DETAILED ACTION
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 .
Applicant’s amendment filed on 02/23/2026 has been entered for the purpose of compact prosecution even though the amendment to the claims does not comply with the requirements of 37 CFR 1.121(c) because changes that have been made in currently amended claim 24 relative to the immediate prior version of the claim are not completely marked. Specifically, the insertion of the term “mammalian” between the terms “vertebrate” and “cell” on line 1 of currently amended independent claim 24 is not underlined.
Amended claims 24-30 and 32-48 are pending in the present application.
Applicant elected previously the following species: (a) gene deletion; (b) a cell clone; (c) an antibody as a species of a polypeptide of interest; (d) both (i) and (ii) recited in claim 30; and (e) SEQ ID NO: 2 as the matriptase reference protein.
Claims 26-27, 42-43 and 45-46 were withdrawn previously from further consideration because they are drawn to non-elected species.
Accordingly, amended claims 24-25, 28-30, 32-41, 44 and 47-48 are examined on the merits herein with the above elected species.
Claim Objections
Amended claim 24 is objected to because of the term “vertebrate mammalian” on line 1 of the claim. The extra “vertebrate” is redundant.
Claim Rejections - 35 USC § 112 (Lack of Written Description)
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.
Amended claims 24-25, 28-30, 32-36, 38-41 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 modified rejection necessitated by Applicant’s amendment.
MPEP 2163 - 35 U.S.C. 112(a) and the first paragraph of pre-AIA 35 U.S.C. 112 require that the “specification shall contain a written description of the invention ....” This requirement is separate and distinct from the enablement requirement. Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1340, 94 USPQ2d 1161, 1167 (Fed. Cir. 2010) (en banc). Vas-Cath Inc. v. Mahurkar, 19USPQ2d 1111 (Fed. Cir. 1991), clearly states that “applicant must convey with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention. The invention is, for purposes of the ‘written description’ inquiry, whatever is now claimed.” Vas-Cath Inc. v. Mahurkar, 19USPQ2d at 1117. The specification does not “clearly allow persons of ordinary skill in the art to recognize that [he or she] invented what is claimed” Vas-Cath Inc. v. Mahurkar, 19USPQ2d at 1116.
The instant claims encompass any isolated recombinant mammalian cell (any mammalian cell derived from a human, a whale, a dog, or a rodent) suitable for recombinant expression of a polypeptide of interest, wherein the mammalian cell is altered to impair the effect of matriptase, wherein the effect of matriptase is impaired because functional expression of the matriptase gene is reduced or eliminated in said cell by gene knock-out, gene mutation, gene deletion, gene silencing or a combination thereof, wherein the mammalian cell comprises at least one heterologous polynucleotide encoding a polypeptide of interest operatively linked to a secretory leader sequence and the polypeptide of interest is secreted from the mammalian cell, and wherein impairing the effect of matriptase in said cell reduces clipping of the secreted polypeptide of interest; methods of making and using the same recombinant mammalian cell.
Apart from disclosing an “unexpected” finding that matriptase is the main protease involved in proteolytic degradation of recombinant proteins in CHO-K1 cells via siRNA, TALEN and ZFN knockdown approaches (examples 1-2); the instant disclosure fails to provide sufficient/complete written description for any other mammalian cell suitable for recombinant expression of any secreted polypeptide of interest, wherein impairing the effect of matriptase via gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof in said cell reduces clipping of the secreted polypeptide of interest as encompassed broadly by the instant claims. For example, which particular essential or critical structural elements do other mammalian cells possess, such that they also acquire the desired property of impairing the effect of matriptase in these cells reduces clipping of the secreted polypeptide of interest? Before the effective filing date of the present application (04/29/2014), Mulvihill et al (US 5,648,254; IDS) disclosed a method for producing proteins of interest by introducing a first DNA sequence encoding a protein of interest (e.g., secreted full-length plasminogen) and an additional DNA sequence encoding a protein which stabilizes the protein of interest (e.g., protease inhibitors such as alpha-1-antitrypsin) into a eukaryotic cell (e.g., COS, BHK, 293 cells; col. 7, lines 18-44 and Example 2). Sandberg et al (Biotechnology and Bioengineering 95:961-971, 2006; IDS) identified metalloproteinases play a major role in destabilizing the production of a recombinant factor VIII from a DHFR- CHO cell line in serum-free medium (Abstract; Table 1), while Robert et al (Biotechnology and Bioengineering 104:1132-1141, 2009; IDS) identified a metalloproteinase and cathepsin D are responsible for the degradation of an Fc-fusion recombinant protein produced from the DFHR deficient DUKX-B11 cell line (Abstract); and Dorai et al (Biotechnol. Prog. 27:220-231, 2011; IDS) reported one or more serine-threonine class of proteases and not metalloproteases are significantly involved in the N-terminal clipping of glucagon-like-peptide-1-antibody fusion proteins produced by the CHOK1SV cell line which is adapted to grow in animal protein free media (Abstract; Table 1). Thus, it is apparent that even among mammalian CHO cell lines they have different endogenously expressed protease profiles that are responsible for the proteolytic degradation of recombinant proteins, let alone any mammalian cell derived from any tissue/organ source, and more particularly identifying the single type II-transmembrane serine protease-type matriptase enzyme being the major cause for proteolytic degradation of a recombinant polypeptide secreted from such mammalian cell. Additionally, the instant specification stated clearly “[s]o far little is known about the proteases expressed by the vertebrate host cells used for recombinant expression, and about the proteases responsible for clipping. One of the major challenges is the number of proteases expressed by vertebrate host cells. E.g. more than 700 proteases are known to be present in rodent cell genomes, many of which could be involved in clipping” (paragraph [4]); and “Considering the large number and variety of proteases expressed in vertebrate cells, such as in particular mammalian cells, it was even more surprising that impairing the function of this single protease – matriptase – is sufficient to significantly reduce or even eliminate clipping of the secreted polypeptide of interest in the cell culture medium. These advantageous effects are not seen with other, even closely related proteases what supports the importance of the finding that matriptase is the key enzyme responsible for clipping of secreted recombinant polypeptides in the cell culture medium” (paragraph [29]). Even in 2018, Laux et al (Biotechnology and Bioengineering DOI:10.1002/bit.26731, pages 2530-2540, 2018; IDS) still stated “Using protease inhibitors, transcriptomics, and genetic knockdowns, we have identified, out of the >700 known proteases in rodents, matriptase-1 as the major protease involved in the degradation of recombinant proteins expressed in CHO-K1 cells” (Abstract); “Proteolytic degradation has been shown to be dependent on the host cell line used, the culture conditions, or the amount of glycosylation of the expressed polypeptide…However, to date, little is known about the endogenously expressed proteases in the host cells or the proteases responsible for proteolytic degradation” (page 2531, left column, top of third paragraph); and “[t]he choice of the mammalian cell line used as the production host has an influence on proteolytic degradation due to differentially expressed proteases…Therefore, one option is to screen different cell lines to identify one in which proteolytic degradation of the polypeptide does not occur. However, this is time consuming, may require the adaptation of production processes, and rarely eliminates the proteolytic degradation. Therefore, better ways are needed to address this problem” (page 2531, left column, bottom of third paragraph). Furthermore, the physiological art is already recognized as unpredictable (MPEP 2164.03).
