DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. 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
2. Applicant’s election without traverse of Group I (claims 1-6, 12-13, and 15) in the reply filed on 21 April 2026 is acknowledged.
Applicant’s election of cesium chloride for liquids L, H1, and H2 in the reply filed on 21 April 2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claims 7-11 and 14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Claim Status
3. Claims 7-11 and 14 are withdrawn.
Claims 1-6, 12-13, and 15 are under consideration.
Priority
4. The Instant Application is a 371 National Stage Application, filed 14 April 2022, that claims priority to U.S. Provisional Application 63/175,296, filed 15 April 2021. Priority is granted to U.S. Provisional Application 63/175,296 for claims 1-6, 12-13, and 15. Thus, the U.S. effective filing date of the Instant Application is 15 April 2021.
Information Disclosure Statement
5. The information disclosure statements (IDS) submitted on 29 July 2025, 18 February 2025, and 29 December 2023 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
6. The listing of references in the specification is not a proper information disclosure statement. 37 CFR 1.98(b) requires a list of all patents, publications, or other information submitted for consideration by the Office, and MPEP § 609.04(a) states, "the list may not be incorporated into the specification but must be submitted in a separate paper." Therefore, unless the references have been cited by the examiner on form PTO-892, they have not been considered.
Specification
7. The use of the term “AAVpro” (¶ [0035]), “Quantstudio” (¶ [0035]), “NuPAGE” (¶ [0035]), “FlowJo” (¶ [0035]), “QuantaSoft” (¶ [0037]), which is a trade name or a mark used in commerce, has been noted in this application. The term should be accompanied by the generic terminology; furthermore the term should be capitalized wherever it appears or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
Note that these are merely examples and all improper uses of trademarks in the specification should be identified by Applicant and properly addressed.
Claim Objections
8. Claims 1-6, 12-13, and 15 are objected to because of the following informalities:
Regarding claim 1,
A comma should be added after both instances of “intermediate virus particles” in lines 6 and 12 for clarity of the lists.
In line 7, the comma should be changed to a semicolon after both instances of “full-genome virus particles” for clarity of the lists.
In line 11, the comma after “a high speed” should be removed.
The “the” before “step (a)” in line 10 and before “step (b)” in line 13 should be removed for clarity.
Regarding claims 2-6, 12-13, and 15, “The production method” should be written as “The method” for consistency.
Regarding claim 2,
"wherein, in the step (a)," should be rewritten as "wherein step (a) further comprises" and "is additionally present" should be removed for clarity.
"wherein in step (a)" in line 5 should read "wherein step (a)"
The phrase "are present" should be added after "liquid H1" in line 6.
Regarding claim 3,
"wherein, in the step (c)," should read "wherein step (c),".
"outside of the diameter direction" should be written as "outside in the diameter direction" for clarity. Examiner is interpreting this to be perpendicular to the rotor axis (See Figure 1A).
Regarding claims 4 and 13,
A comma should be added after "the liquid H1" for clarity of the list.
Examiner suggests removing the CAS numbers in the parentheses as they are the same as the compounds outside of the parentheses.
Regarding claim 5, the comma before “and the density” should be removed.
Regarding claim 12, "wherein, in the step (c), the zonal rotor is rotated at the low speed, and…" should be rewritten as "wherein step (c), the zonal rotor is rotated at the low speed and…" for clarity.
Regarding claim 15, "wherein the low speed rotation is rotation at a speed of…" should be rewritten as "wherein the low speed is…" and likewise for the high speed rotation for clarity.
Appropriate correction is required.
Claim Interpretation
9. In accordance with the Instant Specification, Examiner is interpreting "Full-genome virus particles" to be a virus particle, in which a full-length genome is packaged and which could infect cells
(¶ [0015]).
Claim Rejections - 35 USC § 112
10. The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
11. Claims 1-6, 12-13, and 15 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The term “low” in claims 1, 3, and 12 is a relative term which renders the claim indefinite. The term “low” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The specification merely provides an example for what a “low speed” may be, but does not explicitly define the speed (¶ [0016]). The threshold to qualify as a “low” speed could be interpreted as different speeds to different people.
Claims 2-6 and 12-13, which depend on claim 1, are similarly rejected.
