DETAILED ACTION
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
2. Claims 1-5, 7 and 9-16 are pending upon entry of amendment filed on 1/13/26.
Claims 1-5, 7 and 9-16 are under consideration in the instant application.
3. Applicant’s submission of IDS filed on 1/13/26 has been considered.
4. The following rejection remains.
5. 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 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.
6. 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 of this title, 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.
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.
7. Claims 1-5, 7 and 9-16 are rejected under 35 U.S.C. 103(a) as being unpatentable over WO2013/067301 (IDS reference, of record) in view of EP2583973 (of record) and WO2015/038888 (IDS reference, of record) for the reasons set forth in the office action mailed on 10/14/25.
The ‘301 publication teaches methods of purifying IgG1 or IgG4 from the cell culture comprising loading on the protein A chromatography, washing and eluting varying conductivity. (claims 1-44, p.52). The ‘301 publication teaches protein A chromatography includes MabSelect ([0099]) and varying conductivities from 0-25mS/cm ([0110-0112]) and the antibodies may be purified by this method includes Factor X, IL-13, VEGF, HER2 and CD3 (p. 35-37).
Further, the ‘301 publication teaches that the contaminant from cell culture includes CHOP, host cell proteins, enzymes, aggregated proteins ([0063]). The ‘301 publication teaches loading/washing with conductivity of less than 1mS/cm such as 0.65mS/cm (p.76, Example 9) in ion exchange and leached protein with Protein A (p. 77) at pH 6-8.
The disclosure of the ‘301publication differs from the instant claimed invention in that it does not teach the use of histidine buffer as in claim 1 of the instant application.
The ‘973 publication teaches the use of histidine in protein A chromatography and/or ion exchange chromatography to reduce aggregates in purification of host cell proteins (p.10, Table 3 and claims)
The ‘888 publication teaches PLBL2 is a major host cell protein and can be removed by protein A chromatography (p.33, claims 35-60) with Tris or protein was eluted with buffer containing histidine (p. 67).
It would have been obvious to one of ordinary skill in the art at the time the invention was made to utilize low/high conductivity wash and removal of PLBL2 as taught by the ‘970 and ‘888 publications into the antibody purification method as taught by the ‘301 publication.
One of ordinary skill in the art at the time the invention was made would have been motivated to do so because the wash with low and/or high conductivity improves protein purification and PLBL2 being the major host protein, the protein purification methods using protein A and low/high conductivity wash may be helpful to reduce host cell protein and improve protein quality.
From the teachings of references, it would have been obvious to one of ordinary skill in art to combine the teachings of the references and there would have been a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of the ordinary in the art at the time of invention was made, as evidenced by the references, especially in the absence of evidence to the contrary.
Applicant’s response filed on 1/13/26 has been fully considered but they were not persuasive.
Applicant has asserted that the combination of the references is not obvious as the references fail to teach the host cell protein in phospholipase B-like 2 (PLBL2) and the ‘888 publication teaches away from the combination of the references.
Further, Applicant has asserted that the ‘301 publication fails to teach combination of Tris and histidine buffer and protein A chromatography does not reduce the level of PLBL2.
Although the ‘301 publication utilizes MES buffer in protein A chromatography, the protein A chromatography buffer is not limited to MES as evidenced by the ‘888 and ‘973 publications.
As seen in the ‘888 publication, TRIS and MES is preferred source of buffer in protein A chromatography and combination of the buffer is allowed. As such, use of one source of buffer MES in the ‘301 publication cannot be extrapolated as teaching away from using the combination of buffers. The PLBL2 is defined as host cell protein and histidine buffer reduces aggregation in purification, there is reasonable expectation of success in combining the references to add Tris and Histidine together to reduce host cell protein in antibody purification.
It is noted that the specification uses combination of 25mM Tris and 25mM histidine in low conductivity wash in p. 32-33 of the instant specification.
8. No claims are allowed.
9. THIS ACTION IS MADE FINAL. 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.
10. Any inquiry concerning this communication or earlier communications from the examiner should be directed to YUNSOO KIM whose telephone number is (571)272-3176. The examiner can normally be reached on Mon-Fri 8:30-5. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Misook Yu can be reached on 571-272-0839. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Yunsoo Kim
Patent Examiner
Technology Center 1600
February 18, 2026
/YUNSOO KIM/Primary Examiner, Art Unit 1641