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 .
Application Status and Withdrawn Rejections
Applicant’s amendments filed July 22, 2026, amending claims 1-8, 10-18, 63 and 70, and canceling claims 45 and 50 is acknowledged. Claims 1-8, 10-18, 63 and 69-70 are pending and under examination.
The claim amendments overcome the §102 and §103 rejections of record. The amendment to claim 5 overcomes the §112(b) rejection. Applicant’s arguments regarding the §112(b) rejection of claim 7 is persuasive. The §112(b) rejections are withdrawn.
Any other rejection or objection not reiterated herein has been overcome by amendment. Applicant' s amendments and arguments have been thoroughly reviewed, but are not persuasive to place the claims in condition for allowance for the reasons that follow.
Drawings
The drawings filed July 22, 2026 are still objected to because the letters over shading especially in the figures with vector maps are too small or are not sufficiently dark for reproduction. For instance, in FIG. 11 “sCMV Promoter” and “AttB287” is barely visible in the high-resolution copy and is completely unreadable in the scanned versions. Additionally, the text of the vector elements in FIGs. 5, 17, 21, 23, 25 and 27 is too small.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claim 6 is objected to because of the following informalities:
Claim 6 recites “The host cell of claim 5, wherein the EPR comprises…” but “EPR” is not established as the acronym for “extending packaging region” in claim 5.
To obviate the objection of claim 6, it is suggested that claim 5 be amended to “wherein the nucleic acid construct comprises an extending packaging region (EPR) between the first promoter and the selectable marker, wherein the EPR is a…” Appropriate correction is required.
Claim Interpretation
Claim 1 recites “A mammalian host cell having from about 10 to 200 copies of a nucleic acid construct… wherein the nucleic acid construct is inserted into a plurality of exogenous dock sites integrated into said host cell, and said plurality of exogenous dock sites are flanked by exogenous retroviral vector sequences.” As such, claims 1-9 and 10-18 are product-by-process claims. This product-by-process will be examined according to the structure of the cell that is produced by the process of the claimed nucleic acid integrated 20-100 times in a mammalian cell genome with the claimed dock site elements. See. MPEP 2113. Below is a schematic of one embodiment of an integrated version of the claimed nucleic acid at a claimed dock site. The * indicate possible sites for an “insertion element”. The Specification does not provide any limiting definition for “insertion element” or “dock site”, which is interpreted as being any sequence. Claim 1 requires a cell having 20-200 copies of the arranged elements below and can include additional elements since claim 1 recites the nucleic acid construct “comprising” the following elements.
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Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-8, 10-18, 63 and 69-70 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. This is a new rejection necessitated by amendment.
MPEP 2163.II.A3.(a).(i) states, “whether the specification shows that applicant was in possession of the claimed invention is not a single, simple determination, but rather is a factual determination reached by considering a number of factors. Factors to be considered in determining whether there is sufficient evidence of possession include the level of skill and knowledge in the art, partial structure, physical and/or chemical properties, functional characteristics alone or coupled with a known or disclosed correlation between structure and function, and the method of making the claimed invention.”
Claim 1 recites “A mammalian host cell having from about 10 to 200 copies of a nucleic acid construct… wherein the nucleic acid construct is inserted into a plurality of exogenous dock sites… flanked by exogenous retroviral vector sequences.” A schematic of an integrated version of the claimed nucleic acid is depicted above. Mammalian cells are a broad genus and encompass well known cultured cells like human HEK293 and Chinese hamster ovary (CHO) cells, but also primary cells like mouse embryonic stem cells and human hematopoietic stem cells, and engineered cells like CAR-T cells and induced pluripotent stem cells (iPSC). For the reasons described below, the skilled artisan would have reasonably concluded that Applicant did not possess the genus of mammalian host cells that could predictably comprise 10-200 copies of the claimed nucleic acids that were integrated by retroviral vectors.
