DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Inventive Group I, claims 1-3, 5, 12, 16-17, 21-22, 27, 32, 37-40, 67, and 70-72 in the reply filed on 7/15/2025 is acknowledged. Applicant further elected the required species (the washer buffer of claim 12) with traverse. Upon further consideration, the Examiner finds Applicant’s remarks persuasive and thus the Election of Species requirement is hereby withdrawn.
Claim 74 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 7/15/2025.
Claims 1-3, 5, 12, 16-17, 21-22, 27, 32, 37-40, 67, and 70-72 are under examination on the merits.
Information Disclosure Statement
The Information Disclosure Statements (IDSs) submitted on 12/22/2021, 10/9/2023, and 8/22/2024 are in compliance with 37 CFR 1.97. Accordingly, the IDSs are being considered by the examiner.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 5 & 37-40 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Frei, et al. (WO9941416, filed 2/12/1999; hereinafter referred to as “Frei”).
The claimed invention encompasses a method for purifying an adeno-associated virus (AAV) comprising (a) loading an AAV containing solution onto an affinity resin targeted against the AAV at room temperature and under conditions that allow binding between the AAV in the solution and the affinity resin; (b) undertaking at least one wash step at room temperature; and (c) eluting the AAV from the affinity resin at a temperature of less than 18 °C, as recited in claim. Alternatively, the temperature in step (c) is between 1°C and 12 °C, as recited in claim 2, or between 2 °C and 8 °C, as recited in claim 3. In a specific embodiment, at least two wash steps are performed at room temperature, as recited in claim 5.
In another embodiment, step (c) comprises eluting the AAV with at least one elution buffer, as recited in claim 37, and or more specifically at least one elution buffer is the same as at least one of the wash buffers, as recited in claim 38, or more specifically wherein at least one elution buffer is the same as the last wash buffer used in the final wash step before eluting the AAV in step (c), as recited in claim 39, or the first elution buffer is the same as the last wash buffer used in the final wash step, as recited in claim 40.
The Prior Art
Frei teaches methods for concentrating virus preparations, which are amenable to a wide range of viruses, including adeno-associated virus (Page 16, lines 23-25). Frei’s methods encompass subjecting a virus preparation to anion-exchange chromatography, wherein the virus is eluted as a virus preparation product from an anion-exchange chromatographic medium (Page 4, lines 5-7), embodiments wherein the method is carried about in a temperature range from about 2 °C to 27 °C (Page 17, lines 11-13). Frei further discloses that the virus binds to the resin, whereas the majority of media and host cell impurities pass through the column, after which a column holding the resin is washed with 4 volumes of a first buffer (Buffer A) and then 8 volumes of a second buffer (6% Buffer B and 94% Buffer A) to remove additional impurities (p. 22, lines 9-14; p. 21, lines 41-42). The virus is eluted from the column with a 30 bed volume linear gradient from 6% to 100% buffer B (p. 22, lines 14-16).
Therefore, Frei anticipates claims 1-3, 5 & 37-40.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 70-72 are rejected under 35 U.S.C. 103 as being unpatentable over Frei, as applied to claims 1-3, 5 and 37-40 above, and in further view of Nass, et al. (Mol Ther Methods Clin Dev. 2017 Dec 22;9:33-46. doi: 10.1016/j.omtm.2017.12.004. PMID: 29349097; hereinafter referred to as “Nass”).
In another embodiment of the claimed invention, at least 60% of the AAV capsids eluted from the elution step (c) are full AAV capsids, as recited in claim 70. In a different embodiment, the affinity resin is AAVx resin, as recited in claim 71. In a specific embodiment, the AAV is AAV9, as recited in claim 72.
The Prior Art
The teachings of Frei are described above. However, Frei does not specifically disclose a method wherein at least 60% of the AAV capsids eluted from the elution step are full AAV capsids, the affinity resin is AAVx, or wherein the AAV is AAV9.