Claim 4, which depends on claim 3, is similarly rejected.
The term “high” in claim 1 is a relative term which renders the claim indefinite. The term “high” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The specification merely provides an example for what a “high speed may be, but does not explicitly define the speed (¶ [0018]). The threshold to qualify as a “high” speed could be interpreted as different speeds to different people.
Claims 2-6 and 12-13, which depend on claim 1, are similarly rejected.
The term “about” in claim 15 is a relative term which renders the claim indefinite. The term “about” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. “About x rpm to y rpm” could indicate different ranges to different people.
Claim Rejections - 35 USC § 103
12. 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.
13. 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.
14. Claims 1 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Fiedler (US 20190365835 A1; Published 05 December 2019) (See IDS filed 29 December 2023) in view of Pluisch (02 September 2019, RSC Adv, 9(47): 27549-27559).
Regarding claims 1 and 15, Fiedler teaches a method to separate an adeno-associated virus (AAV) fraction into full and empty AAV capsids (Abstract). Fiedler further teaches “In exemplary embodiments, the methods of the present disclosure comprise an ultracentrifugation step to separate full AAV capsids from empty AAV capsids. In exemplary aspects, the methods comprise (i) loading into a rotor a concentrated AAV fraction with at least two sugar solutions, each of which has a different sugar concentration, (ii) operating an ultracentrifuge comprising the loaded rotor in batch mode to form a sugar gradient, and (iii) obtaining a fraction (fractionating) of the sugar gradient to obtain an AAV fraction comprising full AAV capsids. In exemplary aspects, the rotor is a zonal rotor.” (¶ [0008]) and “In certain embodiments, the first rotational speed is about 3,000 rpm to about 6,000 rpm, optionally, about 4,000 rpm. In certain embodiments, the second rotational speed is about 35,000 rpm” (¶ [0023]). Table 9 shows that the high speed is for separation of the particles. Regarding the empty plasmids, Fiedler teaches “As used herein, the term “empty” with regard to AAV or AAV capsids or AAV particles refer to those that lack the complete (i.e., full) vector genome. […] Such empty AAV or empty AAV capsids or empty AAV particles may lack the vector genome in part or in whole, i.e., they may be partially empty or completely empty, and, as such, are unable to provide a therapeutic benefit.” (¶ [0063]). In addition, “The order of loading sequence can be first the AAV fraction (e.g., a solution comprising AAV) followed by the lowest concentrate of sugar solution, then followed by the next more concentrated sugar solution, and so on.” (¶ [0065]).
In summary, Fiedler teaches a zonal rotor used to separate full AAV capsids from empty capsids (in part, which would be “intermediate”, or in full). Two rotational speeds are used, a low speed that is between 1,000 rpm and 4,000 rpm; and a high speed for separation of particles that is between 35,000 rpm and 40,000 rpm. This is done through a sugar density gradient and thus one sugar solution will have a higher density than the other. It would further be inherent that the lower density solution will have to be a lower density than the full-genome AAV particles in order to facilitate separation between the full, intermediate, and empty particles. Capsids that do not have the full genome would be a lower density than those with the full genome. The loading sequence is also as claimed: the AAV fragment, then the sugar solution with the lower concentration (and thus lower density), and finally the sugar solutions with higher concentrations (and thus higher density). Finally, a fraction containing the full AAV capsids are obtained. Fielder does not teach that the zonal rotor is rotating at a low speed during loading, and that the AAV fraction and sugar solutions are arranged from the rotation axis to the outside.
However, Pluisch teaches the mechanisms of how density gradient centrifugation works (Abstract). Figure 1 further shows an illustration of these mechanisms (Page 27551):
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The Figure 1 caption states: “a density gradient is introduced at the edge of a hollow rotor, while it is spinning at reduced speed. Loading starts with the lightest portion of the gradient first, followed by layers of increasing densities. Once the gradient fills the rotor completely, the sample suspension is introduced at the rotor core as the last material loaded.” It can be seen from the figure that the lowest density of the gradient is closest to the rotor, while the highest is towards the edge. Therefore, it would have been obvious to one of ordinary skill to take the methods of Fiedler and apply the standard loading method of Pluisch of loading the lowest density to highest density, then adding the sample to the core/center of the rotor, all while rotating at a low speed. This will result in an arrangement of the AAV particle mixture at the rotation axis, liquid L (lower density), then liquid H1 (higher density), as claimed. The combination of familiar elements is likely to be obvious when it does no more than yield predictable results. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, A.). A rationale to support a conclusion that a claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would have yielded nothing more than predictable results to one of ordinary skill in the art. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 (2007) (see MPEP §§ 2143, A. and 2143.02).
