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 Status
Claims 1-13 and 15-20 were previously pending.
A non-final Office Action was mailed 04 December 2025.
In response to the 04 December 2025 non-final Office Action, Applicants submitted an Amendment and Response received 02 March 2026.
In their 02 March 2026 response, Applicant has amended claim 20 and added claims 21-22.
Therefore, claims 1-13 and 15-22 are now pending.
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 20-22 are rejected under 35 U.S.C. 103 as being unpatentable over Pierce (“Protein A IgG Purification Kit,” revision dated: January 2007) in further view of Uptima (“Affinity support for the purification of IgG antibodies,” version referenced published online: 19 August 2021 (via WayBack machine) and Amicon (“Amicon Pro Affinity Concentration Kit – Protein G,” revision dated February 2013).
Pierce teaches purification of antibodies from a sample using a Protein A IgG purification kit, whereby the kit contains:
Protein A columns pre-packed with Protein A coupled beaded agarose resin (p. 1);
IgG Elution Buffer, 500 mL, pH 2.8, contains amine (p. 1); and
Protein A IgG Binding Buffer, 1 L, pH 8.0, contains EDTA as a preservative (p. 1).
In addition, Pierce teaches a Neutralization Buffer is required for kit use and provides instructions to prepare 1 mL of a high-ionic strength alkaline buffer such as 1 M phosphate, pH 7.5-9 (p. 2).
Therefore, regarding instant claims 20-22, Pierce teaches the following:
A kit for treating a sample fluid containing a target antibody and a pre-packaged column (housing) containing Protein A coupled beaded agarose resin (sorbent with affinity for the targeted antibody, IgG); and
Use of the kit with a neutralization buffer, 1 M phosphate, between pH 7.5-9. The phosphate buffer is free of amines and Pierce has taught the buffer at a pH range which overlaps with the instantly claimed pH range. See MPEP 2144.05.
Pierce differs from the currently claimed invention in that:
While Pierce teaches an acidic Elution Buffer at pH 2.8, the buffer contains amine (p. 1).
While Pierce teaches use of the kit with a Neutralization Buffer, the buffer itself is not contained within the kit (p. 2).
Elution Buffer free of amines:
Uptima cures this particular deficiency in Pierce by teaching a protein A-affarose reagent kit for purifying IgG antibodies found in biological samples (p. 3), wherein the protein A-affarose reagent is used in preparation of affinity columns (p. 1). Further, Uptima teaches directions for use and guidelines for buffers:
Binding Buffer: moderately alkaline buffers at a pH between 7.5-9.0, whereby PBS functions adequately for IgG;
Elution Buffer: low pH buffers are generally required for antibody elution whereby examples of the elution buffer include 0.1 M sodium citrate (pH 3.0); and
Neuralization Buffer: sensitive antibodies may require the elution pool be neutralized after exposure to low pH, whereby examples of the neutralization buffer include Tris-HCl (pH 8.5)
Therefore, Uptima teaches various buffers for use in an antibody purification kit whereby the Binding Buffer and Elution Buffer are both amine-free. Furthermore, Uptima teaches the elution buffer at a value encompassed by the instantly claimed pH range. See MPEP 4144.05.
Neutralization Buffer contained within kit:
Amicon cures this particular deficiency in Pierce by teaching a kit for purifying IgG from a biological sample (p. 3). The kit in Amicon contains a Bind/Wash Buffer, Elution Buffer, and Neutralization Buffer in addition to Protein G agarose resin (p. 3).
Therefore, Amicon teaches a kit whereby all three buffers are contained within the kit.
The three cited references – Pierce, Uptima, and Amicon – teach kits for antibody purification. In combination, these prior art references contain the limitations of the instantly claimed reference. Pierce teaches a kit containing columns pre-packed with a sorbent, an Elution Buffer at pH 2.8, and a Binding Buffer at pH 8.0. Additionally, Pierce teaches use of the kit requires preparation of a Neutralization Buffer such as 1 M phosphate at pH 7.5-9.
While Pierce teaches the Elution Buffer is acidic, the disclosed buffer is not amine-free as required by instant claim 20. Uptima cures this deficiency by teaching a kit whereby the Elution Buffer used is acidic buffer sodium citrate at pH 3.0. It would have been obvious, before the effective filing date of the claimed invention, to substitute the acidic buffer taught in Pierce with the amine-free buffer taught by Uptima. One would have been motivated to do so because: 1) both prior art elution buffers are acidic (simple substitution of one known element for another in order to yield a predictable outcome); and 2) choosing a buffer would be rooted in downstream post-purification processes (e.g., labeling) and would motivate one of ordinary skill to select the amine-free buffer taught in Uptima (routine optimization).
While Pierce further teaches use of a Neutralization Buffer with the kit, the disclosed buffer is not contained within the kit as required by instant claim 20. Amicon cures this deficiency by teaching a kit whereby all three buffers are contained within the kit. It would have been obvious, before the effective filing date of the claimed invention, to produce a kit wherein all three buffers – binding, elution, and neutralization – are contained within a single kit. One of ordinary skill would be motivated to do so for ease of use and convenience, wherein the teachings of Amicon showed such a kit containing all three buffers was possible (routine optimization). Therefore, claims 20-22 are obvious over Pierce in further view of Uptima and Amicon.
Allowable Subject Matter
Closest Prior Art
As it pertains to claims 1-13 and 15-19:
Coutard (cited in prior Office Action as: US 2017/0274299 A1) remains the closest prior art to the currently claimed invention in claims 1-13 and 15-19. Coutard discloses a method to purify an antibody by:
Using Protein A affinity chromatography (¶ [0088]);
Contacting the sorbent with a sodium chloride (NaCl) washing solution (¶ [0102]) to remove impurities such as host cell proteins (HCP) and host cell DNA (¶ [0103]);
Contacting the sorbent with an acidic elution solution sodium formate (¶ [0107], [0108]);
Neutralizing the eluate with 1M sodium hydroxide (¶ [0116]);
Forming a neutralized solution and subjecting the solution to subsequent processing (¶ [0119]); and
Subjecting the neutralized solution to treatment with TRIS buffer to graft amine groups (¶ [0134], [0136]).
As recited in the previous Office Action and as argued by Applicant, Coutard is deficient in disclosing deglycosylation or glycan labeling in general. In fact, Coutard teaches against deglycosylation by disclosing the glycan is present at the CH2 domain of the glycoprotein, and highlights the importance of such in biological and pharmacokinetic properties of the antibody ([0039]-[0040]). Therefore, the skilled artisan would not seek to modify the method disclosed by Coutard by adding a deglycosylation step. Therefore, claims 1-13 and 15-19 are in condition for allowance.
Conclusion
Claims 20-22 are rejected. Claims 1-13 and 15-19 are allowed.
Communication
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 Julia A Rossi whose telephone number is (571)272-0138. The examiner can normally be reached M-Th 7:30-5:30 (MST).
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/JULIA A ROSSI/Examiner, Art Unit 1615
/Robert A Wax/Supervisory Patent Examiner, Art Unit 1615