Applicant describes two examples in CHO cells, in which 5 or 9 serial transductions of lentiviral vectors comprising an attB docking site resulted in a host cells having 36 landing pads (i.e., dock sites) (Example 2) or 135 landing pads (Example 3) comprising the attP site and flanking 5’ and 3’ SIN LTR sequences. Applicant then introduced a lentiviral vector comprising an attP recombination site, a GS selectable marker driven by a SIN-LTR promoter, and an Fc fusion protein (i.e., the protein of interest) regulated by a strong promoter and polyA sequence. In Example 2, Applicants managed to integrate transgenes at 80% (28) of the possible 36 docking site. In Examples 3-6, starting with 135 landing pads, Applicants succeeded in recovering pools with an estimated 21-100% of the 135 landing pads containing the transgene of interest, resulting in 28-135 copies of the nucleic acid construct in the genome of CHO cells. Importantly, Applicants failed to recapitulate the sequential transduction protocol in any other mammalian host cell. Applicant also failed to provide guidance on how to translate the CHO serial transduction protocol to other mammalian host cells. Thus, in view of the Specification it was unpredictable whether the extremely high docking copy number could also be achieved in non-CHO cells.
A thorough search of the prior and contemporary art only discovered reports of high retroviral vector integration numbers in CHO cells. For instance, Oberbek discloses CHO-DG44 cells transduced with an HIV-1 derived retroviral vector having between 15-35 copies of the transgene (Oberbek et al., Biotechnology and Bioengineering (2010), 108: 600-611; page 602; FIG 6). In another example, Rodriquez used a serial lentiviral transduction protocol in CHO-K1 cells (Rodriguez et al., Biotechnol. Prog. (2017), 33: 1334-1345; page 1335, ¶9), which resulted in 42 copies in the CHO genome (page 1338, ¶7).
However, for mammalian host cells other than CHO cells, it does not appear the art has established a method for integrating 10-200 copies of proviral encoded transgenes. Zielski reported “high” levels of transgene integration into K562 cells, but “high” was considered 18 copies, with only one clone having above 20 copies (Zielski et al., Molecular Therapy (2004), 9: 923-931; FIG 3). Although Zielski first isolated cells with up to 135 proviral copies in a cell (Fig 7), increasing selection pressure of the transgene reduced cell survival, indicating that high copy number puts cell at a growth or survival disadvantage (page 928; ¶2). Importantly Zielski teaches at least in K562 cells “we show a concomitant, linear rise in transgene expression with proviral copy number up to 4 integrations. Above 4 integrations/cell, expression increases modestly in a nonlinear fashion to a plateau.” Thus, there is no need in the art for K562 cells to increase the copy number above 4 copies. Spencer used repeated transduction with high MOIs to transduce lentiviral vectors carrying a fVIII transgene into baby hamster kidney-M cells (Spencer et al., Molecular Therapy (2011), 19: 302-309; page 608, ¶33). However, Spencer only ever achieved 8 proviral copies in a cell genome (Fig 3). Finally, Bleck (US 20040235173 A1) discloses serial transduction method for producing host cells containing multiple integrating vectors (Abstract). Bleck attempts the serial transduction method in rat fibroblasts (208F cell), bovine kidney cells (MDBK cells) and bovine mammary epithelia cells ([0317]). Bleck attempts to determine the transgene copy number in the bovine mammary cells, which appears range from 1-6 copies per genome ([0337]-[0345], Table 5). Thue, from the prior art the skilled artisan would conclude that integrating 30 or more or even 10 or more copies of a proviral transgene in most mammalian cell types is not feasible due to the cytotoxic effects of high-copy integration.
Based on the lack of working examples of non-CHO cells having between 10-200 integrated copies of a retrovirus and a lack of understanding in the art how to select for and maintain non-CHO cells that have 20+ integrated retroviral vectors, the skilled artisan would have reasonably concluded that Applicant did not possess the genus of mammalian host cells having between 10-200 copies of the claimed nucleic acid flanked by retroviral vector sequences.
