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 .
Claim Objections
Claim 21 is objected to because of the following informalities:
In Claim 21, “the sample” in line 1 of the claim should read “the plasma sample”.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
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 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.
Claims 1 and 61-64 are rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky et al (International Patent Application No. WO 2019133842 A1) hereinafter Berzofsky in view of Hong et al (Hong P, Koza S, Bouvier ES. Size-Exclusion Chromatography for the Analysis of Protein Biotherapeutics and their Aggregates. J Liq Chromatogr Relat Technol. 2012 Nov;35(20):2923-2950. doi: 10.1080/10826076.2012.743724. Epub 2012 Nov 30. PMID: 23378719; PMCID: PMC3556795) hereinafter Hong in view of Schlegl et al (International Patent Application No. WO 2016156613 A1) hereinafter Schlegl in view of Hall (Martin Hall, Chapter 21 - Size Exclusion Chromatography (SEC), Biopharmaceutical Processing, Elsevier, 2018, Pages 421-432, ISBN 9780081006238, https://doi.org/10.1016/B978-0-08-100623-8.00021-9) hereinafter Hall in view of Marshall (Dr. William Marshall, “Total Protein”, 2010, https://labmed.org.uk/our-resources.html?searchQuery=total+protein) hereinafter Marshall.
Regarding Claim 1, Berzofsky in view of Hong teach the combination of the basic steps of the process, while Schlegl and Hall teach various optimizations that are well known in the art of chromatography. Marshall is used strictly as a reference for well-known properties of a plasma sample.
Berzofsky teaches a method of purifying extracellular vesicles (i.e., a method for purifying extracellular vesicles; Paragraph 0006) from a biofluid sample that can be plasma (i.e., from a plasma sample; Paragraph 0022) that comprises mixing a resin composition that traps particles by a size exclusion mechanism (i.e., (c) combining the fractions with size-exclusion beads) and then separating the sample from the resin composition to obtain extracellular vesicles at a higher concentration than prior to mixing the resin composition (i.e., and (d) separating and removing the size-exclusion beads from the mixture, such that the extracellular vesicles remain, thereby purifying the extracellular vesicles from the plasma sample; Paragraph 0006) where the beads can be modified to capture small unbound molecules with a molecular weight cut off for entry of less than or equal to 700 kDa (i.e., capable of capturing molecules smaller than about 700 kDa to create a mixture; Paragraph 0018) where the size exclusion resin comprises beads with a porous core comprising at least one affinity ligand and a porous shell wherein the porous shell of the bead is non-functionalized (i.e., wherein the size-exclusion beads comprise an inactive exterior; Paragraph 0029) while extracellular vesicles can be positively selected by affinity binding in a transient manner (Paragraph 0031), and that the affinity ligand can be tri-octyl amine (i.e., and a core with an octylamine ligand; Paragraph 0046). Berzofsky further teaches that the filtering of the sample may be desired to remove some of the unbound molecules prior to the first step of the method (i.e., prior to combining with the size-exclusion beads capable of capturing molecules smaller than about 700 kDa; Paragraph 0021).
Berzofsky does not teach subjecting the plasma sample to a size exclusion chromatography (SEC) column, collecting fractions containing the extracellular vesicles from the SEC column, and combining the fractions collected from the SEC column with size-exclusion beads.
However, Hong teaches that further polishing is required after size exclusion chromatography which includes gel-filtration for the purpose of purification processes for biopharmaceuticals (i.e., subjecting the plasma sample to a size exclusion chromatography (SEC) column, collecting fractions containing the extracellular vesicles from the SEC column, and combining the fractions collected from the SEC column with size-exclusion beads; Page 2942, Paragraph 3). Gel-filtration is a known analogous operation to size exclusion chromatography and Hong is essentially teaching the series operation of multiple size exclusion chromatography with the purpose of the second column to increase the purity of a desired component in the sample.
Hong is analogous to the claimed invention because it pertains to size exclusion chromatography (Abstract) discusses human serum as a known sample characterized by size exclusion chromatography (Page 2938, ‘Flow Rate’). It would have been obvious to one of ordinary skill in the art to modify the method of purifying the extracellular vesicles as taught by Berzofsky with a step of size exclusion chromatography prior as taught by Hong because the prior step would create a higher purity sample of extracellular vesicles as the final product.
Berzofsky in view of Hong does not teach wherein the size-exclusion beads are suspended in an equal volume of a buffer to create a slurry.
