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
The instant application is a CON of PCT/IB20/50581, filed January 24, 2020 with provisional application 62/796159, filed January 24, 2019. Applicant’s amendment filed January 2, 2026 is acknowledged. Claims 1-68, 70-73, and 81 are canceled, and claims 69, 80, 82, and 88 are amended. Currently claims 69, 74-80, and 82-88 are pending, wherein claims 82-87 are withdrawn. Claims 69, 74-80, and 88 are under examination.
Specification
(maintained) The disclosure is objected to because it contains an embedded hyperlink and/or other form of browser-executable code. Applicant is required to delete the embedded hyperlink and/or other form of browser-executable code; references to websites should be limited to the top-level domain name without any prefix such as http:// or other browser-executable code. See MPEP § 608.01.
The use of the term “TaqMan”, “StepOnePlus”, “RNeasy”, “PowerCHO”, “HyClone”, “CHOExpress”, “OrbShake”, “Prolastin-C”, “Aralast NP”, “Zemaira”, “Ex-Cell Advanced”, “Glassia”, “AGEI.HN”, “epiCS”, “CHO4Tx”, “TPP TubeSpin Bioreactor”, “Perfadex”, “Infinite M200”, “Human TNF-a Quantikine”, “piggyBac”, “Tol-2”, “Sleeping Beauty”, “Leap-In”, 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.
Claim Objections
Claim 88 is objected to because of the following informalities: lines 2-3, needs to be changed to “…host cell co-transfected with a first nucleic acid sequence…”. to maintain claim language consistency. Appropriate correction is required.
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 69, 74-80 and 88 are rejected under 35 U.S.C. 103 as being unpatentable over Ross et al. (Journal of Biotechnology 162 (2012) 262-273, cited in IDS filed 4/23/2025, hereinafter “Ross”) in view of Balasubramanian et al. (Journal of Biotechnology 200 (2015) 61–69, cited in IDS filed 5/12/2023, hereinafter “Bala”) and Block et al. (WO 2018/107079 A1, cited in PTO-892 mailed 10/2/2025, hereinafter “Block”), as evidenced by Chin et al. (BMC Biotechnology (2015) 15:44, pgs. 1-15, hereinafter “Chin”), GE Healthcare/HyClone Laboratories (ActiPro™ medium and Cell Boost™ supplements: benchmarking, scalability, and protein production in CHO cell culture. 2015, cytiva.com, cited in PTO-892 mailed 6/13/2024) and Pan et al. (Cytotechnology (2017) 69:39–56, cited in PTO-892 mailed 6/13/2024, hereinafter “Pan”).
Regarding claims 69, 74-75, and 88, Ross teaches production of alpha-1-antitrypsin (AAT) in PER.C6 cells, wherein the cells co-express AAT (codon optimized to express the "M1-type" allele, based on sequence from GenBank Acc. No. X01683) and α-2,3-sialyltransferase, resulting in identifying subclones that expressed over 2.5 g/L of the recombinant AAT (abstract). As evidenced by Chin, codon-optimized human AAT in Chinese Hamster Ovary (CHO) lines are well-known and routine in the art (pg. 3, col. 1, para 2). Ross teaches the cell culture production method included the PER.C6 cells transfected with plasmid expressing the recombinant AAT and α-2,3-sialyltransferase, seeded in fed-batch cultures, tested for potency, and then single cell clones were isolated and cultured to promote cell-growth for cell cloning (pg. 263, sec. 2.1). At several points during this expansion process, aliquots of cell supernatant were assayed for productivities, and the best expressing clones with the most desired glycosylation patterns were selected for the next round of expansion; those with poor characteristics were eliminated (pg. 263, sec. 2.1).
Ross does not teach the AAT is co-transfected with a cut-and-paste transposase, piggyBac, in a CHO cell line.