Furthermore, the low and high rotation speeds are result-effective and it would have been obvious to one of ordinary skill before the time of filing to optimize the speeds. This is further supported by the ranges of speeds given in Fiedler and the Instant Specification. It has long been settled to be no more than routine experimentation for one of ordinary skill in the art to discover an optimum value of a result effective variable. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum of workable ranges by routine experimentation." Application of Aller, 220 F.2d 454, 456, 105 USPQ 233, 235-236 (C.C.P.A. 1955). "No invention is involved in discovering optimum ranges of a process by routine experimentation." Id. at 458, 105 USPQ at 236-237. The "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Application of Boesch, 617 F.2d 272, 276, 205 USPQ 215, 218-219 (C.C.P.A. 1980). Since Applicant has not disclosed that the specific limitations recited in instant claims are for any particular purpose or solve any stated problem, and the prior art teaches that parameter magnitudes that are encompassed by instant claims, often vary according to the sample being analyzed and various matrices, solutions and parameters appear to work equally as well, absent unexpected results, it would have been obvious for one of ordinary skill to discover the optimum workable ranges of the methods disclosed by the prior art by normal optimization procedures known in the art.
15. Claims 2-6 and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Fiedler (supra) and Pluisch (Supra) as applied to claims 1 and 15 above, and further in view of Maga (US 20230407328 A1; Provisional filed 02 November 2020).
Regarding claim 2, Fiedler and Pluisch make claim 1 obvious as discussed supra. All discussions thereon incorporated here. While Fiedler does teach the gradient can have three sugar solutions (¶ [0015]), they do not teach why. However, However, Maga teaches zonal ultracentrifugation (ZUC) of AAV (Abstract) wherein, “In various refinements of ZUC processing, a gradient compound is added to the composition and the composition is loaded between a cushion layer and an overlay layer in a rotor for zonal ultracentrifugation. After ZUC has been completed, a displacement solution is pumped into the rotor to force the cushion layer, composition, and overlay layer from the ZUC rotor. […] In ZUC processing, the overlay layer is first pumped into a spinning or stationary ZUC rotor, followed by the composition with the gradient compound and cushion layer. The cushion layer, overlay layer, and displacement solution also contain a gradient compound. Examples of gradient forming compositions include cesium chloride (CsCl), iodixanol, or sucrose. The cushion layer prevents particles (e.g., therapeutically effective rAAV) from pelleting against the wall of the rotor and the overlay layer prevents particles from migrating out of the gradient formed by the gradient compound. […] the concentration of the gradient compound in the cushion layer is greater than the composition. In further refinements, the concentration of the gradient in the compound is greater than the overlay layer.” (¶ [0067]).
In summary, Maga teaches a similar method to Fiedler, wherein the “overlay layer” would read on the lower density liquid B, the “composition with the gradient compound” would read on liquid L and the AAV particle mixed solution, the “cushion layer” would read on the liquid H1, and the “displacement solution” would read on liquid H2. Maga further teaches the loading order of the overlay layer, the AAV composition, and then the cushion layer. This would result in the overlay layer being the closest to the rotation axis and the cushion layer being the furthest. The loading of a zonal rotor by increasing density is well known in this art. The displacement solution is then used to push all the contents out of the zonal rotor.
Therefore, it would have been obvious to one of ordinary skill before the filing date to take the method of Fiedler and add an “overlay layer” liquid B that is a lower density than the virus particle mixed solution in order to prevent the particles from “migrating out of the gradient formed by the gradient compound.” (¶ [0067]). This prevents the particles from getting stuck at the core of the rotor. A rationale to support a conclusion that a claim would have been obvious is that there is some teaching, suggestion, or motivation in the prior art or in the knowledge generally available to one of ordinary skill in the art to modify the reference or combine reference teachings, and the modification or combination would have a reasonable expectation of success. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 (2007) (see MPEP §§ 2143, G. and 2143.02).
