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 .
Detailed Action
This is the Non-Final Action for application 18/221934 RCE filed 07/27/2026.
Claims 1 & 3-7 are pending and have been fully considered.
Claim 2 has been cancelled.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/27/2026 has been entered.
Information Disclosure Statement
The examiner notes that no IDS has been filed with this application.
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 1, 3 & 6-7 are rejected under 35 U.S.C. 103 as being obvious over GWERDER in US 20210101152 in view of MICHELS in Imaged Capillary Isoelectric Focusing for Charge-Variant Analysis of Biopharmaceuticals in further view of KAHLE in Determination of protein change variants with (imaged) capillary isoelectric focusing and capillary zone electrophoresis.
With respect to Claim 1, GWERDER teaches of systems for performing isoelectric focusing for separation and characterization of protein analyte mixture or other biological molecules by isoelectric point (abstract). GWERDER teaches that the term analyte and specific generally means a molecule that differs in a measurable property from another, wherein the measurable property can be change (paragraph 0093).
GWERDER more specifically teaches of the devices and methods they teach of being used for enrichment of an analyte mixture and analyte fractions (paragraph 0003, 0117-0119, 0158), and specifically of enriching protein fractions so that the enriched proteins migrate out of the sample outlets (paragraph 0272). GWERDER further teaches of characterization of samples through these methods (paragraphs 0003-0002).
GWERDER teaches of the method steps of a) providing a device comprising a planar substrate, wherein the planar substrate comprises a plurality of separation channels; b) introducing a sample comprising a mixture of analytes into at least two separation channels of the plurality of separation channels; c) controlling a voltage applied to the at least two separation channels to perform the plurality of isoelectric focusing reactions to separate the mixture of analytes of the sample in the at least two separation channels; and d) independently monitoring a current flowing through the at least two separation channels as the plurality of isoelectric focusing reactions are performed in parallel (paragraph 0010-0011) to detect separated analyte species—where there is mor than one species (paragraph 0136), species which again can differ by charge(paragraph 0093, 0126, 0138).
GWERDER even further teaches that the disclosed device may be fabricated as a series of parts (paragraph 0106), which includes a series of separation/isoelectric focusing capillary channels (paragraph 0105), so the isoelectric focusing is performed in a series or at least two parts as instant claimed (paragraph 0083, 0160, 0119, 0136, 0138, 0184), and that a series of images are acquired from the two or more separation channels (paragraph 0199, 0158).
GWERDER even further teaches of using capillary isoelectric focusing as the isoelectric focusing in the invention (paragraph 0126), and further that the separation channels (so capillary ISE channels) may be imaged, so this reads on the claimed imaged capillary electrophoresis (paragraph 0158).
GWERDER teaches that the mobilization step for the isoelectric focusing is chemical mobilization and that in some instances, the polarity of the applied electric field used to mobilize separated analyte bands may be such that analytes migrate towards an anode that is in electrical communication with the outlet or distal end of the separation channel (anodic mobilization). In some instances, the polarity of the applied electric field used to mobilize separated analyte bands may be such that analytes migrate towards a cathode that is in electrical communication with the outlet or distal end of the separation channel (cathodic mobilization) (paragraph 0138).
Therefore- GWERDER makes the method for enriching a species (which can be a charge variant) of a protein in a sample by subjecting the sample to isoelectric focusing in series, (so two isoelectric focusing steps as claimed), wherein the isoelectric focusing can be done in a capillary and imaged ( so imaged capillary isoelectric focusing). As GWERDER also teaches that in some instances different polarities are used, negative versus positive, this makes obvious to use a combination of a first polarity, then reversed phase polarity as claimed, to enrich the sample as is also taught above by GWERDER (as is also claimed).
Though GWERDER makes it obvious, if it is unclear that they teach of specifically choosing to separate by charge variants as claimed, MICHELS is used to remedy this.
MICHELS teaches of using imaged capillary isoelectric focusing for charge variant analysis of therapeutic proteins (Page 48, column 1, paragraph 1). MICHELS further teaches that the proteins are separated primarily on the basis of a molecules pI intrinsic net charge (Page 48, column 3, paragraph 1 & 2).
Even more specifically, MICHELS teaches of subjecting a sample to imaged capillary isoelectric focusing (iCIEF) to separate an antibody-drug conjugate (Figure 1) and a rMAb protein (Figure 2) into acidic charge variants and basic charge variants, which means the antibody (protein)-drug conjugate contains “more than one charge variant species,” as instantly claimed.
