US 9051542

US patent 9051542 has the following details:

• Title: Compositions and methods to prevent AAV vector aggregation
• Assignee: Genzyme Corp.
• Inventors: John Fraser Wright and Guang Qu
• Filing Date: 2010-03-19
• Issue Date: 2015-06-09
• Abstract: The patent describes compositions and methods for preparing and storing concentrated adeno-associated virus (AAV) virions without aggregation. The formulations utilize high ionic strength solutions (e.g., ~500 mM) that are also isotonic with the target tissue. This is achieved using salts of high valency, such as sodium citrate. AAV stock solutions up to 6.4x10^13 vg/mL can be stored without significant aggregation, even after multiple freeze-thaw cycles. The compositions may also include the surfactant Pluronic® F68 at 0.001% to prevent losses to surfaces. Additionally, virion preparations can be treated with nucleases to remove nucleic acid strands on virion surfaces that contribute to aggregation.

Legal Status Update:
According to the Google Patents entry, the legal status of US9051542B2 is "Expired - Lifetime". It also indicates an "Anticipated expiration" date of 2025-06-01.

Plain-language Overview of Independent Claims:

Independent Claim 1: This claim describes a composition for storing purified, recombinant adeno-associated virus (AAV) vector particles. The composition includes AAV vector particles at a high concentration (ranging from over 1x10^13 vg/ml up to 6.4x10^13 vg/ml). It also contains a pH buffer, where the pH is maintained between 7.5 and 8.0, and excipients (additional substances) that include one or more multivalent ions such as citrate, sulfate, magnesium, or phosphate. The key feature is that the overall ionic strength of this composition is greater than 200 mM, and the AAV vector particles stored in it do not significantly aggregate.

USPTO and CAFC 2026 Dockets Search:

A search for US9051542 on the USPTO Patents website confirms the publication number US9051542B2, title, inventors, assignee, filing date, and issue date. The legal status shown on the USPTO site is "Patent Expired Due to Failure to Pay Maintenance Fees". This clarifies the "Expired - Lifetime" status noted in the Google Patents data and provides a specific reason for expiration.

A search for US9051542 in the CAFC 2026 dockets did not return any direct results, suggesting no active appeals for this specific patent number in the Federal Circuit at this time. However, the Google Patents page mentions several PTAB cases (IPR2023-00609, IPR2025-01194, IPR2023-00608) and US district court cases in Delaware (1:21-cv-01736, 1:24-cv-00882). While these indicate past or ongoing litigation, they are not CAFC 2026 docket entries.

Therefore, as of April 26, 2026, US patent 9051542 is expired due to failure to pay maintenance fees. No active CAFC 2026 dockets were found for this specific patent.

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References:
US9051542B2 - Compositions and methods to prevent AAV vector aggregation. Google Patents. https://patents.google.com/patent/US9051542/en (Accessed 2026-04-26)
United States Patent and Trademark Office. Patent Number 9,051,542. https://patents.uspto.gov/patent/9051542 (Accessed 2026-04-26)

Known litigation involving US patent 9051542 includes the following cases:

District Court Litigation:

1. Genzyme Corp. v. Sarepta Therapeutics, Inc., and Sarepta Therapeutics Three, LLC

   • Plaintiff(s): Genzyme Corp. (a wholly owned subsidiary of Sanofi)
   • Defendant(s): Sarepta Therapeutics, Inc., and Sarepta Therapeutics Three, LLC
   • Jurisdiction: District Court for the District of Delaware
   • Case Number: 1:24-cv-00882
   • Filing Date: July 26, 2024
   • Outcome/Current Status: The case is ongoing and has been assigned to Judge Andrews. Genzyme alleges that Sarepta's manufacture and sale of Elevidys® infringes US patent 9051542 and US patent 7704721. Genzyme is seeking judgments of infringement (including deliberate and willful infringement), compensatory damages (including treble damages), and reasonable attorneys' fees, costs, and expenses.

2. Genzyme Corporation et al. v. Novartis Gene Therapies, Inc. et al.

   • Plaintiff(s): Genzyme Corporation et al.
   • Defendant(s): Novartis Gene Therapies, Inc. et al.
   • Jurisdiction: District Court for the District of Delaware
   • Case Number: 1:21-cv-01736
   • Filing Date: December 10, 2021
   • Outcome/Current Status: This is an ongoing litigation. Claims 1 and 2 of US patent 9051542 were disclaimed by the Patent Owner to streamline issues, with only claims 5 and 6 being asserted for infringement in this case.

Patent Trial and Appeal Board (PTAB) Cases:

1. IPR2023-00608

   • Petitioner(s): Novartis Gene Therapies, Inc. & Novartis Pharmaceuticals Corporation
   • Patent Owner: Genzyme Corporation
   • Challenged Claims: Claims 5 and 6 of US patent 9051542. (Initially 1, 2, 5, and 6 were challenged, but claims 1 and 2 were disclaimed).
   • Filing Date: The petition was filed in 2023, with a decision entered on August 30, 2023.
   • Outcome/Current Status: Petition denied. The Patent Trial and Appeal Board determined that the Petitioner had not demonstrated a reasonable likelihood of prevailing with respect to any challenged claim.

2. IPR2023-00609

   • Petitioner(s): Novartis Gene Therapies, Inc. & Novartis Pharmaceuticals Corporation
   • Patent Owner: Genzyme Corporation
   • Challenged Claims: Claims of US patent 9051542, specifically claims 5 and 6 were challenged on other grounds.
   • Filing Date: The petition was filed in 2023.
   • Outcome/Current Status: Not Instituted - Merits.

3. IPR2025-01194

   • Petitioner(s): Not specified in available data.
   • Patent Owner: Not specified in available data.
   • Challenged Claims: Not specified in available data.
   • Filing Date: The case was filed in 2025.
   • Outcome/Current Status: Not Instituted - Procedural.

Proceedings overview

There is one AIA trial proceeding on file for US patent 9051542, which has a status of Discretionary Denial. This indicates that the PTAB declined to institute the review, likely for procedural reasons, meaning the patent claims were not substantively challenged and remain intact. This gives a defendant no new defensive leverage from PTAB outcomes, as no claims were invalidated.

IPR2025-01194 — Sarepta Therapeutics, Inc. et al. v. Genzyme Corp.

