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 and arguments filed on 08-28-2026 has been entered. Claims 6-7, 11, 20, 21, 22, 23, 28, 29 and 34 have been amended. Claims 1-5, 8-10, 12-19, 32-33, 36, 39 have been canceled. Claims 42-46 have been added. Claims 6-7, 11, 20-31, 34-35, 37-38, 40-46 are pending.
Election/Restrictions
Applicant's election of claims 6, 7, and 20-27 (Group II) in the reply filed on 08-15-2024 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.0l(a)).
Claims 9-19 are withdrawn from further consideration pursuant to 37 CFR l. l 42(b) as being drawn to a nonelected invention there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 08-15-2024.
However, in view of applicant amendments and upon further consideration, withdrawn claims 11-16 are hereby rejoined with the elected invention. It is noted that claims 12-19 have been canceled.
Claims 6-7, 11, 20-31, 34-35, 37-38, 40-46 are under consideration.
Priority
This application is a 371 of PCT/EP2020/050592 filed on 01/10/2020 that claims priority from a foreign application EP 19151233.4 filed on 01/10/2019. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Maintained in modified form-Claim Rejections - 35 USC § 101- necessitated by amendments
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.
Claims 6-7, 11, 20-21, 24-25, 42, 46 are rejected under 35 U.S.C. 101 because the claimed invention is directed to a product of nature without significantly more.
Step 1: Is the claim to a process, machine, manufacture or composition of matter?
Claim 6 is directed to a Drosophila cell, comprising a genetic modification of the FucT6 gene, wherein said modification reduces expression of the FucT6 gene. Claim 7 specifies the Drosophila cell produces N-glycosylated protein comprising less than 2% core α l,6-fucose. Claim 20 specifies the Drosophila cell, wherein expression of an fdl gene has further been disrupted. Claim 21 specifies a cell clone or cell line comprising the Drosophila cell. Claim 24 specifies the Drosophila cell produces N-glycosylated protein with less than 40% FM3/M3 glycan structures. Claim 25 specifies the Drosophila cell produces N-glycosylated protein comprising at least 2% FAl/Al glycan structures. Claim 27 specifies the Drosophila cell produces N-glycosylated protein comprising less than 15% FM3/M3 glycan structures, less than 30% FAl/Al glycan structures, and more than 50% FA2/A2 glycan structures.
It is noted that the amended claims 11, 42, 46 are now included in this modified rejection necessitated by amendments because the newly added limitations recite the presence of α2,6-sialyltransferase and/or Mgat4 genes which are naturally present in Drosophila species. Thus, claims 11, 42, 46 encompass embodiments with natural occurring α2,6-sialyltransferase and/or Mgat4 genes in Drosophila species.
Under the broadest reasonable interpretation, the terms of the claim are presumed to have their plain meaning consistent with the specification as it would be interpreted by one of ordinary skill in the art. See MPEP 2111. Broadest reasonable interpretation of the claims encompasses a Drosophila cell. Here, because the insect cells are a composition of matter, the claim is to at least one statutory category of invention (Step 1: YES).
Step 2(A), Prong 1: Does the claim recite an abstract idea, law of nature or natural phenomenon?
The markedly different characteristics analysis is performed by comparing the nature-based product limitation of a Drosophila cell comprising a genetic modification of the FucT6/ fdl gene to its naturally occurring counterpart of a Drosophila cell comprising a genetic modification of the FucT6/ fdl gene to determine if it has markedly different characteristics from the counterpart. MPEP 2106.04(c) (II).
The claims recite a Drosophila cell line or clone comprising a genetic modification on FucT6 gene wherein said modification reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells. The Drosophila cell produces N-glycosylated protein comprising less than 2% core α l,6-fucose. Expression of a fdl gene in the Drosophila cell line or clone can be further disrupted. The cells can produce N-glycosylated protein with less than 40% FM3/M3 glycan structures; produce N-glycosylated protein comprising at least 2% FAI/Al glycan structures; produce N-glycosylated protein comprising less than 15% FM3/M3 glycan structures, less than 30% FAI/Al glycan structures, and more than 50% FA2/A2 glycan structures.
Here, the closest natural counterpart is naturally occurring Drosophila cell line or clone with natural mutation occurring on FucT6/ fdl gene and/or regulatory elements such as promoter or enhancers that lead to reduced gene expression of FucT6/ fdl. It is noted that the claimed Drosophila cell line or clone encompass any cell lines such as freshly isolated primary cell line or cell line freshly isolated from organ tissue and maintained for growth in vitro as evidenced by GMP Plastic (https://gmpplastic.com/blogs/useful-articles-on-lab-supplies-faq-section/primary-cells-vs-cell-lines-key-differences-research-applications?srsltid=AU7gw4XryxSnwoUaqPyxN84RNKQuEY7dqq-LqQOdK5bDnfy8-UNPvW7P, Mar 28, 2025). GMP Plastic teach that Primary cells can be directly isolated from living tissues and retain the physiological characteristics of their tissue of origin. These cells are usually extracted from human or animal sources and can be cultured in vitro for a limited number of passages before they undergo senescence. Because they closely mimic in vivo conditions, primary cells are ideal for studies requiring high biological relevance (Page 2). Additionally, the specification of the claimed invention does not define the phrase “cell lines or clone” to be modified to have markedly different from the product of nature other than having reduced expression of the FucT6/ fdl gene due to genetic modifications that can be naturally occurring mutation on promoter, enhancer or on FucT6/ fdl itself which will be discussed as below. Also, the specification of the claimed invention does not define what can be included or excluded to satisfy the term “wild type Drosophila cells”. Since different laboratories use different standard fruit fly strains (such as Canton-S, Oregon-R, or Harwich) as their "wild type", meaning the baseline normal phenotype varies because these isolated strains have genetically diverged from real nature and from each other over decades of captive breeding, the term “wild type” in the instant claims therefore interpreted broadly. Thus, the claims broadly encompass cell line freshly isolated from Drosophila carrying naturally occurring mutation on the FucT6/ fdl gene (such as spontaneous stop codon mutation happened on open reading frame next or near start codon) OR naturally occurring mutation on the elements such as enhancers or promoters that control and cause reduced/null expression of FucT6 gene in a natural occurring cells.