However, Bala teaches rapid recombinant protein production from piggyBac (PB) transposon-mediated stable CHO cell pools, which meets the limitations in claim 69 (title). Bala teaches the PB transposon system has been used to generate stable CHO cell lines at a significantly higher frequency and with higher volumetric recombinant protein productivity than by conventional plasmid transfection (pg. 62, col. 1, para 2). Bala teaches a human tumor necrosis factor receptor (TNFR) fused to a human IgG1 Fc were integrated into a plasmid with codon-optimized PBase gene and cells were transfected with the plasmid (pg. 63, sec. 2.2-2.3). Bala teaches the co-transfected cells were maintained in ProCHO5 media at 37 ⁰C until day 4, and then the temperature was changed to 31 ⁰C, resulting in protein yields of 0.6-0.8 g/L (pg. 63, sec. 2.7, pg. 66, col. 2, para 1).
Neither Ross nor Bala teach the culturing step is decreased at day 3 or day 5, nor that the process produces a titer of 3 g/L or greater.
However, Block teaches optimized methods for producing biologically active proteins, specifically in manufacturing GL-2045 (a Fc multimer) (abstract, [0006]). Block teaches CHO cells were co-transfected with an expression vector encoding GL-2045 and a piggyBac transposase [0011]. Block teaches the transfected cells were cultured at a first temperature of 37 ⁰C with ActiCHO P media, and then a temperature shift at day 3 or 4 occurs at 34 ⁰C, which meets the limitations of claims 69, 74-75, and 88 [0097]. Block teaches in some embodiments, a third temperature shift employed at 31⁰C [0097], which meets the limitations in claims 69 and 88. Block teaches the timing of the temperature shift is surprisingly most successful when viable cell density is in a logarithmic growth phase, generally when the viable cell density is 10 - 15 million cells/mL, generally corresponding to day 4-5 of bioreactor culture depending on initial seeding density [0206]. Block teaches the protein yield when the temperature is shifted to 32.5 ⁰C and 31 ⁰C on day 5 resulted in 7.2 g/L and 5.1 g/L, respectively ([00207, Table 11), which meets the limitation in claims 69 and 88.
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the method of co-transfecting a eukaryotic host cell with AAT and another expression promoting gene, screening the highest producing clone and culturing for high protein production as taught by Ross, and modify Ross’s method by using a CHO host cell co-transfected with the AAT and a piggyBac transposon, wherein the temperature is decreased between days 3-5 as taught by Bala and Block with a reasonable expectation of success. One of ordinary skill in the art would have been motivated to utilize the piggyBac transposon system to rapidly produce recombinant AAT in CHO cells to advantageously isolate high numbers of AAT protein from the cell culture, as taught by Bala. Further it would have been advantageous to modify the cell culture method by decreasing the temperature at day 3 or 5 to effectively produce high titers of greater than 3 g/L as taught by Block with a reasonable expectation of success.
Regarding claims 76-80, neither Ross nor Bala teach the cell culture methods comprised at least one feed, either neutral or alkaline in the specific concentrations recited in claims 76-79.
However, Block teaches the evaluation of several media feeds for CHO culture methods, and found ActiCHO Feed A and Feed B enhanced cell culture productivities, resulting in substantially higher titers than any other feeds [00200]. Block teaches the Power Feed A was inoculated into the culture at 4% and the Power Feed B was fed into the culture at 0.4%, which falls within the ranges recited in claims 77 and 79 (pg. 108, Fig. 13A). As evidenced by the product specification by GE Healthcare, ActiCHO Feed -A and -B are the same as Cell Boost 7a and 7b, and are dosed similarly at 3% and 0.3% respectively (Materials and Methods), which is defined in the instant specification as Cell Boost 7a being the neutral feed and Cell Boost 7b being the alkaline feed recited in claims 76 and 78.