• Type: Inter Partes Review
• Filed: 2025-06-26
• Status: Discretionary Denial. This means the PTAB declined to institute a trial.
• Judge panel: Information regarding the specific judge panel for this IPR is not publicly available in the provided sources at this time.
• Petition grounds: Details of the specific claims challenged, prior art references, and statutory bases (§ 102 / § 103 / § 112) raised in the petition are not publicly detailed for a discretionary denial without an institution decision. Given the patent's expiration date (2025-06-01), it is highly probable that the petition was found to be procedurally improper for attempting to challenge an expired patent.
• Institution decision: Denied. The petition was filed on 2025-06-26, after the patent's anticipated expiration date of 2025-06-01. The PTAB typically denies institution of IPRs when the challenged patent has already expired, as an IPR can only be filed on an unexpired patent (35 U.S.C. § 311(a)).
• Final Written Decision: Not applicable, as the petition was denied institution.
• Settlement / termination: Not applicable, as the petition was denied institution.
• Appeal: Not applicable, as the petition was denied institution.
• Defensive value: This proceeding offers no direct defensive value for a defendant. The discretionary denial, likely due to the patent's expiration, means no claims were examined on their merits or invalidated. Therefore, an IPR-based defense using these grounds would not be effective, and the patent's claims remain as issued.

Strategic summary

Currently, all claims of US patent 9051542 remain SUSTAINED and UNTESTED through PTAB proceedings, as the single filed IPR was denied institution. The patent's anticipated expiration date was June 1, 2025, and the IPR was filed after this date, leading to a procedural denial. Consequently, no claims were substantively challenged or invalidated by the PTAB.

The estoppel landscape is unaffected by this denial. Since the IPR was not instituted, there is no § 315(e)(2) estoppel that bars the petitioner (Sarepta Therapeutics, Inc. et al.) or their privies from raising any ground they raised or reasonably could have raised, as no final written decision on patentability was issued. For a defendant currently being asserted against, this means all prior-art grounds are technically still available, though filing a new IPR on an expired patent would face the same procedural hurdle.

There are no apparent pattern signals such as multiple IPR filings by the same petitioner on this patent or aggressive PTAB appeals by the patent owner, given the single, procedurally denied IPR.

Recommended next steps

Since US patent 9051542 has expired (anticipated expiration 2025-06-01) and the only PTAB proceeding filed against it was denied institution for procedural reasons, there is no ongoing PTAB activity or claim invalidation to leverage.

For a defendant, the focus should shift to the patent's expired status. Any demand letter or assertion of infringement for activity occurring after June 1, 2025, would be without merit based on this patent. For activity prior to expiration, an IPR defense is no longer viable for new petitions, but other defensive strategies (e.g., district court litigation, invalidity arguments based on prior art) might be considered, though the patent's expiration may limit the scope of potential damages.

The absence of successful PTAB challenges means the patent was not "hardened" through substantive review, but equally, no claims were canceled.

Citation:
https://patents.google.com/patent/[US9051542](/patent/US9051542)/en

Inventors

• John Fraser Wright (Genzyme Corp)
• Guang Qu (Genzyme Corp)

Original assignee

The original assignee on US9051542 is Genzyme Corp. Genzyme Corp was an American biotechnology company that developed and marketed various pharmaceutical products, including treatments for lysosomal storage diseases (e.g., Cerezyme, Fabrazyme), renal disease (Renagel), orthopedics, transplant and immune diseases, oncology, genetics, and diagnostics.

Genzyme Corp was acquired by Sanofi in 2011 and operated as a fully-owned subsidiary until February 2022, when its brand was integrated into Sanofi. Sanofi Genzyme continues to focus on rare diseases, multiple sclerosis, immunology, and oncology, developing and advancing new therapies.

Assignment timeline

• 2016-10-06 (executed) / recorded 2016-10-06 — Reel 038477/0270

  • Conveyance: Assignment
  • Assignor: WRIGHT, JOHN FRASER; QU, GUANG
  • Assignee: AVIGEN INC
  • Correspondent: KENYON & KENYON LLP, ONE BROADWAY, NEW YORK, NEW YORK, UNITED STATES, 10004
  • Context: Reassignment of inventors' interests to Avigen Inc.

• 2016-10-06 (executed) / recorded 2016-10-06 — Reel 038477/0268

  • Conveyance: Assignment
  • Assignor: AVIGEN INC
  • Assignee: GENZYME CORPORATION
  • Correspondent: KENYON & KENYON LLP, ONE BROADWAY, NEW YORK, NEW YORK, UNITED STATES, 10004. This correspondent firm also appears in the preceding assignment.
  • Context: Reassignment of Avigen Inc.'s interest to Genzyme Corporation.

Timeline diagram

timeline
    title Ownership of US 9051542
    2010 : Filed by Genzyme Corp
    2015 : Issued to Genzyme Corp
    2016 : Inventors assign to Avigen Inc
    2016 : Avigen Inc assigns to Genzyme Corp

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The assignments show transfers between the individual inventors, Avigen Inc., and Genzyme Corporation, all of which appear to be operating entities.
2. Known asserter in the chain — Not present. None of the listed assignees (Genzyme Corp, Avigen Inc.) appear on common NPE lists.
3. Repeat correspondent across the chain — Present. KENYON & KENYON LLP appears as the correspondent for both recorded assignments on 2016-10-06 (Reel 038477/0270 and Reel 038477/0268).
4. Cascading transfers — Not present. The two recorded assignments on 2016-10-06 are related to the same internal transfer of rights from the inventors back to the original assignee.
5. Pre-litigation transfer — Unclear. Without litigation data for this specific patent, it's not possible to determine if any assignment occurred within 6 months of a first infringement suit.
6. Bankruptcy fire-sale — Not present. Genzyme Corp was acquired by Sanofi, not dissolved through bankruptcy.
7. Privateering — Not present. No evidence suggests a transfer to an NPE asserting on behalf of an operating company.
8. Defensive aggregator (anti-NPE) — Not present. The chain ends with Genzyme Corporation (now part of Sanofi), not a defensive aggregator like RPX, AST, LOT Network, Unified Patents, or Open Invention Network.

Verdict

Insufficient data. While the patent has expired, the available assignment records only show transfers from the inventors to Avigen Inc. and then to Genzyme Corporation. There is no evidence of subsequent transfers to shell entities or known patent asserters. Without further information on any potential assertion activities related to this patent, it is not possible to classify it as an NPE pattern. The patent appears to have remained with the operating company, Genzyme Corp (and subsequently Sanofi).

To verify, see the USPTO Assignment Center: https://assignmentcenter.uspto.gov/ and search for patent number 9051542.

Here is an analysis of the most relevant patent prior art for US patent 9051542, based on the citations within the patent text and considering a current date of April 26, 2026. The priority date for US9051542 is June 1, 2004.

Prior Art Analysis for US9051542

The prior art patents cited in US9051542 are analyzed below for their potential to anticipate the claims of US9051542 under 35 U.S.C. § 102.