Nass teaches a universal method for purification of recombinant AAV vectors of differing serotypes. Nass teaches that most previously reported purification schemas for AAV are serotype dependent, requiring method development for each AAV gene therapy product (Abstract). In contrast, Nass’s platform purification process is compatible with the purification of multiple AAV serotypes, including AAV9, generates vector preparations of high purity that are enriched for capsids with full vector genomes and minimizes the fractional content of empty capsids, based on a two-column purification method, a combination of affinity and ion exchange chromatographies (Abstract; Table 3; Figs. 4D-6). Nass also teaches that AAVX is a new AAV affinity resin, purported by the manufacturer to be useful for the purification of multiple AAV serotypes (p. 44, col. 1, para. 1). Nass further teaches that affinity chromatography is highly selective for the AAV capsid, but typically has a disadvantage in that the affinity ligand cannot discriminate between full-genome-containing and an empty capsid because both populations are indistinguishable at the amino acid level; however, to circumvent that, the scalable chromatographic purification method can be used to separate empty capsids from vector particles, wherein 80% of the vectors were full (p. 39, col. 2, para. 1; Fig. 7A-B; p. 44, col. 1, para. 1).
It would have been obvious to one of ordinary skill in the art to modify the purification method taught by Frei to utilize Nass’s resin and purification processes. Nass teaches that its scalable purification chromatographic purification method is highly selective for the AAV capsid, for multiple AAV serotypes including AAV9, with up 80% of purified AAV capsids being full. One of ordinary skill in the art would have been motivated to purify multiple AAV serotypes, and/or enrich for full capsids. Although Nass does not test AAVX as the affinity resin, there is a reasonable expectation of success with its use in the method as well, because it is purported by the manufacturer to be useful for the purification of multiple AAV serotypes. Therefore, claims 70-72 were prima facie obvious before the priority date of the instant invention.
Claims 1-3, 5, 12, 16-17, 21-22, 32, 37-40, 67, and 72 are rejected under 35 U.S.C. 103 as being unpatentable over Qu, et al. (PGPub US20200299650A1, priority date 3/31/2017, published 9/24/2020; hereinafter referred to as “Qu I”), in further view of Frei (supra) and Qu, et al. (J Virol Methods. 2007 Mar;140(1-2):183-92. doi: 10.1016/j.jviromet.2006.11.019. Epub 2006 Dec 28. PMID: 17196264; hereinafter referred to as “Qu II”).
The claimed invention encompasses a method for purifying an adeno-associated virus (AAV) comprising (a) loading an AAV containing solution onto an affinity resin targeted against the AAV at room temperature and under conditions that allow binding between the AAV in the solution and the affinity resin; (b) undertaking at least one wash step at room temperature; and (c) eluting the AAV from the affinity resin at a temperature of less than 18 °C, as recited in claim. Alternatively, the temperature in step (c) is between 1°C and 12 °C, as recited in claim 2, or between 2 °C and 8 °C, as recited in claim 3. In a specific embodiment, at least two wash steps are performed at room temperature, as recited in claim 5.
In a specific embodiment, at least one wash buffer comprises from about 10 mM to about 200 mM TrisHCl and from about 50 mM to about 500 mM salt at a pH from about 7.5 to about 9.2, as recited in claim 12. In a more specific embodiment, the buffer (claim 67), or at least one (claim 16), wash buffer comprises about 50 mM TrisHCl and about 125 mM salt, and has a pH of about 8.5. In a different embodiment, at least one wash buffer comprises from about 10 mM to about 2000 mM sodium acetate and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 5.0 to about 7.4, as recited in claim 17, or more specifically about 100 mM sodium acetate and about 0.1% (w/w) polysorbate 80, and has a pH of about 6.0, as recited in claim 21. Alternatively, at least one wash buffer comprises from about 10 mM to about 200 mM TrisHCl and from about 10% to about 75% (w/w) ethylene glycol at a pH from about 7.5 to about 9.2, as recited in claim 22. In one embodiment, at least one wash buffer comprises from about 1 mM to about 200 mM TrisHCl, from about 50 mM to about 500 mM salt, and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.8, as recited in claim 32.
