Sarepta Therapeutics, Inc. v. Genzyme Corp.

Sarepta Therapeutics, Inc. has initiated an inter partes review (IPR) against Genzyme Corp. before the U.S. Patent and Trademark Office (PTAB), challenging the validity of U.S. Patent No. 12,298,313. Sarepta Therapeutics is a publicly traded biopharmaceutical company based in Cambridge, Massachusetts, specializing in precision genetic medicines for rare neuromuscular diseases, most notably Duchenne muscular dystrophy (DMD), with key products including the gene therapy Elevidys® and several exon-skipping therapies. Genzyme Corp., a biotechnology company founded in 1981 and acquired by Sanofi in 2011, operates as a global business unit focusing on rare diseases, multiple sclerosis, immunology, and oncology, and has a long history of developing treatments for rare genetic disorders.

This IPR is part of a broader patent dispute where Genzyme has accused Sarepta's gene therapy product, Elevidys® (delandistrogene moxeparvovec-rokl), of infringing its patents. Elevidys is a one-time adeno-associated virus (AAV) vector-based gene therapy for treating DMD. U.S. Patent No. 12,298,313, the patent challenged in this IPR, is directed to methods for the analysis and characterization of preparations of recombinant adeno-associated virus (rAAV) particles. The IPR, filed with the PTAB under case number IPR2026-00270, is currently awaiting an institution decision.

The dispute highlights the intense competition and complex intellectual property landscape within the gene therapy sector for rare diseases. Sarepta has adopted a strategy of filing multiple IPR petitions against Genzyme's patents related to Elevidys, indicating a concerted effort to challenge the underlying patent protection asserted against its significant product. These IPRs are directly linked to an ongoing patent infringement lawsuit filed by Genzyme against Sarepta in the U.S. District Court for the District of Delaware (Case No. 1:24-cv-00882), presided over by Judge Andrews. The use of the PTAB for IPRs is a common procedural step in such high-value pharmaceutical patent litigations, offering a specialized forum to challenge patent validity, often serving as a more streamlined and potentially cost-effective alternative to district court proceedings. Elevidys has demonstrated substantial commercial success, reporting $820.8 million in net revenue in 2024 and $898.7 million in 2025, underscoring the significant market implications of these patent battles.

The patent infringement litigation between Sarepta Therapeutics, Inc. and Genzyme Corp. involves a complex set of proceedings, including a district court case and multiple parallel Inter Partes Reviews (IPRs) before the Patent Trial and Appeal Board (PTAB). The primary district court action is Genzyme Corp. v. Sarepta Therapeutics, Inc. in the U.S. District Court for the District of Delaware, Case No. 1:24-cv-00882.

Here's a chronological overview of the key legal developments and outcomes:

1. District Court Filing & Initial Pleadings

• July 26, 2024: Genzyme Corp. (a wholly owned subsidiary of Sanofi) filed a patent infringement lawsuit against Sarepta Therapeutics, Inc. and Sarepta Therapeutics Three, LLC in the U.S. District Court for the District of Delaware. The case, numbered 1:24-cv-00882, was assigned to Judge Andrews.
• Asserted Patents: Genzyme initially alleged that Sarepta's Duchenne muscular dystrophy treatment, Elevidys® (delandistrogene moxeparvovec-rokl), infringed U.S. Patent Nos. 9,051,542 ('542 patent) and 7,704,721 ('721 patent). These patents relate to methods and compositions for preventing the aggregation of recombinant adeno-associated virus (rAAV) vector particles during gene therapy production.
• Allegations: Genzyme accused Sarepta of both direct and indirect infringement through the manufacture and sale of Elevidys®, including by contracting with Catalent for manufacturing.
• Relief Sought: Genzyme sought judgments of infringement, compensatory damages (including treble damages for willful infringement under 35 U.S.C. § 284), and attorneys' fees under 35 U.S.C. § 285.

2. Parallel PTAB IPR Proceedings

Sarepta Therapeutics has strategically challenged multiple Genzyme patents, including those asserted in the district court litigation, through several IPR petitions.

• June 26, 2025: First Batch of IPR Filings

  • Sarepta filed two IPR petitions against the patents initially asserted in the district court case: IPR2025-01194, challenging claims 3-6 of U.S. Patent No. 9,051,542, and IPR2025-01195, challenging claims 1-4, 6-7, and 11 of U.S. Patent No. 7,704,721.
  • Outcome: Both IPR2025-01194 and IPR2025-01195 were denied institution by the PTAB.