When the claimed Drosophila cell line or clone is compared to this counterpart, the comparison indicates that there are no differences in structure, function, or other characteristics which undergo spontaneous mutations such as reduced/null mutation as explained below:
Watanabe et al (Genetics 181: 1035–1043 (March 2009), DOI: 10.1534/genetics.108.093385) teaches Molecular Spectrum of Spontaneous de Novo Mutations in Male and Female Germline Cells of Drosophila melanogaster (Title), and mutation rate and its variability are central to theoretical population genetics and evolutionary studies (Page 1035, left column) and there is significant variability in rate and pattern of mutation among progenitor genotypes (Page 1035, right column). Keightley et al (Mol. Biol. Evol. 32(1):239–243 doi:10.1093/molbev/msu302, November 3, 2014) estimated the spontaneous mutation rate in Heliconius melpomene by genome sequencing of a pair of parents and 30 of their offspring, based on the ratio of number of de novo heterozygotes to the number of callable site-individuals …… an estimated mutation rate of 2.9x 10-9 (95% confidence interval, 1.3x10-9 –5.5 x10-9), which is similar to recent estimates in Drosophila melanogaster (Abstract). Thus, Watanabe et al and Keightley et al provide evidence that the Drosophila cells of the claimed invention are morphologically and phenotypically similar to Drosophila cells in nature which undergo spontaneous mutation that can encompass null mutations that render the loss of function of genes such as FucT6 and fdl.
Yamamoto-Hino et al (Genes to Cells (2015) 20, 521–542, DOI: 10.1111/gtc.12246, 04 May 2015) teach “Gene silencing in the whole Drosophila body” (Page 522, right column, last para) and “Depigmentation was caused by silencing of da6fut/fucT6, gfr/nac, Csat, and CG33145 (Fig. 6, Table 3). Da6Fut/FucT6 adds a fucose moiety to the core region of N-linked glycans via α1,6- linkage ….” (Page 529, right column, 1st para.).
Yang et al (Entomologia Generalis, Volume 43 (2023), Issue 5, 911–925, DOI: 10.1127/entomologia/2023/2066) provide evidence for a viable FucT6-mutant D. melanogaster larvae: FucT6-mutant D. melanogaster larvae exhibit a somewhat impaired immune response to parasitoid wasp infection, leading to a decreased encapsulation rate (See page 919, right column, 2nd para.).
Zuberova et al (Disease Models & Mechanisms 3, 773-784 (2010) doi:10.1242/dmm.005389) provide evidence for FucT6 on chromosome X can be targeted (insertion) by transposon ( Note: A transposon is a mobile genetic element that can move from one location to another within a genome is a source of mutations that can alter gene function) : Zuberova et al stated that “We screened a total of 49 deletions for chromosome X …… The originally identified deficiency Df(1)Exel9050 in the cytological localization 10D5-10D6 was molecularly defined by the transposon insertions P{XP}d00034 and PBac{RB}FucT6e02394” (Page 774, left column, 4th para.)
It appears that D. melanogaster organism such as larvae and D. melanogaster cells containing FucT6-mutant are viable and the claimed insect cells are identical to what exists in nature (e.g., same genotype and phenotype). Additionally, the claims only require the presence of D. melanogaster cells containing FucT6-mutant not entire D. melanogaster. There is nothing in the claim that are phenotypically different from what exists in nature or any difference that arose due to applicant's efforts. The claim thus encompasses cells that are identical to naturally occurring cells. Because there is no difference between the claimed and naturally occurring cells for at least some of the embodiments encompassed by the claim, the claimed cells do not have markedly different characteristics, and thus are a "product of nature" exception. In re Roslin Institute (Edinburgh), 750 F.3d 1333, 1338-39 (Fed. Cir. 2014).
Step 2(A), Prong 2: Do the claims recite additional elements that integrate the judicial exception into a practical application?
In view of foregoing analysis, the claims recite a judicial exception of a naturally occurring Drosophila cell with naturally mutation occurring on FucT6 gene, they would still be patent-eligible if “the claims as a whole integrate the recited judicial exception insect cell with naturally mutation occurring on FucT6 gene into a practical application of the exception”. Here the claims recite the insect cell produces N-glycosylated protein comprising less than 2% core α l,6-fucose; Expression of a Fdl gene in the insect cell can be further disrupted; The cells can produce N-glycosylated protein with less than 40% FM3/M3 glycan structures; produce N-glycosylated protein comprising at least 2% FAI/Al glycan structures. However, these are structural limitations which are natural properties of the cells as evidenced by applicant own disclosure: “The FucT6 gene was successfully disrupted …… The polyclonal pool showed an effect and the analyzed clone showed 100% absence of α 1,6-fucose.” (Page 22, lines 2-3) (For claim 7). Also, the additional disruption of expression of Fdl gene can also happen naturally as explained above and mutant flies are viable as evidenced by Sarkar et al (THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 281, NO. 18, pp. 12776–12785, May 5, 2006) who teach fused lobe (fdl) mutant flies : fdl mutants were first identified in an enhancer trap screen for genes that are expressed during late larval development in structures that will give rise to the central complex of the adult brain (Page 12783, left column, 1st para) and Df(2R)achi2 flies (Drosophila melanogaster) have a null mutation in the fdl gene (Page 12783, left column, 2nd para.) (For claim 20). Furthermore, the instant disclosure provides evidence for Drosophila cell lacking fdl with characteristic of producing N-glycosylated protein as cited by the claim: “expression of the fdl gene has been disrupted, which has, as shown herein in the examples, the consequence that the FM3/M3 glycan structures are reduced in proportion on expressed protein …… exhibit less than 40% FM3/M3 glycan structures ……the cell of the first aspect produces N-glycosylated protein comprising at least 2% FA1/A1 glycan structures,” (Page 21, lines 3-11) (For claims 24-25).
Thus, the claim as a whole does not amount to significantly more than each "product of nature" by itself. There is no structural or phenotypic difference in any of the claimed differentiated cells that distinguish them from naturally occurring insect cell with naturally occurring mutation occurring on FucT6 gene. Further, there is no additional element that integrates the recited naturally occurring product (naturally occurring Drosophila cell with naturally occurring mutation occurring on FucT6 gene) into a practical application of the judicial exception. In summary, there is no additional elements recited in the claims, considered individually or in combination, that integrate the recited, naturally occurring Drosophila cell with naturally occurring mutation occurring on FucT6 gene into a practical application of the judicial exception and the claim is therefore directed to the judicial exception (Step 2A Yes).
Step 2(B): Does the claim recite additional elements that amount to significantly more than the judicial exception?