However, Schlegl teaches the use of a chromatography resin prepared in a 50% slurry (i.e., wherein the size-exclusion beads are suspended in an equal volume of a buffer to create a slurry) with phosphate buffered solution (PBS) with CAPTO® Core 700 resin (i.e., size-exclusion beads) slurry showing a significant reduction of residual impurities (Page 20, Lines 22-33).
Schlegl is analogous to the claimed invention because it pertains to the separation of small biological particles from biological samples (Page 1). It would have been obvious to one of ordinary skill in the art to modify the resin composition made obvious by Berzofsky in view of Hong with the phosphate buffered solution slurry as taught by Schlegl because the slurry would significantly reduce residual impurities in the sample.
Berzofsky in view of Hong in view of Schlegl does not teach wherein the ratio between the size-exclusion bead slurry and the total protein in the plasma sample is about 2.5 µg protein per 1 µL size-exclusion bead slurry to about 0.6 µg protein per 1 µL size-exclusion bead slurry.
However, Hall teaches that concentrated samples are preferred for size exclusion chromatography and that the column volume of the sample should be 2-30% depending on the type of application and factors such as the size of the target molecule and the size of the molecules that are being removed or exchanged (Page 425, ’21.3 Application Areas’). Marshall teaches that the expected total protein value for a plasma sample from an adult human is between 60-80 g/L (Page 2, Section 5.1.1). Through the combination of these teachings we are given a 50% size exclusion bead slurry, a 2-30% sample volume based upon column volume, and a total protein concentration of blood of 60-80 g/L. Given a column volume of 1 mL, that converts to a 500 µL size exclusion bead volume, a 20-300 µL sample volume, and a total protein concentration of 60-80 µg/µL. Calculating the standard range of protein mass per size exclusion bead volume with the low sample size and protein concentration ((20 µL of sample * 60 µg/µL)/500 µL of bead volume) to the high sample size and protein concentration ((300 µL of sample * 80 µg/µL)/500 µL of bead volume), a range of 2.4 – 48 µg of protein/µL of size exclusion bead volume is obtained (i.e., wherein the ratio between the size-exclusion bead slurry and the total protein in the plasma sample is about 2.5 µg protein per 1 µL size-exclusion bead slurry to about 0.6 µg protein per 1 µL size-exclusion bead slurry).
Hall is analogous to the claimed invention because it pertains to size exclusion chromatography (Page 421, ‘Introduction’) which is used in the purification of plasma molecules (Page 425, ’21.4 Examples’) and Hall is analogous to the claimed invention because it pertains to total protein concentrations of serum, plasma (Page 1, Sections 1 and 2). It would have been obvious to one of ordinary skill in the art to modify the method of purifying the extracellular vesicles made obvious by Berzofsky in view of Hong in view of Schlegl with the protein mass to size exclusion bead volume ratio as taught by Hall in view of Marshall because the sample loading would improve the separation of target molecules from undesired molecules.
Furthermore, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall does not teach the explicit ratio between the size-exclusion bead slurry and the total protein in the plasma sample is about 2.5 µg protein per 1 µL size-exclusion bead slurry to about 0.6 µg protein per 1 µL size-exclusion bead slurry in the instant claim. However, a prima facie case of obviousness exists for claimed ranges that overlap or lie inside ranges disclosed by prior art (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976))(See MPEP 2144.05(I)). It would have been obvious to one having ordinary skill in the art to have selected the ratio that corresponds to the claimed range while experimenting with the range made obvious by Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall.
Regarding Claim 61, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 1. Schlegl further teaches the use of a chromatography resin prepared in a 50% slurry with phosphate buffered solution (PBS) (i.e., wherein the buffer is PBS buffer) with CAPTO® Core 700 resin (i.e., size-exclusion beads) slurry showing a significant reduction of residual impurities (Page 20, Lines 22-33).
Regarding Claim 62, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 1. Berzofsky further teaches contacting (i.e., mixed) the sample with the resin composition and then separating the sample and the resin composition (i.e., wherein the mixture is mixed prior to separating and removing the size-exclusion beads; Abstract).
Regarding Claim 63, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 62. Berzofsky further teaches that the contact time is from 1 hour or less and from 30 minutes or more (i.e., wherein the mixture is mixed for between 30 minutes and 1 hour; Paragraph 0051).
