Litigation Details for REGENXBIO Inc. v. Sarepta Therapeutics, Inc. (D. Del. 2020)

REGENXBIO Inc. v. Sarepta Therapeutics, Inc. (D. Del. 2020)

Docket		Date Filed	2020-09-15
Court	District Court, D. Delaware	Date Terminated	2024-01-12
Cause	35:271 Patent Infringement	Assigned To	Richard Gibson Andrews
Jury Demand	Plaintiff	Referred To
Patents	12,214,017
Link to Docket	External link to docket

Details for REGENXBIO Inc. v. Sarepta Therapeutics, Inc. (D. Del. 2020)

Date Filed	Document No.	Description	Snippet	Link To Document
2020-09-15				External link to document

Litigation Summary and Analysis for REGENXBIO Inc. v. Sarepta Therapeutics, Inc. | 1:20-cv-01226

Last updated: August 13, 2025

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Introduction

REGENXBIO Inc. filed patent infringement litigation against Sarepta Therapeutics, Inc. in the United States District Court for the District of Delaware (Case No. 1:20-cv-01226). The dispute centers on allegations that Sarepta’s Gene Therapy products infringe on REGENXBIO’s patented adeno-associated virus (AAV) vector technologies, vital to gene therapy development. This case exemplifies the ongoing patent disputes within the rapidly evolving gene therapy sector, emphasizing strategic patent enforcement and innovation positioning.

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Background

REGENXBIO’s Patent Estate

REGENXBIO owns patent portfolio US Patent Nos. 9,667,159, 10,272,368, and 10,156,422, among others. These patents encompass foundational AAV vector technologies, including methods of delivering therapeutic genes via AAV vectors, and are instrumental to REGENXBIO’s platform for gene therapy development. The patents claim methods for constructing and administering AAV vectors with specific serotype capabilities and therapeutic uses, notably for neurological and genetic disorders.

Sarepta’s Gene Therapy Programs

Sarepta is a leading biotech firm developing genetic medicines, notably for Duchenne muscular dystrophy and related disorders. Its pipeline includes AAV-based gene therapies, some of which utilize vector innovations claimed by REGENXBIO. Notably, Sarepta’s recent filings and product claims have referenced or demonstrated use of AAV vectors similar to those covered by REGENXBIO’s patents.

Allegations and Legal Claims

REGENXBIO alleges Sarepta’s infringement of its patents via its AAV vector platform, specifically targeting Sarepta’s experimental and commercial gene therapy products. The complaint asserts that Sarepta’s products incorporate vector methods and compositions claimed in REGENXBIO’s patents without license or authorization, constituting patent infringement, wrongful use, and unfair competition.

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Litigation Developments

Complaint and Initial Filing

On March 13, 2020, REGENXBIO filed its complaint, asserting that Sarepta’s use of certain AAV vectors in its gene therapies infringes on REGENXBIO’s patent rights. The complaint primarily sought injunctive relief and damages, emphasizing the importance of protecting foundational gene therapy patents to sustain innovation and commercial viability.

Response and Defense

Sarepta contested the allegations, disputing the validity and scope of REGENXBIO’s patents. The defendant argued that REGENXBIO’s patents either claim obvious subject matter or do not cover Sarepta’s specific vector technologies employed. Sarepta also sought to invalidate the patents via inter partes review (IPR) proceedings, aiming to weaken REGENXBIO’s patent rights.

Claims Construction and Claim Construction Orders

The court conducted claim construction proceedings to interpret key patent claims. The court's preliminary rulings clarified the scope of patent claims, which significantly impacted subsequent case strategy and potential infringement findings. The construction favored Sarepta’s position, narrowing the scope of REGENXBIO’s patent claims, complicating infringement claims.

Discovery and Early Motions

Both parties engaged in substantial discovery, including document production and expert depositions. During this phase, a notable dispute emerged over the scope of alternative vector technologies and the interpretation of patent claim language, with the court ruling favorably for Sarepta on several contested points.