• November 25, 2025: Second Batch of IPR Filings

  • Sarepta filed two additional IPR petitions: IPR2026-00149, challenging U.S. Patent No. 12,013,326 ('326 patent), and IPR2026-00150, challenging U.S. Patent No. 12,031,894 ('894 patent). These patents relate to methods for characterizing recombinant AAV vector preparations.
  • Outcome:
    • May 6, 2026: The PTAB granted institution for IPR2026-00150, concerning U.S. Patent No. 12,031,894.
    • IPR2026-00149, concerning U.S. Patent No. 12,013,326, was denied institution.

• December 2, 2025: Third Batch of IPR Filings (including the prompt's patent)

  • Sarepta filed three more IPR petitions: IPR2026-00166, challenging claims 1–27 of U.S. Patent No. 12,298,313 ('313 patent); IPR2026-00167, challenging claims 1–20 of U.S. Patent No. 11,698,377 ('377 patent); and IPR2026-00168, challenging claims 1–21 of U.S. Patent No. 12,123,880 ('880 patent). These patents generally relate to methods for analyzing AAV particles.
  • Outcome:
    • May 15, 2026: The PTAB denied institution for both IPR2026-00167 and IPR2026-00168.
    • Current Status (IPR2026-00166): IPR2026-00166, challenging U.S. Patent No. 12,298,313, is currently awaiting an institution decision.

• Additional IPR on U.S. Patent No. 12,298,313 (as per prompt metadata)

  • IPR2026-00270: This IPR, also filed by Sarepta against Genzyme's U.S. Patent No. 12,298,313, is currently awaiting an institution decision as of May 18, 2026. This indicates that Sarepta has filed at least two IPRs (IPR2026-00166 and IPR2026-00270) against the '313 patent.

3. Pre-Trial Motions & Milestones in District Court

• April 22, 2026: A Claim Construction (Markman) hearing was scheduled in the District of Delaware case (1:24-cv-00882).
• Institution Decisions for IPRs: The PTAB's discretionary denial of several IPR petitions highlights a recent trend of increased scrutiny by the USPTO Director, particularly concerning factors like parallel litigation schedules, domestic manufacturing, and consistent claim construction positions between forums. Director John Squires took over all IPR institution decisions in October 2025, leading to a more restrictive, policy-driven approach and a reduction in institution rates.

4. Trial Events & Outcome/Current Posture

• January 25, 2027: The jury trial in the District of Delaware case (1:24-cv-00882) is currently scheduled for this date.

As of May 29, 2026, the district court patent infringement litigation is ongoing, with key pre-trial events such as claim construction having recently occurred or still in progress. Several of the parallel IPR proceedings have reached institution decisions, with some being instituted (e.g., IPR2026-00150) and others denied (e.g., IPR2025-01194, IPR2025-01195, IPR2026-00149, IPR2026-00167, IPR2026-00168). The specific IPRs IPR2026-00166 and IPR2026-00270, both challenging U.S. Patent No. 12,298,313, are still awaiting institution decisions.

I'll research counsel for Sarepta (the petitioner/plaintiff-side party) in this IPR and the related proceedings.

Let me dig into the specific IPR2026-00270 docket and petitioner's power of attorney.

Plaintiff/Petitioner representatives — Sarepta Therapeutics, Inc.

Framing note: In this PTAB proceeding Sarepta is the petitioner (the caption supplied in the case metadata — Sarepta Therapeutics, Inc. v. Genzyme Corp., IPR2026-00270 — reverses the district court alignment, where Genzyme is plaintiff in Genzyme Corp. v. Sarepta Therapeutics, Inc., No. 1:24-cv-00882 (D. Del.)). The "plaintiff-side" bench is therefore the petitioner's bench, and it is drawn almost exclusively from Quinn Emanuel Urquhart & Sullivan LLP in New York.

Counsel of record before the PTAB (IPR2026-00270)

Docket basis. IPR2026-00270 was filed February 26, 2026. The petitioner's papers on the docket are Paper 1 (Petition as filed), Paper 2 (Petitioner Notice: Power of Attorney), and Paper 7 (Petitioner's Sotera stipulation, filed March 24, 2026). The docket-sheet summary for IPR2026-00270 identifies "Wilson, Robert et al." as petitioner counsel and "Antons, Amanda et al." as patent-owner counsel (docket summary; IP Verse case page).