There is no additional element recited in the claims that are sufficient to amount to significantly more than the judicial exception, other than the naturally occurring insect cell with naturally occuring mutation occurring on FucT6 gene. The claims only encompass the Drosophila cell which produces N-glycosylated protein with less than 2% core α 1,6-fucose, produces N-glycosylated protein with less than 40% FM3/M3 glycan structures, produces N-glycosylated protein with at least 2% FA1/A1 glycan structures. The insect cell can have Fdl gene expression further disrupted. Additionally, claims 11, 42, 46 recite the Drosophila cells comprise the α2,6-sialyltransferase and/or Mgat4 genes are naturally present in Drosophila species. Thus, the claims recite a naturally occurring Drosophila cell that do not differ markedly from naturally occurring Drosophila cells.
In summary, the claims as a whole do not amount to significantly more than the judicial exception of “product of nature” itself. Thus, the claims do not qualify as patent eligible subject matter. (Step 2B: NO).
Response to Arguments
Applicant's arguments filed 08-28-2026 have been fully considered but they are not persuasive.
1. Applicant argue that
“The amended claims are generally directed to a Drosophila cell line or clone comprising cells with a genetic modification of the FucT6 gene that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells. The claimed Drosophila cells, which are derived from wild type Drosophila cells exhibit modified structural and phenotypic characteristics compared to their parental wild type Drosophila cells, as recited in the amended claims. Thus, the claimed Drosophila cells exhibit markedly different features from their corresponding wild type Drosophila cell, which are a direct result from human intervention”
“The Office has failed to demonstrate that a modified Drosophila cell, let alone a cell line or clone, having a FucT6 genetic modification which reduces expression compared to corresponding wild type Drosophila cells exists in nature (i.e., without human intervention). As described elsewhere herein, the Office merely concludes that a Drosophila cell having the recited genetic modification might be possible in nature”
“ the legal question is not whether the claimed Drosophila cell line or clone could theoretically arise or whether it might someday be found in nature. Rather, the proper legal question is whether the Drosophila cell line or clone, as claimed, occurs naturally. As amended, the Drosophila cells of independent claims 6 and 20 comprise a genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells”.
(Remarks, page 8-9)
Response to Arguments
It is noted that the markedly different characteristics analysis is performed by comparing the nature-based product limitation of a Drosophila cell comprising a genetic modification of the FucT6/ fdl gene to its naturally occurring counterpart of a Drosophila cell comprising a genetic modification of the FucT6/ fdl gene to determine if it has markedly different characteristics from the counterpart. MPEP 2106.04(c) (II). In the instant case, the relevant inquiry is whether the claimed product has markedly different characteristics from its naturally occurring counterpart, the claims broadly encompass cell line freshly isolated from Drosophila carrying naturally occurring mutation on the FucT6/ fdl gene (such as spontaneous stop codon mutation happened on open reading frame early next or near start codon) OR naturally occurring mutation on the elements such as enhancers or promoters that control and cause reduced/null expression of FucT6 gene. The term “cell line” or “clone” does not exclude the freshly isolated cells from Drosophila carrying naturally occurring mutation and maintained for growth in vitro. As described above, Watanabe et al teach that molecular spectrum of spontaneous de novo mutations in male and female germline cells of drosophila melanogaster (Title), and mutation rate and its variability are central to theoretical population genetics and evolutionary studies (Page 1035, left column) and there is significant variability in rate and pattern of mutation among progenitor genotypes (Page 1035, right column). Keightley et al estimated the spontaneous mutation rate in Heliconius melpomene by genome sequencing of a pair of parents and 30 of their offspring, based on the ratio of number of de novo heterozygotes to the number of callable site-individuals …… an estimated mutation rate of 2.9x 10-9 (95% confidence interval, 1.3x10-9 –5.5 x10-9), which is similar to recent estimates in Drosophila melanogaster (Abstract). Thus, Watanabe et al and Keightley et al provide evidence that the Drosophila cells of the claimed invention (which are morphologically and phenotypically similar to Drosophila cells in nature ) would undergo spontaneous mutation that can encompass loss-of-function mutation or null mutations that render the loss of function of genes such as FucT6 and fdl. There is no evidence in record that FucT6/fdl gene would be absolutely spared or exception from natural phenomenon of spontaneous de novo mutations (genetic modification) that reduces or cause null expression of FucT6 or fdl gene.
2. Applicant argue that
“Zuberova (P{XP}d00034 and PBac{RB}FucT6e02394) are not spontaneously occurring transposition events, but rather sitedirected P-element and piggyBac transposon vectors that are engineered laboratory tools routinely used by Drosophila geneticists to generate targeted insertional mutations. The characterization by the Office that these vector insertions are a "natural occurring source of mutation[s]" (Office Action, p. 10) is factually incorrect. Likewise, the gene silencing reported in Yamamoto-Hino was achieved through an inducible RNAi transgene deliberately introduced into the fly genome”
“which include general teachings regarding spontaneous mutation rates, but fail to demonstrate that the claimed genetic modification occurs without human intervention. Office Action, pp. 10-11, bridging paragraph. As such, rather than providing any demonstration that a Drosophila cell having the recited FucT6 genetic modification is an actual product of nature, the Office merely points to a general biological phenomenon and the possibility that Drosophila cells might acquire genetic modifications, as Applicant thoroughly explained previously”
(Remarks, page 10-11)
Response to Arguments
Zuberova et al reference was cited as evidence for FucT6 gene/locus is not immune to the disruption by transposon insertions in Drosophila. The reference is relevant to the functional and phenotypic consequences of FucT6 disruption via transposon insertions which is well known in the art as a mobile genetic element that can move from one location to another within a genome and is a natural occurring source of mutations that can alter gene function. Zuberova et al stated that “We screened a total of 49 deletions for chromosome X …… The originally identified deficiency Df(1)Exel9050 in the cytological localization 10D5-10D6 was molecularly defined by the transposon insertions P{XP}d00034 and PBac{RB}FucT6e02394” (Page 774, left column, 4th para.). Thus, the examiner has provided evidence for FucT6 gene/locus can be disrupted by the transposon insertions while applicants have not provided any evidence for FucT6 gene/locus cannot be disrupted or immune from naturally occurring transposon insertions that exist naturally.
