SGI-DNA, INC.Download PDFPatent Trials and Appeals BoardOct 30, 20202020001253 (P.T.A.B. Oct. 30, 2020) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/051,463 02/23/2016 Vladimir N. Noskov CODEX1270-3 5766 95432 7590 10/30/2020 Synthetic Genomics, Inc. c/o DLA Piper LLP (US) 4365 Executive Drive Suite 1100 San Diego, CA 92121-2133 EXAMINER HILL, KEVIN KAI ART UNIT PAPER NUMBER 1633 NOTIFICATION DATE DELIVERY MODE 10/30/2020 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): gtdocket@dlapiper.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte VLADIMIR N. NOSKOV and RAY-YUAN CHUANG ____________ Appeal 2020-001253 Application 15/051,463 Technology Center 1600 ____________ Before DONALD E. ADAMS, ERIC B. GRIMES, and ULRIKE W. JENKS, Administrative Patent Judges. ADAMS, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from Examiner’s decision to reject claims 1–6 and 10–21 (Appeal Br. 4). We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as “Synthetic Genomics, Inc.” (Appellant’s July 25, 2019 Appeal Brief (Appeal Br.) 4). Appeal 2020-001253 Application 15/051,463 2 STATEMENT OF THE CASE Appellant’s disclosure relates to “methods, nucleic acids, and systems for transfer (cloning) of donor nucleic acids into host cells, for manipulation (e.g., modification) of donor nucleic acids, e.g., within host cells, and for transplantation of modified donor nucleic acids into recipient cells” (Spec. ¶ 9). Appellant’s claim 1 is representative and reproduced below: 1. A method for seamlessly introducing a modification in a target nucleic acid molecule present in a host cell, comprising: a. introducing a mutagenesis construct and a host vector into the host cell whereby the host vector recombines with the mutagenesis construct in the host cell, wherein the mutagenesis construct contains a first portion of homology that is homologous to a sequence of the target nucleic acid molecule upstream or downstream of a target gene to be modified in the target region on the target nucleic acid molecule, wherein upon recombination the first portion of homology generates a tandem repeat with the homologous sequence of the target nucleic acid molecule; a second portion of homology that is homologous to a 5’ portion of the target region on the target nucleic acid molecule upstream of the modification; a gene encoding an endonuclease having an inducible promoter; an endonuclease recognition site for the encoded endonuclease; and a selectable marker; a third portion of homology that is homologous to a 3’ portion of the target region on the target nucleic acid molecule downstream of the modification; wherein the second and/or third portions of homology comprise one or more nucleotide Appeal 2020-001253 Application 15/051,463 3 modifications compared to the homologous portion in the target nucleic acid; and b. incubating the cells under conditions whereby the mutagenesis construct is integrated into the target nucleic acid molecule and tandem repeats are generated that flank the target region on the target nucleic acid molecule between the first portion of homology and a sequence upstream or downstream of the target region; and inducing the inducible promoter, whereby the endonuclease is expressed and promotes one or more double- strand break cleavages in the target nucleic acid molecule; i. whereby recombination occurs between the first portion of homology and the upstream or downstream portion of the target region on the target nucleic acid molecule that is homologous to the first portion of homology, thereby seamlessly removing a portion of the construct; whereby a modification is seamlessly introduced into the target nucleic acid molecule. (Appeal Br. 15–16.) Appeal 2020-001253 Application 15/051,463 4 Claims 1–6 and 10–21 stand rejected under 35 U.S.C. § 103(a) as unpatentable over the combination of Storici,2 Pόsfai,3 Seiko,4 Gibson,5 Ripoll,6 Golic,7 Akada,8 Hirashima,9 and Scherer.10 ISSUE Does the preponderance of evidence relied upon by Examiner support a conclusion of obviousness? 2 Storici et al., US 7,314,712 B2, issued Jan. 1, 2008. 