Caveat on the POA itself. I could not retrieve the text of Paper 2 (the IPR2026-00270-specific power of attorney) directly. The three-attorney roster above is sourced from (a) the materially identical Sarepta POA filed in the companion proceeding IPR2026-00168 (dated Nov. 24, 2025), which lists Wilson as lead and Toker and Glass as back-ups at the same Quinn Emanuel New York address (PTAB document), (b) the signature block on Sarepta's March 4, 2026 filing in the earlier '313-patent IPR, IPR2026-00166, listing Wilson, Toker and Glass as "Attorneys for Petitioner Sarepta Therapeutics, Inc.," and (c) the service e-mail addresses robertwilson@quinnemanuel.com, annetoker@quinnemanuel.com, and jimglass@quinnemanuel.com used in the '313 and '377 proceedings. Treat the roster as highly reliable but not yet confirmed against Paper 2 itself.

No other petitioner-side counsel has appeared at the PTAB. The Finnegan and Morris Nichols attorneys who appear for Sarepta in Delaware do not appear on the PTAB power of attorney, and no Sarepta in-house attorney (e.g., a chief IP counsel) is identified on the PTAB record in the materials reviewed. If any additional back-up counsel were added, they would appear via an updated mandatory notice or POA — none surfaced.

Related district court bench (for cross-reference — not PTAB of record)

Sarepta's Delaware team in No. 1:24-cv-00882, per the signature blocks reproduced in PTAB exhibits, is a three-firm lineup:

• Quinn Emanuel (New York): Andrew M. Berdon, Robert B. Wilson, Anne S. Toker, Anastasia M. Fernandes — Wilson and Toker thus bridge both forums.
• Finnegan, Henderson, Farabow, Garrett & Dunner LLP (Atlanta): John D. Livingstone; M. David Weingarten, Ph.D. Finnegan's William B. Raich, Ph.D. has been co-lead for Sarepta in the DMD-adjacent Nippon Shinyaku v. Sarepta (D. Del. No. 1:21-cv-01015) and Regenxbio v. Sarepta (D. Del. No. 1:20-cv-01226, Judge Andrews) matters, but I found no indication he has appeared in IPR2026-00270 or the Delaware Elevidys® case.
• Morris, Nichols, Arsht & Tunnell LLP (Wilmington, DE) — local counsel: Rodger D. Smith II (#3778), Megan E. Dellinger (#5739), Derek J. Fahnestock (#4705), signing "Attorneys for Defendants Sarepta Therapeutics, Inc. and Sarepta Therapeutics Three, LLC."

Two flags against the previously generated sections

1. Status contradiction (material). The prior "Key legal developments" section states IPR2026-00270 is "awaiting an institution decision." Current reporting indicates the Director issued a bulk order on July 21, 2026 denying institution on the merits of IPR2026-00270, holding Sarepta had not shown a reasonable likelihood of prevailing on at least one challenged claim, without substantive reasoning (Venable's BiologicsHQ, blog post; mirrored on JD Supra). IP Verse likewise lists IPR2026-00270 as "Institution Denied," institution decision date July 21, 2026. The case metadata says "Awaiting an institution decision" only as of May 18, 2026, so this is a timing update rather than a metadata conflict — but the section should be corrected.
2. IPR2026-00166 was not "awaiting institution." The prior section describes IPR2026-00166 (the first '313-patent petition) as pending. The record shows Sarepta moved to withdraw it as prematurely filed under 35 U.S.C. § 311(c) — the Board authorized the motion on February 24, 2026, with Genzyme not opposing — and IP Verse lists IPR2026-00166 as terminated March 25, 2026. IPR2026-00270 (filed Feb. 26, 2026) is the refiled, § 311(c)-compliant replacement petition. The prior section's inference that "Sarepta has filed at least two IPRs against the '313 patent" is technically true but should be reframed as a withdrawal-and-refile, not two live challenges.

Minor correction to the prior "Defendant representatives" section

That section left firms "not explicitly stated" for Sharon K. Gagliardi, Jonathan D.J. Loeb, Katherine A. Helm, Martin J. Black, Amanda K. Antons and Noah M. Leibowitz. The signature blocks confirm all six are Dechert LLP (Antons in Lake Forest, IL; Helm, Black, Gagliardi and Leibowitz in New York/Philadelphia), with Dechert's Antons as lead counsel and Helm as provisionally recognized back-up counsel for Genzyme in the '313 patent IPRs.

I'll research Genzyme's counsel across the IPR and the parallel Delaware litigation.

Now let me pin down the actual counsel listing in the IPR2026-00270 docket and related '313 IPR.

Let me pull the IPR2026-00270 mandatory notice and confirm the full Genzyme PTAB team, plus verify the current case posture.