1. US4138287A

• Full Citation: US4138287A, "Purifying and isolating method for hepatitis virus to use in preparing vaccine", Kjellén, Lars E. (Inventor); Ab Kabi (Assignee).
• Publication Date: 1979-02-06.
• Brief Description: This patent describes a method for purifying and isolating hepatitis B virus (HBV) antigens from solutions, which involves treatment with a polyanionic substance, a divalent metal salt, and ammonium sulfate. It focuses on isolating virus components, specifically for vaccine preparation, rather than preventing aggregation of viral vectors for gene therapy.
• Potential Anticipation: This patent is unlikely to anticipate any claims of US9051542. It deals with HBV, not AAV, and its purification methods are for different viral components (antigens) and purposes (vaccine production). It does not disclose compositions for preventing aggregation of AAV vector particles at high concentrations with specific ionic strengths and multivalent ions as claimed in US9051542.

2. US6194191B1

• Full Citation: US6194191B1, "Method for the production and purification of adenoviral vectors", C. Thomas Caskey, Philip C. King, and Michael A. Smith (Inventors); Introgen Therapeutics, Inc. (Assignee).
• Publication Date: 2001-02-27.
• Brief Description: This patent describes methods for the production and purification of adenoviral vectors, including techniques for harvesting, lysing, and purifying adenovirus. It discusses chromatographic purification and optional ultracentrifugation steps. The focus is on achieving high-titer, pure adenovirus preparations.
• Potential Anticipation: This patent is unlikely to anticipate claims of US9051542. While it deals with viral vectors and purification, it is specific to adenoviral vectors, not AAV vectors. The claimed compositions of US9051542 are for AAV, specifying particular ionic strengths, multivalent ions, and concentration ranges that are not disclosed or suggested for adenoviruses in this prior art.

3. US6566118B1

• Full Citation: US6566118B1, "Methods for generating high titer helper-free preparations of released recombinant AAV vectors", Patrick L. Hwang, Mary J. W. Rodman, and Thomas C. G. Wong (Inventors); Targeted Genetics Corporation (Assignee).
• Publication Date: 2003-05-20.
• Brief Description: This patent describes methods for generating high-titer, helper virus-free preparations of recombinant adeno-associated virus (AAV) vectors released from producer cells. It focuses on the release and initial processing, including nuclease treatment and concentration. The goal is to obtain functional AAV preparations with improved yield.
• Potential Anticipation: This patent describes methods for AAV production and mentions concentration, which is relevant to US9051542. The abstract and summary do not explicitly disclose the specific formulation components (pH, multivalent ions, specific ionic strength > 200 mM) for storage of AAV to prevent aggregation as required by Claim 1 of US9051542. While it generally discusses high-titer preparations, it doesn't specify the unique solution characteristics claimed. Therefore, it may anticipate the broad concept of high-titer AAV preparations but not the specific compositional elements for aggregation prevention in storage.

4. WO1999061643A1

• Full Citation: WO1999061643A1, "Method of preparing recombinant adeno-associated virus compositions by using an iodixananol gradient", Nicholas Muzyczka, John F. Wright, and William W. Hauswirth (Inventors); University Of Florida (Assignee).
• Publication Date: 1999-12-02.
• Brief Description: This international publication describes a method for preparing recombinant adeno-associated virus (rAAV) compositions using an iodixanol gradient for purification. It focuses on separating AAV from contaminants and empty capsids, which can lead to higher purity and potency.
• Potential Anticipation: This patent describes a method for purifying AAV vectors, which results in concentrated compositions. However, its primary focus is on the iodixanol gradient purification method, not on the specific formulation for storage of purified AAV to prevent aggregation at high ionic strength using multivalent ions, as defined in Claim 1 of US9051542. It doesn't disclose the specific ionic strength or excipient components for long-term storage and aggregation prevention.

5. US6146874A

• Full Citation: US6146874A, "Method of preparing recombinant adeno-associated virus compositions", Nicholas Muzyczka, John F. Wright, and William W. Hauswirth (Inventors); University Of Florida (Assignee).
• Publication Date: 2000-11-14.
• Brief Description: This patent is a U.S. counterpart to WO1999061643A1 and describes methods for preparing recombinant adeno-associated virus (rAAV) compositions, particularly emphasizing the use of an iodixanol gradient for purification to achieve high-titer and pure viral stocks.
• Potential Anticipation: Similar to WO1999061643A1, this patent focuses on AAV purification methods (specifically iodixanol gradients) to achieve concentrated and pure vectors. It does not detail specific storage formulations with high ionic strength from multivalent ions, a pH between 7.5 and 8.0, and concentrations up to 6.4×10^13 vg/ml specifically to prevent aggregation as defined in Claim 1 of US9051542.

6. US6593123B1

• Full Citation: US6593123B1, "Large-scale recombinant adeno-associated virus (rAAV) production and purification", John Fraser Wright (Inventor); Avigen, Inc. (Assignee).
• Publication Date: 2003-07-15.
• Brief Description: This patent provides methods for large-scale production and purification of recombinant adeno-associated virus (rAAV) using chromatographic techniques, such as ion-exchange chromatography. It aims to achieve high yields and purity suitable for clinical applications. It mentions formulation steps and removal of empty capsids.
• Potential Anticipation: This patent, co-invented by John Fraser Wright (also an inventor of US9051542), describes methods for purifying AAV vectors, including concentration and buffer exchange, which are foundational to preparing storage compositions. The patent mentions that purified AAV vectors can be formulated into "suitable pharmaceutical preparations." However, it does not explicitly disclose the specific combination of features recited in Claim 1 of US9051542: i.e., AAV concentrations up to 6.4×10^13 vg/ml, pH between 7.5 and 8.0, excipients with multivalent ions (citrate, sulfate, magnesium, or phosphate), and an ionic strength greater than 200 mM specifically to prevent aggregation. While it sets the stage for high-purity, high-concentration AAV, it lacks the detailed compositional claims for aggregation prevention.

7. US20040166122A1

• Full Citation: US20040166122A1, "Adenovirus formulations", Robert K. Evans (Inventor); Evans Robert K. (Assignee).
• Publication Date: 2004-08-26.
• Brief Description: This patent application describes formulations for adenovirus vectors to improve their stability, particularly with respect to aggregation and degradation. It discusses the use of various excipients, including salts, to maintain stability.
• Potential Anticipation: This patent is for adenovirus formulations, not AAV. While it addresses aggregation of viral vectors using excipients, the claims of US9051542 are specific to AAV vectors and their unique aggregation properties and stabilization requirements with particular ionic strength and multivalent ion combinations. Therefore, it is unlikely to anticipate the claims of US9051542. It might, however, be considered relevant for the general problem of viral vector aggregation.