Since the prior art before the effective filing date of the present application (04/29/2014) did not provide sufficient description and/or guidance regarding the above issue as evidenced at least by the teachings of Mulvihill et al (US 5,648,254; IDS), Fang et al (US 2007/0059820; IDS), Sanberg et al (Biotechnology and Bioengineering 95:961-971, 2006; IDS), Robert et al (Biotechnology and Bioengineering 104:1132-1141, 2009; IDS), Dorai et al (Biotechnology and Bioengineering 103:162-176, 2009; IDS), Dorai et al (Biotechnol. Prog. 27:220-231, 2011; IDS), and Zhu, J. (Biotechnology Advances 30:1158-1170, 2012; IDS); it is incumbent upon the present specification to do so. The present application also fails to provide a representative number of species for a broad genus of an isolated recombinant mammalian cell suitable for recombinant expression of secreted polypeptide of interest, and methods of making and using the same vertebrate cell as claimed broadly.
The claimed invention as a whole is not adequately described if the claims require essential or critical elements which are not adequately described in the specification and which are not conventional in the art as of Applicants’ filing date. Possession may be shown by actual reduction to practice, clear depiction of the invention in a detailed drawing, or by describing the invention with sufficient relevant identifying characteristics such that a person skilled in the art would recognize that the inventor had possession of the claimed invention. Pfaff v. Wells Electronics, Inc., 48 USPQ2d 1641, 1646 (1998). The skilled artisan cannot envision the complete detailed structure of a representative number of species for a broad genus of an isolated recombinant vertebrate cell suitable for recombinant expression of secreted polypeptide of interest, and methods of making and using the same vertebrate cell as claimed broadly, and therefore conception is not achieved until reduction to practice has occurred, regardless of the complexity or simplicity of the method. Adequate written description requires more than a mere statement that it is part of the invention and reference to a method of isolating it. See Fiers v. Revel, 25 USPQ2d 1601, 1606 (Fed. Cir. 1993) and Amgen Inc. v. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016 (Fed. Cir. 1991). One cannot describe what one has not conceived. See Fiddes v. Baird, 30 USPQ2d 1481, 1483.
Applicant is reminded that Vas-Cath makes clear that the written description provision of 35 U.S.C. §112 is severable from its enablement provision (see page 1115).
Response to Arguments
Applicant’s arguments related to the above 112(a) rejection in the Amendment filed on 02/23/2026 (pages 11-13) have been fully considered, but they are respectfully not found persuasive for the reasons discussed below.
Applicant argued that the specification provides an extensive description of the structural features of matriptase, and numerous working examples supporting the claimed invention, as well as demonstrating the broad relevance of matriptase across different rodent species, and not only in CHO-K1 derived cells. For instance, Example 3 shows that mouse MT-SP1 (matriptase) also directly cleaves recombinantly expressed and secreted proteins (clipping targets), further confirming that the findings related to matriptase are not limited to CHO-K1 derived cells. Accordingly, a person of skill with Applicant’s specification in hand understands that mammalian cells, other than CHO-K1, can be modified to impair matriptase utilizing any one of Applicant’s claimed methodologies. Applicant also argued that the cited Laux reference affirmatively bolsters Applicant’s position by expressly identifying matriptase as a “major protease involved in the degradation of recombinant proteins” in a mammalian cell line. Accordingly, a person of ordinary skill in the art would have readily applied Applicant’s disclosed methodologies to impair matriptase in other mammalian cell lines without undue experimentation. Applicant further cited the Ahmed reference (FEBS J. 273:615-627, 2006; IDS) demonstrated that small interfering RNAs targeting matriptase efficiently reduce matriptase expression and inhibit matriptase-dependent cleavage of IGFBP-rP1 in human ovarian carcinoma (OVISE) cells (FIG. 9B-C). Moreover, Applicant argued that Ahmed reports detectable matriptase expression and activity across multiple human epithelial and carcinoma cell lines, including OVISE, MKN-45, DLD-1, and HEK293 (Fig. 3B). The presence of both soluble and membrane-associated matriptase in the majority of tested cell lines confirms that matriptase is widely expressed in mammalian cells and readily susceptible to genetic and molecular manipulation, as described in Applicant’s specification.
First, the main issue is that apart from disclosing an “unexpected” finding that matriptase is the main protease involved in proteolytic degradation of recombinant proteins in CHO-K1 cells via siRNA, TALEN and ZFN knockdown approaches (examples 1-2); the instant disclosure fails to provide sufficient/complete written description for any other mammalian cell suitable for recombinant expression of any secreted polypeptide of interest, wherein impairing the effect of matriptase via gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof in said cell reduces clipping of the secreted polypeptide of interest as encompassed broadly by the instant claims. For example, which particular essential or critical structural elements do other mammalian cells possess, such that they also acquire the desired property of impairing the effect of matriptase in these cells reduces clipping of the secreted polypeptide of interest? An ordinary skill in the art would readily recognize that a recombinant mammalian cell even with a functional expression of a matriptase gene being reduced or eliminated would not have reduced clipping of any heterologous secreted polypeptide of interest unless matriptase is a major active protease relative to a plethora of proteases expressed in said cell. For example, how would a clipping of a heterologous secreted polypeptide of interest is reduced in a mammalian cell if matriptase is present only in trace amount relative to an abundance of other proteases such as other serine proteases, metalloproteases, aspartic proteases and/or cysteine proteases expressed in the cell? Even among mammalian CHO cell lines, they have different endogenously expressed protease profiles that are responsible for the proteolytic degradation of recombinant proteins as evidenced at least by the teachings of Sandberg et al, Robert et al, and Dorai et al that are presented and discussed above.