In another embodiment, step (c) comprises eluting the AAV with at least one elution buffer, as recited in claim 37, and or more specifically at least one elution buffer is the same as at least one of the wash buffers, as recited in claim 38, or more specifically wherein at least one elution buffer is the same as the last wash buffer used in the final wash step before eluting the AAV in step (c), as recited in claim 39, or the first elution buffer is the same as the last wash buffer used in the final wash step, as recited in claim 40.
The Prior Art
Qu I teaches methods of purifying recombinant adeno-associated (rAAV) vector particles using columns (Abstract; title). Qu’s method comprises the steps of:, (a) harvesting cells and/or cell culture supernatant comprising rAAV vector particles to produce a harvest; (b) optionally concentrating the harvest produced in step (a) to produce a concentrated harvest; (c) lysing the harvest produced in step (a) or the concentrated harvest produced in step (b) to produce a lysate; (d) treating the lysate to reduce contaminating nucleic acid in the lysate thereby producing a nucleic acid reduced lysate; (e) filtering the nucleic acid reduced lysate produced in step (d) to produce a clarified lysate, and optionally diluting the clarified lysate to produce a diluted clarified lysate; (f) subjecting the clarified lysate or diluted clarified lysate produced in step (e) to anion or cation exchange column chromatography to produce a column eluate comprised of rAAV vector particles, and optionally concentrating the column eluate to produce a concentrated column eluate; (g) subjecting the column eluate or the concentrated column eluate produced in step (f) to size exclusion column chromatography to produce a second column eluate comprised of rAAV vector particles, thereby separating rAAV vector particles from protein impurities, and optionally diluting the second column eluate to produce a diluted second column eluate; (h) subjecting the second column eluate or the diluted second column eluate produced in step (g) to cation or anion exchange column chromatography to produce a third column eluate comprised of rAAV vector particles thereby separating rAAV vector particles from protein or other production impurities, and optionally concentrating the third column eluate to produce a concentrated third column eluate; and (i) filtering the third column eluate or the concentrated third column eluate produced in step (h) thereby producing purified rAAV vector particles (para. [0010]). Qu I further teaches that equilibration, wash, and elution solutions may have a pH from about pH 5 to pH 12 (para. [0089]), comprises washing the column with wash buffers that include polyethylene glycol (PEG) solution prior to elution of the rAAV vector particles from the column (para. [0017]) wherein the PEG wash solutions range from about 0.1 to about 20% PEG (paras. [0091]-[0093]). Additionally, Qu discloses aqueous TrisCl/NaCl buffer that comprises 50-200 mM NaCl and phosphate/NaCl buffer that comprises between about 100-500 mM NaCl (paras. [0017-0018]). Qu I also teaches that the column steps may comprise washing with an aqueous surfactant solution prior to elution of rAAV vector particles from the column (claims 38, 53). Qu I also teaches purification of AAV9 by its methods (claim 74).
However, Qu I does not teach loading and washing steps at room temperature and eluting at less than 18 °C, or between 2 °C - 8 °C, or the specific claimed buffer parameters.
Frei teaches methods for concentrating virus preparations, which are amenable to a wide range of viruses, including adeno-associated virus (Page 16, lines 23-25). Frei’s methods encompass subjecting a virus preparation to anion-exchange chromatography, wherein the virus is eluted as a virus preparation product from an anion-exchange chromatographic medium (Page 4, lines 5-7), embodiments wherein the method is carried about in a temperature range from about 2 °C to 27 °C (Page 17, lines 11-13). Frei further discloses that the virus binds to the resin, whereas the majority of media and host cell impurities pass through the column, after which a column holding the resin is washed with 4 volumes of a first buffer (Buffer A) and then 8 volumes of a second buffer (6% Buffer B and 94% Buffer A) to remove additional impurities (p. 22, lines 9-14; p. 21, lines 41-42). The virus is eluted from the column with a 30 bed volume linear gradient from 6% to 100% buffer B (p. 22, lines 14-16). Frei discloses that a surfactant, such as polysorbate 80, can act as a stabilizer in AAV compositions and may be present at a concentration of 0.03 to 0.3 mg/ml (p. 9, lines 23-25).