Claims 2-8, 10-18, 63 and 69-70 do not limit the genus of mammalian host cells are rejected for the reasons described above for claim 1.
Claims 15 and 16 additionally recite wherein the insertion element is a transposon insertion element and is an inverted terminal repeat, and wherein the two inverted terminal repeats are positioned 5’ to the first promoter and 3’ to the polyA sequence. Transposons having inverted terminal repeats are known in the art, e.g., Sleeping Beauty (SB) and piggyBAC. The Specification does not provide a working example of lentiviral vector also comprising transposon ITRs such that when integrated there are transposon ITRs flanked by retroviral sequences. A thorough search of the prior art also failed to find art that uses integrating lentiviral vectors to deliver SB or piggyBAC flanked sequences. This is likely because transposons like SB integrate randomly in the genome, similar to lentiviral vectors. As such, there is no motivation to deliver a randomly integrating transgene flanked by additional sequences that randomly integrate. Based on the lack of working examples of any mammalian cell having between 10-200 integrated copies of a retrovirus that also comprises transposon sequences at the 5’ and 3’ ends of the transgene cassette and a lack of understanding in the art for how the skilled artisan would use a retrovirus that also comprises transposon sequences at the 5’ and 3’ ends of the transgene cassette, the skilled artisan would have reasonably concluded that Applicant did not possess the integrated nucleic acid of claims 15 and 16 in any mammalian cell as claimed.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Section 33(a) of the America Invents Act reads as follows:
Notwithstanding any other provision of law, no patent may issue on a claim directed to or encompassing a human organism.
Claims 1-8, 10-18 and 69-70 are rejected under 35 U.S.C. 101 and section 33(a) of the America Invents Act as being directed to or encompassing a human organism. See also Animals - Patentability, 1077 Off. Gaz. Pat. Office 24 (April 21, 1987) (indicating that human organisms are excluded from the scope of patentable subject matter under 35 U.S.C. 101).
Claims 1-8, 10-18 and 69-70 are drawn to a “mammalian host cell” or a system comprising the mammalian host cell. The specification defines a “host cell” as referring to any eukaryotic cell… whether located in vitro or in vivo (page 12, ¶2) and does not exclude human host cells. Indeed, the Specification provides examples of “mammalian host cells” including human lung cells and human liver cells (page 6, ¶1). Thus, the term “cell” could reasonably be interpreted as encompassing cells within a human organism, which is non-statutory subject matter. The rejection may be obviated by requiring that the cell, be an in vitro human cell or to limit the cells to non-human cells, such as Chinese hamster ovary (CHO) cells as provided in the working examples.
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.
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 1-8, 11-14, 17-18, 63 and 69-70 are rejected under 35 U.S.C. 103 as being unpatentable over Bennett (US 20040219516 Al, published November 4, 2004) in view of Zaiss (Zaiss et al., Journal of Virology (2002), 76: 7209-7219; of record) and Oberbek (Oberbek et al., Biotechnology and Bioengineering (2010), 108: 600-611). Claim 6 is evidenced by Evans (Evans et al., Journal of Virology (2004), 78: 7677-7684).