3 Gyӧrgy Pόsfai et al., Markerless gene replacement in Escherichia coli stimulated by a double-strand break in the chromosome, 27 Nucleic Acids Research 4409–4415 (1999). 4 Ryu Seiko et al., JP 2007-111015, published May 10, 2007, machine translated. 5 Daniel G. Gibson et al., Complete Chemical Synthesis, Assembly, and Cloning of a Mycoplasma genitalium Genome, 319 Science 1215–1220 (2008). 6 Pierre-Jean Ripoll et al., A new yeast artificial chromosome vector designed for gene transfer into mammalian cells, 210 Gene 163–172 (1998). 7 Golic et al., US 2003/0175968 A1, published Sept. 18, 2003. 8 Rinji Akada et al., PCR-mediated seamless gene deletion and marker recycling in Saccharomyces cerevisiae, 23 Yeast 399–405 (2006). 9 Kyotaro Hirashima et al., A simple and effective chromosome modification method for large-scale deletion of genome sequences and identification of essential genes in fission yeast, 34 Nucleic Acids Research 1–7 (2006), available at doi:10.1093/nar/gnj011. 10 Stewart Scherer & Ronald W. Davis, Replacement of chromosome segments with altered DNA sequences constructed in vitro, 76 Proc. Natl. Acad. Sci. 4951–4655 (1979). Appeal 2020-001253 Application 15/051,463 5 FACTUAL FINDINGS (FF) FF 1. Examiner finds that individuals of ordinary skill in this art will be highly educated individuals such as medical doctors, scientists, or engineers possessing advanced degrees, including M.D.’s and Ph.D.’s . . . [who] most likely will be knowledgeable and well-read in the relevant literature and have the practical experience in molecular biology, genetics, methods of gene editing and chromosome manipulation. Therefore, the level of ordinary skill in this art is high. (Ans. 9). FF 2. Storici “relates to methods of in vivo site-directed mutagenesis, particularly mutagenesis mediated by oligonucleotides” (Storici 1:15–17 (see generally Ans. 3)). FF 3. Storici discloses a “modification[] of the delitto perfetto [mutagenesis] system that provides . . . improved recombination efficiency, in some embodiments over 1000-fold increase in efficiency. These embodiments, using methods termed generally delitto perfetto-DSB, exploit the use of induced site-specific DSBs in the genome to increase oligonucleotide targeted mutagenesis” (Storici 2:59–65; see id. at 5:4–5 (Storici defines the term “DSB” as “a double-strand break”)). Appeal 2020-001253 Application 15/051,463 6 FF 4. Storici’s Figure 7 is reproduced below: [Storici’s] FIG. 7 illustrates an embodiment of the delitto perfetto-DSB system, which utilizes integrative recombinant oligo-nucleotides (IROs) to generate mutations. The DSB-CORE cassette[, which] contains the COunterselectable and REporter genes plus the I-SceI endonuclease under the control of an inducible promoter, such as the illustrated GAL 1/10 promoter. Expression of I-SceI leads to a double-strand break (DSB) at the unique target site, also contained in the cassette. Appeal 2020-001253 Application 15/051,463 7 Step 1: A DSB-CORE cassette is inserted by standard DNA targeting procedures at a desired site. The insertion site is anywhere in the sequence which has been chosen to be deleted or is close to a site where a specific mutation, or multiple mutations, is to be created. The DSB-CORE cassette contains the following: i) Gal 1/10 promoter fused to I-SceI open reading frame (GAL 1/10::I-SceI). The I-SceI creates a DSB at a cut site included on the cassette. Any inducible (ie., on/off) promoter can be used and any DSB site-specific cutting enzyme can be included in the DSB-CORE cassette, provided that the only DNA site that is cut in the cell is located in the cassette. ii) I-SceI cut site (or other unique cut site that is the target of a DSB site-specific cutting enzyme) located at one end of the cassette or internally. iii) COunterselectable REporter genes (i.e., the counterselectable gene K1-URA3+ the kanMX4 reporter gene). Step 2: Immediately prior to transformation with IRO(s), cells are grown in the presence of galactose, which induces I- SceI endonuclease expression. The enzyme targets its single site in the cassette and generates a DSB. Step 3: Transformation of cells with IROs leads to loss of the cassette, creation of the desired mutation(s), or deletion