Previously, Applicants argue that silencing fucT6 would not be possible due to there would be no viable fucT6 organism (the claims are directed to a Drosophila cell not a Drosophila insect itself). Yamamoto-Hino et al was cited to teach viable fucT6 cells: “Depigmentation was caused by silencing of da6fut/fucT6, gfr/nac, Csat, and CG33145 (Fig. 6, Table 3). Since depigmentation in Drosophila is a naturally occurring event driven by genetic variation and environmental adaptation, and Yamamoto-Hino et al found that depigmentation was caused by at least in part by silencing of fucT6, these findings support Watanabe et al and Keightley et al teachings for de novo mutations Drosophila Melanogaster. Although Yamamoto-Hino et al stated that “silencing of 56 of these genes resulted in lethality before eclosion” (Page 522, left column, last para), it is clear that the cells with fucT6 silencing exist up to some points before eclosion. In support for this, the above cited reference Yang et al teach silencing FucT6 in D. melanogaster : “Lethal before adult eclosion or specific defects depending on studies” (Page 918, Table 3), and “FucT6-mutant D. melanogaster larvae exhibit a somewhat impaired immune response to parasitoid wasp infection, leading to a decreased encapsulation rate” (See page 919, right column, 2nd para.). Thus, it is clear that mutation in FucT6 exist in cells such as in D. melanogaster larvae.
3. Applicant argue that
“The claimed Drosophila cell clone or line has been produced through human intervention and is not a product of nature. In fact, page 32 of the specification as filed, describes the claimed genetic modification resulted from Applicant's work disrupting the FucT6 gene in a wild type cell line, demonstrating that the claimed Drosophila cells were derived from wild type Drosophila cells. As previously described by Applicant, the modified Drosophila cells are grown in vitro under artificial conditions suitable for their proliferation, including the steps of forcing the cells to adapt to in vitro growth and thereby rendering them suitable for culture conditions. It is not likely that the same genetic modification could or would arise in the absence of such human intervention, and could be why the Office cannot identify evidence of the claimed cells in nature”
(Remarks, page 12)
Response to Arguments
Applicants arguments are not commensurate with the claims: The base claims encompass any cell lines such as freshly isolated primary cell line that can be directly isolated from living tissues and retain the physiological characteristics of their tissue of origin. These cells are usually extracted from human or animal sources and can be cultured in vitro for a limited number of passages before they undergo senescence. Additionally, the specification of the claimed invention does not define the phrase “cell lines or clone” to be modified to have markedly different from the product of nature. The specification of the claimed invention also does not define what can be included or excluded to satisfy the term “wild type Drosophila cells”. Since different laboratories use different standard fruit fly strains (such as Canton-S, Oregon-R, or Harwich) as their "wild type", meaning the baseline normal phenotype varies because these isolated strains have genetically diverged from real nature and from each other over decades of captive breeding. Nevetherless, the amended limitation “modification reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells” at least encompass natural phenomenon of loss-of-function mutation or null mutation on expression of FucT6 such as spontaneous stop codon mutation happened on open reading frame next or near start codon) OR naturally occurring mutation on the elements such as enhancers or promoters that control and cause reduced/null expression of FucT6 gene. As described above, Watanabe et al and Keightley et al provide evidence that the Drosophila cells of the claimed invention (which are morphologically and phenotypically similar to Drosophila cells in nature ) would undergo spontaneous mutation that can encompass loss-of-function mutation or null mutations that render the loss of function of genes such as FucT6 and fdl.
It is also noted that the features upon which applicant relies in the arguments (i.e., “modified Drosophila cells are grown in vitro under artificial conditions suitable for their proliferation, including the steps of forcing the cells to adapt to in vitro growth and thereby rendering them suitable for culture conditions”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
New-Claim Rejections - 35 USC § 112- necessitated by amendments
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 6-7, 11, 20-31, 34-35, 37-38, 40-46 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.
In analyzing whether the written description requirement is met for the genus claim, it is determined whether a representative number of species have been sufficiently described by other relevant identifying characteristics, specific features and functional attributes that would distinguish different members of the claimed genus. To satisfy the written description requirement, a patent specification must describe the claimed invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention. See, e.g., Moba, B. V. v. Diamond Automation, Inc., 325 F.3d 1306, 1319, 66 USPQ2d 1429, 1438 (Fed. Cir. 2003); Vas-Cath, Inc. v. Mahurkar, 935 F.2d at 1563, 19 USPQ2d at 1116. An applicant shows possession of the claimed invention by describing the claimed invention with all of its limitations using such descriptive means as words, structures, figures, diagrams, and formulas that fully set forth the claimed invention. Lockwood v. Amer. Airlines, Inc., 107 F.3d 1565, 1572, 41 USPQ2d 1961, 1966 (Fed. Cir. 1997). Possession may be shown in a variety of ways including description of an actual reduction to practice, or by showing that the invention was "ready for patenting" such as by the disclosure of drawings or structural chemical formulas that show that the invention was complete, or by describing distinguishing identifying characteristics sufficient to show that the applicant was in possession of the claimed invention. See, e.g., Pfaffv. Wells Elecs., Inc., 525 U.S. 55, 68, 119 S.Ct. 304,312, 48 USPQ2d 1641, 1647 (1998); Eli Lilly, 119 F.3d at 1568, 43). USPQ2d at 1406; Amgen, Inc. v. Chugai Pharm., 927 F.2d 1200, 1206, 18 USPQ2d 1016, 1021 (Fed. Cir. 1991).
The claims are directed to a Drosophila cell line or clone that comprise a genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells. The claims encompass a genus of any genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells. This functional limitation encompass any known or unknown genetic elements or genetic manipulation of FucT6 gene expression to reduce expression of the FucT6 gene compared to corresponding wild type Drosophila cells. A genetic modification that reduces expression of gene encompasses micro RNAs (miRNAs), small interfering RNAs (siRNAs), CRISPR interference (CRISPRi), antisense oligonucleotides (ASOs), DNA methylation, histone modifications that are capable of modifying genetic elements to disrupt gene expression such as promoter, enhancer, silencers (DNA sequences that bind repressor proteins to stop or slow down transcription), operators (DNA segments in bacteria (part of an operon) where repressor proteins bind to block RNA polymerase), insulators (sequences that can block the interaction between enhancers and promoters when positioned between them).
The instant specification only exemplifies using CRISPR/Cas9 application within the Drosophila melanogaster genome to disrupt/delete fdl gene and FucT6 (see page 27, lines 13-15 of the instant specification) or RNAi suppressed fdl (Page 33, line 15). However, the claims define an extremely broad genus of genetic modification solely by the desired result of reduced FucT6 expression without identifying structural/sequence characteristics common to the claimed modification, and without describing a representative number of species across that genus.