Regarding claim 1, Bennett teaches the features of the pLENTI6/UbC/V5-DEST plasmid (i.e., a nucleic acid construct for expression of a protein of interest (FIG. 36D; [0873]). Bennett teaches the plasmid comprises PUBC (i.e., a first promoter) followed by an attR1 (i.e., an insertion element), the PSV40 and the EM7 promoters (i.e., second promoter sequences), operably linked to the blasticidin resistance gene (i.e., a selectable marker sequence operably linked to a promoter sequence), and an SV40 polyadenylation signal sequence ([FIG. 36D; [0873]). Bennett teaches using the GatewayTM vector to clone in a GFP or LacZ coding sequence (i.e., a protein of interest) ([0727]). Bennett teaches Gateway technology uses attR/L recombination sites to easily clone in the gene of interest, during which the attR/L sites are converted to attB/P sites (FIG 2). Therefore, the pLENTI6/UbC/V5-DEST with the GFP or LacZ coding sequences comprises the following genetic structure: 1st Prom – attB – Protein of Interest – attB – 2nd promoter – Selectable Marker – polyA signal. Bennett teaches the pLENTI6 destination vectors are lentiviral vectors having 5’ and 3’ long terminal repeats (LTR) (i.e., exogenous retroviral vector sequences that are used to integrate the LV vector into the host genome) (FIG. 36D). Bennett also teaches transfecting CHO host cells with the lentiviral pDEST ([0727]). Therefore, Bennett teaches a mammalian host cell with at least one copy of the nucleic acid sequence above flanked by exogenous retroviral sequences as follows:
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Bennett does not teach the selectable marker 5’ of the protein of interest coding sequence. Bennett does not teach the pLENTI-DEST vectors integrated 20-200 times in the host cell genome.
Zaiss teaches a lentiviral vector comprising a nucleic acid construct comprising from 5' to 3' 1) an EF1a E/P (i.e., a first promoter) operable linked to 2) a tk coding sequence (i.e., a selectable marker), 3) a PGK promoter (i.e., a second promoter sequence) operably linked to 4) neo (i.e., a first protein of interest), and 5) bGHpA (i.e., a polyA signal sequence) (Fig 6A). Zaiss teaches the nucleic acid construct also comprises two loxP sites (i.e., recombinase elements) that are between the first promoter and the poly A sequence (Fig 6A).
Oberbek teaches a retroviral vector comprising 5’ and 3’ LTRs, an EF1a promoter driving expression of a transgene and a GFP selection protein (Fig 1). Oberbek teaches serial transduction of CHO DG44 cells the retroviral vector resulting in cells having between 15-35 copies of the transgene (page 602; FIG 6). Oberbek teaches that that cell clone 30 had about 30 copies of the transgene (Fig 6) and also had one of the highest productions of the protein of interest, which did not affect growth rate (Tabel II).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have 1) swapped the position of the protein of interest and blasticidin selection marker in Bennett’s pLENTI-Dest vectors and 2) used the serial transduction method of Oberbek to integrate over 20 copies of the lentiviral vector into the genome of CHO cells. It would have amounted to a simple rearrangement of parts and a simple combination of method steps to yield predictable results. Rearrangement of parts is prima facie obvious that the court has held normally require only ordinary skill in the art and hence are considered routine expedients. See MPEP 2144.04.VI.C. Nonetheless, the skilled artisan would have predicted that the swapping of positions of the selectable marker and gene of interest would function as intended because Zaiss provides an example of a selectable marker operably linked to a first promoter 5’ of a gene of interest operably linked to a second promoter. The skilled artisan would have also predicted that Bennett’s pLENTI-DEST gateway vectors could be serial transduced into CHO cells to result in 10+ copies of the integrated nucleic acid because Oberbek demonstrates such a method. The skilled artisan would have been motivated to have done so and selected CHO cells that have 10+ integrations because Oberbek teaches that increased transgene copy number is generally correlated with increased transgene expression.
Regarding claim 2, Bennett teaches there is no polyA signal sequence between attR recombination site and the SV40 promoter (FIG. 36D, [0873]). In the lentiviral vector rendered obvious above, there would likewise not be a polyA sequence between the selectable marker and the second promoter.
Regarding claim 3, in the lentiviral vector rendered obvious above, the selectable marker would be just upstream (i.e., adjacent) to the second promoter.
Regarding claim 4, in the lentiviral vector rendered obvious above, the second promoter would be adjacent to the sequence encoding the protein of interest.