Qu II teaches a chromatography equilibration and wash buffer for AAV purification that is 20 mM TrisCl pH 8.5, 100 mM NaCl (pp. 185-186, bridging para.). Qu II also teaches loading rAAV empty capsids or vector with 20 mM TrisCl, 50 mM sodium acetate, pH 7.4 onto a chromatography column and then washing with 3 column volumes of the buffer prior to elution with a sodium acetate gradient from 50 to 300 mM over 10 column volumes (p. 184, col. 2, para. 3).
It would have been obvious to one of ordinary skill in the art to modify the purification method taught by Qu I to incorporate the temperatures taught by Frei and the buffer considerations taught by Qu II. Although Qu I, Frei, and Qu II fail to teach several of the precise buffer compositions of the instant invention claims (e.g., 16, 21, 27, and 67), the claimed buffer compositions would be obvious to one of ordinary skill in the art by routine optimization. The claimed wash buffers would have been obvious in view of the cited references because they teach each component (for instance, Qu II teaches TrisHCl at 20 mM, sodium acetate at 50 mM, Qu I teaches TrisHCl buffers with 50-200 mM NaCl, buffers in the range of pH 5 and pH 12, and addition of polyethylene glycol in wash buffers between 0.1% to about 20%, and Frei teaches polysorbate at 0.03 to 0.3 mg/ml). The cited references demonstrate the suitability for these components in wash and elution buffers for affinity-based chromatography to purify AAV, and one of ordinary skill in the art would be motivated to optimize the buffer conditions to optimize purification of AAV with full capsids and in a stable form. See MPEP §2144.05. One of ordinary skill in the art would have been motivated to purify multiple AAV serotypes, and/or enrich for full capsids. There would be a reasonable expectation of success because each method describes resin-based AAV affinity purification. Therefore, claims 1-3, 5, 12, 16-17, 21-22, 32, 37-40, 67, and 72 were prima facie obvious before the priority date of the instant invention.
Claims 70-71 are rejected under 35 U.S.C. 103 as being unpatentable over Qu I, Frei, and Qu II (supra), as applied to claims 1-3, 5, 12, 16-17, 21-22, 32, 37-40, 67, and 72 above, and in further view of Nass (supra).
In another embodiment of the claimed invention, at least 60% of the AAV capsids eluted from the elution step (c) are full AAV capsids, as recited in claim 70. In a different embodiment, the affinity resin is AAVx resin, as recited in claim 71.
The Prior Art
The teachings of Qu I and Frei, and Qu II are described above. However, they do not specifically disclose a method wherein at least 60% of the AAV capsids eluted from the elution step are full AAV capsids, or the affinity resin is AAVx.
Nass teaches a universal method for purification of recombinant AAV vectors of differing serotypes. Nass teaches that most previously reported purification schemas for AAV are serotype dependent, requiring method development for each AAV gene therapy product (Abstract). In contrast, Nass’s platform purification process is compatible with the purification of multiple AAV serotypes, including AAV9, generates vector preparations of high purity that are enriched for capsids with full vector genomes and minimizes the fractional content of empty capsids, based on a two-column purification method, a combination of affinity and ion exchange chromatographies (Abstract; Table 3; Figs. 4D-6). Nass also teaches that AAVX is a new AAV affinity resin, purported by the manufacturer to be useful for the purification of multiple AAV serotypes (p. 44, col. 1, para. 1). Nass further teaches that affinity chromatography is highly selective for the AAV capsid, but typically has a disadvantage in that the affinity ligand cannot discriminate between full-genome-containing and an empty capsid because both populations are indistinguishable at the amino acid level; however, to circumvent that, the scalable chromatographic purification method can be used to separate empty capsids from vector particles, wherein 80% of the vectors were full (p. 39, col. 2, para. 1; Fig. 7A-B; p. 44, col. 1, para. 1).