Second, the instant specification also stated clearly “[s]o far little is known about the proteases expressed by the vertebrate host cells used for recombinant expression, and about the proteases responsible for clipping. One of the major challenges is the number of proteases expressed by vertebrate host cells. E.g. more than 700 proteases are known to be present in rodent cell genomes, many of which could be involved in clipping” (paragraph [4]); and “Considering the large number and variety of proteases expressed in vertebrate cells, such as in particular mammalian cells, it was even more surprising that impairing the function of this single protease – matriptase – is sufficient to significantly reduce or even eliminate clipping of the secreted polypeptide of interest in the cell culture medium. These advantageous effects are not seen with other, even closely related proteases what supports the importance of the finding that matriptase is the key enzyme responsible for clipping of secreted recombinant polypeptides in the cell culture medium” (paragraph [29]). Even in 2018, Laux et al (Biotechnology and Bioengineering DOI:10.1002/bit.26731, pages 2530-2540, 2018; IDS) still stated “Using protease inhibitors, transcriptomics, and genetic knockdowns, we have identified, out of the >700 known proteases in rodents, matriptase-1 as the major protease involved in the degradation of recombinant proteins expressed in CHO-K1 cells” (Abstract); “Proteolytic degradation has been shown to be dependent on the host cell line used, the culture conditions, or the amount of glycosylation of the expressed polypeptide…However, to date, little is known about the endogenously expressed proteases in the host cells or the proteases responsible for proteolytic degradation” (page 2531, left column, top of third paragraph); and “[t]he choice of the mammalian cell line used as the production host has an influence on proteolytic degradation due to differentially expressed proteases…Therefore, one option is to screen different cell lines to identify one in which proteolytic degradation of the polypeptide does not occur. However, this is time consuming, may require the adaptation of production processes, and rarely eliminates the proteolytic degradation. Therefore, better ways are needed to address this problem” (page 2531, left column, bottom of third paragraph). Thus, these teachings support the Examiner’s position and the unpredictability in a reduction or elimination of matriptase expression in any mammalian cell to attain a reduced clipping of a heterologous secreted polypeptide of interest expressed in said cell.
Third, with respect to the Ahmed article it is noted that Ahmed et al stated clearly “Of nine human cell lines tested, seven cell lines secreted IGFBP-rP1 at high levels, and two of them, ovarian clear cell adenocarcinoma (OVISE) and gastric carcinoma (MKN-45) highly produced the cleaved IGFBP-rP1…The conditioned medium of OVISE cells did not cleave purified IGFBP-rP1, but their membrane fraction had an IGFBP-rP1-cleaving activity” (Abstract), and “These results suggested that OVISE and MKN-45 cells expressed a high level of proteinase(s) responsible for the processing of IGFBP-rP1” (right column, last sentence of first full paragraph at page 616). Thus, only 2/7 (29%) of tested human cell lines in the Ahmed article showed a high level of processed IGFBP-rP1 with trace amounts of processed IGFBP-rP1 being detected in HLE and HEK293 cells via immunoblotting with anti-TAF/IGFBP-rP1 antibody (FIG. 1). It is also noted that the proteolytic processing of IGFBP-rP1 greatly reduced its insulin/IGF-dependent growth promoting activity but enhanced it syndecan-1-mediated cell adhesion activity, thus the proteolytic processed IGFBP-rP1 possesses a functional biological activity (left column, last paragraph at page 626). Ahmed et al also stated “Our recent analysis has detected soluble matriptase in 19 of 24 human carcinoma cell lines tested, which included carcinomas of the breast, lung, stomach and colon [32]. The soluble matriptase mostly existed in a single-chain, latent form as a major component and two-chain forms complexed with its inhibitor HAI-I, in agreement with the past reports [18,30]. Therefore, soluble matriptase released from cell membrane is expected to have a very low, if any, proteolytic activity” (a paragraph bridging left and right columns at page 623). Moreover, Ahmed et al also taught that the 95- and 110-kDa bands in zymography (Figs. 3A and 4), and these gelatinolytic activities are results from partial dissociation of an active matriptase from its inhibitor HAI-I after SDS/PAGE; while the 75-kDa activity is thought to be active matriptase which had been dissociated from HAI-I by the SDS treatment (left column at page 619). Thus, at best Ahmed et al teach that matriptase seems to be a major IGFPB-rP1-processing enzyme in OVISE cells, and possibly in MKN-45 cells. However, the Ahmed article did not characterize the expression of active matriptase in OVISE (ovarian clear cell adenocarcinoma) cells and/or gastric carcinoma MKN-45 cells relative to other proteases such as MT1-MMP, MMP-7 and MMP-2/9 which are known to play important roles in the process of tumor invasion and metastasis, as well as serine proteases such as plasminogen activators, plasmin and trypsin that contribute to malignant phenotypes in tumor cells (Ahmed article; left column, second paragraph at page 616). Ahmed et al even stated “Although the present study demonstrates that matriptase cleaves IGFBP-rP1, our data do not exclude the possibility that other proteinases, especially serine proteinases, also cleave IGFBP-rP1. We previously reported that many human cancer cell lines secrete an active or latent form of trypsin and a 75-kDa serine proteinase [20], the later of which was identified as matriptase in a recent study [32]” (right column, top of second paragraph at page 623).
Accordingly, the cited Ahmed article did not teach or suggest that matriptase plays a major role and/or a key enzyme responsible for clipping of any heterologous secreted recombinant polypeptides in a cell culture medium because the majority of nine human cell lines tested did not express and/or a weak expression of active matriptase, along with the vast majority of previously tested 19 of 24 human carcinoma cell lines simply produce soluble matriptase mostly existed in a single-chain, latent form as a major component and two-chain forms complexed with its inhibitor HAI-I, with a very low, if any, proteolytic activity.