Defendant representatives — Genzyme Corp. (Patent Owner in the IPR; Plaintiff in D. Del.)

Threshold framing note. In IPR2026-00270 Genzyme is the patent owner / respondent, not a defendant in the conventional sense; the "defendant" label attaches to Sarepta in the co-pending Delaware suit. Genzyme's IPR team and its Delaware plaintiff team are drawn from the same core group, so I cover both. Contrary to the prior section's description of this IPR as "awaiting an institution decision," my searches indicate IPR2026-00270 was denied institution on July 21, 2026 by a Director-issued bulk order — see the contradiction flag at the end.

A. Counsel of record at the PTAB — IPR2026-00270

Docket backbone (PTAB docket, IPR2026-00270, petition filed 2/26/2026): Paper 4 (PO Power of Attorney, 3/19/2026); Paper 5 (PO Mandatory Notice, 3/19/2026); Paper 6 + Ex. 2001 (Helm back-up counsel notice, 3/23/2026); Paper 7 (Petitioner's Sotera stipulation, 3/24/2026). PTAB docket mirror

Same team in the companion '313 petition. In IPR2026-00166 (filed 12/2/2025, same patent), Genzyme's § 42.10(b) power of attorney dated 12/11/2025 names exactly the same trio: Antons (lead), Helm and Hackman (back-up), all Dechert. PO Power of Attorney, IPR2026-00166 Service certificates in that case list only Antons, Helm, and Hackman as counsel of record.

B. Genzyme's counsel in the parallel Delaware action (1:24-cv-00882, Judge Andrews)

Genzyme is plaintiff there; the same Dechert team runs the case with Delaware local counsel.

Sources: CourtListener docket/parties; Justia docket (PHV motions D.I. 5–12); PACER Monitor; service certificates reproduced on PTACTS (example, IPR2025-01194 filing).

C. Gaps and confidence

• No sealed or missing appearances identified on the PTAB side: the power of attorney and back-up counsel notice are public papers, and the trio above appears to be the complete counsel of record in IPR2026-00270.
• I could not verify whether the Board issued an objection to Dr. Helm's 3/23/2026 Notice of Intent (the Deputy Chief Clerk raised a § 42.10(c)(2) formatting objection to her equivalent notices in IPR2026-00149/00150 by email of 12/18/2025, requiring refiling within 5 business days). Treat Helm's status as provisionally recognized.
• I found no evidence Genzyme filed a Patent Owner Preliminary Response in IPR2026-00270 before the July 21, 2026 denial; the docket mirror I could access shows no POPR paper. This may simply be an indexing gap.
• The PTAB docket does not, in the entries I could retrieve, list any in-house attorney as counsel of record — Lisa Rasmussen appears only as the POA signatory.

D. Contradictions with the existing sections (flagged)

1. Status of IPR2026-00270. The metadata/status line and the prior "Key legal developments" section say the IPR is "awaiting an institution decision." Venable's BiologicsHQ reports that on July 21, 2026 the Director issued a bulk order denying institution on the merits, finding no reasonable likelihood of prevailing on any challenged claim (no substantive reasoning given), following the earlier denials in IPR2026-00167 and IPR2026-00168. IP Verse likewise lists IPR2026-00270 as "Institution Denied." Venable BiologicsHQ. Per your operating rules I have not overwritten the metadata, but the metadata appears stale as of today's date.
2. IPR2026-00166 is not pending. The prior section lists it as "awaiting an institution decision." In fact Sarepta sought and obtained authorization to withdraw the petition on the ground that it was filed prematurely — before the nine-month post-issuance period for the '313 claims had run (Board email of 2/24/2026; Genzyme did not oppose) — and IP Verse records a termination date of 3/25/2026. That withdrawal explains why the '313 challenge was re-filed as IPR2026-00270 on 2/26/2026.
3. Petitioner-side roster is incomplete in the prior section. A PHV motion filed 8/28/2026 (D.I. 247) adds Fish & Richardson attorneys to Sarepta's Delaware defense — Michael A. Morin, David P. Frazier, Rebecca L. Rabenstein, Rosalynd Upton, Alessandra My-Linh Schaschberger, Michele D. Johnson, Rachel R. Blitzer, Herman H. Yue, Denise Laspina, Sophia Lam, Sahil Agrawal, Yi Sun, and Daniel Hemming — none of whom appear in the earlier "Plaintiff representatives" list. Also, the Quinn Emanuel associate's surname appears as both "Fernands" and "Fernandes" across filings; the service certificates use "Anastasia M. Fernands."