Regarding claim 5, Bennett teaches the pLENTI-DEST vectors comprise psi (i.e., an extending packaging region, EPR), which are between the LTRs and therefore integrated into the host genome. Bennett teaches the pLENTI-DEST vectors are based on HIV-1 retroviral vectors ([0670]). However, Bennett also teaches lentiviral vectors based on MMLV systems have been traditionally used ([0016], [0670]). Zaiss’s lentiviral vector comprises the MLV (i.e., MMLV) 5’ LTR and psi signal (FIG 6). Zaiss also demonstrates that both HIV-1-based and MMLV-based lentiviral vectors can be used for transgene integration into host cells (Fig 6).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have use the MMLV EPR in the lentiviral vector rendered obvious for claim 1. It would have amounted to the simple substitution of one known lentiviral vector for another by known means to yield predictable results. The skilled artisan would have predicted that MMLV-derived vectors could have been used to because Zaiss demonstrates that HIV-1 and MMLV-based vectors are effective at integrating into the host genome for gene expression (Fig 6). Because the prior art recognizes the equivalence of HIV-1 and MMLV based vectors for the purpose of integrating a transgene into a host cell genome, an express suggestion to substitute one equivalent component or process for another is not necessary to render such substitution obvious. MPEP 2144.06.II.
Regarding claim 6, Zaiss and Bennett are silent as to the sequence of the MMLV psi region. However, Evans teaches the sequence of the MMLV psi, which contains 3 AUG sequences (i.e., potential ATG translation start sites) (FIG 1). Therefore, the lentiviral vector rendered obvious above for claim 5 comprising an EPR having a potential translational start sites.
Regarding claim 7, Bennett's pLENTI-DEST plasmid comprises the UBC promoter as the first promoter (FIG 36D, [0873]), which the Specification indicates is a weak promoter (page 29, ¶2).
Regarding claim 8, the first promoter sequence in the integrated lentiviral vector rendered obvious above for claim 1 is a UBC promoter. However, Bennett also teaches the promoter for the blasticidin selectable marker includes the SV40 promoter (FIG. 36D). Zaiss teaches the promoter for the tk marker is EF1a (FIG 6).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have use the SV40 promoter of Bennett or the EF1a promoter of Zaiss to drive expression of the selectable marker in the integrated pLENTI vector rendered obvious for claim 1. It would have amounted to the simple substitution of one known promoter for another by known means to yield predictable results. The skilled artisan would have predicted that the SV40 or EF1a promoters could be used to drive selection marker expression, and been motivated to do so, because both Bennett and Zaiss provide working examples of such an expression system.
Regarding claim 11, the selection marker in the integrated lentiviral vector rendered obvious above for claim 1 is blasticidin. However, Zaiss also teaches a neomycin selection marker for selecting for cells comprising the integrated lentiviral vector (FIG 6).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have used the neomycin gene as the selectable marker in the integrated pLENTI vector rendered obvious for claim 1. It would have amounted to the simple substitution of one known eukaryotic cell selection maker for another to yield predictable results. The skilled artisan would have predicted that neomycin could be used because Zaiss demonstrates using the neomycin gene in integrated lentiviral vectors. Because the prior art recognizes the equivalence of blasticidin and neomycin selection markers in integrated lentiviral vectors, an express suggestion to substitute one equivalent component or process for another is not necessary to render such substitution obvious. MPEP 2144.06.II.
Regarding claim 12, in the lentiviral vector rendered obvious above, the second promoter is the SV40 promoter.
Regarding claim 13, Zaiss teaches the protein of interest is a TNFR-Fc fusion (i.e., the protein of interest encodes heavy chain immunoglobulin sequences) (FIG 6).
Regarding claims 14, 17 and 18, in the lentiviral vector rendered obvious above, the insertion element is attB, which is a recombinase insertion element.
Regarding claim 63, Bennett teaches using the integrated pLENTI-Dest vectors for producing a recombinant protein of interest after culturing the stably transduced cells (FIG. 35). Bennett teaches that recombinant proteins of interest can be expressed with a purification tag ([0046]) and therefore teaches use of the vectors for recombinant protein purification. Oberbek teaches using transduced CHO cells for the production of TNFR:Fc fusion protein (FIG. 6) and suggests using the system for harvesting (i.e., purification) of recombinant proteins (page 609, ¶1).