Claim Rejections - 35 USC § 112 (Scope of Enablement)
Amended claims 24-25, 28-30, 32-41, 44 and 47-48 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for:
An isolated recombinant CHO-K1 cell suitable for recombinant expression of a polypeptide of interest, wherein the CHO-K1 cell is altered to impair the functional expression of its endogenous matriptase gene by gene-knockout, gene mutation, gene deletion, gene silencing or a combination thereof, and wherein the CHO-K1 cell comprises at least one heterologous polynucleotide encoding the polypeptide of interest operatively linked to a secretory leader sequence and the polypeptide of interest is secreted from said CHO-K1 cell, and wherein impairing the effect of matriptase in said cell reduces clipping of the secreted polypeptide of interest; and methods of making and using the same recombinant CHO-K1 cell.
does not reasonably provide enablement for any other isolated mammalian cells and other methods of making and using other isolated mammalian cells as claimed broadly. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention commensurate in scope with these claims. This is a modified rejection necessitated by Applicant’s amendment.
The factors to be considered in the determination of an enabling disclosure have been summarized as the quantity of experimentation necessary, the amount of direction or guidance presented, the state of the prior art, the relative skill of those in the art, the predictability or unpredictability of the art and the breadth of the claims. Ex parte Forman, (230 USPQ 546 (Bd Pat. Appl & Unt, 1986); In re Wands, 858 F.2d 731, 8 USPQ 2d 1400 (Fed. Cir. 1988)).
When read in light of the instant specification, the sole purpose for the preparation of an isolated vertebrate cell that is altered to impair its functional expression of the matriptase gene by gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof is to significantly reduce or even completely prevent clipping/degradation of recombinant polypeptides of interest secreted by the vertebrate cell (see at least paragraphs 1, 6-7 and 13). It is also noting that the term “matriptase” is defined by the present application to refer to “suppressor of tumorigenicity 14 protein” and its homologs and/or orthologs, but the term does not include matriptase-2 and matriptase-3 (see paragraph 31 and Table 1). Additionally, the term “clipping” refers to proteolytic degradation of expressed and secreted polypeptide of interest in a cell culture medium of vertebrate host cells for recombinant expression (first sentence of paragraph 1). The instant specification is not enabled for the instant broadly claimed invention for the reasons discussed below.
1. The breadth of the claims
Claims 24-25, 28-30, 32-36 and 38-41 are drawn to any isolated mammalian cell (any mammalian cell derived from a human, a whale, a dog, or a rodent) in various forms (e.g., a cell line or a cell clone as the elected species) suitable for recombinant expression of a polypeptide of interest (e.g., an antibody as the elected species), wherein the mammalian cell is altered to impair the effect of matriptase (e.g., at least one or all copies of the matriptase gene are deleted as the elected species), wherein the effect of matriptase is impaired because functional expression of the matriptase gene is reduced or eliminated in said cell by gene knock-out, gene mutation, gene deletion, gene deletion or a combination thereof, and wherein the mammalian cell comprises at least one heterologous polynucleotide encoding a polypeptide of interest operatively linked to a secretory leader sequence and the polypeptide of interest is secreted from the mammalian cell, and wherein impairing the effect of matriptase in said cell reduces clipping of the secreted polypeptide of interest; and methods of making and using the same mammalian cell.
Claims 37 and 44 are drawn to a method for selecting any mammalian cell for recombinant production of secreted polypeptide of interest comprising the steps (i)-(iii) recited in independent claim 37, including the step of selecting a mammalian cell in which the effect of an endogenous protease matriptase is impaired by reduction or elimination of functional expression of the matriptase gene by gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof for recombinant production of a secreted polypeptide of interest; while claims 47-48 are directed to any isolated human cell suitable for recombinant expression of a polypeptide of interest, wherein the isolated human cell comprises a genomic alteration of at least a portion of a gene encoding matriptase, wherein the genomic alteration suppresses or eliminates expression of matriptase encoded by the gene; and at least one heterologous polynucleotide encoding a polypeptide of interest operatively linked to a secretory leader sequence, wherein the human cell secretes the polypeptide of interest; including the isolated human cell in which an unaltered endogenous matriptase share at least 80% identity to a matriptase reference protein comprising one or more of the amino acid sequences set forth in SEQ ID NOs: 2 to 5, and has the same proteolytic activity as said matriptase reference protein.
2. The state and the unpredictability of the prior art
Before the effective filing date of the present application (04/29/2014), virtually nothing was known about using a mammalian host cell in which its functional expression of the matriptase gene is reduced or eliminated by gene knock-out, gene mutation, gene deletion, gene deletion, gene silencing or a combination thereof for recombinant expression of a secreted heterologous polypeptide of interest as evidenced at least by the teachings of Mulvihill et al (US 5,648,254; IDS), Fang et al (US 2007/0059820; IDS), Sanberg et al (Biotechnology and Bioengineering 95:961-971, 2006; IDS), Robert et al (Biotechnology and Bioengineering 104:1132-1141, 2009; IDS), Dorai et al (Biotechnology and Bioengineering 103:162-176, 2009; IDS), Dorai et al (Biotechnol. Prog. 27:220-231, 2011; IDS) and Zhu, J. (Biotechnology Advances 30:1158-1170, 2012; IDS). Mulvihill et al disclosed a method for producing proteins of interest by introducing a first DNA sequence encoding a protein of interest (e.g., secreted full-length plasminogen) and an additional DNA sequence encoding a protein which stabilizes the protein of interest (e.g., protease inhibitors such as alpha-1-antitrypsin) into a eukaryotic cell (e.g., COS, BHK, 293 cells; col. 7, lines 18-44 and Example 2). Sandberg et al identified metalloproteinases play a major role in destabilizing the production of a recombinant factor VIII from a DHFR- CHO cell line in serum-free medium (Abstract; Table 1), while Robert et al identified a metalloproteinase and cathepsin D are responsible for the degradation of an Fc-fusion recombinant protein produced from the DFHR deficient DUKX-B11 cell line (Abstract). Additionally, Dorai et al (Biotechnol. Prog.) reported one or more serine-threonine class of proteases and not metalloproteases are significantly involved in the N-terminal clipping of glucagon-like-peptide-1-antibody fusion proteins produced by the CHOK1SV cell line which is adapted to grow in animal protein free media (Abstract; Table 1). Moreover, Wurm (Processes 1:296-311; doi:10.3390/pr1030296, 2013; IDS) disclosed that CHO cells are immortalized cells that are characterized by a high degree of genetic and phenotypic diversity; and stated “It is proposed that the name CHO represents many different cell types; based on their inherent genetic diversity and their dynamic rate of genetic change. The continuing remodeling of genomic structure in clonal or non-clonal cell populations; particularly due to the non-standardized culture conditions in hundreds of different labs renders CHO cells a typical case for “quasispecies”” (Abstract). Lewis et al (Nature Biotechnology 31: 759-765; 2013; IDS) sequenced and analyzed the genomes of six CHO cell lines from the CHO-K1, DG44 and CHO-S lineages; and identified hamster genes missing in different CHO cell lines, detected >3.7 million single-nucleotide polymorphisms (SNPs), 551,240 indels and 7,063 copy number variations that highlight genetic heterogeneity and diversity among CHO cell lines (Abstract). Lewis et al concluded “There are important differences in genomic content among CHO cell lines that can influence cell line traits. These are likely to be further influenced by differences in gene expression” (page 764, left column, second full paragraph). Warner (Glycobiology 3:455-463, 1993; IDS) also taught that CHO cell lines are highly mutagenized and have profound chromosomal rearrangements, and stated “In CHO K 1 cells, one allele of the sialidase gene was localized on the terminus of chromosome 2. The second allele, however was localized on a marker chromosome M1, which appears as a fragmented derivatives of chromosome 2. In contrast, in DG 44 cells, no intact chromosome 2 was identified and one allele of the sialidase gene was found on marker chromosome M1. The other allele was located on marker chromosome M16 q+ which appears as a fusion of M1 with chromosome 5. These results dramatically demonstrate the complexity of targeting in mutagenized cells” (page 847, right column, second paragraph continues to first sentence of third paragraph).