Regarding Claim 64, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 1. Berzofsky further teaches in an example that, after mixing the sample and the resin composition, the tubes were spun in a centrifuge and the resin forms a pellet (i.e., wherein the size-exclusion beads are separated from the mixture using centrifugation; Paragraph 0140).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall as applied to claim 1 above, and further in view of Hof et al (US Patent Application No. 20170052154 A1) hereinafter Hof.
Regarding Claim 19, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 1. Hong further teaches that agarose is a known polymeric resin for size exclusion chromatography (Page 2925, Paragraph 2 to Page 2926, Paragraph 1). Hall further teaches that resins for size exclusion chromatography may be constructed from cross-linked agarose (Page 421, ’21.1 Introduction’).
Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall does not explicitly teach wherein the size exclusion chromatography column comprises a stationary phase comprising a 6% cross-linked agarose size exclusion chromatography base matrix.
However, Hof teaches that agarose resins are typically known to contain 2-6% crosslinked agarose by weight for use in size exclusion chromatography because the agarose porous channels are large enough to allow biomolecules to pass through (i.e., wherein the size exclusion chromatography column comprises a stationary phase comprising a 6% cross-linked agarose size exclusion chromatography base matrix; Paragraph 0097).
Hof is analogous to the claimed invention because it pertains to chromatography columns to separate biomolecules (Abstract). Hof teaches a range of 2%-6% crosslinked agarose for size exclusion chromatography. Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall in view of Hof does not explicitly teach a 6% cross-linked agarose size exclusion chromatography base matrix. However, a prima facie case of obviousness exists for claimed ranges that overlap or lie inside ranges disclosed by prior art (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976))(See MPEP 2144.05(I)). It would have been obvious to one of ordinary skill in the art to have selected the 6% cross-linked agarose when experimenting with the range made obvious by Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall in view of Hof.
Claims 21-22 are rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall as applied to claim 1 above, and further in view of Frechet et al (US Patent No. 5316680 A) hereinafter Frechet.
Regarding Claim 21, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 1. Berzofsky further teaches that the filtering of the sample may be desired to remove some of the unbound molecules prior to the first step of the method (i.e., prior to combining with the size-exclusion beads capable of capturing molecules smaller than about 700 kDa; Paragraph 0021). Hong further teaches that further polishing is required after size exclusion chromatography which includes ion exchange for the purpose of purification processes for biopharmaceuticals (Page 2942, Paragraph 3). Hall further teaches a chromatography process that contained two size exclusion chromatography steps and one ion exchange step (Page 427, Paragraph 2).
Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall does not teach wherein the sample is further subjected to a cation exchange chromatography resin after the size exclusion chromatography column.
However, Frechet teaches size exclusion chromatography combined with ion exchange used consecutively (i.e., further subjected to an ion exchange chromatography resin after the size exclusion chromatography column; Col. 6, Line 53 to Col. 7, Line 6) where the ion chromatography separates ionic species, typically low molecular weight cations (i.e., a cation exchange chromatography resin; Col. 2, Lines 26-32) with the purpose of separating molecules that have different sizes and polarities from samples with multiple different molecules (Col. 5, Lines 27-34).
It would be obvious to one of ordinary skill in the art to modify the method made obvious by Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall with the prefilter chromatography as taught by Frechet because it would reduce the amount of unbound particles from the sample by size and polarity prior to purifying the extracellular vesicles.
Regarding Claim 22, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall in view of Frechet makes obvious the method of claim 21. Frechet further teaches that the fixed ions of the ion exchange are from acidic groups such as carboxyl and sulfonate (i.e., wherein the cation exchange chromatography resin comprises a stationary phase comprising a functional group selected from the group consisting of sulfonate; Col. 2, Lines 15-25).
Claim 65 is rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall as applied to claim 64 above, and further in view of James et al (James KT, Cooney B, Agopsowicz K, Trevors MA, Mohamed A, Stoltz D, Hitt M, Shmulevitz M. Novel High-throughput Approach for Purification of Infectious Virions. Sci Rep. 2016 Nov 9;6:36826. doi: 10.1038/srep36826. PMID: 27827454; PMCID: PMC5101806) hereinafter James.
Regarding Claim 65, Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall makes obvious the method of claim 64. Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall does not teach wherein the centrifugation is about 600g, 700g, 800g, or 900g.
However, James teaches the purification of a resin bead slurry by subjecting the sample to centrifugation at 800 x g for 10 minutes after adding the slurry to the sample (i.e., wherein the centrifugation is about 800g; Supplementary Materials and Methods, (C) Purification Capto700 Slurry, Pages 14-15) for the purpose of efficiently removing confounding cellular contaminants in a high-throughput manner (Abstract).