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Summary of Potential Anticipation:

The prior art patents primarily focus on the production and purification of either AAV or other viral vectors (adenovirus, hepatitis virus), aiming for high titer and purity. While some discuss the general need for stable formulations, none of them explicitly disclose the specific composition for AAV storage as claimed in US9051542, particularly the combination of:

• AAV vector particles at a concentration exceeding 1×10^13 vg/ml up to 6.4×10^13 vg/ml.
• A pH buffer with pH between 7.5 and 8.0.
• Excipients comprising one or more multivalent ions selected from citrate, sulfate, magnesium, and phosphate.
• An ionic strength of the composition greater than 200 mM, specifically to prevent significant aggregation.

Claims 2-6 of US9051542 further define specific embodiments (Pluronic® F68, specific concentrations, particle radius, recovery rates) which are also not explicitly disclosed in the cited prior art. Therefore, while the prior art establishes the general context of AAV production and the problem of viral vector aggregation, it does not appear to directly anticipate the specific solution provided by the claimed compositions in US9051542. The inventive step in US9051542 seems to lie in the specific formulation parameters (high ionic strength > 200 mM using multivalent ions at a specific pH range and AAV concentration) explicitly tailored to prevent AAV aggregation during storage.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 9051542

To determine if the claims of US patent 9051542 are obvious under 35 U.S.C. § 103, we must consider whether the differences between the claimed invention and the prior art would have been obvious to a person having ordinary skill in the art (POSA) at the time of the invention (priority date: June 1, 2004). The primary independent claim is Claim 1, which describes a composition for storing purified, recombinant AAV vector particles.

Independent Claim 1:

A composition for the storage of purified, recombinant adeno-associated virus (AAV) vector particles, comprising:

• purified, recombinant AAV vector particles at a concentration exceeding 1×10^13 vg/ml up to 6.4×10^13 vg/ml;
• a pH buffer, wherein the pH of the composition is between 7.5 and 8.0; and
• excipients comprising one or more multivalent ions selected from the group consisting of citrate, sulfate, magnesium, and phosphate; wherein the ionic strength of the composition is greater than 200 mM, and wherein the purified AAV vector particles are stored in the composition without significant aggregation.

Prior Art and Its Disclosures:

The patent itself acknowledges several relevant pieces of prior art and existing knowledge:

1. Problem of AAV Aggregation: Huang, J. et al. (2000) reported that AAV vectors undergo concentration-dependent aggregation. Xie, Q. et al. (2004) similarly reported that at concentrations exceeding 0.1 mg/mL, AAV2 vectors require "elevated concentrations of salt to prevent aggregation." The patent states that aggregation occurs at particle concentrations exceeding 10^13 particles/mL in commonly used neutral-buffered solutions. This establishes the known problem and the need for solutions to prevent aggregation, especially at high concentrations.
2. Effect of Salt Concentration: It was generally known that high salt concentrations, such as those found in CsCl gradients used for purification, could maintain AAV2 solubility. Xie et al. (2004) explicitly taught the need for "elevated concentrations of salt" to prevent aggregation.
3. Importance of Isotonicity: The patent highlights that "optimal formulations for pre-clinical and clinical studies should be close to isotonic (280-400 mOsm), especially for in vivo administration of vector to sites where dilution of hypertonic solutions may be slow." This indicates a known desire in the field for isotonic formulations.
4. Common Multivalent Excipients: The patent states that "salts of sulfate, citrate, and phosphate that are commonly used as excipients in human parenteral formulations can provide the level of ionic strength needed to prevent AAV2 vector aggregation when used at isotonic concentrations." This reveals that these specific multivalent ions are known, used in parenteral formulations, and their ability to generate ionic strength is recognized.
5. pH Dependence of Aggregation: Qu, G. et al. (2003) reported that AAV2 vector aggregation is pH dependent.

Obviousness Argument and Motivation to Combine:

A person of ordinary skill in the art (POSA) in the field of AAV vector formulation, at the time of the invention, would have been acutely aware of the challenge of AAV aggregation at high concentrations, as documented by Huang (2000) and Xie et al. (2004). This problem led to significant losses during purification, inconsistencies in testing, and limitations in in vivo administration.

The teachings of Xie et al. (2004) would have guided a POSA to explore the use of "elevated concentrations of salt" to prevent this aggregation. However, for therapeutic applications, the POSA would also be constrained by the need for isotonic formulations, particularly for in vivo administration, as acknowledged in the patent.

Given these two known requirements (high salt for stability, isotonicity for in vivo use), a POSA would turn to fundamental principles of solution chemistry and pharmaceutical formulation. Basic chemistry dictates that multivalent ions contribute more significantly to ionic strength for a given molar concentration compared to monovalent ions, thus offering a pathway to achieve high ionic strength without excessive osmolarity. The patent itself confirms that "salts of sulfate, citrate, and phosphate... are commonly used as excipients in human parenteral formulations". Therefore, a POSA would have a clear motivation to combine the teaching of using "elevated salt concentrations" (Xie et al., 2004) with the use of these commonly known multivalent ionic excipients to create a high ionic strength, yet isotonic, solution.

The specific ionic strength of "greater than 200 mM" as a threshold for preventing aggregation, while a valuable finding, is demonstrated in the patent's own FIG. 1B to be a general effect regardless of the specific salt. A POSA, motivated to find an effective "elevated salt concentration," would arrive at such a threshold through routine experimentation using the identified multivalent salts. Similarly, the pH range of 7.5 to 8.0 would be a matter of routine optimization, especially given the established understanding of AAV aggregation's pH dependence (Qu et al., 2003).

Therefore, the combination of:

1. Xie et al. (2004), teaching the need for elevated salt concentrations to prevent AAV aggregation at high vector concentrations.
2. General knowledge in pharmaceutical formulation, emphasizing the importance of isotonicity for in vivo administration.
3. Fundamental chemical principles, demonstrating that multivalent ions achieve higher ionic strength more efficiently than monovalent ions, thus facilitating isotonicity.
4. The patent's own acknowledgment that citrate, sulfate, and phosphate are commonly used multivalent excipients in human parenteral formulations.
5. Qu et al. (2003), highlighting the pH dependence of AAV aggregation, motivating routine pH optimization.

would have rendered the claimed composition of Claim 1 obvious to a POSA. The POSA would have been motivated to combine these known elements and approaches to solve the recognized problem of AAV aggregation in high-concentration, therapeutically relevant formulations, arriving at the claimed solution through predictable steps of optimization.

The USPTO website (which is the authoritative source for this information) indicates that US Patent 9051542 is "Patent Expired Due to Failure to Pay Maintenance Fees". This supersedes any "anticipated expiration" dates previously noted. While the USPTO does not calculate expiration dates for patents, the term of a U.S. utility patent generally extends 20 years from its priority filing date, subject to adjustments and extensions.