Thus, it is apparent that even among mammalian CHO cell lines they have different endogenously expressed protease profiles that are responsible for the proteolytic degradation of recombinant proteins, let alone any mammalian cell derived from any tissue/organ, and more particularly identifying the single type II-transmembrane serine protease-type matriptase enzyme being the major cause for proteolytic degradation of a recombinant polypeptide of interest secreted from any mammalian cell as encompassed by the instant claims and/or contemplated by Applicant. Moreover, the physiological art is already recognized as unpredictable (MPEP 2164.03).
3. The amount of direction or guidance provided
Apart from disclosing an “unexpected” finding that matriptase is the main protease involved in proteolytic degradation of recombinant proteins in CHO-K1 cells via siRNA, TALEN and ZFN knockdown approaches (examples 1-2 and 5); the instant specification fails to provide sufficient guidance on the issue that matriptase is also the major protease that is responsible for the degradation of recombinant proteins expressed and secreted from any other mammalian cells, such that these other mammalian cells with their impaired endogenous matriptase gene expression via gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof can express and secrete recombinant polypeptides of interest with significantly less and/or reduced clipping of the recombinant polypeptides as contemplated by Applicant and/or encompassed by the instant claims. As already noted above, proteolytic degradation of recombinant secreted polypeptides can differ even among mammalian CHO cell lines as evidenced at least by the teachings of Sandberg et al identifying metalloproteinases being major proteases in destabilizing the production of a recombinant factor VIII, while Robert et al identified a metalloproteinase and cathepsin D are responsible for the degradation of an Fc-fusion recombinant protein; let alone any vertebrate cell derived from any species and/or from any tissue/organ, including a human cell in which its endogenous unaltered matriptase has at least 80% sequence identity to SEQ ID NO: 2 of the present application (SEQ ID NO: 2 is the human 855-amino acid matriptase sequence). Particularly, the instant specification stated clearly “[s]o far little is known about the proteases expressed by the vertebrate host cells used for recombinant expression, and about the proteases responsible for clipping. One of the major challenges is the number of proteases expressed by vertebrate host cells. E.g. more than 700 proteases are known to be present in rodent cell genomes, many of which could be involved in clipping” (paragraph [4]); and “Considering the large number and variety of proteases expressed in vertebrate cells, such as in particular mammalian cells, it was even more surprising that impairing the function of this single protease – matriptase – is sufficient to significantly reduce or even eliminate clipping of the secreted polypeptide of interest in the cell culture medium. These advantageous effects are not seen with other, even closely related proteases what supports the importance of the finding that matriptase is the key enzyme responsible for clipping of secreted recombinant polypeptides in the cell culture medium” (paragraph [29]). Even in 2018, Laux et al (Biotechnology and Bioengineering DOI:10.1002/bit.26731, pages 2530-2540, 2018; IDS) still stated “Using protease inhibitors, transcriptomics, and genetic knockdowns, we have identified, out of the >700 known proteases in rodents, matriptase-1 as the major protease involved in the degradation of recombinant proteins expressed in CHO-K1 cells” (Abstract); “Proteolytic degradation has been shown to be dependent on the host cell line used, the culture conditions, or the amount of glycosylation of the expressed polypeptide…However, to date, little is known about the endogenously expressed proteases in the host cells or the proteases responsible for proteolytic degradation” (page 2531, left column, top of third paragraph); and “[t]he choice of the mammalian cell line used as the production host has an influence on proteolytic degradation due to differentially expressed proteases…Therefore, one option is to screen different cell lines to identify one in which proteolytic degradation of the polypeptide does not occur. However, this is time consuming, may require the adaptation of production processes, and rarely eliminates the proteolytic degradation. Therefore, better ways are needed to address this problem” (page 2531, left column, bottom of third paragraph).
Before the effective filing date of the present application (04/29/2014), Dalton et al (Protein Scient 23:517-525, February 2014) already reviewed over-expression of secreted proteins from mammalian cell lines, with popular mammalian cell lines that include CHO-DG44; the Adenovirus 5 transformed human embryonic kidney cell line, HEK293; the SV40 transformed African green monkey CV-1 line, COS-1; and the non-Ig secreting sub-clone of NS1 cells, NS0; without suggesting reduction or elimination of functional expression of any protease, let alone matriptase specifically. Additionally, Clark et al (J. Biol. Chem. 285:27130-27143, 2010; IDS) already demonstrated that CHO-K1 cells have to be co-transfected with a plasmid encoding human matriptase and a plasmid encoding ASC1-GFP to show matriptase cleaving ASC1 (a H+-gated channel protein) specifically, but not CHO-K1 cells transfected with a plasmid encoding ASC1-GFP alone; suggesting that CHO-K1 cells express no or very little endogenous cell surface serine protease matriptase (Abstract; page 27138, left column, first paragraph; and Figures 6A and 6C). Moreover, Desilets et al (J. Biol. Chem. 283:10535-10542, 2008) also showed at least that HEK293 cells do not apparently express any endogenous matriptase due to the lack of any matriptase band detected in Mock lanes 1 and 6 of Figure 3 for the cell membrane fraction, soluble fraction and conditioned medium. There is also no evidence of record that any human cell in any form (e.g., a cell line or a cell clone) in which impairing the effect of matriptase via gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof at least reduces clipping of the secreted polypeptide of interest as contemplated by Applicant and/or encompassed by the instant claims.