James is analogous to the claimed invention because it pertains to high-throughput chromatography with resin beads being added to a sample (Abstract). It would have been obvious to one of ordinary skill in the art to modify the centrifugation step made obvious by Berzofsky in view of Hong in view of Schlegl in view of Hall in view of Marshall to be performed at 800g as taught by James because it would efficiently remove confounding cellular contaminants in a high-throughput manner.
Claims 66-70 are rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky et al (International Patent Application No. WO 2019133842 A1) hereinafter Berzofsky in view of Schlegl et al (International Patent Application No. WO 2016156613 A1) hereinafter Schlegl in view of GE Healthcare Bio-Sciences AB (GE Healthcare Bio-Sciences AB, ‘Instructions 28-9958-81 AF’, 04/2014) hereinafter GE in view of Bourque et al (Pierre R. Bourque, Ari Breiner, David Moher, John Brooks, Harald Hegen, Florian Deisenhammer, Christopher R. McCudden, Adult CSF total protein: Higher upper reference limits should be considered worldwide. A web-based survey, Journal of the Neurological Sciences, Volume 396, 2019, Pages 48-51, ISSN 0022-510X, https://doi.org/10.1016/j.jns.2018.10.033.) hereinafter Bourque.
Regarding Claim 66, Berzofsky teaches the basic steps of the process, while Schlegl and GE teach various optimizations that are well known in the art of chromatography. Bourque is used strictly as a reference for well-known properties of a cerebrospinal fluid sample.
Berzofsky teaches a method of purifying extracellular vesicles (i.e., a method for purifying extracellular vesicles; Paragraph 0006) from a biofluid sample that can be cerebrospinal fluid (i.e., from a cerebrospinal fluid (CSF) sample; Paragraph 0022) that comprises mixing a resin composition that traps particles by a size exclusion mechanism (i.e., (a) combining the fractions with size-exclusion beads) and then separating the sample from the resin composition to obtain extracellular vesicles at a higher concentration than prior to mixing the resin composition (i.e., and (b) separating and removing the size-exclusion beads from the mixture, such that the extracellular vesicles remain, thereby purifying the extracellular vesicles from the plasma sample; Paragraph 0006) where the beads can be modified to capture small unbound molecules with a molecular weight cut off for entry of less than or equal to 700 kDa (i.e., capable of capturing molecules smaller than about 700 kDa to create a mixture; Paragraph 0018) where the size exclusion resin comprises beads with a porous core comprising at least one affinity ligand and a porous shell wherein the porous shell of the bead is non-functionalized (i.e., wherein the size-exclusion beads comprise an inactive exterior; Paragraph 0029) while extracellular vesicles can be positively selected by affinity binding in a transient manner (Paragraph 0031), and that the affinity ligand can be tri-octyl amine (i.e., and a core with an octylamine ligand; Paragraph 0046).
Berzofsky does not teach wherein the size-exclusion beads are suspended in an equal volume of a buffer to create a slurry.
However, Schlegl teaches the use of a chromatography resin prepared in a 50% slurry (i.e., wherein the size-exclusion beads are suspended in an equal volume of a buffer to create a slurry) with phosphate buffered solution (PBS) with CAPTO® Core 700 resin (i.e., size-exclusion beads) slurry showing a significant reduction of residual impurities (Page 20, Lines 22-33).
Schlegl is analogous to the claimed invention because it pertains to the separation of small biological particles from biological samples (Page 1). It would have been obvious to one of ordinary skill in the art to modify the resin composition as taught by Berzofsky with the phosphate buffered solution slurry as taught by Schlegl because the slurry would significantly reduce residual impurities in the sample.
Berzofsky in view of Schlegl does not teach wherein the ratio between the size-exclusion bead slurry and the total protein in the CNF sample is about 10 µg protein per 1 µL size-exclusion bead slurry to about 2.5 µg protein per 1 µL size-exclusion bead slurry.