It would have been obvious to one of ordinary skill in the art to choose to separate by charge variant as is done by MICHELS in the method of GWERDER and one would have had reasonable expectation of success due to the advantage analyzing by charge variants of therapeutic proteins has for characterizing and monitoring quality attributes of antibodies (MICHELS, Page 48, column 1, first line).
Though GWERDER makes it obvious, GWERDER and MICHELS do not teach specifically choosing reversed phased capillary isoelectric focusing as a second step in a process.
KAHLE is used to remedy this and teaches of a method for determination of protein charge variants using imaged capillary isoelectric focusing (cIEF) (title and abstract). KAHLE teaches that in cIEF/icEIF, a pH gradient is built up in the capillary and ampholytic analytes migrate to the pH zone that corresponds to their pI value. This self-regulating process is called focusing and is responsible for the high separation efficiency of cIEF. To detect the analytes, the capillary content must pass the detector. This can be done in several ways, mostly through a following chemical or pressure mobilization step (Page 2492, column 2, last paragraph, lines 12-19).
KAHLE further teaches of make consecutive cIEF/icIEF separations (Figure 1 description, Page 2507, column 1, last paragraph).
KAHLE further teaches that the mobilization for the cIEF/icIEF can be performed using a reversed pH gradient, and to do this the positions of the anolyte and catholyte changing, and also carryings out both focusing and mobilization in negative polarity (Page 2502, column 2, paragraph 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to reverse the polarity as is done in KAHLE in the method of MICHELS and GWERDER and one would have had reasonable expectation of success due to the advantage in situations where analytes focus near the anolyte to reduce the mobilization path (KAHLE, page 2502, column 2, paragraph 2).
With respect to Claim 3, GWERDER teaches introducing a plurality of samples (paragraph 0010, 0011), and further of analyzing a plurality of analyte species (paragraph 0096, 0093, 0083, 0106) so this reads on the claimed repeating to provide “one or more additional enriched fractions, as instantly claimed.
With respect to Claim 6, GWERDER teaches introducing a plurality of samples (paragraph 0010, 0011), and further of analyzing a plurality of analyte species in series where the species can be different charge variants (paragraph 0096, 0093, 0083-0106) so this reads on the claimed repeating to provide “one or more additional enriched fractions, as instantly claimed. MICHELS teaches of using imaged capillary isoelectric focusing for charge variant analysis of therapeutic proteins (Page 48, column 1, paragraph 1).
MICHELS also teaches that the proteins are separated primarily on the basis of a molecules pI intrinsic net charge (Page 48, column 3, paragraph 1 & 2).MICHELS teaches of subjecting a sample to imaged capillary isoelectric focusing (iCIEF) to separate an antibody-drug conjugate (Figure 1) and a rMAb protein (Figure 2) into acidic charge variants and basic charge variants, which means the antibody (protein)-drug conjugate contains “more than one charge variant species,” as instantly claimed.
With respect to Claim 7, GWERDER teaches that the protein of interest is a biologic therapeutic, an antibody therapeutic (paragraph 0254) or antibody among other things (paragraph 0096). MICHELS also teaches of the protein being an antibody (Figure 1) or of it being a rMAB (recombinant monoclonal antibody/protein (Figure 2).
Claim 5 is rejected under 35 U.S.C. 103 as being obvious over GWERDER in US 20210101152 in view of MICHELS in Imaged Capillary Isoelectric Focusing for Charge-Variant Analysis of Biopharmaceuticals in further view of KAHLE in Determination of protein change variants with (imaged) capillary isoelectric focusing and capillary zone electrophoresis and further in view of GENTALEN in US 20210181148.
With respect to Claim 5, GWERDER and MICHELS and KAHLE teach of the above, including separation of many species (which would include 2-10) by charge variant (paragraph 0093, 0096). GWERDER also teaches of using ion exchange, but does not call out using it specifically after IEF (paragraph 0134).
GENTALEN is used to remedy this. GENTALEN teaches of a method for characterization of analyte mixtures. Some methods described herein include performing enrichment steps on a device before expelling enriched analyte fractions from the device for subsequent analysis (abstract). More specifically, GENTALEN teaches that the method is for separating a mixture of charge variants of one or more biologics (Claim 31) (which reads on 2 to 10), which can be proteins (paragraph 0009-0010).
GENTALEN more specifically teaches that ion exchange chromatography can be used for chromatographic separation (paragraph 0045-0046), and that enriching the sample can include ion exchange chromatography and isoelectric focusing (paragraph 0076, 0100, 0101). GENTALEN further teaches that any combination of components and features described therein can be used together (paragraph 0137).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instant invention to use ion exchange chromatography in addition to isoelectric focusing as is done in GENTALEN in the methods of MICHELS and KAHLE and one would have had reasonable expectation of success due to the advantage ion exchange offers for capturing analytes based on charge (GENTALEN, paragraph 0046, 0101).