of the desired region. Oligonucleotide targeting in the vicinity of the DSB (delitto perfetto-DSB method) is increased up to 1000-fold, compared to oligo-mediated changes without the DSB (delitto perfetto method). (Storici 4:65–5:34; see Ans. 3–4.) Appeal 2020-001253 Application 15/051,463 8 FF 5. Examiner finds that Storici discloses that a “mutagenesis construct may be used to modify a host vector in the host cell whereby the host vector recombines with the mutagenesis construct in the host cells, e.g. modification of yeast artificial chromosomes (YACs)” (Ans. 8 (citing Storici 27:45–29:34)). FF 6. Examiner finds that Storici fails to disclose a “mutagenesis construct [that] . . . comprise[s] a portion of homology that is homologous to a sequence of the target nucleic acid molecule upstream or downstream of a target region on the target nucleic acid molecule” (Ans. 4). FF 7. Pόsfai discloses: A simple and efficient gene replacement method, based on the recombination and repair activities of the cell, . . . [that] permits the targeted construction of markerless deletions, insertions and point mutations in the Escherichia coli chromosome. A suicide plasmid, carrying the mutant allele and the recognition site of meganuclease I-SceI, is inserted into the genome by homologous recombination between the mutant and the wild- type (wt) alleles. Resolution of this cointegrate by intramolecular recombination of the allele pair results in either a mutant or a wt chromosome which can be distinguished by allele-specific PCR screening. The resolution process is stimulated by introducing a unique double-strand break (DSB) into the chromosome at the I-SceI site. Cleavage by the nuclease not only enhances the frequency of resolution by two to three orders of magnitude, but also selects for the resolved products. (Pόsfai, Abstract.) Appeal 2020-001253 Application 15/051,463 9 FF 8. Pόsfai’s Figure 1 is reproduced below: [Pόsfai’s] Figure 1 [illustrates a] [g]eneral scheme of the DSB- stimulated gene replacement procedure. Cointegrates of the chromosome and the suicide plasmid can form via homologous recombination between the mutant and the wt alleles of the target gene. The plasmid carries a temperature-sensitive (ts) replicon, an antibiotic (Ab) resistance gene and the recognition site for I-SceI. Cointegrates are selected by their Ab resistance at the non-permissive temperature for plasmid replication. Next, cleavage of the chromosome by I-SceI is induced. The DSB stimulates recombination between the duplications resulting either in a reversion to the wt chromosome or in a markerless gene replacement event. (Pόsfai 4411; see generally Ans. 4; see also Ans. 7 (Examiner finds that “the integration of [Pόsfai’s] mutagenesis cassette[, i.e. suicide plasmid,] creates a tandem duplicated region of the homologous sequence from which the modification is seamlessly produced”).) Appeal 2020-001253 Application 15/051,463 10 FF 9. Seiko discloses “a method for deleting a selective marker gene used in selecting a transformant simultaneously with deleting a DNA fragment of a host DNA” (Seiko, Abstract; see generally Ans. 5). FF 10. Seiko’s Figure 1 is reproduced below: Seiko’s Figure 1 illustrates a process involving two homologous recombination events. The first homologous recombination results in the insertion of donor DNA into a host DNA sequence, wherein the donor DNA comprises from 5’ to 3’: (a) a DNA sequence that is homologous to the host DNA region that is 3’ of the first homologous recombination insertion site, (b) a cat gene, and (c) an araR gene (see Seiko ¶¶ 54–57; see generally Ans. 5). The second homologous recombination involves the recombination of DNA sequence (a) with its homologous 3’ host DNA sequence (see Seiko Appeal 2020-001253 Application 15/051,463 11 ¶ 57; see generally Ans. 5). The second recombination results in the deletion of the cat gene, araR gene, and a portion of host DNA, which is illustrated in Figure 1 with hatching (see Seiko ¶ 57; see generally Ans. 5– 6). FF 11. Examiner finds that Seiko’s “mutagenesis construct . . . comprise[s] a portion of homology that is homologous to a sequence of [a] target nucleic acid molecule upstream or downstream of a target region . . . or target gene” (Ans. 5 (citing Seiko, Figures 1 and 4)). FF 12. Examiner relies on Gibson to disclose a method of introducing a modification in a target nucleic acid molecule present in a host cell, the method comprising the step of introducing a donor construct, e.g. a second YAC clone, and a host vector, e.g. a first YAC clone, into the host cell, e.g. a yeast spheroplast, whereby the host vector recombines with the mutagenesis construct in the host cell via homologous recombination. (Ans. 8 (citing Gibson 1218, Figure 6; Gibson 1218: cols. 1–2).) FF 13. Examiner finds that Ripoll discloses a method of introducing a modification in a target nucleic acid molecule present in a host cell, the method comprising the step of introducing a donor construct . . . into the host cell . . . whereby the host vector recombines with the mutagenesis construct in the host cell via homologous recombination. (Ans. 8 (citing Ripoll, Abstract, §§ 2.4, 3.3, 3.4, and Figure 4).) FF 14. Examiner finds that Golic discloses a method of introducing a modification in a target nucleic acid molecule present in a host cell, the method comprising a mutagenesis construct comprising: a first portion of homology to a 5' portion of the target nucleic acid molecule upstream of the modification; Appeal 2020-001253 Application 15/051,463 12 an endonuclease recognition site, e.g. an I-Sce1 or Cre endonuclease recognition site; a selectable marker; and another portion of homology that is homologous to a 3' portion of the target region on the target nucleic acid molecule downstream of the modification, the mutagenesis construct further comprising tandem repeat regions, e.g. LoxP or FRT sites, that flank the target region or portion thereof on the target nucleic acid molecule, including the selectable marker. (Ans. 8–9 (citing Golic ¶ 165 and Figures 1, 3, 21, and 22); see also Ans. 9 (citing Golic Figure 9) (Examiner finds that Golic discloses a “mutagenesis construct ha[ving] a first portion of homology that is homologous to a sequence upstream or downstream of a target region to be modified, wherein upon recombination the first portion of homology generates a tandem repeat with the homologous sequence of the target nucleic acid molecule.”).) FF 15. Akada discloses a method of “[s]eamless gene deletion” (Akada 402). Appeal 2020-001253 Application 15/051,463 13 FF 16. Akada’s Figure 1 is reproduced below: Akada’s Figure 1 illustrates: A short sequence (black arrows) copied from the adjacent region of the targeted locus is inserted into a disruption fragment containing a counter-selectable URA3 marker and homologous targeting sequences. PCR 1, chromosomal sequence amplification. PCR 2, URA3 marker amplification with sequences for targeting (dotted bars), a repeat sequence copied from the chromosome (black arrows) and an annealing sequence for fusion PCR (grey bars with an arrow inside). PCR 3, fusion PCR producing a chromosomal sequence upstream of Appeal 2020-001253 Application 15/051,463 14 HIS3 attached to the URA3 fragment. Integration of the construct simultaneously generates gene disruption and direct repeats on both sides of URA3 in the chromosome, making it possible to delete URA3 without any extraneous sequences being left behind in the chromosome. (Akada 402, Figure 1 legend; see generally Ans. 6.) FF 17. Hirashima discloses a “chromosome modification method for large- scale deletion of genome sequences and identification of essential genes in fission yeast” (Hirashima, Abstract). FF 18. Hirashima’s Figure 1B is reproduced below: Hirashima’s Figure 1B is a “[s]chematic representation of the deletion (recycling) of [a] selectable marker using direct repeats. The gray squares show the direct repeats. The portions enclosed with a dotted line show the introduced modification fragments. . . . [T]he ura4 and target genes are placed between direct repeats on the chromosome,” which facilitate the recombination event and resulting deletion of nucleic acid between the direct repeats in the deletant (Hirashima, Figure 1, legend; see Ans. 6 (Examiner finds that “[h]omologous recombination [according to Hirashima’s method] occurs between the tandem repeats to remove the undesired construct Appeal 2020-001253 Application 15/051,463 15 elements while achieving the desired modification in the target gene/target region”)). FF 19. Scherer discloses a method “for the stable introduction of foreign sequences or deletions, constructed in vitro, into the chromosomes of Saccharomyces cerevisiae” (Scherer, Abstract). FF 20. Scherer’s Figure 1 is reproduced below: Scherer’s Figure 1 illustrates the “[r]eplacement of a chromosome segment with an altered DNA sequence,” wherein [t]he transforming DNA . . . recombines with the homologous DNA sequence in the chromosomes and results in a direct, nontandem duplication separated by the vector and marker DNAs. A second recombinational event, on the other side of the sequence alteration relative to the first, generates a chromosome with the altered sequence replacing those in the untransformed cell. The vector and marker DNAs are lost. Homologous sequences on both sides of the alteration must be present in the transforming DNA but the molecule need not be capable of autonomous replication in the organism where the replacement will occur. The classical prokaryotic examples of this type of manipulation would be transduction of mutant Appeal 2020-001253 Application 15/051,463 16 galactose gene with phage λ as the vector and immunity as the selection. (Scherer, Figure 1, legend.) FF 21. Examiner finds that Scherer’s mutagenesis construct has a first portion of homology (a' and/or c') that is homologous to a sequence (a and/or c) upstream or downstream of a target gene to be modified, wherein upon recombination the first portion of homology generates a tandem repeat with the homologous sequence of the target nucleic acid molecule. Homologous recombination occurs between the tandem repeats (c' and c are illustrated) to remove the undesired elements (loss of marker, a', b regions) while achieving the desired modification in the target gene/target region (black box, b'). . . . Thus, the black box (b') illustrated in Figure 1 may reasonably be interpreted as a “target region” or a “target gene”. Segments a' and c' are tandem repeats upstream and downstream, respectively, of the “target region” or “target gene”. (Ans. 6–7 (citing Scherer 4951 and Figure 1).) ANALYSIS Based on the combination of Storici, Pόsfai, Seiko, Gibson, Ripoll, Golic, Akada, Hirashima, and Scherer, Examiner concludes that, at the time Appellant’s invention was made, it would have been prima facie obvious to modify Storici’s in vivo site-directed mutagenesis to include a tandem repeat region upstream or downstream of a target gene to be modified (see Ans. 12; see generally id. at 9–13 and 14–38). We are not persuaded. On this record, Examiner identified a number of documents, which disclose various mutagenesis methods (see FF 1–21). Examiner failed, however, to adequately articulate a reason why a person of ordinary skill in this art would have, absent hindsight, combined the various mutagenesis methods in the manner necessary to arrive at Appellant’s claimed invention. Appeal 2020-001253 Application 15/051,463 17 “[E]xaminer bears the initial burden, on review of the prior art or on any other ground, of presenting a prima facie case of unpatentability.” In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). Obviousness requires more than a mere showing that the prior art includes separate references covering each separate limitation in a claim under examination. