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 .
Priority
The instant application is a national stage entry of PCT application PCT/CN2021/100958, filed 12/16/2022 under 35 USC 371. Acknowledgment is made of applicant's claim for foreign priority based on an application CN202010568508.7 filed in PEOPLE’S REPUBLIC OF CHINA on 06/19/2020.
Election/Restrictions
Applicant's election with traverse of Group I, claims 1-3, 5, 8-10, 12, 13, 15, 17, 19, 20, 22, and 24, drawn to a genetically modified non-human animal expressing a fusion protein comprising a β2 microglobulin (B2M) and a neonatal Fc receptor (FcRn), in the reply filed on 12/29/2025 is acknowledged. The traversal is on the ground(s) that groups I-IV are closely related and searching these groups do not substantially increase the search burden. This is not found persuasive because this application is a national stage filing of an international application. Restriction in such applications is based on lack of unity practice. Burden is not a consideration in a finding of lack of inventive unity; rather, according to M.P.E.P. §1850, the only consideration is whether the inventions share a special technical feature. In instant case, the groups lack unity of invention based on the reason as stated in the Restriction Requirement mailed 10/29/2025. Briefly, the groups share a technical feature of a genetically-modified non-human animal expressing a fusion protein comprising a ß2 microglobulin (B2M) and a neonatal Fc receptor (FcRn), however, this technical feature is not a special technical feature as it does not make a contribution over the prior art in view of Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) and Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS). Therefore the requirement is still deemed proper and is made FINAL. Accordingly, claims 1-3, 5, 8-10, 12, 13, 15, 17, 19, 20, 22, and 24 are under current examination. Claims 26, 28, 42, 48 and 52 are withdrawn from consideration pursuant 37 CFR 1.142(b).
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-3, 5, 8-10, 12-13, 15, 17, 22 and 24 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.
From M.P.E.P. § 2163, the analysis of whether the specification complies with the written description requirement calls for the examiner to compare the scope of the claim with the scope of the description to determine whether applicant has demonstrated possession of the claimed invention from the standpoint of one of skill in the art at the time the application was filed. For inventions in emerging and unpredictable technologies, or for inventions characterized by factors not reasonably predictable which are known to one of ordinary skill in the art, more evidence is required to show possession. For claims drawn to a genus, possession may be shown (for example) through sufficient description of a representative number of species by actual reduction to practice, reduction to drawings, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus. See Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406. A “representative number of species” means that the species which are adequately described are representative of the entire genus, and is an inverse function of the skill and knowledge in the art. Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to
reflect the variation within the genus. For inventions in an unpredictable art, adequate written description of a genus which embraces widely variant species cannot be achieved by disclosing only one species within the genus. See, e.g., Eli Lilly. If a representative number of adequately described species are not disclosed for a genus, the claim to that genus must be rejected as lacking adequate written description under 35 U.S.C. 112, para. 1.
Instant claims are directed to a genetically-modified non-human animal expressing a fusion protein comprising a β2 microglobulin (B2M) and a neonatal Fc receptor (FcRn). The claims encompass any non-human animals, including but by far not limited to mice, rats, rabbits, bovines, ovines, porcines, caprines, dogs, cats, guinea pigs, frogs, snakes, lizards, chickens, dove, quail, ducks, geese, opossums, armadillos, kangaroos, horseshoe crabs, shrimp, lobster, shark, fish, snails, mollusks, C. elegans, fruit flies, slugs, and other invertebrate animals. Thus the breadth of instant claims is extremely broad. Claims 19 and 20 further limit the genetically-modified non-human animal to a rodent and an immunodeficient mouse. The issue at hand is whether or not Applicants have possession of the full scope of the genetically-modified non-human animal expressing a fusion protein comprising a B2M and a FcRn at the time the application was filed.