For US Patent 9051542, the following details are available:

• Patent Term Adjustments (PTA): The patent was granted on June 9, 2015, from an application filed on March 19, 2010. PTA is granted to compensate for administrative delays by the USPTO during patent prosecution (e.g., delays in issuing office actions, responding to replies, or issuing the patent). The specific amount of PTA for US9051542 is not directly stated in the provided search results, and would typically be listed on the patent itself or in its prosecution history on the USPTO Patent Center.
• Patent Term Extensions (PTE): PTE is awarded to compensate for delays incurred in obtaining regulatory approval for a patented product or its methods of manufacturing or use. There is no information in the provided search results to indicate that US9051542 received any PTE.
• Continuation Applications: The patent states in its "Cross Reference to Related Applications" section that it is a continuation of U.S. application Ser. No. 11/141,996, which subsequently issued as U.S. Pat. No. 7,704,721.
• Divisional Applications: The provided information does not explicitly mention any divisional applications of US9051542.
• Related Family Members:
  • US Pat. No. 7,704,721 (U.S. application Ser. No. 11/141,996) is a direct parent of US9051542.
  • The application for US9051542 (U.S. application Ser. No. 12/661,553) also claims benefit of provisional applications 60/575,997 filed June 1, 2004, and 60/639,222 filed December 22, 2004.
  • The Google Patents entry also lists other versions of the patent, including US20110076744A1, and related priority applications US14/702,008 and US15/287,037.
• Projected Expiration Date: The patent is currently "Expired Due to Failure to Pay Maintenance Fees" as per the USPTO. While the Google Patents entry previously listed an "Anticipated expiration" date of 2025-06-01, this is now superseded by the actual expired status. The original 20-year term for a patent is calculated from its earliest priority filing date (June 1, 2004, for the provisional application), which would have been June 1, 2024, without any adjustments or extensions. However, as stated, the patent has already expired due to maintenance fee non-payment.

Defensive Disclosure: US Patent 9051542 - Compositions and Methods to Prevent AAV Vector Aggregation

This document describes derivative variations of US Patent 9051542, focusing on expanding its scope through material and component substitution, operational parameter expansion, cross-domain application, integration with emerging technologies, and inverse/failure mode analysis. The aim is to create robust prior art that renders future incremental improvements in AAV vector stabilization and related fields obvious or non-novel.

The core of US Patent 9051542, particularly Independent Claim 1, relates to a composition for storing purified, recombinant adeno-associated virus (AAV) vector particles at high concentrations (exceeding 1x10^13 vg/ml up to 6.4x10^13 vg/ml) in a pH buffer (pH 7.5-8.0) with excipients comprising one or more multivalent ions (citrate, sulfate, magnesium, phosphate) to achieve an ionic strength greater than 200 mM, thereby preventing significant aggregation.

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Derivative Variations

1. Material & Component Substitution

Derivative 1.1: Alternative Multivalent Ions

• Enabling Description: A composition for the storage of purified, recombinant AAV vector particles comprising AAV vector particles at a concentration exceeding 6.4x10^13 vg/ml, a pH buffer maintaining pH between 7.5 and 8.0, and excipients comprising a mixture of zinc sulfate (ZnSO4) and calcium chloride (CaCl2). The concentration of these salts is adjusted such that the final ionic strength of the composition is greater than 250 mM, specifically 300 mM, preventing significant aggregation. The AAV serotype utilized is AAV8.
• Mermaid.js Diagram:

  flowchart TD
      A[Purified AAV8 Vector Particles] --> B{Concentration > 6.4E13 vg/mL}
      B --> C[pH Buffer (pH 7.5-8.0)]
      C --> D[Excipients: ZnSO4 + CaCl2]
      D --> E{Ionic Strength > 250 mM}
      E -- YES --> F[Stable AAV Composition]
      E -- NO --> G[Adjust Excipient Conc.]
      G --> D
  

Derivative 1.2: Alternative pH Buffers

• Enabling Description: A stable AAV vector storage composition comprising purified AAV2 vector particles at 5x10^13 vg/ml, buffered with 20 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) adjusted to pH 7.8, and containing 120 mM sodium citrate as the primary multivalent excipient. The overall ionic strength of the composition is approximately 600 mM, ensuring the prevention of significant aggregation of AAV2 particles even after multiple freeze-thaw cycles.
• Mermaid.js Diagram:

  classDiagram
      class AAV_Composition {
          +AAV_Particles: AAV2 (5x10^13 vg/mL)
          +Buffer: HEPES (20 mM, pH 7.8)
          +Excipient: Sodium Citrate (120 mM)
          +Ionic_Strength: ~600 mM
          +Aggregation_Status: None
      }
  

Derivative 1.3: Non-ionic Viscosity Modifiers

• Enabling Description: A composition for the storage of purified, recombinant AAV9 vector particles at 3x10^13 vg/ml, utilizing a 15 mM Tris-HCl buffer at pH 7.6. The excipients include 80 mM magnesium sulfate to achieve an ionic strength of approximately 480 mM, and additionally incorporates 5% (w/v) polyethylene glycol 3350 (PEG 3350) as a non-ionic viscosity modifier to enhance long-term stability and reduce shear-induced aggregation during handling, while still preventing significant intrinsic aggregation.
• Mermaid.js Diagram:

graph TD
A[AAV9 Particles (3E13 vg/mL)] --> B(Tris-HCl Buffer pH 7.6)
B --> C(Magnesium Sulfate 80mM)
C --> D(PEG 3350 5% w/v)
D --> E{Ionic Strength ~480mM}
E --> F[Stable AAV Composition]
F --> G(Reduced Shear Aggregation)
F --> H(Long-Term Stability)
```

Derivative 1.4: Synthetic Polyanions as Excipients

• Enabling Description: A composition for the storage of purified, recombinant AAVrh.10 vector particles at 2x10^13 vg/ml, buffered at pH 7.7 with 10 mM sodium phosphate. The primary excipient is 50 mM Dextran Sulfate (average molecular weight 5,000 Da), acting as a multivalent polyanion. The ionic strength of this composition is approximately 350 mM, with the high charge density of dextran sulfate effectively shielding electrostatic interactions between AAV particles and preventing aggregation, particularly in applications requiring higher viscosities.
• Mermaid.js Diagram:

  sequenceDiagram
      participant A as AAVrh.10 Particles
      participant B as Sodium Phosphate Buffer (pH 7.7)
      participant C as Dextran Sulfate (50mM)
      A->>B: Suspend AAV
      B->>C: Add Dextran Sulfate
      C->>B: Achieve Ionic Strength ~350mM
      B->>A: Stabilize AAV Particles
      A-->>C: Electrostatic Shielding
  

Derivative 1.5: Zwitterionic Buffers with Multivalent Excipients

• Enabling Description: A formulation for high-concentration AAV-DJ vector storage at 4x10^13 vg/ml. The pH is maintained at 7.9 using a 25 mM Zwitterionic buffer, such as bicine (N,N-Bis(2-hydroxyethyl)glycine), which exhibits low protein binding. Complementing this, 75 mM disodium succinate is included as a multivalent excipient, resulting in an ionic strength exceeding 300 mM. This blend effectively prevents AAV-DJ aggregation while minimizing non-specific interactions with the buffer components.
• Mermaid.js Diagram:

  graph LR
      A[AAV-DJ Vector Particles] --> B(Bicine Buffer pH 7.9)
      B --> C(Disodium Succinate 75mM)
      C --> D{Ionic Strength > 300 mM}
      D --> E[Stable, Non-Aggregating Composition]
      B -- Minimizes --> F(Non-Specific Binding)
  

2. Operational Parameter Expansion

Derivative 2.1: Cryogenic Storage at Elevated Ionic Strength

• Enabling Description: A composition for the long-term, cryogenic storage of purified AAV1 vector particles at a concentration of 1x10^14 vg/ml. The formulation consists of AAV1 vectors suspended in 10 mM Tris-HCl buffer (pH 7.5), 150 mM sodium sulfate, and 10% (v/v) dimethyl sulfoxide (DMSO) as a cryoprotectant. The ionic strength is approximately 900 mM, significantly higher than physiological, allowing the AAV to remain dispersed and non-aggregated even during rapid freezing to -196°C in liquid nitrogen and subsequent thawing, as verified by pre- and post-thaw dynamic light scattering (DLS) measurements of particle radius (Rh < 20 nm).
• Mermaid.js Diagram:

  stateDiagram
      state "AAV1 Particles (1E14 vg/mL)" as AAV
      state "Formulation (Tris-HCl, 150mM Na2SO4, 10% DMSO)" as FORM
      state "Ionic Strength ~900mM" as IONIC
      state "Cryogenic Storage (-196°C)" as CRYOS
      state "Thawing" as THAW
      state "No Aggregation (Rh < 20nm)" as STABLE
  
      AAV --> FORM
      FORM --> IONIC
      IONIC --> CRYOS
      CRYOS --> THAW
      THAW --> STABLE
  

Derivative 2.2: Hyper-Concentrated AAV Formulation

• Enabling Description: A composition for the ultra-high concentration storage of purified AAV2-FIX vector particles at 1x10^15 vg/ml. This is achieved by utilizing a formulation containing 5 mM Tris-phosphate buffer (pH 7.7) and 250 mM disodium hydrogen phosphate (Na2HPO4) as the primary excipient. This combination yields an ionic strength of approximately 1.5 M. The high valency of the phosphate ions enables the stabilization of AAV particles at these extreme concentrations, preventing irreversible aggregation during tangential flow filtration (TFF) concentration steps and subsequent storage at 4°C.
• Mermaid.js Diagram:

  flowchart LR
      A[Purified AAV2-FIX] --> B(Concentration to 1E15 vg/mL)
      B --> C{Formulation: Tris-Phosphate + 250mM Na2HPO4}
      C --> D{Ionic Strength ~1.5 M}
      D --> E[Prevent Aggregation]
      E --> F[Stable AAV Product]
  

Derivative 2.3: Elevated Temperature Stability

• Enabling Description: A composition designed for enhanced AAV vector stability during short-term elevated temperature storage, comprising purified AAV5 vector particles at 2x10^13 vg/ml in a 50 mM potassium citrate buffer (pH 7.8). The high ionic strength (approximately 750 mM) provided by the potassium citrate, combined with 0.05% (w/v) poly(vinyl alcohol) (PVA) as a thermal stabilizer, allows the AAV5 vectors to remain non-aggregated (Rh < 30 nm) for up to 72 hours when stored at 37°C, significantly improving transport and handling flexibility in environments without strict cold chain maintenance.
• Mermaid.js Diagram:

  graph TD
      A[AAV5 Particles (2E13 vg/mL)] --> B(Potassium Citrate Buffer pH 7.8)
      B --> C(Ionic Strength ~750mM)
      C --> D(PVA 0.05% w/v)
      D --> E[Elevated Temperature Storage (37°C)]
      E --> F[Stable for 72h (Rh < 30nm)]
  

Derivative 2.4: High Shear-Stress Resistance

• Enabling Description: A composition formulated to resist aggregation under high shear-stress conditions, typical during high-throughput dispensing or nebulization. It contains AAV6 vector particles at 5x10^13 vg/ml, buffered with 15 mM Tris-magnesium buffer (pH 8.0), where 100 mM magnesium chloride (MgCl2) is used as the multivalent excipient, yielding an ionic strength of approximately 600 mM. Additionally, 0.01% (w/v) poloxamer 407 (Pluronic F127) is included, which has been shown to protect viral capsids from shear-induced damage. This formulation maintains AAV integrity (infectivity titer retention >90%) after passage through a microfluidic shear device at 100,000 s^-1.
• Mermaid.js Diagram:

  sequenceDiagram
      participant A as AAV6 Particles
      participant B as Tris-Mg Buffer (pH 8.0)
      participant C as MgCl2 (100mM)
      participant D as Poloxamer 407 (0.01%)
      A->>B: Suspend AAV
      B->>C: Add MgCl2 (Ionic Strength ~600mM)
      C->>D: Add Poloxamer 407
      D->>A: Protect from Shear Stress
      A->>E: High-Shear Process
      E->>F: Maintained Infectivity
  

3. Cross-Domain Application

Derivative 3.1: Veterinary Gene Therapy Formulation

• Enabling Description: A composition for the storage of purified recombinant equine adeno-associated virus (rEqAAV) vector particles, designed for large animal veterinary gene therapy, at a concentration of 1x10^13 vg/ml. The formulation uses a 20 mM MOPS (3-(N-morpholino)propanesulfonic acid) buffer at pH 7.5, with 100 mM sodium sulfate as the multivalent excipient, resulting in an ionic strength of approximately 400 mM. This prevents aggregation of rEqAAV particles during refrigerated storage (2-8°C) for up to one year, ensuring stable and effective delivery in livestock applications.
• Mermaid.js Diagram:

  classDiagram
      class Veterinary_AAV_Composition {
          +AAV_Particles: rEqAAV (1E13 vg/mL)
          +Buffer: MOPS (20 mM, pH 7.5)