Since the prior art before the effective filing date of the present application (04/29/2014) did not provide any guidance regarding to the aforementioned issue, it is incumbent upon the present application to do so. Given the state of the prior art and coupled with the lack of sufficient guidance provided by the present application, it would have required undue experimentation for a skilled artisan to make and use the instant broadly claimed inventions.
As set forth in In re Fisher, 166 USPQ 18 (CCPA 1970), compliance with 35 USC 112, first paragraph requires:
That scope of claims must bear a reasonable correlation to scope of enablement provided by specification to persons of ordinary skill in the art; in cases involving predictable factors, such as mechanical or electrical elements, a single embodiment provides broad enablement in the sense that, once imagined, other embodiments can be made without difficulty and their performance characteristics predicted by resort to known scientific laws; in cases involving unpredictable factors, such as most chemical reactions and physiological activity, scope of enablement varies inversely with degree of unpredictability of factors involved.
Moreover, the courts have also stated that reasonable correlation must exist between scope of exclusive right to patent application and scope of enablement set forth in the patent application (27 USPQ2d 1662 Ex parte Maizel.).
Accordingly, due to the lack of sufficient guidance provided by the specification regarding to the issues set forth above, the unpredictability of the relevant physiological art, and the breadth of the instant claims, it would have required undue experimentation for one skilled in the art to make and use the instant broadly claimed invention.
Response to Arguments
Applicant’s arguments related to the above 112(a) rejection in the Amendment filed on 02/23/2026 (pages 14-19) have been fully considered, but they are respectfully not found persuasive for the reasons discussed below.
Applicant argued that it would not have required undue experimentation for a skilled artisan to have taken any mammalian cell, reduced or eliminated the expression of matriptase, and confirmed that the reduction or elimination in expression of matriptase reduced the clipping of the secreted polypeptide of interest using standard art-recognized techniques such as the clipping assay and analyses described in the specification (e.g., Examples 1, 2 and 5). Particularly, the instant claims encompass only mammalian cells which have impaired matriptase, thereby reducing clipping of a secreted polypeptide of interest. Applicant argued that none of the references such as Mulvihill, Fang, Sandberg, Robert, Dorai and Zhu that are cited by the Examiner support the reduction or elimination of matriptase in those cells would not reduce clippings of a secreted polypeptide of interest; and that the present claims do not require that recombinant protein clipping is exclusively affected by matriptase. Rather, the present claims require that “impairing the effect of matriptase in said cell reduces clipping of the secreted polypeptide of interest”. Applicant also argued that the claims encompass mammalian cells in which clipping of the secreted protein of interest is reduced when the expression of matriptase is reduced or eliminated, regardless of whether other proteases also contribute to clipping, and the possibility that additional degradation routes may exist for specific recombinant polypeptides is irrelevant. Applicant also argued that the relevance of both the Wurm and Lewis references to the present claims is unclear and they do not call into question of their enablement. With respect to the amount of guidance provided and existence of working examples, Applicant argued that the specification provides an extensive description of the structural features of matriptase, methods for producing a mammalian cell with impaired expression of matriptase, and numerous working examples supporting the claimed invention as well as demonstrating the broad relevance of matriptase across different mammalian species and not only in CHO-K1 derived cells. Applicant further argued that a skilled artisan would not reasonably doubt that the claimed invention could also be applied to any other type of mammalian cell, particularly in view of the provided working examples showing that matriptase is even more broadly relevant across different mammalian species, not just CHO cells; as well as data described in Ahmed article demonstrating that siRNAs targeting matriptase efficiently reduce matriptase expression and inhibit matriptase-dependent cleavage of IGFBP-rP1 in human ovarian carcinoma (OVISE) cells (FIGS. 9B-9C), and reporting detectable matriptase expression and activity across multiple human epithelial and carcinoma cell lines, including OVISE, MKN-45, DLD-1, and HEK 293 (FIG. 3B). Applicant further argued that the Office’s reliance on Dalton and Desilets references suggesting HEK293 cells do not express endogenous matriptase is misplaced since Ahmed et al expressly report detectable matriptase expression and activity in HEK293 cells (FIG. 3B); and noted that the claims are directed to mammalian cells in which matriptase is impaired, and not to cells that express high levels of matriptase.
First, apart from disclosing an “unexpected” finding that matriptase is the main protease involved in proteolytic degradation of recombinant proteins in CHO-K1 cells via siRNA, TALEN and ZFN knockdown approaches (examples 1-2 and 5); the instant specification fails to provide sufficient guidance on the issue that matriptase is also the major protease that is responsible for the degradation of recombinant proteins expressed and secreted from any other mammalian cells, such that these other mammalian cells with their impaired endogenous matriptase gene expression via gene knockout, gene mutation, gene deletion, gene silencing or a combination thereof can still express and secrete recombinant polypeptides of interest with significantly less and/or reduced clipping of the recombinant polypeptides as contemplated by Applicant and/or encompassed by the instant claims. An ordinary skill in the art would readily recognize that a recombinant mammalian cell even with a functional expression of a matriptase gene being reduced or eliminated would not have reduced clipping of any heterologous secreted polypeptide of interest unless matriptase is a major active protease relative to a plethora of proteases expressed in said cell. For example, how would a clipping of a heterologous secreted polypeptide of interest is reduced in a mammalian cell if matriptase is present only in trace amount relative to an abundance of other proteases such as other serine proteases, metalloproteases, aspartic proteases and/or cysteine proteases expressed in the cell? Accordingly, it would have required undue experimentation for a skilled artisan to determine and/or identify which mammalian cell derived from which tissue/organ from about 5,416 different mammalian species that the single type II-transmembrane serine protease-type matriptase enzyme is a major cause for proteolytic degradation of a heterologous recombinant polypeptide of interest secreted in a mammalian cell. Please refer to the detailed Wands factor analysis set forth in the above 112(a) rejection.
