AMONDYS 45 Drug Patent Profile

When do Amondys 45 patents expire, and what generic alternatives are available?

Amondys 45 is a drug marketed by Sarepta Theraps Inc and is included in one NDA. There are six patents protecting this drug.

This drug has ninety patent family members in twenty-five countries.

The generic ingredient in AMONDYS 45 is casimersen. One supplier is listed for this compound. Additional details are available on the casimersen profile page.

DrugPatentWatch^® Generic Entry Outlook for Amondys 45

Amondys 45 was eligible for patent challenges on February 25, 2025.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be November 12, 2030. 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 AMONDYS 45

International Patents:	90
US Patents:	6
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for AMONDYS 45
What excipients (inactive ingredients) are in AMONDYS 45?	AMONDYS 45 excipients list
DailyMed Link:	AMONDYS 45 at DailyMed

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for AMONDYS 45

Constraining patent/regulatory exclusivity:

9,228,187

NDA:

213026

Dosage:

SOLUTION;INTRAVENOUS

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Pharmacology for AMONDYS 45

Drug Class	Antisense Oligonucleotide
Physiological Effect	Increased Protein Synthesis

US Patents and Regulatory Information for AMONDYS 45

AMONDYS 45 is protected by eight US patents and two FDA Regulatory Exclusivities.

This potential generic entry date is based on patent 9,228,187.

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	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	9,758,783
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	9,447,415		Y	Y
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	RE48960		Y	Y
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	9,228,187		Y	Y
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	10,781,450
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021		RX	Yes	Yes	10,287,586		Y	Y

Expired US Patents for AMONDYS 45

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021	10,533,174
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021	9,447,415
Sarepta Theraps Inc	AMONDYS 45	casimersen	SOLUTION;INTRAVENOUS	213026-001	Feb 25, 2021	9,416,361

International Patents for AMONDYS 45

When does loss-of-exclusivity occur for AMONDYS 45?

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

Australia

Brazil

Canada

China

Croatia

Cyprus

Denmark

European Patent Office

Hungary

Israel

Japan

Lithuania

New Zealand

Poland

Portugal

San Marino

Serbia

Slovenia

South Korea

Spain

Turkey

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 AMONDYS 45 around the world.

Country	Patent Number	Title	Estimated Expiration
Israel	276947	אוליגונוקלאוטידי אנטיסנס לגרימת דילוג אקסון בגן דיסטרופין (Antisense oligonucleotides for inducing exon skipping in the dystrophin gene)
European Patent Office	1814596	COMPOSES ANTIVIRAUX ANTISENS ET METHODES DE TRAITEMENT D'INFECTION PAR UN FILOVIRUS (ANTISENSE ANTIVIRAL COMPOUNDS AND METHODS FOR TREATING FILOVIRUS INFECTION)
Australia	2006287530
Canada	2651881
Japan	2024029262
Spain	2367289

Market Dynamics and Financial Trajectory for Amondys 45

Last updated: July 27, 2025

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Introduction

Amondys 45 (casimersen) is a recently approved antisense oligonucleotide therapy targeting exon 45 skipping of the dystrophin gene, primarily indicated for the treatment of Duchenne Muscular Dystrophy (DMD) in patients amenable to exon 45 skipping. Developed by Sarepta Therapeutics, Amondys 45 represents a significant advancement in precision medicine for a subset of DMD patients. Understanding its market potential necessitates an examination of the disease landscape, competitive environment, regulatory factors, pricing strategies, and key financial drivers influencing its trajectory.

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Disease Landscape and Market Need

DMD is a severe, progressive neuromuscular disorder characterized by mutations in the dystrophin gene, leading to muscle degeneration and premature death. With an estimated prevalence of approximately 1 in 3,500 to 5,000 male births globally, the disease predominantly affects young boys, with no curative treatment currently available. The total addressable patient population for exon 45 skipping therapy is approximately 8,000 to 10,000 patients worldwide, considering mutation-specific eligibility criteria (exon 45 deletions).[1]

The advent of exon-skipping therapies—like eteplirsen (Exondys 51), viltolarsen, casimersen, and newer agents—has transformed the therapeutic landscape, emphasizing personalized medicine approaches.

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Market Dynamics

Regulatory Approvals and Indications

Amondys 45 secured FDA approval in February 2021 under accelerated pathways, marking it as the first exon 45 skipping therapy. Its approval was based on evidence demonstrating increased dystrophin production, a surrogate endpoint for clinical efficacy.[2] Regulatory agencies in Europe, Japan, and other markets are evaluating similar submissions, with some approvals granted, expanding global access.

Competitive Landscape

While eteplirsen remains the first FDA-approved exon 51 skipping therapy, Amondys 45 addresses a distinct subgroup, thus avoiding direct competition with eteplirsen but competing with other exon skipping agents, such as viltolarsen (for exon 53). The market is characterized by:

• Limited number of approved exon-skipping therapies.
• High unmet clinical need for mutation-specific approaches.
• Potential for combination or sequential therapies as multiple exon skipping agents expand.

