Zafirlukast - Generic Drug Details

What are the generic sources for zafirlukast and what is the scope of patent protection?

Zafirlukast is the generic ingredient in two branded drugs marketed by Strides Pharma Intl, Annora Pharma, Aurobindo Pharma, Dr Reddys Labs Ltd, and Rising Pharms, and is included in five NDAs. Additional information is available in the individual branded drug profile pages.

There are four drug master file entries for zafirlukast. Seven suppliers are listed for this compound.

Summary for zafirlukast

US Patents:	0
Tradenames:	2
Applicants:	5
NDAs:	5
Drug Master File Entries:	4
Finished Product Suppliers / Packagers:	7
Raw Ingredient (Bulk) Api Vendors:	85
Clinical Trials:	7
Patent Applications:	7,287
Drug Prices:	Drug price trends for zafirlukast
What excipients (inactive ingredients) are in zafirlukast?	zafirlukast excipients list
DailyMed Link:	zafirlukast at DailyMed

See drug prices for zafirlukast

Recent Clinical Trials for zafirlukast

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Allergy & Asthma Medical Group & Research Center	Phase 2
King Abdullah International Medical Research Center	Phase 3
Dana-Farber Cancer Institute	Phase 2

See all zafirlukast clinical trials

Pharmacology for zafirlukast

Drug Class	Leukotriene Receptor Antagonist
Mechanism of Action	Cytochrome P450 2C9 Inhibitors Leukotriene Receptor Antagonists

Anatomical Therapeutic Chemical (ATC) Classes for zafirlukast

R03DC	Leukotriene receptor antagonists
R03D	OTHER SYSTEMIC DRUGS FOR OBSTRUCTIVE AIRWAY DISEASES
R03	DRUGS FOR OBSTRUCTIVE AIRWAY DISEASES
R	Respiratory system

Paragraph IV (Patent) Challenges for ZAFIRLUKAST

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
ACCOLATE	Tablets	zafirlukast	10 mg and 20 mg	020547	1	2008-02-29

US Patents and Regulatory Information for zafirlukast

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-003	Sep 17, 1999	AB	RX	Yes	No
Rising Pharms	ZAFIRLUKAST	zafirlukast	TABLET;ORAL	204928-002	Aug 25, 2022	AB	RX	No	No
Dr Reddys Labs Ltd	ZAFIRLUKAST	zafirlukast	TABLET;ORAL	090372-001	Nov 18, 2010	AB	RX	No	No
Aurobindo Pharma	ZAFIRLUKAST	zafirlukast	TABLET;ORAL	213163-001	Nov 27, 2023	AB	RX	No	No
Annora Pharma	ZAFIRLUKAST	zafirlukast	TABLET;ORAL	212475-001	Sep 10, 2020	AB	RX	No	No

Expired US Patents for zafirlukast

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-003	Sep 17, 1999	6,143,775
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-001	Sep 26, 1996	5,583,152
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-003	Sep 17, 1999	4,859,692
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-001	Sep 26, 1996	4,859,692
Strides Pharma Intl	ACCOLATE	zafirlukast	TABLET;ORAL	020547-001	Sep 26, 1996	5,612,367

Market Dynamics and Financial Trajectory for Zafirlukast (Accolate)

Last updated: September 4, 2025

Introduction
Zafirlukast, marketed under the brand name Accolate, is a leukotriene receptor antagonist indicated primarily for the maintenance treatment of asthma. Since its approval in the late 1990s, Zafirlukast’s market dynamics and financial prospects have been shaped by evolving respiratory disease management paradigms, competitive drug landscape, regulatory considerations, and broader healthcare industry trends. This analysis explores these factors, the competitive environment, and future financial trajectories for Zafirlukast.

Pharmacological Profile and Market Position
Zafirlukast was developed by AstraZeneca and received FDA approval in 1996 for asthma maintenance therapy (1). Its mechanism involves antagonizing leukotriene D4 at cysteinyl leukotriene receptors, reducing airway inflammation and bronchoconstriction. Its role is particularly significant in mild-to-moderate persistent asthma, often prescribed as an alternative or adjunct to inhaled corticosteroids.

Despite its efficacy, Zafirlukast’s market share has gradually declined, primarily due to the advent of more potent, convenient, and better-tolerated drugs such as montelukast and newer biologics (2). These alternatives offer medication adherence advantages, broader indications, and fewer drug interactions, impacting Zafirlukast’s standing.

Market Dynamics

1. Competitive Landscape

   • Montelukast's Dominance: Launched shortly after Zafirlukast, montelukast (Singulair) quickly became the leading leukotriene receptor antagonist. Its once-daily dosing and favorable safety profile contributed to superior market penetration (3). As of 2022, montelukast holds over 80% of the leukotriene receptor antagonist market share, overshadowing Zafirlukast.
   • Biologics and Advanced Therapies: The emergence of biologics like omalizumab and mepolizumab for severe asthma further narrows the niche for Zafirlukast, which remains primarily indicated for mild-to-moderate cases.
   • Generic Manufacturers: Patent expiry and downstream generic competition have reduced Zafirlukast’s pricing and margins, limiting financial incentives for AstraZeneca or other producers to prioritize its marketing efforts.