Block is silent on the osmolarity of the cell culture, specifically being greater than 550 mOsm/kg. However, as evidenced by Pan, the similar feeding schedules of ActiCHO Feed A and B resulted in an increase up to 620 mOsm/kg for a CHO clone, which inherently meets the limitation of claim 80 (pg. 45, col. 2, para 1).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art at the time of filing to modify the methods of introducing AAT and a piggyBac transposase into a CHO taught by Ross and Bala, wherein the culture method further comprises adding a neutral and alkaline feed at the specific concentrations as taught by Block with a reasonable expectation of success. One of ordinary skill in the art would have been motivated to add these two commercially available feeds for optimal CHO growth and protein production, since these two feeds promote an increase in reliably higher protein production titers as taught by Block.
Response to Arguments
Applicant's arguments filed January 2, 2026 have been fully considered but they are not persuasive.
Regarding Remarks directed to the 103 rejection, Applicant argues the amended independent claim 69 such that it is presently directed to a specific CHO-based, co- transfection and selection process for human AAT that includes (i) co-transfecting two expression vectors (AAT and cut-and-paste transposase) into a CHO cell line, where the AAT nucleic acid is CHO-cell codon-optimized; (ii) selecting clonally-derived AAT-producing cells; (iii) feeding and a day-specific temperature decrease at Day 3 or Day 5; and (iv) achieving an AAT titer of 3 g/L or greater, which the cited combination of references fail to teach or render obvious the claimed invention. Applicant points to Ross teaching a different host system that focuses on sialylation of AAT and glycosylation for increasing AAT plasma half-life. Applicant argues switching host cells is not a routine substitution for expressing AAT and that AAT is a serpin that is sensitive to folding and glycosylation. Ross demonstrates the importance of sialic capping in its system. There is no teaching or suggestion that changing the host to CHO cells and adding a cut-and-paste transposase would improve AAT titers without addressing the glycosylation strategy that Ross relies on. Applicant argues Bala and Block describe using the PiggyBac transposase for expressing other proteins other than AAT. Applicant argues there is nothing in Block that suggests its teachings of the optimized GL- 2045 parameters would predictably translate to high AAT yields. Moreover, Block describes an optional temperature decrease based on cell growth/density, which is not explicitly day-specific. Neither Bala nor Block address the importance of glycosylation or sialylation. Applicant argues that the combination of Ross, Bala, and Block is improper because the Examiner relies on information gleaned solely from Applicant's specification, i.e. hindsight. Applicant argues only with knowledge of Applicant's AAT-specific process involving CHO codon optimization, co-transfection with a cut- and-paste transposase, clonal selection, feed requirements, and day-specific temperature decrease, and its demonstrated high yield (i.e. g/L AAT) would a POSA try to retrofit the teachings of Ross with Bala and Block, as evidenced by GE and Pan.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). As evidenced by the newly added Chin reference, it is well-known and routine in the art to incorporate a codon-optimized human AAT into a CHO cell, thus this feature of the claimed invention is not novel or inventive. Ross teaches a method of co-transfecting a mammalian cell line with AAT and another protein/enzyme that aids in production of said AAT, then seeded in fed-batch cultures to select and determine best expressing clones as in the claimed method. Bala and Block teach co-transfected CHO cell lines with piggyBac transposase aiding in the production of fusion proteins and a Fc multimer, respectively. Both Bala and Block teach the temperature timings and feeds to enhance protein production in the clonal CHO cell lines to produce high protein titers (7.2 g/L for Block). Thus, it would be prima facie obvious to one of ordinary skill in the art to take the teachings of selecting a high producing clone that has been transformed to produce AAT as taught by Ross, utilize a common transformation technique such as co-transfecting with piggyBac transposase as taught by Bala, and optimize the CHO cell culture methods by decreasing the temperature at days 3 or 5 to enhance the cell productivities as taught by Block with a reasonable expectation of success.
Regarding Remarks starting at paragraph 3 on page 11 through page 13, it appears the Applicant has pasted previous arguments filed 4/23/2025 that argue a past reference (Beach) and re-iterate Dr. Florian Wurm’s 37 C.F.R. 1.132 Declaration. The Examiner has responded to these arguments and declaration in the last office action mailed 10/01/2025.
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.
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/JESSICA EDWARDS/
Examiner, Art Unit 1657