However, GE teaches that it is typical for 5 to 20 column volumes of sample to be able to be loaded onto Capto Core 700 but the maximum sample volume should be optimized for the desired purity (Page 9, ‘Sample Load’). Bourque teaches that the expected total protein value for an adult cerebrospinal fluid sample is between 0.15-0.6 g/L (Page 48). Through the combination of these teachings we are given a 50% size exclusion bead slurry, a 5x-20x sample volume based upon column volume, and a total protein concentration of blood of 0.15-0.6 g/L. Given a column volume of 1 mL, that converts to a 500 µL size exclusion bead volume, a 5,000-20,000 µL sample volume, and a total protein concentration of 0.15-0.6 µg/µL. Calculating the standard range of protein mass per size exclusion bead volume with the low sample size and protein concentration ((5,000 µL of sample * 0.15 µg/µL)/500 µL of bead volume) to the high sample size and protein concentration ((20,000 µL of sample * 0.6 µg/µL)/500 µL of bead volume), a range of 1.5 – 24 µg of protein/µL of size exclusion bead volume is obtained (i.e., wherein the ratio between the size-exclusion bead slurry and the total protein in the CNF sample is about 10 µg protein per 1 µL size-exclusion bead slurry to about 2.5 µg protein per 1 µL size-exclusion bead slurry).
GE is analogous to the claimed invention because it pertains to size exclusion chromatography, and more specifically the use of Capto Core 700 chromatography medium which has an inert outer layer with a ligand-activated core used for the purification and polishing of large biomolecules (Page 1) and Bourque is analogous to the claimed invention because it pertains to total protein concentrations of cerebrospinal fluid (Page 48). It would have been obvious to one of ordinary skill in the art to modify the method of purifying the extracellular vesicles made obvious by Berzofsky in view of Schlegl with the protein mass to size exclusion bead volume ratio as taught by GE in view of Bourque because the sample loading would improve the purity of the desired biomolecules.
Furthermore, Berzofsky in view of Schlegl in view of GE in view of Bourque does not teach the explicit ratio between the size-exclusion bead slurry and the total protein in the CNF sample is about 10 µg protein per 1 µL size-exclusion bead slurry to about 2.5 µg protein per 1 µL size-exclusion bead slurry in the instant claim. However, a prima facie case of obviousness exists for claimed ranges that overlap or lie inside ranges disclosed by prior art (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976))(See MPEP 2144.05(I)). It would have been obvious to one having ordinary skill in the art to have selected the ratio that corresponds to the claimed range while experimenting with the range made obvious by Berzofsky in view of Schlegl in view of GE in view of Bourque.
Regarding Claim 67, Berzofsky in view of Schlegl in view of GE in view of Bourque makes obvious the method of claim 66. Schlegl further teaches the use of a chromatography resin prepared in a 50% slurry with phosphate buffered solution (PBS) (i.e., wherein the buffer is PBS buffer) with CAPTO® Core 700 resin (i.e., size-exclusion beads) slurry showing a significant reduction of residual impurities (Page 20, Lines 22-33).
Regarding Claim 68, Berzofsky in view of Schlegl in view of GE in view of Bourque makes obvious the method of claim 66. Berzofsky further teaches contacting (i.e., mixed) the sample with the resin composition and then separating the sample and the resin composition (i.e., wherein the mixture is mixed prior to separating and removing the size-exclusion beads; Abstract).
Regarding Claim 69, Berzofsky in view of Schlegl in view of GE in view of Bourque makes obvious the method of claim 68. Berzofsky further teaches that the contact time is from 1 hour or less and from 30 minutes or more (i.e., wherein the mixture is mixed for between 30 minutes and 1 hour; Paragraph 0051).
Regarding Claim 70, Berzofsky in view of Schlegl in view of GE in view of Bourque makes obvious the method of claim 66. Berzofsky further teaches in an example that, after mixing the sample and the resin composition, the tubes were spun in a centrifuge and the resin forms a pellet (i.e., wherein the size-exclusion beads are separated from the mixture using centrifugation; Paragraph 0140).
Claim 71 is rejected under 35 U.S.C. 103 as being unpatentable over Berzofsky in view of Schlegl in view of GE in view of Bourque as applied to claim 70 above, and further in view of James.
Regarding Claim 71, Berzofsky in view of Schlegl in view of GE in view of Bourque makes obvious the method of claim 70. Berzofsky in view of Schlegl in view of GE in view of Bourque does not teach wherein the centrifugation is about 600g, 700g, 800g, or 900g.
However, James teaches the purification of a resin bead slurry by subjecting the sample to centrifugation at 800 x g for 10 minutes after adding the slurry to the sample (i.e., wherein the centrifugation is about 800g; Supplementary Materials and Methods, (C) Purification Capto700 Slurry, Pages 14-15) for the purpose of efficiently removing confounding cellular contaminants in a high-throughput manner (Abstract).