The functional effect of a genetic/regulatory modification cannot necessarily be predicted merely from the fact that the modification is intended to repress transcription; activity depends on the particular regulatory effector and genomic context. A genetic modification intended to repress a gene does not necessarily produce effective repression because additional, potentially unidentified/context dependent factors can influence repression efficacy. The art recognized that additional factors affecting repression efficacy were not fully understood as described below:
Motorina at al (Int. J. Mol. Sci. 2024, 25, 5231, Doi: 10.3390/ijms25105231) teach “The efficiency of the repression achieved by CRISPRi is influenced by many factors, the contributions of which are not yet well understood. For instance, information concerning the best location for a targeting site varies. For Magnaporthe oryzae, the most efficient targeting site position is 100–200 bp upstream of the transcription start site. Similar results were observed using CRISPRi in Saccharomyces cerevisiae. The optimal distance between the targeting site and transcription start site might be affected by the repressor domain of the CRISPRi system and its chromatin status” (page 15, 1st para.), and “RNAi has been the primary tool for targeted gene repression for many years…..However, it is necessary to note that the RNAi method is often not efficient enough and only leads to a slight decrease in the quantity of the transcripts of the gene of interest, ultimately reducing the amount of protein by only 1.5–2 times and having no significant phenotypic effect. Additionally, the RNAi method has drawbacks that are associated with its off-target effects, which can lead to a misinterpretation of the results” (Page 5, 2nd para.).
Verkuijl et al (Current Opinion in Biotechnology 2019, 55:68–73, Doi: 10.1016/j.copbio.2018.07.005) teach “CRISPR/Cas technologies have rapidly become in routine use for site-directed genetic or transcriptional manipulation. Despite this, the efficiency of CRISPR/Cas9 functioning cannot entirely be predicted, and it is not fully understood which factors contribute to this variability. Recent studies indicate that heterochromatin can negatively affect Cas9 binding and functioning. Investigating chromatin factors indicates that DNA cytosine-5 methylation does not directly block Cas9 binding. Nucleosomes, however, can completely block Cas9 access to DNA in cell-free assays and present a substantial hurdle in vivo. In addition to being associated with an open chromatin state, active transcription can directly stimulate DNA cleavage by influencing Cas9 release rates in a strand-specific manner” (Abstract)
Tycko et al (Nature Biotechnology | Volume 43 | September 2025 | 1525–1538, Doi: 10.1038/s41587-024-02442-6) teach “Transcriptional effectors are protein domains known to activate or repress gene expression; however, a systematic understanding of which effector domains regulate transcription across genomic, cell type and DNA-binding domain (DBD) contexts is lacking. Here we develop dCas9-mediated high-throughput recruitment (HT-recruit), a pooled screening method for quantifying effector function at endogenous target genes and test effector function for a library containing 5,092 nuclear protein Pfam domains across varied contexts. We also map context dependencies of effectors drawn from unannotated protein regions using a larger library tiling chromatin regulators and transcription factors. We find that many effectors depend on target and DBD contexts, such as HLH domains that can act as either activators or repressors. To enable efficient perturbations, we select context-robust domains, including ZNF705 KRAB, that improve CRISPRi tools to silence promoters and enhancers. We engineer a compact human activator called NFZ, by combining NCOA3, FOXO3 and ZNF473 domains, which enables efficient CRISPRa with better viral delivery and inducible control of chimeric antigen receptor T cells” (Abstract).
Kristof et al (Genome Biology (2025) 26:164; doi: 10.1186/s13059-025-03640-4) teach that CRISPRi platforms can often have incomplete knockdown, performance variability across cell lines and gene targets, and inconsistencies dependent on the guide RNA sequence employed (abstract) and “continued variance of CRISPRi functionality across cell lines or lineages, as well as stochasticity depending on the sgRNA sequence used, can still hinder their utility” (Page 2, 2nd para), and “Some residual variation in degree of gene knockdown is to be expected and may originate from individual sgRNA binding dynamics or local chromatin architecture” (bridging page 7-8).
The specification lacks sufficient variety of species of any genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells. The specification does not provide sufficient descriptive support for the myriad of variant embraced by the claims. The analysis above demonstrates that Applicant has not determined the desired effects/functions of the broadly claimed various genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells.
The skilled artisan cannot envision the detailed compositions/functions of the encompassed any genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells other than those described in the specification, and therefore conception is not achieved until reduction to practice has occurred, regardless of the complexity or simplicity of the method of preparation. Adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method of preparing/using it. See Fiers v. Revel, 25 USPQ2d 1601, 1606 (Fed. Cir. 1993) and Amgen lnc. v.Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016 (Fed. Cir. 1991). Thus, it is concluded that the written description requirement is not satisfied for the claimed genus of any genetic modification that reduces expression of the FucT6 gene compared to corresponding wild type Drosophila cells.
Withdrawn - Claim Rejections - 35 USC § 103
Claims 15-16 were rejected under 35 U.S.C. 103 as being unpatentable over Kanda et al (Pub. No.: US 2006/0078991 Al, Pub. Date: Apr. 13, 2006) in view of Johansson et al (Methods Mol Biol. 2012:907:359-70. doi: 10.1007/978-1-61779-974-7_21) as applied to claim 6-7 and further in view of Young et al (J. Microbiol. Biotechnol. (2008), 18(2), 383–391). In view of applicants’ amendments and cancelation of claim 15-16, the previous rejections of claims are hereby withdrawn. Applicants' arguments with respect to the withdrawn rejections are thereby rendered moot. The claims are, however, subject to new rejections over the prior art of record, as set forth below.
Maintained in modified form and New-Claim Rejections - 35 USC § 103 - necessitated by amendments
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Kanda et al (Pub. No.: US 2006/0078991 Al, Pub. Date: Apr. 13, 2006) in view of Johansson et al (Methods Mol Biol. 2012:907:359-70. doi: 10.1007/978-1-61779-974-7_21)
Claim interpretation:
The specification of the claimed invention teaches that "FucT6 gene" is a term which also is meant to cover alpha-(1,6)- fucosyltransferase encoding genes in other insect cells than Drosophila melanogaster derived cells. In fact, the term "FucT6 gene" in the present context covers not only the gene in D. melanogaster, which encodes alpha-(1,6)-fucosyltransferase, but any equivalent gene encoding alpha-(1,6)-fucosyltransferase in other insect cells (see the instant specification Page 22, lines 6-10). Thus, FucT6 gene is interpreted to encompass alpha-(1,6)- fucosyltransferase encoding genes in other insect cells and Drosophila melanogaster derived cells.
