EXONDYS 51 Drug Patent Profile

Which patents cover Exondys 51, and what generic alternatives are available?

Exondys 51 is a drug marketed by Sarepta Theraps Inc and is included in one NDA. There are five patents protecting this drug.

This drug has one hundred and twenty-eight patent family members in twenty-three countries.

The generic ingredient in EXONDYS 51 is eteplirsen. One supplier is listed for this compound. Additional details are available on the eteplirsen profile page.

DrugPatentWatch^® Generic Entry Outlook for Exondys 51

Exondys 51 was eligible for patent challenges on September 19, 2020.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be October 27, 2028. This may change due to patent challenges or generic licensing.

There has been one patent litigation case involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

Indicators of Generic Entry

Summary for EXONDYS 51

International Patents:	128
US Patents:	5
Applicants:	1
NDAs:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for EXONDYS 51

US Patents and Regulatory Information for EXONDYS 51

EXONDYS 51 is protected by seven US patents.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Sarepta Theraps Inc	EXONDYS 51	eteplirsen	SOLUTION;INTRAVENOUS	206488-001	Sep 19, 2016		RX	Yes	Yes
Sarepta Theraps Inc	EXONDYS 51	eteplirsen	SOLUTION;INTRAVENOUS	206488-001	Sep 19, 2016		RX	Yes	Yes			Y
Sarepta Theraps Inc	EXONDYS 51	eteplirsen	SOLUTION;INTRAVENOUS	206488-002	Sep 19, 2016		RX	Yes	Yes
Sarepta Theraps Inc	EXONDYS 51	eteplirsen	SOLUTION;INTRAVENOUS	206488-002	Sep 19, 2016		RX	Yes	Yes
Sarepta Theraps Inc	EXONDYS 51	eteplirsen	SOLUTION;INTRAVENOUS	206488-002	Sep 19, 2016		RX	Yes	Yes			Y

International Patents for EXONDYS 51

When does loss-of-exclusivity occur for EXONDYS 51?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Australia

Canada

China

Croatia

Cyprus

Denmark

European Patent Office

Hong Kong

Hungary

Israel

Japan

New Zealand

Poland

Portugal

Slovenia

Spain

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering EXONDYS 51 around the world.

Country	Patent Number	Title	Estimated Expiration
Japan	2008513012
Canada	2741629
Lithuania	2735568
European Patent Office	1802777	COMPOSÉ ANTIVIRAL ANTISENS ET MÉTHODE DE TRAITEMENT D'UNE INFECTION VIRALE À ARNSS (ANTISENSE ANTIVIRAL COMPOUND AND METHOD FOR TREATING SSRNA VIRAL INFECTION)
Hungary	E028662

Investment Scenario and Fundamentals Analysis for Exondys 51 (Eteplirsen)

Last updated: February 20, 2026

What Is Exondys 51?

Exondys 51 (eteplirsen) is a Duchenne muscular dystrophy (DMD) treatment approved by the FDA in 2016. It employs exon skipping technology to restore dystrophin production in specific genetic variants of DMD. The medication is marketed exclusively by Sarepta Therapeutics.

Market and Competitive Landscape

Factor	Details
Addressable Population	Approx. 13,000 U.S. patients with DMD amenable to exon 51 skipping (per Sarepta).
Approval Status	Approved in the U.S.; regulatory submissions pending in European markets and others.
Competition	Limited; other exon skipping therapies targeting different exons are in development.
Pricing	Approx. $300,000 per year per patient in the U.S.

Revenue and Sales Trends

Year	U.S. Sales (USD millions)	Notes
2018	<$50 million	Initial launch phase
2019	~$78 million	Growing adoption
2020	~$150 million	Increased payer coverage and awareness
2021	~$200 million	Expansion of eligible patients

Sarepta projects peak U.S. sales between $750 million to $1 billion in certain forecasts, contingent on approval in additional markets and broader adoption.

Key Drivers and Risks

Drivers

• Expansion of Approved Patients: Label updates expanding indications increase the eligible cohort.
• Pricing Power: Limited competition sustains high price points.
• Disease Severity: DMD's progressive nature incentivizes early treatment to slow deterioration.
• Market Penetration: Growing diagnosis rates and better reimbursement facilitate sales.

Risks

• Regulatory Hurdles: European approval processes are ongoing; delays could impact global revenue.
• Pricing and Reimbursement: Payer resistance or coverage limitations threaten revenue stability.
• Efficacy Data: Limited clinical outcome data compared to traditional standards of care.
• Competing Technologies: Emerging therapies employing gene editing or alternative exon skipping methods.

Financial Perspective

Property	Details
R&D Investment	Estimated at over $500 million, including trials and approvals (2016–2022).
Cost of Goods Sold (COGS)	Estimated at 20-25% of sales due to manufacturing complexities.
Margins	Gross margins reportedly exceed 80%, with net margins variable based on R&D and commercialization costs.
Market Cap	As of early 2023, approximately $6 billion, reflecting growth potential and market sentiment.

Valuation Metrics

Applying discounted cash flow (DCF) models, assuming:

• Peak sales in U.S. reach $1 billion.
• Revenue growth stabilizes at 5% post-peak.
• Discount rate: 10-12%.
• Operating margins: 60-70%.

Sensitivity analyses show valuations range from $4 billion to $10 billion, heavily dependent on market access and pricing dynamics.

Regulatory and Legal Context

In 2019, Sarepta received a Complete Response Letter from the European Medicines Agency for its orphan drug designation, with ongoing discussions. Patent challenges are active concerning exons targeted and composition of matter claims, potentially impacting exclusivity timelines.

Investment Outlook

The outlook depends on regulatory approvals in key markets, reimbursement environment stability, and clinical data demonstrating meaningful patient benefit. The firm’s recent investments in pipeline expansion and registrational studies suggest a strategic focus on maintaining competitive advantage.

Key Takeaways

• Exondys 51 has a specialized, high-value market with limited direct competition.
• Revenue forecasts indicate significant upside, with peak sales potentially exceeding $1 billion.
• Risks include regulatory, reimbursement, and clinical efficacy uncertainties.
• Current market capitalization reflects strong growth expectations, but valuation hinges on broader market access.
• Pipeline development and regulatory outcomes remain critical.

FAQs

1. What is the current approval scope of Exondys 51?
   Approved in the U.S. for specific DMD genotypes; European approval is pending based on ongoing EMA review.

2. How significant are the reimbursement challenges for Exondys 51?
   Payers have historically shown resistance to high-cost orphan drugs, impacting sales growth and access.

3. What clinical data support Exondys 51's efficacy?
   Evidence shows increased dystrophin production; however, long-term functional benefits are less definitively established.

4. Are there any competitors to Exondys 51?
   No direct competitors in exon 51 skipping; other exon skipping therapies are in different stages or target different exons.

5. What are the main patent protections for Exondys 51?
   Patent filings cover composition of matter, specific exon skipping oligonucleotides, and delivery methods, with expirations projected around 2030–2035.

---

References

[1] U.S. Food and Drug Administration. (2016). FDA approves first medicine for Duchenne muscular dystrophy.
[2] Sarepta Therapeutics. (2022). Annual Report.
[3] EvaluatePharma. (2022). Oncology and rare disease pipeline analysis.
[4] European Medicines Agency. (2022). Exondys 51 review process update.
[5] MarketWatch. (2023). Sarepta Therapeutics stock analysis.