It would have been obvious to one of ordinary skill in the art to modify the centrifugation step made obvious by Berzofsky in view of Schlegl in view of GE in view of Bourque to be performed at 800g as taught by James because it would efficiently remove confounding cellular contaminants in a high-throughput manner.
Response to Amendment
The amendment filed 07/14/2025 has been entered.
In view of the amendment to the claims, the amendment of claims 1, 19, 22, and 61, the cancellation of claims 2, 5, 13, 18, 24, and 60, and the addition of new claims 66-71 have been acknowledged.
In view of the amendment to the specification, the objections to the specification have been withdrawn.
In view of the amendment to claims 1 and 22 and the cancellation of claims 13, 18, and 60, the previous claim objections have been withdrawn.
In view of the amendment to claims 1, 19, 22, and 61 and the cancellation of claims 13, 18, and 24, the rejections under 35 U.S.C. 112(b) have been withdrawn.
In view of the amendment to claim 1, the rejections under 35 U.S.C. 102 have been withdrawn and new rejections under 35 U.S.C. 103 have been made.
Response to Arguments
Applicant’s arguments filed on 07/14/2025 have been fully considered.
Applicant argues, regarding claims 1 and 61, that Berzofsky in view of Schlegl does not teach the newly amended limitations of claim 1 (Arguments filed 07/14/2025, Pages 11-15).
Applicant argues, regarding claims 1 and 21-22, that Berzofsky in view of Frechet does not teach the newly amended limitations of claim 1 (Arguments filed 07/14/2025, Page 16 to Page 18, Paragraph 4).
Applicant argues, regarding claims 1 and 19, that Berzofsky in view of Frechet in view of Hof does not teach the newly amended limitations of claim 1 (Arguments filed 07/14/2025, Page 18, Paragraph 5 to Page 20).
Applicant argues, regarding claims 1 and 65, that Berzofsky in view of James does not teach the newly amended limitations of claim 1 (Arguments filed 07/14/2025, Pages 21-23).
Applicant argues that the process of the instant application is superior to the prior art because the process completely removes albumin, requires only a small sample volume of 1 mL, is extremely efficient, capable of being used in high throughput applications, and able to recover at least 2 fold more extracellular vesicles from cerebrospinal fluid samples (Arguments filed 07/14/2025, Page 13, Paragraph 5 to Page 15).
The Examiner respectfully disagrees.
Applicant’s arguments with respect to claims 1 and 61 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant’s arguments with respect to claims 1 and 21-22 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant’s arguments with respect to claims 1 and 19 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant’s arguments with respect to claims 1 and 65 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
The arguments presented above have all been addressed with new prior art. Additionally, the new rejections include evidence that the general method is known in the art and that the specific limitations are parameters that are known in the art of chromatography for routine optimization. Essentially, Berzofsky introduces the use of size exclusion beads that encompass the well-known Capto Core 700 beads. Other prior art demonstrates that it is known to serially combine various chromatography processes and that Capto Core 700 beads are known to function within certain sample volume ranges, to be loaded in a column with certain bead to buffer ratios, and to be removed from a sample via certain centrifugal forces.
Regarding Applicant’s arguments for the unexpected benefits of the instant method, the application for the removal of albumin is not claimed and is an expected result which would occur with the normal use of Capto Core 700 beads. The benefits of being extremely efficient, capable of being used in high throughput applications, and able to recover at least 2 fold more extracellular vesicles from cerebrospinal fluid samples are also expected results of an improvement. The main goals of chromatography are purity and quantity of target molecule(s). Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established (In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)). See MPEP §2112.01(I).
Regarding Applicant’s arguments for the unexpected benefits of the instant method, the small sample volume is shown to be an optimizable factor with column volumes ranging from a single milliliter to hundreds of milliliters and sample volumes being measure in 2% of column volume up to 20 times the column volume. Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation absent unexpected results or evidence indicating such optimum or workable ranges are critical (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP§2144.05).
Applicant’s arguments have been fully considered but they are not persuasive. All other arguments have been indirectly addressed.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ADAM ADRIEN GERMAIN whose telephone number is (703)756-5499. The examiner can normally be reached Mon - Fri 7:30-4:30.
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/A.A.G./Examiner, Art Unit 1777
/Ryan B Huang/Primary Examiner, Art Unit 1777