It would have been obvious to one of ordinary skill in the art to modify the purification methods taught by Qu I, Frei, and Qu II to utilize Nass’s resin and purification processes. Nass teaches that its scalable purification chromatographic purification method is highly selective for the AAV capsid, for multiple AAV serotypes including AAV9, with up 80% of purified AAV capsids being full. One of ordinary skill in the art would have been motivated to purify multiple AAV serotypes, and/or enrich for full capsids. Although Nass does not test AAVX as the affinity resin, there is a reasonable expectation of success with its use in the method as well, because the There would be a reasonable expectation of success because it is purported by the manufacturer to be useful for the purification of multiple AAV serotypes. Therefore, claims 70-71 were prima facie obvious before the priority date of the instant invention.
Claims 1-3, 5, 12, 16-17, 21-22, 27, 32, 37-40, 67, and 70-72 are rejected under 35 U.S.C. 103 as being unpatentable over Fiedler, et al. (WO 2019133677 A1, priority date 12/29/2017, published 9/24/2020; hereinafter referred to as “Fiedler”), in further view of Frei (supra).
The applied reference (Fiedler, et al.) has common inventors with the instant application. Based upon the earlier effectively filed date of the reference, it constitutes prior art under 35 U.S.C. 102(a)(2). This rejection under 35 U.S.C. 102(a)(2) might be overcome by: (1) a showing under 37 CFR 1.130(a) that the subject matter disclosed in the reference was obtained directly or indirectly from the inventor or a joint inventor of this application and is thus not prior art in accordance with 35 U.S.C. 102(b)(2)(A); (2) a showing under 37 CFR 1.130(b) of a prior public disclosure under 35 U.S.C. 102(b)(2)(B) if the same invention is not being claimed; or (3) a statement pursuant to 35 U.S.C. 102(b)(2)(C) establishing that, not later than the effective filing date of the claimed invention, the subject matter disclosed in the reference and the claimed invention were either owned by the same person or subject to an obligation of assignment to the same person or subject to a joint research agreement.
The claimed invention encompasses a method for purifying an adeno-associated virus (AAV) comprising (a) loading an AAV containing solution onto an affinity resin targeted against the AAV at room temperature and under conditions that allow binding between the AAV in the solution and the affinity resin; (b) undertaking at least one wash step at room temperature; and (c) eluting the AAV from the affinity resin at a temperature of less than 18 °C, as recited in claim. Alternatively, the temperature in step (c) is between 1°C and 12 °C, as recited in claim 2, or between 2 °C and 8 °C, as recited in claim 3. In a specific embodiment, at least two wash steps are performed at room temperature, as recited in claim 5.
In a specific embodiment, at least one wash buffer comprises from about 10 mM to about 200 mM TrisHCl and from about 50 mM to about 500 mM salt at a pH from about 7.5 to about 9.2, as recited in claim 12. In a more specific embodiment, the buffer (claim 67), or at least one (claim 16), wash buffer comprises about 50 mM TrisHCl and about 125 mM salt, and has a pH of about 8.5. In a different embodiment, at least one wash buffer comprises from about 10 mM to about 2000 mM sodium acetate and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 5.0 to about 7.4, as recited in claim 17, or more specifically about 100 mM sodium acetate and about 0.1% (w/w) polysorbate 80, and has a pH of about 6.0, as recited in claim 21. Alternatively, at least one wash buffer comprises from about 10 mM to about 200 mM TrisHCl and from about 10% to about 75% (w/w) ethylene glycol at a pH from about 7.5 to about 9.2, as recited in claim 22. In a different embodiment, at least one wash buffer comprises from about 10 mM to about 200 mM glycine, about 1 mM to about 100 mM histidine, about 20 mM to about 500 mM salt, about 1% to about 10% (w/w) trehalose, and about 0.0005% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.0, as recited in claim 27. In one embodiment, at least one wash buffer comprises from about 1 mM to about 200 mM TrisHCl, from about 50 mM to about 500 mM salt, and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.8, as recited in claim 32.
