CAYSTON Drug Patent Profile

Which patents cover Cayston, and what generic alternatives are available?

Cayston is a drug marketed by Gilead and is included in one NDA.

The generic ingredient in CAYSTON is aztreonam. Five suppliers are listed for this compound. Additional details are available on the aztreonam profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Cayston

A generic version of CAYSTON was approved as aztreonam by FRESENIUS KABI USA on June 18^th, 2010.

Summary for CAYSTON

US Patents:	0
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for CAYSTON

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Gilead	CAYSTON	aztreonam	FOR SOLUTION;INHALATION	050814-001	Feb 22, 2010		RX	Yes	Yes

International Patents for CAYSTON

See the table below for patents covering CAYSTON around the world.

Country	Patent Number	Title	Estimated Expiration
Argentina	053305	PROCESO PARA LA FABRICACION DE SOLUCIONES MASIVAS Y LISINATO DE AZTREONAM ALFA PURO LIOFILIZADO
Austria	502623
Australia	2002231244
Australia	2004257632
Australia	2009233632

Supplementary Protection Certificates for CAYSTON

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
2158901	122018000044	Germany		PRODUCT NAME: AZTREONAMIYSIN; REGISTRATION NO/DATE: EU/1/09/543/001 20090921
2158901	2018C/001	Belgium		PRODUCT NAME: CAYSTON - AZTREONAM; AUTHORISATION NUMBER AND DATE: EU/1/09/543/001 20090923
1353647	11C0030	France		PRODUCT NAME: AZTREONAM LYSINE; REGISTRATION NO/DATE IN FRANCE: EU/1/09/543/001 DU 20090921; REGISTRATION NO/DATE AT EEC: EU/1/09/543/001 DU 20090921
1353647	365	Finland
1353647	SPC/GB11/049	United Kingdom		PRODUCT NAME: AZTREONAM LYSINE; REGISTERED: UK EU/1/09/543/001 20090921

Last updated: February 15, 2026

What Is CAYSTON and Its Market Position?

CAYSTON (aztreonam for inhalation solution) is an antibiotic developed by Gilead Sciences for treating inhalation-resistant Pseudomonas aeruginosa infections, primarily in cystic fibrosis (CF) patients. Approved by the FDA in 2010, CAYSTON targets a niche but critical segment of CF therapy, competing mainly against inhaled antibiotics such as tobramycin (TOBI) and aztreonam lysine (Cayston's active component).

Market-wise, the CF inhaled antibiotic segment has grown significantly over the past decade. The global CF drug market was valued at approximately $3.2 billion in 2021 and is expected to expand at around 7–8% compound annual growth rate (CAGR) through 2027[1].

What Are the Key Drivers and Challenges for CAYSTON Investment?

Drivers

• Rising prevalence of cystic fibrosis worldwide
• Increasing use of inhaled antibiotics as standard of care
• Development of combination therapies expanding CF treatment options
• Growing awareness and early diagnosis of CF

Challenges

• Limited indications confined to P. aeruginosa-infected CF patients
• Competition from more established inhaled antibiotics like tobramycin
• Market penetration hurdles due to treatment complexity
• Patent exclusivity expiration risk
• Slow adoption rate in some regions owing to established treatment protocols

How Does CAYSTON’s Pharmacology and Development History Impact Investment?

CAYSTON is a monobactam antibiotic with a specific focus on inhalation to deliver high local concentrations to the lungs, minimizing systemic exposure. Its mechanism involves inhibiting bacterial cell wall synthesis. It was approved via a standard review process, signaling regulatory confidence.

Development efforts have primarily revolved around demonstrating clinical efficacy and safety in CF patients with stable P. aeruginosa infections. Several trials have shown CAYSTON reduces bacterial load and improves respiratory function but with challenges in demonstrating superiority or added benefit over existing therapies.

Due to its narrow spectrum and route of administration, CAYSTON’s market growth hinges on physician adoption, which depends on factors such as ease of administration, side effect profile, and competitive pricing.

What Are the Financial and Investment Risks?

• Patent expiration is projected around 2028[2], opening potential generic competition.
• Moderate market share—estimates suggest CAYSTON held around 10–15% in the inhaled antibiotic segment as of 2022[3].
• Limited pipeline; no significant reformulation or combination products announced.
• Dependence on CF epidemiology, which remains stable but is susceptible to variations due to better diagnostics and new therapies.
• Potential regulatory changes impacting reimbursement or approval pathways.

What Are the Strategic Opportunities and Future Outlook?

• Integration with CF disease-modifying therapies (e.g., CFTR modulators) might improve management of P. aeruginosa infections.
• Growth in global CF populations, especially in regions like Asia, which currently have less penetration.
• Development of more convenient delivery devices or formulations to improve adherence.
• Potential for licensing or partnership deals for pipeline expansion or combination products.

Summary of Investment Fundamentals

Aspect	Details
Market Size	$3.2 billion (2021), growing at 7–8% CAGR through 2027[1]
Key Competitors	Tobramycin (TOBI), Cayston, Levofloxacin inhalation (not direct)
Patent Expiry	Approx. 2028[2]
Revenue (2022)	Estimated $100–150 million[3] (market share approximately 10–15%)
Development Pipeline	No major pipeline updates announced
Regulatory Status	FDA approval (2010), EMA approval in 2011

Key Takeaways

• CAYSTON remains a niche drug with limited growth potential, heavily reliant on the CF market's expansion.
• Patent expiration risks and intense competition warrant caution.
• Opportunities exist in conjunction with CFTR modulators and expanding geographic reach.
• The drug's pharmacology favors niche targeting, but market adoption depends on clinical and economic factors.
• Strategic partnerships could extend its lifecycle or open new indications.

FAQs

1. What is the main competitive advantage of CAYSTON?
Its targeted inhalation route delivers high lung concentrations with minimal systemic absorption, reducing side effects relative to systemic antibiotics.

2. When is patent expiration expected, and how does it impact the market?
Approximately 2028, after which generic competitors could enter, pressuring prices and market share.

3. Are there combination therapies involving CAYSTON?
Currently, no; development efforts have not emphasized combination formulations, but integrating with CFTR modulators presents a potential strategy.

4. What is the growth outlook for CAYSTON’s market?
The CF inhaled antibiotic market is expected to grow at 7–8% CAGR through 2027, but CAYSTON’s share might plateau due to competition.

5. Are regulatory risks significant?
Limited, as the drug is already approved; however, future indications or label updates could face delays or challenges.

---

Sources

[1] Grand View Research: "Cystic Fibrosis Market Size and Forecast" (2022).
[2] Gilead Sciences: Patent filings and expiry estimates.
[3] Market estimates based on industry reports and company disclosures (2022).