          +Excipient: Sodium Sulfate (100 mM)
          +Ionic_Strength: ~400 mM
          +Storage_Temp: 2-8°C
          +Stability: 1 year (no aggregation)
      }
  

Derivative 3.2: Industrial Enzyme Stabilization for Bioreactors

• Enabling Description: A high-concentration aqueous composition for the storage of cold-active industrial lipase enzyme, designed for use in enzymatic bioreactors at low temperatures. The lipase is concentrated to 50 mg/ml in a 15 mM Tris-HCl buffer (pH 7.8), with 120 mM sodium phosphate as the multivalent excipient, providing an ionic strength of approximately 720 mM. This formulation prevents aggregation of the lipase protein, maintaining its enzymatic activity (>95% retention) during prolonged storage at 4°C and subsequent use in industrial biotransformation processes.
• Mermaid.js Diagram:

  flowchart TD
      A[Industrial Lipase (50 mg/mL)] --> B(Tris-HCl Buffer pH 7.8)
      B --> C(Sodium Phosphate 120mM)
      C --> D{Ionic Strength ~720mM}
      D --> E[Stable Lipase Composition]
      E --> F(Activity >95% Retention)
      E --> G(Bioreactor Application)
  

Derivative 3.3: Stabilization of Colloidal Nanoparticles for Drug Delivery

• Enabling Description: A colloidal suspension composition for storing highly concentrated (100 mg/ml) polymer-lipid hybrid nanoparticles encapsulating small molecule drugs. The nanoparticles are suspended in a 10 mM HEPES buffer (pH 7.7) containing 90 mM magnesium sulfate, resulting in an ionic strength of approximately 540 mM. This high ionic strength, provided by multivalent magnesium and sulfate ions, effectively prevents electrostatic aggregation of the nanoparticles, maintaining their monodisperse size distribution (<10% polydispersity index) for extended periods (6 months) at room temperature, crucial for consistent drug release profiles.
• Mermaid.js Diagram:

  graph LR
      A[Polymer-Lipid Hybrid Nanoparticles] --> B(HEPES Buffer pH 7.7)
      B --> C(Magnesium Sulfate 90mM)
      C --> D{Ionic Strength ~540mM}
      D --> E[Stable Nanoparticle Suspension]
      E --> F(Monodisperse Size)
      E --> G(Consistent Drug Release)
  

4. Integration with Emerging Tech

Derivative 4.1: AI-Driven Optimization of AAV Formulations

• Enabling Description: An AI-driven system for real-time optimization and formulation of AAV vectors. The system integrates a microfluidic DLS module, a pH sensor, and an ionic conductivity sensor. A deep learning algorithm (e.g., a neural network trained on historical formulation data) continuously monitors aggregation of AAV vector particles (e.g., AAV-LK03 at 2x10^13 vg/ml) in a candidate buffer (10 mM Tris, pH 7.8). Based on real-time DLS data (Rh values and polydispersity), the AI dynamically adjusts the precise concentrations of multivalent excipients (e.g., sodium citrate and magnesium phosphate) via automated micropumps, maintaining an optimal ionic strength within the 300-600 mM range. This minimizes aggregation while ensuring the lowest effective excipient concentration, reducing formulation cost and complexity.
• Mermaid.js Diagram:

  flowchart TD
      A[AAV Vector Feed] --> B(Mixing Chamber)
      B --> C(pH Sensor)
      B --> D(Conductivity Sensor)
      B --> E(Microfluidic DLS)
      E --> F{AI Optimization Engine}
      C,D,E --> F
      F --> G(Automated Micropumps)
      G --> H(Excipient A: Sodium Citrate)
      G --> I(Excipient B: Magnesium Phosphate)
      H,I --> B
      F --> J(Optimal Ionic Strength Control)
      J --> K[Stable AAV Output]
  

Derivative 4.2: IoT-Enabled Smart AAV Storage Vial

• Enabling Description: A smart storage vial for AAV vector compositions, incorporating IoT sensors for continuous, real-time monitoring of formulation stability. The vial contains purified AAV-PHP.B vector particles at 6x10^13 vg/ml in a formulation comprising 10 mM sodium phosphate (pH 7.6) and 150 mM sodium sulfate (ionic strength ~900 mM). Integrated miniaturized sensors within the vial cap (e.g., a micro-electromechanical system (MEMS) based DLS sensor, a temperature probe, and a pH electrode) wirelessly transmit data via a low-power Bluetooth module to a central cloud platform. This allows for continuous monitoring of particle radius, temperature excursions, and pH shifts, triggering alerts if aggregation (Rh > 25 nm) or out-of-spec conditions are detected, ensuring cold chain integrity and product quality.
• Mermaid.js Diagram:

  graph TD
      A[AAV Storage Vial] --> B(MEMS DLS Sensor)
      A --> C(Temperature Probe)
      A --> D(pH Electrode)
      B,C,D --> E(Bluetooth Module)
      E --> F(IoT Gateway)
      F --> G(Cloud Platform)
      G --> H{Aggregation Alert (Rh > 25nm)}
      H --> I[Quality Control Action]
  

Derivative 4.3: Blockchain-Verified AAV Supply Chain

• Enabling Description: A blockchain-based system for secure and transparent verification of AAV vector product formulation and storage conditions across the entire supply chain. Each batch of purified AAV7 vector (5x10^13 vg/ml in 10 mM Tris, 100 mM sodium citrate, pH 8.0, ionic strength ~500 mM) is associated with a unique cryptographic hash. At critical stages (e.g., manufacturing, packaging, shipment, receipt), key parameters such as ionic strength, excipient batch numbers, pH, and measured aggregation data (DLS Rh values) are recorded and timestamped as immutable transactions on a private blockchain ledger. This provides an auditable, tamper-proof record of the AAV product's stability and compliance with formulation specifications, enhancing trust and regulatory oversight.
• Mermaid.js Diagram:

  sequenceDiagram
      participant A as Manufacturer
      participant B as Shipper
      participant C as Distributor
      participant D as Clinical Site
      participant E as Blockchain Ledger
  
      A->>E: Record AAV Batch + Formulation Params (Ionic Strength, pH, Excipients, DLS Rh)
      B->>E: Record Shipment Condition (Temp, Humidity, Aggregation Check)
      C->>E: Record Receipt & Storage Condition (Temp, Aggregation Check)
      D->>E: Record Final Usage Condition (Pre-Administration Aggregation Check)
      E-->>A: Immutable Audit Trail
      E-->>D: Verified Product History
  

5. The "Inverse" or Failure Mode

Derivative 5.1: Reversible Aggregation for Enhanced Purification

• Enabling Description: A method for purifying AAV vector particles that leverages controlled, reversible aggregation. A crude lysate containing AAV2 particles is first subjected to a low ionic strength buffer (e.g., 20 mM sodium phosphate, 50 mM NaCl, pH 7.2) to deliberately induce aggregation of AAV particles (Rh > 100 nm). This aggregated material is then separated from soluble contaminants via low-speed centrifugation or microfiltration. The pellet containing the aggregated AAV is subsequently resuspended in a high ionic strength solution (e.g., 10 mM Tris, 200 mM sodium citrate, pH 8.0, ionic strength ~1 M) causing the AAV particles to disaggregate and return to a monomeric state (Rh < 20 nm), facilitating further purification steps without significant loss of infectious titer.
• Mermaid.js Diagram:

  flowchart TD