In another embodiment, step (c) comprises eluting the AAV with at least one elution buffer, as recited in claim 37, and or more specifically at least one elution buffer is the same as at least one of the wash buffers, as recited in claim 38, or more specifically wherein at least one elution buffer is the same as the last wash buffer used in the final wash step before eluting the AAV in step (c), as recited in claim 39, or the first elution buffer is the same as the last wash buffer used in the final wash step, as recited in claim 40.
In another embodiment of the claimed invention, at least 60% of the AAV capsids eluted from the elution step (c) are full AAV capsids, as recited in claim 70. In a different embodiment, the affinity resin is AAVx resin, as recited in claim 71. In a specific embodiment, the AAV is AAV9, as recited in claim 72.
The Prior Art
Fiedler teaches methods of producing and purifying AAV, wherein AAV is loaded onto an affinity resin, wash steps are undertaken, and AAV is eluted from the affinity resin, and Fiedler further discloses various buffers for use in the wash steps and elution (Abstract). Fiedler’s method comprises (a) loading an AAV containing solution onto an affinity resin targeted against AAV under conditions that allow binding between the AAV in the solution and the affinity resin; (b) undertaking at least two wash steps; and (c) eluting the AAV from the affinity resin (claim 1). Fiedler teaches at least three wash steps are performed (claim 14). Fiedler also teaches wash buffers that comprise i) from about 50 to about 2000 mM sodium acetate and from about 0.05 to about 0.2% polysorbate 80 with a pH from about 5.2 to about 6.8, (ii) about 30 to about 200 mM TrisHCl and from about 75 to about 500 mM salt with a pH from about 7.5 to about 9.2, (iii) about 30 to about 200 mM TrisHCl and from about 30 to about 75 vol% ethylene glycol, with a pH from about 7.3 to about 8.8 (claim 20). Another wash buffer taught by Fiedler comprises about 30 to about 300 mM glycine with a pH from about 7.5 to 9.2 (claim 22), at least one of the wash steps comprises applying to the affinity resin a buffer that comprises Histidine, and discloses buffers containing histidine at a concentration of about 50 mM (claim 61). Fiedler teaches that the organic solvent or detergent may be polysorbate 80, ethylene glycol, or trehalose (claim 17). Fiedler discloses that addition of a nonionic detergent such as polysorbate may result in the partial to complete inactivation of lipid enveloped viruses where AAV is bound on the ligand (e.g., during the wash step), since such additives can inactivate lipid enveloped viruses (para. [0118]). Additionally, Fiedler discloses that an elution buffer may comprise ethylene glycol, a salt such as NaCl, and a buffer such as TrisHCl, wherein the pH is at least 7.0, which encompasses the wash buffer (ii) from claim 20 (claim 46). Fiedler also teaches purification of AAV9 (claim 76), use of AAVx resin to purify AAV (para. [0110]), and that the majority of capsids in the AAV fraction are full capsids (para. [0175]).
However, Fiedler does not teach loading an AAV containing solution onto an affinity resin at room temperature, washing the resin at room temperature, and eluting the AAV from the resin at a temperature of less than 18 °C, or more specifically between 2 °C and 8 °C. Fiedler also does not specifically teach a single wash buffer that comprises from about 10 mM to about 200 mM glycine, about 1 mM to about 100 mM histidine, about 20 mM to about 500 mM salt, about 1% to about 10% (w/w) trehalose, and about 0.0005% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.0 (instant claim 27). Fiedler also does not specifically teach a buffer comprising from about 1 mM to about 200 mM TrisHCl, from about 50 mM to about 50 mM salt, and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.8 (instant claim 32).