Regarding to claim 6, Kanda et al teach “antibody composition-producing cell” and “an isolated host cell which have low or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity” (see claim 1, page 101). Kanda et al teach “As the host cell used for the production of the host cell of the present invention, any cell such as yeast, animal cell, insect cell or plant cell can be used, so long as it has a gene encoding the target enzyme relating to the synthesis of an intracellular sugar nucleotide, GDP-fucose or the target enzyme relating to the modification of a sugar chain wherein 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α-bond in the complex N-glycoside-linked sugar chain” ([0342], page 16) and “Examples of the enzyme relating to the modification of a sugar chain wherein 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α-bond in the complex N-glycoside-linked sugar chain include α-1,6-fucosyltransferase, α-L-fucosidase and the like ([0438], page 23). Kanda et al teach “The gene disruption method may be any method, so long as it can disrupt the gene of the target enzyme is included” ([0334], page 16). Kanda et al teach antibodies produced from the modified cells have higher ADCC activities than antibodies from parent cells ([0069]-[0070], page 4).
Although Kanda et al teach antibody production in host cell such as insect cell or any cell having a gene encoding enzyme relating to the modification of a sugar chain such as α -1,6-fucosyltransferase can be used for antibody producing cell as described above, Kanda et al do not specify a Drosophila cell. Johansson et al cure the deficiency.
Johansson et al teach “production of recombinant antibodies in drosophila melanogaster S2 cells” (Title). Johansson et al teach “One of the major bottlenecks in antibody discovery for research and therapeutic applications is the need for large quantities of protein in a short amount of time. Here we describe an alternative method using the Drosophila melanogaster S2 expression system to produce high levels of antibodies (both IgG and Fab) with equivalent binding properties to antibodies produced in mammalian cell expression systems. Using the Drosophila S2 expression system for antibody production has many advantages over current mammalian systems making antibody expression, purification, and evaluation a much less time-consuming process” (Abstract)
Therefore, it would have been prima facie obvious for a person of ordinary skill in the art before the effective filing date of the rejected claims to combine the teachings of prior art to modify the method and host cells of Kanda et al by using drosophila melanogaster s2 cells for production of recombinant antibodies, with a reasonable expectation of success. Said modification amounting to combining prior art elements according to known methods to yield predictable results. One of ordinary skill in the art would have been motivated to do so because Johansson et al teach “the Drosophila expression system for antibody production offers the production of large amounts of pure, high quality mAbs or Fabs, utilizing a relatively low-cost and time-effective procedure” (Page 361, 3rd para.), and “Using the Drosophila S2 expression system for antibody production has many advantages over current mammalian systems making antibody expression, purification, and evaluation a much less time-consuming process” (Abstract). One of ordinary skill in the art would have had a reasonable expectation of success in doing so because Johansson et al were successful in production of antibody with Drosophila expression system, and provided detailed protocols with working example and data.
Since Kanda et al “an isolated host cell which have low or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity” (see claim 1, page 101), it is expected that deleted gene encoding α l,6-fucosyltransferase gene such as FucT6 would have no expression compared to corresponding wild type Drosophila cells.
Regarding to claims 7, since Kanda et al teach an isolated host cell which has little or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity (see claim 1, page 101). Thus, it is expected that there is little or no 1,6-fucosyltransferase activity for adding fucose to N-acetylglucosamine of N-glycoside-linked sugar chains (little or no α l,6-fucose). Additionally, if one were to knock out the gene encoding the drosophila 1,6-fucosyltransferase activity in an isolated host cell which has little or no 1,6- fucosyltransferase activity then one would expect that the resulting cells would produce N-glycosylated protein comprising less than 2% core α1,6-fucose. For example, this appears to be what happened when Applicant knocked out activity of the Fuct6 gene in drosophila cells: the instant disclosure teaches that “The FucT6 gene was successfully disrupted in a WT S2 cell line by the use of CRISPR/Cas9. The polyclonal pool showed an effect and the analyzed clone showed 100% absence of αl,6-fucose” (Page 34, lines 1-3) and “secretome glycan patterns with 0% fucose on the glycans upon LC-MS …. This clone shows a complete phenotypical knockout of the fucosyltransferase encoded by FucT6.” (see the instant specification on page 32, lines 17-20).
Claims 11, 20-31, 34-35, 37-38, 40-46 are rejected under 35 U.S.C. 103 as being unpatentable over Kanda et al (Pub. No.: US 2006/0078991 Al, Pub. Date: Apr. 13, 2006) in view of Johansson et al (Methods Mol Biol. 2012:907:359-70. doi: 10.1007/978-1-61779-974-7_21, First Online: 01 January 2012) as applied to claim 6-7 above and further in view of Mabashi-Asazuma et al ( hereinafter “Mabashi-Asazuma-2015”, ACS Chem. Biol. 2015, 10, 2199−2208, DOI: 10.1021/acschembio.5b00340) and Jarvis et al (Pub. No.: US 2007/0067855A1, Pub. Date: Mar. 22, 2007).
The teachings of Kanda et al and Johansson et al above are incorporated herein in their entirety.
The combined references do not teach Fdl gene has been disrupted. However, Mabashi-Asazuma-2015 cures the deficiency.
Regarding to claims 20, 21 Mabashi-Asazuma-2015 teach that “considering its functional and biotechnological significance, knocking out fdl has been of great interest for some time, as this would provide further information on FDL function and produce a novel insect cell derivative that would be an excellent starting point for efficient, bottom-up glycoengineering of its N-glycan processing pathway” (Page 2200, left column, 3rd para.) and this novel insect cell derivative would be an excellent starting point because Mabashi-Asazuma-2015 teach that “the new FDL-deficient S2 cell derivative produced in this study will enable future bottom-up glycoengineering efforts designed to isolate insect cell lines that can efficiently produce recombinant glycoproteins with chemically predefined oligosaccharide side-chain structures” (Abstract). Mabashi-Asazuma-2015 used the CRISPR-Cas9 system to edit the fdl gene in Drosophila melanogaster S2 cells. CRISPR-Cas9 editing produced a high frequency of site-specific nucleotide insertions and deletions, reduced the production of insect-type, paucimannosidic products (Man3GlcNAc2), and led to the production of partially elongated, mammalian-type complex Nglycans (GlcNAc2Man3GlcNAc2) in S2 cells …… the new FDL-deficient S2 cell derivative produced in this study will enable future bottom-up glycoengineering efforts …. (Abstract).