      A[Crude AAV Lysate] --> B{Low Ionic Strength Buffer (Induce Aggregation)}
      B --> C[Aggregated AAV (Rh > 100nm)]
      C --> D(Separation from Soluble Contaminants)
      D --> E[AAV Pellet]
      E --> F{High Ionic Strength Buffer (Disaggregate AAV)}
      F --> G[Monomeric AAV (Rh < 20nm)]
      G --> H[Further Purification]
  

Derivative 5.2: Low-Power/Limited-Functionality Storage for Research-Grade AAV

• Enabling Description: A low-cost, low-power storage composition for research-grade AAV-GFP vector particles (e.g., AAV2-GFP) at a concentration of 5x10^12 vg/ml. The formulation utilizes a basic 5 mM phosphate buffer (pH 7.5) with only 50 mM magnesium chloride as the multivalent excipient, yielding an ionic strength of approximately 150 mM. While this ionic strength is below the threshold for preventing all aggregation as per the patent, it results in tolerable aggregation (Rh between 30-50 nm) over 3 months at 4°C, which is acceptable for non-critical, exploratory research applications where high purity and monomeric state are less stringent requirements, minimizing formulation cost.
• Mermaid.js Diagram:

  classDiagram
      class Research_AAV_Storage {
          +AAV_Particles: AAV2-GFP (5x10^12 vg/mL)
          +Buffer: Phosphate (5 mM, pH 7.5)
          +Excipient: MgCl2 (50 mM)
          +Ionic_Strength: ~150 mM
          +Aggregation_Status: Tolerable (Rh 30-50nm)
          +Application: Non-Critical Research
      }
  

Derivative 5.3: Self-Degrading AAV Formulation for Safety Control

• Enabling Description: A "smart" AAV formulation designed to rapidly degrade viral particles if critical storage conditions are compromised, serving as a safety mechanism to prevent the administration of ineffective or potentially immunogenic degraded product. The composition contains AAVX vector particles (e.g., a novel AAV serotype for cancer therapy) at 3x10^13 vg/ml in a pH 7.8 Tris-citrate buffer (ionic strength ~400 mM). Embedded within the formulation is a temperature-sensitive liposome encapsulating a highly active nuclease (e.g., Benzonase). Upon exposure to temperatures exceeding 10°C for more than 4 hours (indicating cold chain breach), the liposomes destabilize, releasing the nuclease which then degrades the AAV vector genomes, effectively rendering the product non-functional.
• Mermaid.js Diagram:

  stateDiagram
      state "Stable AAV (3E13 vg/mL)" as STABLE
      state "Tris-Citrate Buffer (pH 7.8, ~400mM)" as BUF
      state "Temp-Sensitive Liposomes + Nuclease" as LIPNUC
  
      STABLE --> BUF
      BUF --> LIPNUC
  
      state "Normal Storage (<10°C)" as NORM_STORE
      state "Cold Chain Breach (>10°C for >4h)" as BREACH
      state "Liposome Destabilization" as DESTAB
      state "Nuclease Release" as RELEASE
      state "AAV Genome Degradation" as DEGRADE
  
      NORM_STORE --> STABLE
      BREACH --> DESTAB
      DESTAB --> RELEASE
      RELEASE --> DEGRADE
      DEGRADE --> "Non-functional Product"
  

---

Combination Prior Art Scenarios

These scenarios combine the principles of US Patent 9051542 (high ionic strength AAV formulation to prevent aggregation) with existing open-source standards.

Combination Prior Art 1: AAV Production using BacMam System + High Ionic Strength Formulation

• Description: The production of recombinant AAV vectors is performed using the open-source BacMam baculovirus expression system (e.g., as detailed in commonly available protocols and reagents like Bac-to-Bac® system from Thermo Fisher Scientific, which itself has open-access elements for non-commercial use) in insect cells. Following purification (e.g., by chromatography), the resulting AAV particles (any serotype, e.g., AAV2, AAV8) are immediately formulated into a high ionic strength buffer as described in US90515542. Specifically, the purified AAV vectors are diafiltered into a solution containing 10 mM Tris (pH 8.0) and 100 mM sodium citrate (ionic strength ~500 mM) to prevent aggregation during concentration, storage at 4°C, and multiple freeze-thaw cycles, thereby ensuring consistent product quality from an established production platform. The open-source nature of BacMam protocols and the patent's formulation strategy create a comprehensive prior art for stable AAV production.
• Relevant Open-Source Standard: BacMam System protocols (e.g., those widely published in academic literature for AAV production, representing an open-source methodology rather than a strict software standard).

Combination Prior Art 2: Formulation for AAV in Pre-filled Syringes (ISO 11040) + High Ionic Strength Formulation

• Description: Recombinant AAV vectors, formulated according according to US9051542 (e.g., AAV2 at 6x10^13 vg/ml in 10 mM Tris, 100 mM sodium citrate, pH 8.0, ionic strength ~500 mM), are loaded into pre-filled syringes that comply with the open-source standard ISO 11040 (Prefilled syringes) for design, materials, and testing. The specific aspects of ISO 11040 relating to plunger stopper integrity, barrel strength, and siliconization are critical to ensuring the stability of the highly concentrated AAV formulation within the device during storage and transport. This combination describes a stable and deliverable AAV product within an established, standardized pharmaceutical device. The open standard ensures the physical container does not compromise the chemical stability provided by the patent's formulation.
• Relevant Open-Source Standard: ISO 11040 (Prefilled syringes) – while ISO standards are purchased, the principles and specifications are widely documented and adopted in open literature and form the basis of open industry practices. For the purpose of "defensive publishing," referencing such a standard extends the scope to standardized delivery.

Combination Prior Art 3: AAV Formulation Data Management with FAIR Data Principles & Open Source Ontologies

• Description: Detailed data pertaining to the AAV vector formulations disclosed in US9051542 (e.g., specific excipient concentrations, measured ionic strength, pH, AAV serotype, vector genome concentration, and dynamic light scattering (DLS) aggregation data (Rh, PDI)) are collected and managed according to the FAIR (Findable, Accessible, Interoperable, Reusable) Data Principles. This data is then structured using open-source ontologies for biologics and pharmaceutical formulations (e.g., the Biopharmaceutical Ontology (BPO) or the Ontology for Biomedical Investigations (OBI)) and stored in an open-access repository. This ensures that the detailed parameters of effective AAV aggregation prevention are openly documented, semantically enriched, and readily discoverable and reusable by the scientific community. This combination makes the knowledge of effective AAV stabilization accessible and interoperable, extending the prior art beyond the physical composition to its underlying data and knowledge representation.
• Relevant Open-Source Standard: FAIR Data Principles, Biopharmaceutical Ontology (BPO) / Ontology for Biomedical Investigations (OBI) (open-source ontologies/data schemas).

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