy designations. Intended for adults and high-risk populations including elderly and immunocompromised individuals.
• Rezafungin An antifungal candidate developed for treatment of serious invasive fungal diseases. Part of Cidara's pipeline of long-acting therapeutics built on the Cloudbreak drug-Fc conjugate platform.
• Cloudbreak Platform Proprietary drug-Fc conjugate technology platform that enables development of targeted therapeutics for serious diseases including oncology, viral infections, and autoimmune conditions. Serves as the foundation for Cidara's product pipeline.

Quantifiable outcome

• 76.1% prevention efficacy against influenza A and B in unvaccinated adults (Phase 2b trial)
• +2 more outcomes

Named customers1 record

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Two partnerships are on record, tiered minor and core.

• Janssen (Johnson & Johnson)minorStrategic or Co-development Partner · 3 October 2025Previously partnered with Janssen for CD388 development. Cidara regained full rights to the asset in 2024 after Janssen wound down its infectious disease and vaccine R&D operations
• hVIVO plccoreStrategic or Co-development PartnerhVIVO contributed significantly to the development and clinical trials of CD388, providing clinical trial services and expertise in human challenge studies for the antiviral candidate

Scale indicators8 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Roche / Genentech: Markets XOFLUZA (baloxavir marboxil), an oral antiviral for influenza treatment and post-exposure prophylaxis, in partnership with Shionogi. Most directly comparable to CD388 as an antiviral influenza agent, though CD388's prevention positioning and long-acting mechanism are differentiated.
• Shionogi: Originated baloxavir marboxil (XOFLUZA) and develops infectious disease therapeutics, including antivirals for influenza. Comparable as a developer of novel antiviral influenza agents, with similar therapeutic area focus and regulatory pathway experience.
• Moderna: Develops mRNA-based influenza vaccines (mRNA-1010 and next-gen candidates) targeting improved efficacy over traditional flu vaccines. Directly competes with CD388 in the influenza prevention market with a differentiated mRNA technology platform.
• BioNTech: Developing mRNA-based influenza vaccines through partnership with Pfizer, targeting improved strain coverage and efficacy. Competes with CD388 in seasonal flu prevention with a Phase 3-stage mRNA vaccine candidate.
• Novavax: Develops protein nanoparticle-based influenza vaccines, including a Phase 3-stage candidate. Competes with CD388 in the flu prevention market with a differentiated vaccine platform targeting improved efficacy.

Broad incumbents

• CSL Seqirus: World's largest influenza vaccine manufacturer (Fluad, Fluzone, etc.) and a major incumbent in flu prevention. Competes with CD388 in the seasonal flu market as the dominant vaccine supplier, particularly for high-risk elderly populations.
• Sanofi Pasteur: Major flu vaccine manufacturer with Fluzone High-Dose and Fluzone HD, particularly strong in elderly and high-risk segments. Competes with CD388 in the high-risk flu prevention market that Cidara is targeting.
• GSK: Markets Fluarix and other seasonal influenza vaccines globally. Competes with CD388 as an established flu vaccine manufacturer with broad distribution and payer access.

Emerging players

• Vir Biotechnology: Clinical-stage infectious disease company developing antiviral therapeutics, including for influenza and other respiratory viruses. Comparable as a focused antiviral developer with platform technology targeting serious viral infections.
• Arcturus Therapeutics: Develops mRNA-based therapeutics for infectious diseases, including influenza vaccine candidates. Comparable as an emerging platform-based developer of novel infectious disease therapeutics.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks5 records

Key highlights6 records

Customer concentration

• Xx.com/CidaraThera
• Facebookfacebook.com/CidaraTherapeutics
• LinkedInlinkedin.com/company/cidara-therapeutics

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Funding overview

Funding rounds12 records

Investors22 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Cidara Therapeutics