Therefore, it would have been prima facie obvious for a person of ordinary skill in the art before the effective filing date of the rejected claims to combine the teachings of prior art to modify the method of insect cells of the above references by using CRISPR-Cas9 system to edit the fdl gene as taught by Mabashi-Asazuma-2015, with reasonable expectation of success. Said modification amounting to combining prior art elements according to known methods to yield predictable results. One of ordinary skill in the art would have been motivated to introduce fdl genetic discruption into genetically modified drosophila cells as taught by the above references because Mabashi-Asazuma-2015 teaches that knocking out fdl gene would be an excellent starting point for efficient, bottom-up glycoengineering of its N-glycan processing pathway (Page 2200, left column, 3rd para.) because this approach can be used to isolate insect cell lines that can efficiently produce recombinant glycoproteins with chemically predefined oligosaccharide side-chain structures (Abstract). One of ordinary skill in the art would have had a reasonable expectation of success in doing so because Mabashi-Asazuma-2015 were successful in using CRISPR-Cas9 system to edit the fdl gene with instructions and working examples.
Regarding to claims 22-23 and 44-45, Mabashi-Asazuma-2015 teach a baculovirus expression vector in Drosophila cells (S2 cells) and method for producing an N-glycosylated polypeptide of interest: “S2R+ cells were routinely maintained at 28 °C as adherent cultures in Schneider’s Drosophila medium …...” (Page 2205, right column, Methods, 4th para.) and “experiments were designed to assess the impact of fdl editing by CRISPR-Cas9 on the glycosylation of a recombinant human glycoprotein expressed in the S2 cell system. To achieve this goal, we transduced S2R+, DmFDLt1, DmFDLt2, and DmFDLt3 cells with a recombinant baculovirus encoding 8X His-tagged human erythropoietin (hEPO) under the control of the ie1 promoter as described in Methods. We subsequently affinity-purified hEPO from the cell-free media, treated equivalent samples with peptide-N4-(N-acetyl-β-glucosaminyl)asparagine amidase-F (PNGase-F) or reaction buffer alone, and analyzed the products by SDS-PAGE with Coomassie Brilliant Blue staining or Western blotting with anti-hEPO, as described in Methods.” (Page 2203, right column, 1st para.). Mabashi-Asazuma-2015 also teach Figure 5. Glycosidase analysis of the impact of fdl editing on hEPO glycosylation (N-glycosylated hEPO) (Page 2203).
Additionally, Mabashi Asazuma et al teach “…baculovirus-insect cell expression systems …… exploited a bacterial enzyme, GDP-4-dehydro-6 -deoxy-D-mannose reductase (Rmd),which consumes the precursor to GDP-L-fucose …... genetically transformed two different insect cell lines …… we constructed a novel baculovirus vector designed to express Rmd immediately after infection and to facilitate the insertion of genes encoding any glycoprotein of interest for expression at a later time after infection …...” ([0031], page 4). Mabashi Asazuma et al also teach “Recombinant Protein Expression and Purification : For small scale recombinant protein expression experiments ….” ([0062], page 8).
Regarding to claims 29, 30, 31, 35, 38, and 41, Mabashi-Asazuma-2015 used the CRISPR-Cas9 system to edit the fdl gene in Drosophila melanogaster S2 cells (Abstract).
Regarding to claim 43, since Kanda et al teach an isolated host cell which has little or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity (see claim 1, page 101). Thus, it is expected that there is little or no 1,6-fucosyltransferase activity for adding fucose to N-acetylglucosamine of N-glycoside-linked sugar chains (little or no α l,6-fucose). Additionally, if one were to knock out the gene encoding the drosophila 1,6-fucosyltransferase activity in an isolated host cell which has little or no 1,6- fucosyltransferase activity then one would expect that the resulting cells would produce N-glycosylated protein comprising less than 2% core α1,6-fucose. For example, this appears to be what happened when Applicant knocked out activity of the Fuct6 gene in drosophila cells: the instant disclosure teaches that “The FucT6 gene was successfully disrupted in a WT S2 cell line by the use of CRISPR/Cas9. The polyclonal pool showed an effect and the analyzed clone showed 100% absence of αl,6-fucose” (Page 34, lines 1-3) and “secretome glycan patterns with 0% fucose on the glycans upon LC-MS …. This clone shows a complete phenotypical knockout of the fucosyltransferase encoded by FucT6.” (see the instant specification on page 32, lines 17-20).
The above references do not teach insertion of at least one of a functional GlcNAcTI gene and a functional GlcNAcTII gene. However, Jarvis et al cures the deficiency.
Regarding to claims 26, 28, 34, 37, 40, Jarvis et al teach that the invention relates, e.g., to transgenic insects, or progeny thereof, whose cells contain at least one genomically integrated, expressible, nucleic acid encoding two or more of a set of Nglycosylation enzymes that can glycosylate a heterologous protein with a mammalianized (e.g., humanized) glycosylation pattern. The glycosylation genes are prefer ably expressed in the insect cells in catalytic amounts (Abstract). Jarvis et al teach “we incorporate mammalian glycosylation enzyme genes, including GlcNAc-TII, B4Gal-TI, ST6Gall, ST3GalIV. sialic acid synthase (SAS), and/or CMP-sialic acid synthetase (CMP-SAS) genes, into an insect genome to compensate for the lack of these enzymes in insect larvae.” ([0173], page 12) and “Addition of these transgenically engineered mammalian genes enables transgenic insect larvae to produce complex, terminally sialylated N-glycans ….additional mammalian genes encoding GlcNAc-TI or a CMP-sialic acid transporter into the transgenic insects are incorporated as necessary …...” ([0174], page 12-13). Jarvis et al also teach suitable expression control sequences that can function in insect cells such as Drosophila melanogaster hsp70 ([0102], page 6) and “Example VII : testing transformation efficiency and the effect of transgene expression in the model insect system, Drosophila melanogaster” (Page 15).
Therefore, it would have been prima facie obvious for a person of ordinary skill in the
art to combine the teachings of prior art to modify the insect cells of the above references by using mammalian glycosyltransferase genes such as GlcNAc-TI, GlcNAc-TII to glycosylate a heterologous protein with a mammalianized glycosylation pattern as taught by Jarvis et al as instantly claimed, with a reasonable expectation of success. Said modification amounting to combining prior art elements according to known methods to yield predictable results. One of ordinary skill in the art would be motivated to do so because Jarvis et al provide explicit advantage of using mammalian glycosyltransferase genes: “Partially or completely mammalianized polypeptides exhibit a number of advantages compared to polypeptides produced by an insect that lacks the glycosylation enzymes of the invention. These advantages include, e.g., enhanced stability when introduced into a mammal, altered activities, or the like.” ([0069], page 4). One of skill in the art would have been expected to have a reasonable expectation of success because Jarvis et al provide working example and data for using mammalian glycosyltransferase genes.