Second, although none of Mulvihill, Fang, Sandberg, Robert, Dorai and Zhu disclose matriptase, they represent the state of the prior art and their teachings are relevant to the instant claimed invention as they clearly demonstrated that many other proteases belonging to different proteinase classes (e.g., metalloproteinases, serine-threonine proteases, aspartic proteases) play a major role in destabilizing the production of secreted recombinant polypeptides.
Third, the contribution of other proteases that play a major role in destabilizing/clipping secreted recombinant polypeptides in a mammalian host cell is relevant because what is the use of a degraded recombinant polypeptide of interest mediated by other proteases and is secreted by a mammalian host, even said mammalian host has a reduced or eliminated functional expression of matriptase gene and/or the mammalian host has a trace amount of matriptase activity? Please note that the specification is required to teach how to make and/or use the claimed invention under 35 U.S.C. 112(a).
Fourth, the instant specification also stated clearly “[s]o far little is known about the proteases expressed by the vertebrate host cells used for recombinant expression, and about the proteases responsible for clipping. One of the major challenges is the number of proteases expressed by vertebrate host cells. E.g. more than 700 proteases are known to be present in rodent cell genomes, many of which could be involved in clipping” (paragraph [4]); and “Considering the large number and variety of proteases expressed in vertebrate cells, such as in particular mammalian cells, it was even more surprising that impairing the function of this single protease – matriptase – is sufficient to significantly reduce or even eliminate clipping of the secreted polypeptide of interest in the cell culture medium. These advantageous effects are not seen with other, even closely related proteases what supports the importance of the finding that matriptase is the key enzyme responsible for clipping of secreted recombinant polypeptides in the cell culture medium” (paragraph [29]). Even in 2018, Laux et al (Biotechnology and Bioengineering DOI:10.1002/bit.26731, pages 2530-2540, 2018; IDS) still stated “Using protease inhibitors, transcriptomics, and genetic knockdowns, we have identified, out of the >700 known proteases in rodents, matriptase-1 as the major protease involved in the degradation of recombinant proteins expressed in CHO-K1 cells” (Abstract); “Proteolytic degradation has been shown to be dependent on the host cell line used, the culture conditions, or the amount of glycosylation of the expressed polypeptide…However, to date, little is known about the endogenously expressed proteases in the host cells or the proteases responsible for proteolytic degradation” (page 2531, left column, top of third paragraph); and “[t]he choice of the mammalian cell line used as the production host has an influence on proteolytic degradation due to differentially expressed proteases…Therefore, one option is to screen different cell lines to identify one in which proteolytic degradation of the polypeptide does not occur. However, this is time consuming, may require the adaptation of production processes, and rarely eliminates the proteolytic degradation. Therefore, better ways are needed to address this problem” (page 2531, left column, bottom of third paragraph). Thus, these teachings support the Examiner’s position and the unpredictability in a reduction or elimination of matriptase expression in any mammalian cell to attain a reduced clipping of a heterologous secreted polypeptide of interest expressed in said cell.
Fifth, Wurm and Lewis references were cited to show that mammalian CHO cells are immortalized cells that are characterized by a high degree of genetic and phenotypic diversity. Additionally, Sandberg et al already identified metalloproteinases play a major role in destabilizing the production of a recombinant factor VIII from a DHFR- CHO cell line in serum-free medium (Abstract; Table 1), while Robert et al also identified a metalloproteinase and cathepsin D are responsible for the degradation of an Fc-fusion recombinant protein produced from the DFHR deficient DUKX-B11 cell line (Abstract). Moreover, Dorai et al (Biotechnol. Prog.) reported one or more serine-threonine class of proteases and not metalloproteases are significantly involved in the N-terminal clipping of glucagon-like-peptide-1-antibody fusion proteins produced by the CHOK1SV cell line which is adapted to grow in animal protein free media (Abstract; Table 1). Accordingly, it is apparent that even among mammalian CHO cell lines, they have different endogenously expressed protease profiles that are responsible for the proteolytic degradation of recombinant proteins, let alone any mammalian cell derived from any tissue/organ, and more particularly identifying the single type II-transmembrane serine protease-type matriptase enzyme being the major cause for proteolytic degradation of a recombinant polypeptide of interest secreted from any mammalian cell as encompassed by the instant claims and/or contemplated by Applicant.
Sixth, Ahmed et al stated clearly “Of nine human cell lines tested, seven cell lines secreted IGFBP-rP1 at high levels, and two of them, ovarian clear cell adenocarcinoma (OVISE) and gastric carcinoma (MKN-45) highly produced the cleaved IGFBP-rP1…The conditioned medium of OVISE cells did not cleave purified IGFBP-rP1, but their membrane fraction had an IGFBP-rP1-cleaving activity” (Abstract), and “These results suggested that OVISE and MKN-45 cells expressed a high level of proteinase(s) responsible for the processing of IGFBP-rP1” (right column, last sentence of first full paragraph at page 616). Thus, only 2/7 (29%) of tested human cell lines in the Ahmed article showed a high level of processed IGFBP-rP1 with trace amounts of processed IGFBP-rP1 being detected in HLE and HEK293 cells via immunoblotting with anti-TAF/IGFBP-rP1 antibody (FIG. 1). Ahmed et al also stated “Our recent analysis has detected soluble matriptase in 19 of 24 human carcinoma cell lines tested, which included carcinomas of the breast, lung, stomach and colon [32]. The soluble matriptase mostly existed in a single-chain, latent form as a major component and two-chain forms complexed with its inhibitor HAI-I, in agreement with the past reports [18,30]. Therefore, soluble matriptase released from cell membrane is expected to have a very low, if any, proteolytic activity” (a paragraph bridging left and right columns at page 623). Moreover, Ahmed et al also taught that the 95- and 110-kDa bands in zymography (Figs. 3A and 4), and these gelatinolytic activities are results from partial dissociation of an active matriptase from its inhibitor HAI-I after SDS/PAGE; while the 75-kDa activity is thought to be active matriptase which had been dissociated from HAI-I by the SDS treatment (left column at page 619). Fig. 3 B in the Ahmed article also simply showed a faint 75 kDa band corresponding to a single-chain, latent matriptase (non-active matriptase) secreted by HEK293 cells (legend of Fig. 3B at page 618).