Regarding claims 3 and 12, Fiedler and Pluisch make claim 1 obvious as discussed supra. All discussions thereon incorporated here. Maga teaches the “displacement solution”, as discussed supra. Maga further teaches “After ZUC has been completed, a displacement solution is pumped into the rotor to force the cushion layer, composition, and overlay layer from the ZUC rotor.” (¶ [0067]). Maga does not teach the relative density of the displacement solution, where it is pumped, and where the fractions are eluted.
However, Pluisch teaches the mechanisms of how density gradient centrifugation works (Abstract). Figure 1 further shows an illustration of these mechanisms (Page 27551):
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wherein “At the end of the centrifuge run, the rotor speed is reduced again and its content is displaced out through the center exit by pumping a sufficiently dense solution into the edge line.” (Figure 1 caption). This would meet the limitation of being “introduced to the outside of the diameter direction”, as adding the displacement solution to the edge line (the left line in Figure 1) pushes it all the way to the outside of the gradient perpendicularly to the rotor axis.
Therefore, it would have been obvious to one of ordinary skill to take the method made obvious and further add a displacement solution that is denser than the liquid H1 to the outermost edge (“edge line”) to push out the fractions and remove them from the rotational axis side (“center exit”). The combination of familiar elements is likely to be obvious when it does no more than yield predictable results. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, A.). A rationale to support a conclusion that a claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would have yielded nothing more than predictable results to one of ordinary skill in the art. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 (2007) (see MPEP §§ 2143, A. and 2143.02).
Regarding claims 4 and 13, the usage of cesium chloride instead of sucrose is discussed by Fielder supra. It would further be obvious to use a cesium chloride solution for the concentration gradient instead of sucrose (the sugar gradient in Fiedler), as both are readily used in the art for this purpose. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, B.).
Regarding claims 5-6, Fiedler teaches that the virus particles are AAV particles, as discussed supra. Maga further teaches, in reference to the virus sample, “In various refinements, the density of the composition loaded into a ZUC rotor for ZUC processing is at least 1.347 grams per milliliters (g/mL)” (¶ [0072]). Therefore, it would be obvious for liquid L to be a lower density than the AAV mixture and liquid H1 to be a higher density than the AAV mixture. The relative densities of these liquids to the AAV mixtures and each other are discussed supra.
Furthermore, the densities of both of these liquids are result-effective as their relative densities will allow for the separation of the different AAV particles. Having a liquid L with a lower density than the AAV mixture will allow for separation of the lower-density empty AAV particles. Having a liquid H1 with a higher density than the AAV mixture will allow for the separation of higher-density full AAV particles. Additionally, it would have been obvious to one of ordinary skill before the time of filing to optimize these parameters. For the invention to work, the densities of the liquids and virus mixture do not necessarily need to be an exact number, they simply must be lower/higher relative to each other. It has long been settled to be no more than routine experimentation for one of ordinary skill in the art to discover an optimum value of a result effective variable. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum of workable ranges by routine experimentation." Application of Aller, 220 F.2d 454, 456, 105 USPQ 233, 235-236 (C.C.P.A. 1955). "No invention is involved in discovering optimum ranges of a process by routine experimentation." Id. at 458, 105 USPQ at 236-237. The "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Application of Boesch, 617 F.2d 272, 276, 205 USPQ 215, 218-219 (C.C.P.A. 1980). Since Applicant has not disclosed that the specific limitations recited in instant claims are for any particular purpose or solve any stated problem, and the prior art teaches that parameter magnitudes that are encompassed by instant claims, often vary according to the sample being analyzed and various matrices, solutions and parameters appear to work equally as well, absent unexpected results, it would have been obvious for one of ordinary skill to discover the optimum workable ranges of the methods disclosed by the prior art by normal optimization procedures known in the art.
Conclusion
16. No claim is allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KRISTINA E LY whose telephone number is (571)272-5169. The examiner can normally be reached Monday - Thursday, 8:00 am - 5:00 pm EST.
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/KRISTINA E. LY/Examiner, Art Unit 1671 /Michael Allen/Supervisory Patent Examiner, Art Unit 1671
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