Regarding to claims 11, 42, 46, Jarvis et al teach “a transgenic insect, or progeny thereof, whose somatic and germ cells contain recombinant nucleic acid encoding …... a β-1,4-galactosyltransferase (see claim 1, page 23 of Jarvis et al). Jarvis et al teach “ …. sialyltransferase genes are incorporated because ST6GalI and ST3GalTV transfer sialic acids in alpha 2.6- or alpha 2.3-linkages, respectively, …. ” ([0173], page 12). Jarvis et al teach “ …. additional mammalian genes encoding GlcNAc-TI or a CMP-sialic acid transporter into the transgenic insects are incorporated as necessary ….” ([0174], page 12-13).
Regarding to claims 24, 25, 27, since the structural limitations of the claimed cells were rendered obvious by Kanda et al, Johansson et al, Mabashi-Asazuma-2015 and Jarvis et al, it would be expected that the cells would produce N-glycosylated protein with less than 40% FM3/M3 glycan structures; produce N-glycosylated protein comprising at least 2% FAI/Al glycan structures; produce N-glycosylated protein comprising less than 15% FM3/M3 glycan structures, less than 30% FAI/Al glycan structures, and more than 50% FA2/A2 glycan structures.
Response to Arguments
Applicant's arguments filed 08-28-2026 have been fully considered but they are not persuasive.
Applicant argue that
“Those having skill in the art would have no reason to consider the teachings of Kanda, let alone reasonably expect to arrive at the claimed Drosophila cells by combining the teachings of Kanda with those of Johansson. Notwithstanding the deficient teachings of Kanda as they relate to Drosophila cells, as described above, Kanda fails to teach recombinant proteins having the claimed fucose levels …. There is no reason one having skill would expect the teachings of Kanda would predictably apply to Drosophila cells. Nothing in Kanda would lead those having skill in the art to reasonably expect the claimed fucose levels could be achieved, let alone in a Drosophila cell having a FucT6 gene disruption. The Office has failed to articulate any reason why one would be motivated to consider Johansson in view ofKanda's teachings”
“Kanda's teachings are drawn exclusively to mammalian antibody-producing cell lines, which possess N-glycan processing machinery fundamentally different from that of Drosophila cells ….. Given this substantial biological divergence, one of ordinary skill would have no reasonable basis to expect that disrupting a fucosyltransferase gene in a mammalian cell line, as in Kanda, would predictably translate into comparable reductions in core fucosylation upon FucT6 disruption in the evolutionarily distant Drosophila system ….. Applicant's specification demonstrates that FucT6 disruption in Drosophila S2 cells achieved 0% fucose on the analyzed glycans (specification, p. 32, lines 17-20). This result is not merely incremental but represents complete elimination of core fucosylation unattainable in the mammalian systems of Kanda. Such a stark disparity constitutes objective evidence of unexpected results sufficient to rebut any primafacie case of obviousness.”
(Remarks, page 15-16)
Response to Arguments
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In the instant case,
Kanda et al teach “an isolated host cell which have low or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity” (see claim 1, page 101). Kanda et al teach “As the host cell used for the production of the host cell of the present invention, any cell such as yeast, animal cell, insect cell or plant cell can be used, so long as it has a gene encoding the target enzyme relating to the synthesis of an intracellular sugar nucleotide, GDP-fucose or the target enzyme relating to the modification of a sugar chain wherein 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α-bond in the complex N-glycoside-linked sugar chain” ([0342], page 16) and “Examples of the enzyme relating to the modification of a sugar chain wherein 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α-bond in the complex N-glycoside-linked sugar chain include α-1,6-fucosyltransferase, α-L-fucosidase and the like ([0438], page 23). Kanda et al teach “The gene disruption method may be any method, so long as it can disrupt the gene of the target enzyme is included” ([0334], page 16).
Additionally, Johansson et al teach “production of recombinant antibodies in drosophila melanogaster s2 cells” (Title). Johansson et al teach “One of the major bottlenecks in antibody discovery for research and therapeutic applications is the need for large quantities of protein in a short amount of time. Here we describe an alternative method using the Drosophila melanogaster S2 expression system to produce high levels of antibodies (both IgG and Fab) with equivalent binding properties to antibodies produced in mammalian cell expression systems. Using the Drosophila S2 expression system for antibody production has many advantages over current mammalian systems making antibody expression, purification, and evaluation a much less time-consuming process” (Abstract)
One of ordinary skill in the art would have been motivated to do so because Johansson et al teach “the Drosophila expression system for antibody production offers the production of large amounts of pure, high quality mAbs or Fabs, utilizing a relatively low-cost and time-effective procedure” (Page 361, 3rd para.), and “Using the Drosophila S2 expression system for antibody production has many advantages over current mammalian systems making antibody expression, purification, and evaluation a much less time-consuming process” (Abstract). One of ordinary skill in the art would have had a reasonable expectation of success in doing so because Johansson et al were successful in production of antibody with Drosophila expression system, and provided detailed protocols with working example and data.
In response to applicants’ arguments of “Applicant's specification demonstrates that FucT6 disruption in Drosophila S2 cells achieved 0% fucose on the analyzed glycans ……….unexpected results sufficient to rebut any prima facie case of obviousness”, as per MPEP 716.02: Allegations of Unexpected Results: Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986), in the instant case, Kanda et al teach “an isolated host cell which have low or no 1,6- fucosyltransferase activity for adding fucose to N-acetylglucosamine of a reducing terminus of N-glycoside-linked sugar chains by deleting the gene encoding α l,6-fucosyltransferase gene or by adding a mutation to said gene to reduce or eliminate the fucosyltranferase activity” (see claim 1, page 101) for any cell such as insect cell ([0342], page 16). Thus, a person of ordinary skill in the art before the effective filing date of the claimed invention who practicing deleting the gene encoding α l,6-fucosyltransferase gene as same as the claimed invention would expect 0% fucose because of no 1,6- fucosyltransferase activity.
Conclusion
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.
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/KHOA NHAT TRAN/Examiner, Art Unit 1632
/PETER PARAS JR/Supervisory Patent Examiner, Art Unit 1632
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