Thus, at best Ahmed et al simply teach that matriptase seems to be a major IGFPB-rP1-processing enzyme in OVISE cells, and possibly in MKN-45 cells. However, the Ahmed article did not characterize the expression of active matriptase in OVISE (ovarian clear cell adenocarcinoma) cells and/or gastric carcinoma MKN-45 cells relative to other proteases such as MT1-MMP, MMP-7 and MMP-2/9 which are known to play important roles in the process of tumor invasion and metastasis, as well as serine proteases such as plasminogen activators, plasmin and trypsin that contribute to malignant phenotypes in tumor cells (Ahmed article; left column, second paragraph at page 616). Ahmed et al even stated “Although the present study demonstrates that matriptase cleaves IGFBP-rP1, our data do not exclude the possibility that other proteinases, especially serine proteinases, also cleave IGFBP-rP1. We previously reported that many human cancer cell lines secrete an active or latent form of trypsin and a 75-kDa serine proteinase [20], the later of which was identified as matriptase in a recent study [32]” (right column, top of second paragraph at page 623).
Accordingly, the cited Ahmed article did not teach or suggest that matriptase plays a major role and/or a key enzyme responsible for clipping of any heterologous secreted recombinant polypeptides in a cell culture medium because the majority of nine human cell lines tested did not express and/or a weak expression of active matriptase, along with the vast majority of previously tested 19 of 24 human carcinoma cell lines simply produce soluble matriptase mostly existed in a single-chain, latent form as a major component and two-chain forms complexed with its inhibitor HAI-I, with a very low, if any, proteolytic activity.
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.
Amended claims 24-25, 28-30, 32-41 and 44 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-27 of U.S. Patent No. 11,512,335 (IDS)
Although the claims at issue are not identical, they are not patentably distinct from each other because an isolated recombinant CHO-K1 derived CHO cell suitable for recombinant expression of a polypeptide of interest, wherein the CHO-K1 derived CHO cell is altered to impair the effect of matriptase, wherein the effect of matriptase is impaired because functional expression of the matriptase gene is reduced or eliminated in said cell by gene knock-out, gene mutation, gene deletion, gene silencing or a combination thereof, wherein the CHO-K1 derived CHO cell comprises at least one heterologous polynucleotide encoding a polypeptide of interest operatively linked to a secretory leader sequence and the polypeptide of interest is secreted from the CHO-K1 derived CHO cell, and wherein impairing the effect of matriptase in said cell reduces clipping of the secreted polypeptide of interest; a method for producing the same CHO cell; a method for recombinantly producing a polypeptide of interest using the same CHO cell; a method for selecting a host cell which recombinantly expresses a polypeptide of interest using the same CHO cell; and a method for selecting a CHO-K1 derived CHO cell for recombinant production of a secreted polypeptide of interest in claims 1-27 of U.S. Patent No. 11,512,335 anticipate the claimed genus in the application being examined and, therefore, a patent to the genus would, necessarily, extend the rights of the species or sub- should the genus issue as a patent after the species of sub-genus.
Amended claims 24-25, 28-30, 32, 34 and 38-41 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-2, 8-10, 13 and 16-17 of U.S. Patent No. 10,414,802 (IDS).
Although the claims at issue are not identical, they are not patentably distinct from each other because a recombinant CHO cell (e.g., CHO-K1 cells, CHO-DUXB11, CHO-DG44, or CHO-S cell; dependent claim 2), comprising: a polynucleotide sequence encoding cytomegalovirus (CMV) pentameric complex (including secreted pentameric complex, see dependent claim 13), wherein said pentameric complex comprises: gH or a complex-forming fragment thereof, gL or a complex-forming fragment thereof, pUL128 or a complex-forming fragment thereof, pUL130 or a complex-forming fragment thereof, and pUL131 or a complex-forming fragment thereof; wherein said one or more polynucleotide sequences are integrated into the genomic DNA of said CHO cell; and wherein the expression level or activity of matriptase is reduced in said cell as compared to a control (e.g., via a mutation in exon 2 of the matriptase gene, or by gene knock-out; see dependent claims 9-10); and a process of producing CMV pentameric complex by culturing the same CHO cell under suitable condition, and harvesting the pentameric complex from the culture that further includes purifying the pentameric complex in claims 1-2, 8-10, 13 and 16-17 of U.S. Patent No. 10,414,802 anticipate the claimed genus in the application being examined and, therefore, a patent to the genus would, necessarily, extend the rights of the species or sub- should the genus issue as a patent after the species of sub-genus.
It is noted that in the Amendment filed on 02/23/2026 (page 20) Applicant simply requested that the above nonstatutory double patenting rejections be held in abeyance until an allowable subject matter is identified.
Conclusions
No claim is allowed.
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 Quang Nguyen, Ph.D., at (571) 272-0776.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s SPE, James Douglas (Doug) Schultz, Ph.D., may be reached at (571) 272-0763.
To aid in correlating any papers for this application, all further correspondence regarding this application should be directed to Group Art Unit 1631; Central Fax No. (571) 273-8300.
Any inquiry of a general nature or relating to the status of this application or proceeding should be directed to (571) 272-0547.
Patent applicants with problems or questions regarding electronic images that can be viewed in the Patent Application Information Retrieval system (PAIR) can now contact the USPTO’s Patent Electronic Business Center (Patent EBC) for assistance. Representatives are available to answer your questions daily from 6 am to midnight (EST). The toll-free number is (866) 217-9197. When calling please have your application serial or patent number, the type of document you are having an image problem with, the number of pages and the specific nature of the problem. The Patent Electronic Business Center will notify applicants of the resolution of the problem within 5-7 business days. Applicants can also check PAIR to confirm that the problem has been corrected. The USPTO’s Patent Electronic Business Center is a complete service center supporting all patent business on the Internet. The USPTO’s PAIR system provides Internet-based access to patent application status and history information. It also enables applicants to view the scanned images of their own application file folder(s) as well as general patent information available to the public.
/QUANG NGUYEN/Primary Examiner, Art Unit 1631
Prosecution Insights