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418, 127 S.Ct. 1727, 167 L.Ed.2d 705 (2007). Rather, obviousness requires the additional showing that a person of ordinary skill at the time of the invention would have selected and combined those prior art elements in the normal course of research and development to yield the claimed invention. Id. at 421, 127 S.Ct. 1727. Unigene Laboratories, Inc. v. Apotex, Inc., 655 F.3d 1352, 1360 (Fed. Cir. 2011). In presenting a prima facie case of unpatentability, “[c]are must be taken to avoid hindsight reconstruction by using ‘the patent in suit as a guide through the maze of prior art references, combining the right references in the right way so as to achieve the result of the claims in suit.’” In re NTP, Inc., 654 F.3d 1279, 1299 (Fed. Cir. 2011) (Fed. Cir. 2011) (citations omitted). Further, “rejections on obviousness grounds cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006). As Appellant explains, “Seiko does not appear to teach or suggest any method utilizing a mutagenesis construct having a gene encoding an endonuclease and an endonuclease recognition site, nor the use of such endonuclease to promote a double-stranded break, thereby provoking a recombination event, as claimed” (Appeal Br. 9). In addition, Appellant explains that “Storici does not teach or suggest generating a tandem repeat upon introduction of the construct between a sequence on the target nucleic Appeal 2020-001253 Application 15/051,463 18 acid and a homologous sequence on the mutagenesis construct” (Appeal Br. 7). In Storici’s method “the purpose of the CORE cassette is to carry the endonuclease . . . so that it can be induced to perform the double-stranded break. This increases the successful targeting of the IRO containing the desired modification by 1000-fold” (id. at 10 (citing Storici 5:29–34)). In addition, “the CORE cassette is [subsequently] eliminated [in Storici’s method] by homologous recombination between the IRO cassette and a sequence on the target nucleic acid” (id. (citing Storici 21:3–16 and Figure 7)). Thus, as Appellant explains, if Examiner’s proposed modification “were on the CORE cassette . . . it would be lost with the CORE cassette” and, in the alternative, if the basis of Examiner rejection is to “eliminate [Seiko’s] IRO or incorporate it on the CORE cassette, then how would the CORE cassette be removed” (id.). We acknowledge Examiner’s assertion that Pόsfai taught the use of the first portion of homology to introduce the construct comprising the cassette encoding endonuclease target site . . ., the artisan’s modification of interest, a first portion of homology upstream of the target region, a second portion of homology 5’ to the target region, and a third portion of homology 3’ to the target region[, wherein] [u]pon introduction of the endonuclease . . . homologous recombination is stimulated to yield the seamless modification in the target nucleic acid molecule. (Ans. 32 (citing Pόsfai, Figure 1); cf. Appeal Br. 7 (Appellant contends that Pόsfai “does not teach or suggest” “a first portion of homology that is homologous to a sequence upstream or downstream of the target gene to be modified,” but instead “replaces the gene with an amended copy and removes the suicide plasmid through homology with the gene copy itself . . . , not with a sequence ‘upstream or downstream’ of the target gene”).) We Appeal 2020-001253 Application 15/051,463 19 find, however, that even if Examiner correctly interpreted Pόsfai as including a region of homology upstream or downstream of a target gene; Examiner failed to adequately explain why a person of ordinary skill in this art would have modified Storici’s method to include features disclosed by Pόsfai, Seiko, Gibson, Ripoll, Golic, Akada, Hirashima, and Scherer (see Appeal Br. 10–11 (Appellant contends that “the skilled person finds no motive to include the sequence modification on the CORE cassette as the Office proposes. The proposed modification of Storici does not appear to result in any benefit and would require substantial, inventive changes to the methods disclosed by both Storici and Pόsfai” and none of Seiko, Gibson, Ripoll, Golic, Akada, Hirashima, and Scherer make up for this deficiency); see generally id. at 11). CONCLUSION The preponderance of evidence relied upon by Examiner fails to support a conclusion of obviousness. The rejection of claims 1–6 and 10–21 under 35 U.S.C. § 103(a) as unpatentable over the combination of Storici, Pόsfai, Seiko, Gibson, Ripoll, Golic, Akada, Hirashima, and Scherer is reversed. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–6, 10–21 103 Storici, Pόsfai, Seiko, Gibson, Ripoll, Golic, Akada, Hirashima, Scherer 1–6, 10–21 REVERSED Copy with citationCopy as parenthetical citation