Claim 4 is rejected under 35 U.S.C. 103 as being obvious over GWERDER in US 20210101152 in view of MICHELS in Imaged Capillary Isoelectric Focusing for Charge-Variant Analysis of Biopharmaceuticals in further view of KAHLE in Determination of protein change variants with (imaged) capillary isoelectric focusing and capillary zone electrophoresis and further in view of LIU in US 20080206102.
With respect to Claim 4, GWERDER and MICHELS and KAHLE teach of the claims as shown above, but do not teach of combining the fractions for an enriched sample.
LIU teaches of a method and device for simultaneous separation, fractionation, and collection of samples simultaneously (abstract). LIU further teaches that the method uses isoelectric focusing (IEF) in capillary tubes (paragraph 0023)—so reads on capillary isoelectric focusing. LIU teaches that the separation is based on the charge properties (charges and charge variants) of the protein and sample (paragraph 0004).
LIU further teaches the IEF sample is prepared by mixing ampholytes with a protein sample (paragraph 0025-0027), the sample is the loaded into the continuous capillary (the thin-line of FIG. 1A) (paragraph 0029), and then the IEF is run (paragraph 0030) that the sample including protein of interest is subjected to isoelectric focusing to separate said charge variant of protein of interest as claimed.
The proteins are collected inside the segmented capillaries. It is noted that although the sample is "split" into 100 fractions, proteins of similar pI are "focused" in one or two (combined) fractions after IEF (paragraphs 0030-0031, & 0023 & 0025). This reads on the instant step b), which requires collecting, “at least one,” fraction, and also instant step c) which requires repeating steps a) and b) “at least once,” since the 100 initial fractions read on repeating the IEF, and collecting “two,” fractions reads on repeating the collecting. Since the 100 fractions are narrowed down to two collected samples, this means that from the 100 samples the proteins of interested are collected and combined into one or two samples as claimed for instant step d). So, as claimed, combining of two charge variants as is the very least that is done here, reads on the instant claiming of combining the enriched fractions from step a) -c) since only one additional fraction to that in Claim 1 is required.
Protein “enrichment,” is the concentrating of specific proteins or making them more abundant for analysis. LIU teaches of concentration of the proteins by IEF so this reads on the claimed “method for enriching,” (paragraph 0016). The protein separated is the “charge variant,” of the protein of interest (paragraph 0004).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to collect the protein samples as is done in LIU in the methods of GWERDER and MICHELS and KAHLE and one would have had reasonable expectation of success due to the advantage this offers for retaining resolution of IEF (paragraph 0031).
Response to Arguments
Applicant's arguments filed 06/26/2026 have been fully considered but they are not persuasive.
With respect to the prior 112 rejection, it has been overcome due to amendments made 06/26/2026.
Applicant’s arguments with respect to claim(s) have been considered but are moot because the new ground of rejection does not rely on the combination of references applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
MADDEN in Reverse Isoelectric Focusing Procedure Resolves Charge Variants of Basic Proteins
MADDEN is used to remedy this. MADDEN further teaches of reverse isoelectric focusing for resolving charge variants of basic proteins (title). MADDEN further teaches that NEPHGE, nonequilibrium pH gradient electrophoresis is used (Page 203, column 2, paragraphs 1-2), and that they have chosen to call this procedure “reverse IEF,” (page 203, column 1, paragraph 1) and that this technique resolves/separates charge variants of basic proteins (title). NEPHGE, which MADDEN names reverse IEF, is the same method used in LIU.
REN in Isoforms analysis of recombinant human erythropoietin by polarity-reversed capillary isoelectric focusing.
REN teaches of methods for analysis of proteins using isoelectric focusing and more specifically of using reversed polarity capillary isoelectric focusing, after a method is performed using regular capillary isoelectric focusing (abstract)—this reads on the claimed enriching and providing of an enriched sample through broadest reasonable interpretation. REN teaches that the second step is done to enable for better detection of acid proteins with pI < 5.5 (See Figure 1, figure 1 description, and Page 2057, column 1, first paragraph).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to REBECCA M FRITCHMAN whose telephone number is (303)297-4344. The examiner can normally be reached 9:30-4:30 MT Monday-Friday.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Maris Kessel, can be reached on 571-270-7698. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/REBECCA M FRITCHMAN/Primary Examiner, Art Unit 1758
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