In instant claims, Applicants have failed to disclose a sufficient number of species to be representative of the full scope of the genus of non-human animals as claimed. Applicants’ disclosure is limited to the generation of an immunodeficient mice expressing B2M/FcRn fusion protein by CRISPR/Cas gene editing, which is specifically genetically modified at the targeting sites (i.e., endogenous FcRn gene locus, Example 1), detect the immunophenotyping (Example 2), histopathological section of spleen (Example 3) and pharmacokinetics (Example 4) of the genetically modified mice, as well as immune reconstitution (Example 5) in the mice and having drug efficiency verification (Examples 6 and 7). Applicants do not disclose the generation of any other species of non-human animal expressing the B2M/FcRn fusion protein. Thus Applicants failed to disclose the generation of a genus of non-human animals expressing the B2M/FcRn fusion protein which can represent the full scope of the genetically-modified non-human animal expressing a fusion protein comprising a B2M and a FcRn as recited in instant claims.
Furthermore, Applicants have failed to provide disclosure of relevant, identifying characteristics, such as the phenotypic changes associated with the structure of the fusion protein comprising B2M and FcRn. While Applicants have recited the genetically-modified non-human animals expressing a fusion protein comprising B2M and FcRn, they have failed to identify or show a known correlation exists between the phenotypic changes of a genus of non-human animals and the genus structure of the fusion protein comprising B2M and FcRn. Thus, one of ordinary skill in the art, in looking to the instant specification, would not be able to determine that Applicants were in possession of the invention, as claimed, at the time the invention was made.
Claim Rejections - 35 USC § 112
Scope of enablement
Claims 1-3, 5, 8-10, 12-13, 15, 17, 22 and 24 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for generating a genetically-modified mouse expressing a fusion protein comprising a B2M and a FcRn, does not reasonably provide enablement for generating ANY genetically-modified non-human animal comprising B2M and FcRn. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the invention commensurate in scope with these claims.
In determining whether Applicant’s claims are enabled, it must be found that one of skill in the art at the time of invention by applicant would not have had to perform “undue experimentation” to make and/or use the invention claimed. Such a determination is not a simple factual consideration, but is a conclusion reached by weighing at least eight factors as set forth in In re Wands, 858 F.2d at 737, 8 USPQ 1400, 2d at 1404. Such factors are: (1) The breadth of the laims; (2) The nature of the invention; (3) The state of the art; (4) The level of one of ordinary skill in the art; (5) The level of predictability in the art; (6) The amount of direction and guidance provided by Applicant; (7) The existence of working examples; and (8) The quantity of experimentation needed to make and/or use the invention.
The office has analyzed the specification in direct accordance to the factors outlines in Jn re Wands. MPEP 2164.04 states: “[W]hile the analysis and conclusion of a lack of enablement are based on factors discussed in MPEP 2164.01(a) and the evidence as whole, it is not necessary to discuss each factor in written enablement rejection.” These factors will be analyzed, in turn, to demonstrate that one of ordinary skill in the art would have had to perform “undue experimentation” to make and/or use the invention and therefore, applicant’s claims are not enabled.
Nature of the Invention and Breadth of the claims:
Instant claim 1 is directed to a genetically-modified non-human animal expressing a fusion protein comprising a B2M and a FcRn. The claims encompass any non-human animals, including but by far not limited to mice, rats, rabbits, bovines, ovines, porcines, caprines, dogs, cats, guinea pigs, frogs, snakes, lizards, chickens, dove, quail, ducks, geese, opossums, armadillos, kangaroos, horseshoe crabs, shrimp, lobster, shark, fish, snails, mollusks, C. elegans, fruit flies, slugs, and other invertebrate animals. Moreover, instant claim does not limit whether the B2M and FcRn (in the fusion protein) are endogenous or exogenous (i.e. from a different species), or whether the genetically-modified non-human animal having the fusion protein introduced into any chromosome by random integration or to a targeted chromosome by targeted integration. Therefore the breadth of instant claim is extremely broad. Claims 19 and 20 further limit the genetically-modified non-human animal to a rodent and an immunodeficient mouse. Claims 2 and 3 further limits the fusion protein is incorporated in the chromosome and in the endogenous FcRn gene locus or B2M gene locus in the chromosome.