Frei teaches methods for concentrating virus preparations, which are amenable to a wide range of viruses, including adeno-associated virus (Page 16, lines 23-25). Frei’s methods encompass subjecting a virus preparation to anion-exchange chromatography, wherein the virus is eluted as a virus preparation product from an anion-exchange chromatographic medium (Page 4, lines 5-7), embodiments wherein the method is carried about in a temperature range from about 2 °C to 27 °C (Page 17, lines 11-13). Frei further discloses that the virus binds to the resin, whereas the majority of media and host cell impurities pass through the column, after which a column holding the resin is washed with 4 volumes of a first buffer (Buffer A) and then 8 volumes of a second buffer (6% Buffer B and 94% Buffer A) to remove additional impurities (p. 22, lines 9-14; p. 21, lines 41-42). The virus is eluted from the column with a 30 bed volume linear gradient from 6% to 100% buffer B (p. 22, lines 14-16). Frei discloses that a surfactant, such as polysorbate 80, can act as a stabilizer in AAV compositions and may be present at a concentration of 0.03 to 0.3 mg/ml (p. 9, lines 23-25). Frei also teaches elution from anionic chromatography columns wherein the last wash buffer used is the start of the gradient for elution (p. 20, lines 9-16)
It would have been obvious to one of ordinary skill in the art to modify the methods of Fiedler to incorporate Frei’s teaching of carrying out the temperatures in a range from about 2 °C to about 27 °C. Frei teaches methods for concentrating virus preparations, which are amenable to a wide range of viruses, including adeno-associated virus (Page 16, lines 23-25). Frei’s methods encompass subjecting a virus preparation to anion-exchange chromatography, wherein the virus is eluted as a virus preparation product from an anion-exchange chromatographic medium (Page 4, lines 5-7), embodiments wherein the method is carried about in a temperature range from about 2 °C to 27 °C (Page 17, lines 11-13). Frei also teaches elution from anionic chromatography columns wherein the last wash buffer used is the start of the gradient for elution (p. 20, lines 9-16). Therefore, it would have been obvious to one of ordinary skill in the art to modify the methods of Fiedler to perform the method in a temperature range from about 2 °C to 27 °C , to achieve stable AAV compositions, and at least one elution buffer is the same as the last wash buffer used, as taught by Frei.
Although Fiedler does not specifically teach a wash buffer that comprises from about 10 mM to about 200 mM glycine, about 1 mM to about 100 mM histidine, about 20 mM to about 500 mM salt, about 1% to about 10% (w/w) trehalose, and about 0.0005% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.0, or a wash buffer comprising from about 1 mM to about 200 mM TrisHCl, from about 50 mM to about 50 mM salt, and from about 0.001% to about 1% (w/w) polysorbate 80 at a pH from about 6.0 to about 8.8, such buffers would be obvious to one of ordinary skill in the art because Fiedler teaches each of the components within or at approximately the claimed ranges, or describes similar components present within the claimed parameters.
One of ordinary skill in the art would have been motivated to achieve a highly pure and stable AAV formulation, which includes eluting full AAV capsids which amount to at least 60% of the capsids eluted There would be a reasonable expectation of success because each cited reference was concerned with purification of AAV by employing similar methods and components. Therefore, claims 1-3, 5, 12, 16-17, 21-22, 27, 32, 37-40, 67, and 70-72 were prima facie obvious before the priority date of the instant invention.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
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Claims 1-3, 5, 12, 16-17, 21-22, 27, 32, 37-40, 67, & 70-72 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-29 of U.S. Patent No. US11981934B2 in view of Frei (supra) and Nass (supra).
