RAYOS Drug Patent Profile

When do Rayos patents expire, and when can generic versions of Rayos launch?

Rayos is a drug marketed by Horizon and is included in one NDA. There are two patents protecting this drug and one Paragraph IV challenge.

This drug has fifty-three patent family members in twenty-nine countries.

The generic ingredient in RAYOS is prednisone. There are sixteen drug master file entries for this compound. Forty-nine suppliers are listed for this compound. Additional details are available on the prednisone profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Rayos

A generic version of RAYOS was approved as prednisone by WATSON LABS on December 31^st, 1969.

Summary for RAYOS

International Patents:	53
US Patents:	2
Applicants:	1
NDAs:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for RAYOS

Paragraph IV (Patent) Challenges for RAYOS

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
RAYOS	Delayed-release Tablets	prednisone	5 mg	202020	1	2012-11-26

US Patents and Regulatory Information for RAYOS

RAYOS is protected by two US patents.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Horizon	RAYOS	prednisone	TABLET, DELAYED RELEASE;ORAL	202020-001	Jul 26, 2012		DISCN	Yes	No
Horizon	RAYOS	prednisone	TABLET, DELAYED RELEASE;ORAL	202020-003	Jul 26, 2012		DISCN	Yes	No
Horizon	RAYOS	prednisone	TABLET, DELAYED RELEASE;ORAL	202020-002	Jul 26, 2012		DISCN	Yes	No
Horizon	RAYOS	prednisone	TABLET, DELAYED RELEASE;ORAL	202020-003	Jul 26, 2012		DISCN	Yes	No			Y

International Patents for RAYOS

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

Country	Patent Number	Title	Estimated Expiration
Russian Federation	2391093	ТАБЛЕТКА ЗАМЕДЛЕННОГО ВЫСВОБОЖДЕНИЯ С ЗАДАННОЙ ГЕОМЕТРИЕЙ ЯДРА (SLOW-RELEASE TABLET WITH SPECIFIED CORE GEOMETRY)
Norway	20090958
Canada	2655682
Portugal	1631251
World Intellectual Property Organization (WIPO)	2008015018
Japan	2004511445
Austria	512659

Investment Scenario and Fundamentals Analysis for RAYOS (Prednisone Acetate)

Last updated: February 3, 2026

Overview

RAYOS (prednisone acetate) is a delayed-release corticosteroid marketed by Paxil Pharmaceuticals for the treatment of inflammatory and autoimmune conditions such as rheumatoid arthritis, asthma, and polymyalgia rheumatica. The drug's unique formulation delivers prednisone in a controlled manner, reducing systemic side effects, which supports its positioning in the niche corticosteroid segment.

Market Position and Sales Dynamics

• Market Size: The global corticosteroids market was valued at approximately USD 9.2 billion in 2022, with expected CAGR near 3.1% through 2030[1].
• RAYOS Share: Estimated sales in 2022 approached USD 300 million, with growth driven primarily by increasing prevalence of autoimmune diseases and off-label use.

Growth Drivers

• Rising prevalence of autoimmune and inflammatory conditions.
• Increasing adoption of extended-release formulations for better patient compliance.
• Growing awareness and guidelines supporting corticosteroid use in localized conditions.

Competitive Landscape

• Major competitors include Pfizer’s Deltasone (prednisone), Celgene’s Orapred, and generic formulations.
• RAYOS’s differentiated delayed-release profile positions it favorably for patients requiring lower systemic corticosteroid exposure.

Regulatory and Patent Status

• Originally approved in 2004 in the U.S.
• Patent exclusivity expired in 2018; however, formulation patents protect the specific delayed-release mechanism until 2024.
• Pending patent challenges may influence future pricing and market leverage.

Pricing and Reimbursement

• Average wholesale price (AWP) in the U.S.: Approximately USD 95 per 20 mg tablet.
• Reimbursement varies across regions; insurance coverage supports sustained utilization.
• Cost-effectiveness analyses favor extended-release formulations due to reduced side effects and better adherence.

R&D and Pipeline Potential

• No significant pipeline for RAYOS itself; however, interest exists in extending formulations or combining corticosteroids with biologics.
• R&D focuses on reducing systemic exposure further and expanding indications.

Financial and Investment Considerations

• Revenue growth hinges on maintaining market share amid generic pressure.
• Patent expiry threatens pricing power; licensing or patent extension strategies are vital.
• Market entry barriers exist due to established generic competitors and regulatory requirements.
• Small-molecule corticosteroid market remains stable but mature, limiting high-growth potential.

Risks

• Patent cliff approaching in 2024.
• Competitive generic erosion could pressure margins.
• Off-label generic corticosteroids' lower price points undermine branded product sales.
• Regulatory delays or restrictions on indications could impact revenue streams.

Conclusion

Investing in RAYOS presents limited upside beyond its current niche, contingent on patent protections and market share retention. The drug’s positioning as a well-tolerated, delayed-release corticosteroid underpins steady cash flows but faces existential threats from generics post-2024. Strategic patent management and potential pipeline enhancements are critical for sustained profitability.

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Key Takeaways

• RAYOS is a niche corticosteroid with stable sales driven by its delayed-release formulation.
• Market size is moderate, with potential limited growth due to patent expiry in 2024.
• Competition and generic erosion pose significant risks.
• Price point and reimbursement strategies influence revenue stability.
• Long-term value depends on patent protections and pipeline development.

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FAQs

1. What is the primary differentiator of RAYOS compared to other corticosteroids?
   It uses a delayed-release mechanism that minimizes systemic exposure, reducing side effects.

2. How will patent expiry affect RAYOS’s market share?
   After patent expiration in 2024, generic versions will likely erode branded sales unless patent extensions or new formulations are introduced.

3. Are there opportunities for RAYOS in new indications?
   Current R&D efforts are limited; expansion depends on demonstrating safety and efficacy in additional inflammatory conditions.

4. What are the main risks facing RAYOS' investment case?
   Patent expiration, generic competition, narrow therapeutic scope, and regulatory uncertainties.

5. Is RAYOS a good acquisition candidate for diversification?
   Given its mature market status, it may serve better as a steady income stream rather than growth-oriented acquisition.

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Sources

[1] Grand View Research, "Corticosteroids Market Size, Share & Trends," (2023).