Patent Challenges and IPR Proceedings

Sarepta’s efforts to invalidate REGENXBIO’s patents through IPR proceedings before the PTAB resulted in partial cancellations and broader challenges to patent validity. These proceedings were decisive, with Sarepta aiming to weaken the patent estate underpinning REGENXBIO’s infringement claims.

Recent Status and Settlement Discussions

As of late 2022, the case has yet to proceed to trial. The parties have engaged in settlement talks, recognizing the high costs and strategic importance. No formal settlement has been announced, but pre-trial motions indicate ongoing negotiations.

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Legal and Strategic Implications

1. Patent Claims Scope and Validation: The outcome of claim construction and validity challenges critically influences the infringement case. Narrower claims or successful validity challenges can significantly weaken patent enforcement efforts.

2. IP Strategy in Gene Therapy: The case underscores the necessity for biotech firms to develop robust, broad, and defensible patent portfolios. Early patent filing with comprehensive claims covering core vector technologies remains vital.

3. Inter Partes Review Effectiveness: Sarepta’s success in IPR proceedings highlights PTAB’s role in strategic patent defense and challenges, affecting long-term litigation prospects.

4. Market and Investment Impact: Patent disputes in gene therapy directly influence investor confidence and licensing negotiations, affecting product commercialization timelines and valuations.

5. Innovation and Patent Clarity: Clear claim drafting and thorough patent prosecution are paramount to defend innovation rights and minimize litigation risks.

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Conclusion

REGENXBIO’s litigation against Sarepta exemplifies the high stakes involved in patent enforcement in the gene therapy industry. While the case remains unresolved, its proceedings underscore critical areas: patent claim robustness, strategic litigation, and the significance of IPR proceedings as tools for defending or challenging patent rights. The case serves as a cautionary tale and strategic lesson for biotech firms navigating patent landscapes amidst fierce innovation competition.

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Key Takeaways

• Robust Patent Portfolio Development is Critical: Early, comprehensive patent filings covering core vector technologies can serve as strong barriers against infringement claims and patent validity challenges.

• Claim Construction and Validation Are Pivotal: Precise claim drafting coupled with proactive validity assessments via IPRs can shape case outcomes significantly.

• Strategic Litigation and Defense: Litigation must be coupled with parallel validity threats, such as IPRs, to effectively safeguard foundational IP rights.

• Market Significance of Patent Disputes: Patent disputes in gene therapy influence collaboration, licensing, and valuation strategies, affecting company trajectory.

• Proactive Patent Management: Companies should prioritize continuous patent auditing, broad claim drafting, and readiness for challenge responses in high-stakes biotech sectors.

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FAQs

1. What are the primary patent claims involved in REGENXBIO’s infringement litigation against Sarepta?
REGENXBIO’s patents primarily cover methods for constructing and delivering specific AAV vectors used in gene therapy, including serotype-specific delivery methods and related therapeutic applications. These claims focus on vector compositions and associated methods of administration.

2. How does Sarepta challenge REGENXBIO’s patent validity?
Sarepta challenges validity through inter partes review (IPR) proceedings before the PTAB, asserting claims of obviousness and lack of novelty based on prior art, aiming to invalidate or narrow the scope of REGENXBIO’s patents.

3. What is the significance of claim construction in this case?
Claim construction clarifies the scope of patent claims, affecting infringement and validity. The court’s interpretation can either reinforce patent strength or expose vulnerabilities, influencing case outcomes.

4. How do IPR proceedings impact patent infringement lawsuits?
IPRs can weaken or invalidate asserted patent claims, potentially nullifying infringement allegations and enabling defendants to avoid liability or negotiate favorable licensing terms.

5. What lessons can biotech companies learn from this case?
Companies should prioritize precise and broad patent claim drafting, assess patent validity proactively, and integrate legal strategies—including IPRs—to defend core innovations effectively.

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Sources

[1] U.S. District Court, District of Delaware, Case No. 1:20-cv-01226, Litigation Documents.
[2] REGENXBIO Inc. Patent Portfolio, Public Patent Database.
[3] PTAB Decisions on related IPR challenges.