U.S. Patent No. US11981934B2 teaches a method of purifying an AAV comprising (a) loading an AAV containing solution onto an affinity resin targeted against AAV under conditions that allow binding between the AAV in the solution and the affinity resin; (b) undertaking at least two wash steps; and (c) eluting the AAV from the affinity resin, wherein at least one of the wash steps comprises applying to the affinity resin a buffer comprising an organic solvent or detergent (claim 1). U.S. Patent No. US11981934B2 further describes wash buffers comprising from about 30 to about 200 mM TrisHCl and from about 75 to about 500 mM salt, with a pH from about 7.5 to 9.2 (claim 6), from about 50 to about 200 mM sodium acetate and from about 0.05 to about 0.2% polysorbate 80, with a pH from about 5.5 to about 6.5 (claim 15), about 50 mM TrisHCl and about 50% ethylene glycol, with a pH of about 8.5 (claim 14). U.S. Patent No. US11981934B2 also discloses contacting the affinity resin with a variety of elution buffers (claims 18-24 and 27-29), which can comprise polyethylene glycol, a salt, and TrisHCl with a pH of at least 7.0 (claim 16). Additionally, U.S. Patent No. US11981934B2 discloses that the purified AAV is AAV9 (claim 24).
Notably, U.S. Patent No. US11981934B2 does not specifically disclose loading an AAV containing solution onto an affinity resin at room temperature, washing the resin at room temperature, and eluting the AAV from the resin at a temperature of less than 18 °C, or more specifically between 2 °C and 8 °C. U.S. Patent No. US11981934B2 also doesn’t directly disclose that at least one elution buffer is the same as the last wash buffer used. Additionally, U.S. Patent No. US11981934B2 fails to specifically disclose the buffers of instant claims 27 and 32. However, U.S. Patent No. US11981934B2 teaches other, similar buffers with similar component ranges for identical purposes, and thus the subject matter of instant claims 27 and 32 are obvious in view of U.S. Patent No. US11981934B2.
As discussed above, Frei teaches methods for concentrating virus preparations, which are amenable to a wide range of viruses, including adeno-associated virus (Page 16, lines 23-25). Frei’s methods encompass subjecting a virus preparation to anion-exchange chromatography, wherein the virus is eluted as a virus preparation product from an anion-exchange chromatographic medium (Page 4, lines 5-7), embodiments wherein the method is carried about in a temperature range from about 2 °C to 27 °C (Page 17, lines 11-13). Frei also teaches elution from anionic chromatography columns wherein the last wash buffer used is the start of the gradient for elution (p. 20, lines 9-16).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the methods of U.S. Patent No. US11981934B2 to perform the method in a temperature range from about 2 °C to 27 °C , to achieve stable AAV compositions, and at least one elution buffer is the same as the last wash buffer used, as taught by Frei.
As discussed above, Nass universal method for purification of recombinant AAV vectors of differing serotypes. Nass also teaches that AAVX is a new AAV affinity resin, purported by the manufacturer to be useful for the purification of multiple AAV serotypes (p. 44, col. 1, para. 1). Nass further teaches that affinity chromatography is highly selective for the AAV capsid, but typically has a disadvantage in that the affinity ligand cannot discriminate between full-genome-containing and an empty capsid because both populations are indistinguishable at the amino acid level; however, to circumvent that, the scalable chromatographic purification method can be used to separate empty capsids from vector particles, wherein 80% of the vectors were full (p. 39, col. 2, para. 1; Fig. 7A-B; p. 44, col. 1, para. 1).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the methods of U.S. Patent No. US11981934B2 to utilize Nass’s platform to achieve >60% of full AAV vectors and use of AAVX resin.
Conclusion
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/JEFFREY MARK SIFFORD/Examiner, Art Unit 1671
/BENJAMIN P BLUMEL/Primary Examiner, Art Unit 1671