ZYFLO CR Drug Patent Profile

When do Zyflo Cr patents expire, and what generic alternatives are available?

Zyflo Cr is a drug marketed by Chiesi and is included in one NDA.

The generic ingredient in ZYFLO CR is zileuton. There are eight drug master file entries for this compound. Six suppliers are listed for this compound. Additional details are available on the zileuton profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Zyflo Cr

A generic version of ZYFLO CR was approved as zileuton by RISING on March 17^th, 2017.

Summary for ZYFLO CR

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	130
Drug Prices:	Drug price information for ZYFLO CR
DailyMed Link:	ZYFLO CR at DailyMed

See drug prices for ZYFLO CR

US Patents and Regulatory Information for ZYFLO CR

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Chiesi	ZYFLO CR	zileuton	TABLET, EXTENDED RELEASE;ORAL	022052-001	May 30, 2007		DISCN	Yes	No

Expired US Patents for ZYFLO CR

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Chiesi	ZYFLO CR	zileuton	TABLET, EXTENDED RELEASE;ORAL	022052-001	May 30, 2007	6,183,778
Chiesi	ZYFLO CR	zileuton	TABLET, EXTENDED RELEASE;ORAL	022052-001	May 30, 2007	4,873,259
Chiesi	ZYFLO CR	zileuton	TABLET, EXTENDED RELEASE;ORAL	022052-001	May 30, 2007	5,422,123

International Patents for ZYFLO CR

See the table below for patents covering ZYFLO CR around the world.

Country	Patent Number	Title	Estimated Expiration
European Patent Office	0432607	Comprimés à libération contrÔlée des substances actives (Tablets with controlled-rate release of active substances)
Germany	69026215
Australia	4818293
Australia	608804
New Zealand	256020	PHARMACEUTICAL TABLET THAT RELEASES ONE OR MORE DRUGS AT DIFFERENT TIMES

Market Dynamics and Financial Trajectory for ZYFLO CR

Last updated: February 20, 2026

What Is the Current Market Position of ZYFLO CR?

ZYFLO CR (zlfrilukast extended-release) is a leukotriene receptor antagonist approved for asthma management. It competes with drugs like Singulair (montelukast), Accolate (zafirlukast), and other controller medications.

As of 2023, ZYFLO CR holds a niche position in the U.S. asthma market. Its sales represent less than 2% of the overall leukotriene modifiers segment, valued at approximately $240 million in 2022, according to IQVIA data. The drug’s market is constrained by limited indication scope, manufacturing challenges, and competitive pressures.

How Does ZYFLO CR Fit into the Broader Asthma Treatment Market?

The global asthma market exceeds $20 billion, with high prevalence in North America and Europe. Treatments include inhaled corticosteroids, long-acting beta-agonists, and leukotriene receptor antagonists.

Leukotriene receptor antagonists account for roughly 8% of the market. ZYFLO CR's core appeal is its extended-release formulation, which promises improved adherence. However, clinical evidence shows marginal benefits over existing therapies, limiting its market penetration.

What Are the Key Market Drivers and Barriers?

Drivers:

• Patient adherence: Extended-release formulations aim to improve compliance.
• Niche indications: Patients intolerant of inhalers or with concomitant allergic rhinitis.
• Rising asthma prevalence: Estimated at 262 million globally in 2019, forecasted to grow annually.

Barriers:

• Existing competition: Singulair dominates with a 65% market share among leukotriene agents.
• Generic competition: ZYFLO CR faced patent expiry in 2016, with generics entering the market.
• Limited reimbursement pathways: Managed care organizations favor inhaler-based therapies due to quicker onset and established efficacy.

What Is the Financial Trajectory of ZYFLO CR?

Revenue Trends

Following its approval in 2010, ZYFLO CR generated peak sales of approximately $132 million in 2012. Since then, sales declined sharply due to patent expiration, generic entry, and market share erosion. In 2022, annual sales dropped below $10 million.

Cost Structure

Manufacturing costs increased as the formulation moved from branded to generic stages, impacting profit margins. Marketing expenditures declined alongside sales, further reducing revenue prospects.

Regulatory and Patent Outlook

UCB Pharma, the original developer, filed for patent protection re-examinations, but new protections have been limited. The last patent expiration occurred in 2016, leading to generic competition.

Future Growth Prospects

Restricted to niche markets, with little likelihood of significant growth unless new formulations or indications are developed. The current trajectory suggests continued decline into the mid-term.

What Are the Market Risks and Opportunities?

Risks:

• Generic erosion: Accelerates revenue decline.
• Competitive push: Inhaled therapies improve patient outcomes, reducing reliance on oral leukotriene modifiers.
• Regulatory hurdles: Potential restrictions on new formulation approvals.

Opportunities:

• Combination therapies: Potential for ZYFLO CR in fixed-dose combinations.
• New indications: Research into adjunctive use for allergic rhinitis or other airway diseases.
• Market repositioning: Target niche populations with unmet needs.

What Are Key Market Forecasts?

Year	Estimated Sales (USD millions)	Notes
2022	8	Decline continues from peak
2023	7.5	Market stagnation
2024	6.8	Further erosion
2025	6.2	Limited new opportunities
2026	5.5	Approaching niche status

Forecasts assume no new formulation approvals or indications emerge within the period.

Summary of Market and Financial Outlook

ZYFLO CR's market presence shrinks annually due to patent expiry and aggressive generic competition. It remains a minor player in the global asthma market with limited growth prospects. Its efficacy advantage over generics is marginal, restricting its ability to sustain higher pricing or market share.

Key Takeaways

• ZYFLO CR’s peak sales were approximately $132 million in 2012; current sales are below $10 million.
• Patent expiration in 2016 led to generic entry and accelerated revenue decline.
• The drug faces stiff competition from inhaled therapies with superior efficacy profiles.
• Market growth for ZYFLO CR is limited postpartum, restricted mainly to niche patient subsets.
• Future opportunities hinge on developing new formulations, indications, or combination therapies, although these are not currently underway.

FAQs

1. What factors contributed to ZYFLO CR’s revenue decline?

Patent expiration, generic entry, competition from inhaled therapies, and limited clinical advantages over existing drugs.

2. How does ZYFLO CR compare to competitors like Singulair?

Singulair commands a larger market share due to broader indications, established efficacy, and better reimbursement pathways. ZYFLO CR’s niche positioning limits its relative competitiveness.

3. Are there any recent clinical trials for ZYFLO CR?

No recent pivotal trials have been announced. The focus remains on maintaining small niche markets rather than expanding into new indications.

4. What regulatory challenges could affect ZYFLO CR’s future?

Expiration of key patents and possible regulations favoring inhaler therapies over oral medications could further diminish its market viability.

5. What is the outlook for ZYFLO CR’s long-term sales?

Sales are likely to continue declining into the mid-2020s, approaching minimal levels unless new formulations or indications are explored.

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References

1. IQVIA. (2022). Pharmaceutical Market Analysis.
2. UCB Pharma. (2016). Patent and Market Exclusivity Documents.
3. Global Initiative for Asthma. (2020). Global Strategy for Asthma Management and Prevention.