2. Regulatory and Prescribing Trends

   • Guideline Preferences: Recent asthma management guidelines emphasize inhaled corticosteroids, long-acting beta-agonists, and biologic therapies over leukotriene receptor antagonists. Zafirlukast’s prescribing frequency is consequently declining, especially in regions adhering strictly to these guidelines (4).
   • Safety and Tolerance: Concerns over rare neuropsychiatric adverse events associated with montelukast shifted some clinicians towards alternative therapies; however, Zafirlukast’s safety profile remains acceptable, albeit lesser known (5).

3. Market Expansion Opportunities

   • Emerging Markets: In developing countries, the cost of newer biologics limits adoption, leaving room for older drugs like Zafirlukast. Market penetration potential hinges on pricing strategies and healthcare infrastructure.
   • Repurposing and New Indications: Limited evidence supports its off-label use, which could be explored via clinical research for other inflammatory conditions, providing incremental revenue streams.

Financial Trajectory Analysis

1. Historical Revenue Trends

   • Zafirlukast’s revenues peaked in the early 2000s, reflecting high prescription volumes. Following the rise of montelukast and the introduction of newer therapies, global sales have declined significantly. AstraZeneca’s 2021 report estimated annual sales of Zafirlukast at below $50 million, a steep decline from its peak (6).

2. Current Market Valuation and Competition Impact

   • The generic status of Zafirlukast diminishes profit margins. Its niche positioning limits potential growth, especially in mature markets like North America and Europe. No substantial pipeline developments or reformulations are publicly reported, emphasizing stagnation.

3. Forecasted Outlook

   • Short-term forecasts project continued decline unless repositioned. Possible avenues include targeting low-cost markets or niche indications, but these are speculative without strategic investments.
   • The global respiratory drug market, estimated at over $25 billion in 2021 (7), is projected to grow at a CAGR of approximately 4% until 2028. However, Zafirlukast is unlikely to contribute significantly to this growth.

4. Implications for Stakeholders

   • Pharmaceutical Companies: Potential for slight revenue stabilization via cost-effective manufacturing and niche marketing, especially in emerging markets. Large-scale investments are unlikely given limited ROI prospects.
   • Investors: Diminishing returns and limited growth prospects may render Zafirlukast an unfavorable asset unless strategic repositioning occurs.
   • Healthcare Systems: Cost-sensitive regions may sustain Zafirlukast’s usage, influencing sales data in those areas.

Future Strategic Considerations

• Lifecycle Management: To sustain relevance, AstraZeneca or new market entrants might consider reformulations or combination therapies integrating Zafirlukast with other agents.
• Regulatory Strategy: Pursuit of new indications could open incremental pathways, pending supportive clinical evidence and regulatory approval.
• Partnerships: Licensing or co-marketing agreements in emerging markets could bolster sales.

Conclusion
Zafirlukast’s market trajectory is characterized by obsolescence in the face of superior oral and biologic therapies, regulatory shifts, and patent expirations. Its financial future appears marginal unless supplemented by strategic repositioning in underserved regions or niche indications. The drug’s trajectory exemplifies the broader challenges faced by older therapeutic agents in a rapidly evolving pharmaceutical landscape.

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Key Takeaways

• Zafirlukast once held a prominent role but now faces steep market decline amid competition from montelukast and biologics.
• Its primary use remains in low-resource settings or specific patient niches where newer therapies are inaccessible or contraindicated.
• Revenue prospects are limited, with significant declines expected unless strategic repositioning occurs.
• The drug’s future depends on opportunities in emerging markets and potential new indications, though current signals suggest minimal growth.
• Stakeholders must continuously assess competitive dynamics and regulatory pathways to optimize resource allocation.

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FAQs

1. Why did Zafirlukast lose market share so rapidly after its initial approval?
The emergence of montelukast with a more convenient dosing schedule, comparable efficacy, and better safety profile overshadowed Zafirlukast. Additionally, guideline shifts favoring inhaled therapies further marginalized it.

2. Are there any new therapeutic indications for Zafirlukast under investigation?
Currently, no significant clinical programs aim to expand Zafirlukast's indications. Its development has largely stagnated, focusing instead on existing asthma management roles.

3. How do generic formulations impact Zafirlukast’s market viability?
Patent expiration enabled generic manufacturers to produce cost-effective versions, drastically reducing price points and profit margins, limiting promotional efforts, and diminishing overall revenue.

4. Could Zafirlukast find a niche in emerging markets?
Yes. In regions with limited access to biologics or newer therapies, Zafirlukast's low cost and established profile could sustain modest demand, especially if marketed effectively.

5. What strategic moves could prolong Zafirlukast’s lifecycle?
Potential strategies include reformulation, combination therapies, seeking new indications, or targeted marketing in low-resource settings. However, the feasibility and profitability of these options are uncertain.

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Sources

1. AstraZeneca. (1996). FDA Approval Letter for Zafirlukast.
2. GlobalData. (2022). Respiratory Drugs Market Report.
3. IMS Health (2021). Analysis of Leukotriene Receptor Antagonist Market Share.
4. GINA. (2022). Global Strategy for Asthma Management and Prevention.
5. FDA. (2019). Advisory Committee on Neuropsychiatric Events Associated with Montelukast.
6. AstraZeneca Annual Report 2021.
7. MarketsandMarkets. (2021). Respiratory Drug Market Analysis.