Regarding claims 69-70, the Speficiation does not provide a limiting definition for “a system”, which is interpreted as merely the sum of its components. As indicated above for claim 1, the obvious integrated lentiviral vector in the CHO cells required the use of the Gateway recombinase to clone the protein of interest coding sequence into the lentiviral vector.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Bennett (US 20040219516 A1, published November 4, 2004; of record), Zaiss (Zaiss et al., Journal of Virology (2002), 76: 7209-7219; of record) and Oberbek (Oberbek et al., Biotechnology and Bioengineering (2010), 108: 600-611), as applied to claims 1-8, 11-14, 17-18, 63 and 69-70 above, and further in view of Rodríguez (Rodríguez et al., "Production of therapeutic enzymes by lentivirus transgenesis." Therapeutic Enzymes: Function and Clinical Implications (2019): 25-54).
The teachings of Bennett, Zaiss and Oberbek are recited above and applied as for claims 1-8, 11-14, 17-18, 63 and 69-70. Bennett also teaches various selection methods are known in the art and can be used to accomplish selection with the invention ([0177]).
Bennett, Zaiss and Oberbek do not teach the selection marker is glutamine synthase (GS) or dihydrofolate reductase (DHFR).
Rodríguez reviews the state of the art of using lentiviral vectors as a recombinant protein production platform (Abstract). Rodríguez teaches that GS and DHFR are the most frequently used selection markers (page 31, ¶2). Rodríguez teaches mammalian cells lacking the DHFR DNA sequence, such as CHO-DG44 can be used with DHFR selection methods (page 31, ¶2).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have used the DFHR selectable marker taught in Rodríguez in the integrated pLENTI vector rendered obvious for claim 1. It would have amounted to the simple substitution of one known eukaryotic cell selection maker for another to yield predictable results. The skilled artisan would have predicted that DHFR could be used because Bennett teaches that selection markers known in the art can be used in the Gateway vectors. The skilled artisan would have been motivated to have used the DHFR in the obvious CHO cell integrated with the obvious lentiviral vector as recited for claim 1, because Rodríguez teaches DHFR can be used with CHO-DG44 cells, which are the cells used in Oberbek’s serial lentiviral transfection method.
Allowable Subject Matter
Applicant provides a working example of integrating a lentiviral-delivered attB recombinase site in 10+ sites in the CHO genome followed by integrase-mediated recombination of a selection marker and transgene of interest at 20-100% of the attB sites, such that the integrated nucleic acid construct comprises recombinase attachment flanked on the outside by retroviral sequences. This combination appears free of the prior art. The prior art provides numerous examples of delivering high copy number of transgenes by lentiviral integration. However, integrase- or recombinase- mediated integration appears to be site-specific and instead uses stacked integrations at a single site to increase copy number. See e.g., Kawabe et al., Cytotechnology (2012), 64: 267-279 who describes antibody gene stacking using Cre/Lox system. See e.g., Chang (US 20210115413 A1) who integrates three attB sequences at three specific sites using homologous recombination (i.e., site specific targeting) and then integrates multiple transgenes at each site. A thorough search of the prior art found no example of using serial transductions of a lentiviral vector comprising a single attB recombination site such that attB sites would be present at over 10 sites randomly throughout the genome. A claim that recites the features of claim 1 and requires that recombinase attachment sites 5’ of the first promoter and 3’ of the polyA sequence appears to be free of the prior art.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1, 4, 7-8, 10, 13-14, 17 and 63 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-18 of U.S. Patent No. 12157897 in view of Delenda (Christophe Delenda, Journal of Gene Medicine (2004), 6: S125-S138 and Bennett (US 20040219516 A1). This is a maintained rejection.