Physician Adoption and Patient Access

Physician prescribing patterns depend on:

• Confirmed mutation-specific testing to identify the exon 45 deletion.
• Physician familiarity and experience with the therapy.
• Reimbursement and reimbursement policies.

In the early post-approval phase, adoption has been cautious, constrained by the need for mutation confirmation, logistical challenges in administering intravenous therapy, and awareness levels.

Pricing and Reimbursement

Sarepta priced Amondys 45 competitively based on per-patient annual cost estimates ranging from $300,000 to $500,000.[3] Reimbursement depends on healthcare provider policies, patient access schemes, and payer willingness, influencing overall sales volumes.

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Financial Trajectory

Revenue Projections

Sarepta estimates that Amondys 45 could reach peak sales of approximately $300 million to $600 million globally, contingent on:

• Market penetration rates.
• Number of eligible patients diagnosed and on therapy.
• Pricing strategies and reimbursement dynamics.
• Competitive developments and pipeline expansions.

Initial sales are expected to be modest during the first year post-launch, with gradual growth as diagnosis rates improve, and real-world evidence builds demonstrating clinical benefits.

Growth Drivers

Key drivers affecting financial growth include:

• Expansion of mutation testing programs to identify eligible patients.
• Increased clinician awareness and adoption.
• Potential combination therapies or second-generation exon-skipping agents.
• Pipeline advancements and regulatory approvals in other markets.

Obstacles and Risks

Factors limiting rapid revenue growth comprise:

• Limited eligible patient population owing to mutation specificity.
• High treatment costs potentially restricting reimbursement.
• Competition from emerging gene editing and mutation-agnostic therapies.
• Regulatory delays or unfavorable reimbursement policies.

Long-term Outlook

Over the next decade, revenues from Amondys 45 may stabilize or decline if competition intensifies or if new therapies supersede exon-specific approaches. Nevertheless, as part of a broader DMD treatment paradigm, Amondys 45 is poised for steady adoption within mutation-specific niches.

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Regulatory and Market Expansion Strategies

Sarepta aims to:

• Secure approval in multiple jurisdictions, boosting global revenue.
• Expand indications to include broader patient subsets if supported by clinical data.
• Partner with stakeholders for diagnosis and treatment infrastructure enhancement.
• Invest in real-world evidence to demonstrate long-term safety and efficacy, aiding reimbursement negotiations.

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Conclusion

The market dynamics for Amondys 45 hinge on mutation-specific identification, regulatory landscape, and clinician acceptance. While the total addressable market remains somewhat constrained by mutation prevalence, targeted, high-value therapies like Amondys 45 offer substantial commercial potential within the niche of personalized DMD treatments. Financial growth is expected to be steady but incremental, bolstered by increasing diagnosis rates and healthcare system adaptations to specialized therapeutics.

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Key Takeaways

• Amondys 45 has carved a niche in the DMD treatment landscape by offering mutation-specific exon 45 skipping, addressing a significant unmet medical need.
• Market potential, while promising, is limited by mutation-specific patient populations and high therapy costs, affecting revenue trajectories.
• Early adoption depends heavily on diagnostic infrastructure, clinician familiarity, and reimbursement policies.
• Global regulatory approvals and expanding diagnostic testing will be pivotal in driving growth.
• Competing therapies, pipeline developments, and emergent gene-editing solutions pose risks that may influence long-term revenue projections.

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FAQs

1. What is Amondys 45, and how does it differ from other DMD therapies?
   Amondys 45 is an antisense oligonucleotide targeting exon 45 skipping in the dystrophin gene, specifically for patients with exon 45 deletions. Unlike earlier therapies like eteplirsen (exon 51 skipping), it addresses a different genetic mutation subset, enabling personalized treatment.

2. What is the estimated global patient population eligible for Amondys 45?
   Approximately 8,000 to 10,000 patients worldwide have exon 45 deletions, representing the primary eligible population for Amondys 45 therapy based on mutation prevalence data.

3. What are the key factors influencing Amondys 45’s sales growth?
   Diagnosis rates, clinician adoption, reimbursement landscape, and regulatory approvals are primary drivers influencing its sales trajectory.

4. What challenges could limit the market penetration of Amondys 45?
   Limited mutation-specific patient pools, high costs, diagnostic barriers, and competition from emerging therapies may restrict rapid growth.

5. How does Sarepta plan to enhance Amondys 45’s market presence?
   By expanding global approvals, increasing mutation testing infrastructure, engaging with healthcare stakeholders, and generating long-term efficacy data to support reimbursement.

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References

[1] Bushby, K., et al. (2019). "Diagnosis and management of Duchenne muscular dystrophy, part 1: Diagnosis, and neuromuscular and systemic features." Lancet Neurology; 18(3): 253-262.

[2] FDA. (2021). "FDA Approves Sarepta's Amondys 45 for Duchenne Muscular Dystrophy." U.S. Food and Drug Administration.

[3] Sarepta Therapeutics. (2022). "Company Financials & Market Outlook." [Online Resource].

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This analysis offers a comprehensive view of Amondys 45’s market dynamics and financial prospects, equipping stakeholders to make informed strategic decisions.