Patented claim 1 recites A vector for expression of a protein of interest comprising a nucleic acid sequence encoding a selectable marker in operable association with a first promoter sequence and a nucleic acid sequence encoding the protein of interest operably linked to a second promoter sequence, wherein the first promoter sequence is a viral Self-Inactivating (SIN) Long Terminal Repeat (LTR) promoter sequence that is at least 95% identical to SEQ ID NO:3. Patented claims 3-4 recite wherein the selectable marker is Glutamine Synthetase (GS) or Dihydrofolate Reductase (DHFR). Patented claim 6 recites wherein the vector comprises a first poly A signal sequence in operable association with said selectable marker and a second poly A signal sequence in operable association with said nucleic acid encoding the protein of interest. Patented claim 7 recites wherein the protein of interest is selected from the group consisting of an Fc-fusion protein, an enzyme, an albumin fusion, a growth factor, a protein receptor, a single chain antibody (scFv), a single chain-Fc (scFv-Fc), a diabody, and minibody (scFv-CH3), Fab, single chain Fab (scFab), an immunoglobulin heavy chain, and an immunoglobulin light chain. Patented claims 10 and 14 recite A host cell comprising the vector of claim 1, wherein the host cell comprises from about 1 to 1000 copies of the vector. Patented claim 18 recites A process for producing a protein of interest comprising culturing host cells according to claim 10 and purifying the protein of interest from the host cell culture.
The patented claims do not recite the 5’ to 3’ order of the genetic elements of the vector. The patented claims do not recite one or more insertion elements in the vector
Delenda teaches optimization of lentiviral vectors. Delenda teaches the overall structure and modularity of lentiviral vector elements (Fig 3). Delenda teaches an LTR at the 5’ end of the vector (Figure 3).
Bennet teaches a lentiviral vector comprising a 5’ LTR, internal promoters, selectable markers and attR sites (i.e., insertion elements) for the incorporation of additional genetic elements into the lentiviral vector.
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to have arranged the elements in the patented vector such that they are 5’ to 3’: LTR promoter – selectable marker – second promoter – GOI – polyA, and included one or more insertion elements 5’ of, 3’ of, or in between the claimed elements. It would have amounted to arranging the patented elements to accommodate the known architecture of lentiviral vectors and including known insertion elements by known means to yield predictable results. The skilled artisan would have been motivated to arrange the patented elements and included attR insertion elements with a reasonable expectation of success because Delenda teaches an LTR is at the 5’ end of lentiviral vectors and Bennett demonstrates attR sites in a lentiviral vector.
Claims 1-2, 7-8 and 63 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 34, 37, 38 and 108 of copending Application No. 18007302. This is a maintained rejection.
Copending claim 1 recites A host cell comprising a genome, the genome comprising from 1 to 500 integrated docking sites, each docking site comprising at least one dock site insertion element. Copending claims 34, 37 and 38 recite The host cell line of claim 1, further comprising nucleic acid expression constructs inserted at 1 or more of the docking sites, wherein the nucleic acid expression construct further comprises the following elements in operable association in 5' to 3' order: a first promoter sequence; a selectable marker sequence; a second promoter sequence; a nucleic acid sequence encoding a first protein of interest that is operably linked to the internal promoter; and a poly A signal sequence, wherein the nucleic acid construct further comprising at least one insertion element at a position or positions selected from the group consisting of 5' to the first promoter, 3' to the poly A signal sequence, between the first promoter and the poly A signal sequence, between the selectable marker and the second promoter sequence, and both 5' to the first promoter and 3' to the poly A signal sequence. Copending claim 108 recites A process for producing a protein of interest comprising culturing host cells according to claim 34 conditions that the protein of interest is expressed and purifying the protein of interest from the host cell culture. Therefore, the copending claims anticipate examined claims 1-2, 7-8, 45, 50, 63.
This is a provisional nonstatutory double patenting rejection.
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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/CATHERINE KONOPKA/Primary Examiner, Art Unit 1635
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