Guidance of the Specification and The Existence of Working Examples:
The specification discloses the generation of an immunodeficient mice expressing B2M/FcRn fusion protein (Example 1). The gene modification is precisely at the targeting site of FcRn gene locus by CRISPR/Cas gene editing technology, and the genetically engineered mice (i.e., BNDG-B2M/FcRn mice) are generated with the endogenous B2M gene is knocked out, but a cDNA sequence encoding B2M protein is inserted at the FcRn gene locus to generate a B2M/FcRn fusion gene (p72, L22-25). When homozygous BNDG-B2M/FcRn mice are obtained, the immunophenotyping is detected (Example 2), histological morphology of mouse spleen is observed (Example 3), and pharmacokinetics is determined (Example 4). The specification further discloses the and immune reconstitution in the BNDG-B2M/FcRn mice (i.e., injection of hPBMC from donors to the BNDG-B2M/FcRn mice, see Example 5), and having drug efficiency verification in in BNDG-B2M/FcRn immune reconstituted mice (Examples 6 and 7). The specification does not disclose any other species of non-human animals, neither does the specification disclose any other gene-editing methods (i.e., gene modification of embryonic stem cells).
State of the Art and Predictability of the Art and the Amount of Experimentation Necessary:
The state of the art at the time of the invention held that gene editing (i.e., by CRISPR-CAS system at endogenous gene locus or gene modification in embryonic stem cells) in non-human animal was unpredictable. This was summarized by Li et al. (Comput Struct Biotechnol J. 2019 Jun 8;17:689-698), Lee et al. (Anim Cells Syst (Seoul). 2020 Feb 17;24(1):8-16) and Sato et al. (J Hum Genet. 2018 Feb;63(2):125-131). Li et al. teach the applications of genome editing in constructing animal disease models and gene therapies, as well as its future prospects and challenges (Abstract). Li et al. teach gene editing such as CRISPR technology on endogenous gene of mice, zebrafish (p691, right column), germline genome editing bigger mammalian models including rats, rabbits, pigs and even nonhuman primates (NHP) (p692, left column). Li et al. teach four traditional genetic modification ways (p691, figure 2): gene modification in embryonic stem cells, zygote, combining somatic cell genome editing and somatic cell nuclear transfer(SCNT) technology, or engineered virus with transgene. Li et al. teach new gene editing technologies such as CRISPR, ZFNs or TALENs (p690, figure 1). Li et al. teach traditional gene editing method such as gene modification of embryonic stem cells limit to animals such as mice that easily acquire embryonic stem cells. In addition, the gene integration generated by transgenic technology is random along with low efficiency and applicability (p696). Li et al. teach new gene editing technology such as CRISPR, the efficiency of off-target of engineered nucleases need be concerned. Off-target effects may lead to unexpected and uncontrollable genome change thus increase the risk of malignant transformation (p696, left column). Except for nucleases, host immune responses to delivery vehicles also influence therapeutic effects (p696, left column). Lee et al. teach various strategies based on the CRISPR-Cas9 system for building animal models of human diseases and describe various in vivo delivery methods of CRISPR-Cas9 that are applied to disease models for therapeutic purposes (Abstract). Lee et al. teach animal models of human diseases using genome editing methods (p6, Table 1), the animals include mouse, rat, pig, monkey, dog, rabbit. Lee et al. teach problems such as
low HDR efficiency, off-target effects and immune rejection are steadily being raised (p14, left column). Sato et al. summarize the generation of conventional disease model Nonhuman primate (NHPs) and discuss new solutions to the problem of mosaicism in genome-editing technology (Abstract). Sato et al. teach genetic modification efficiency and genetic modification patterns are different in each experiment (p130, left column). None of the arts teach that gene editing can be conducted at any non-human animals. With respect to the problems as discussed in the arts and the absent of specific guidance, one skilled in the art before the effective filing date of the claimed invention would have to perform undue experimentation to determine how to make/use a non-human animal expressing a fusion protein comprising a B2M and a FcRn, without reasonable expectation of success.
In conclusion, in view of breadth of the claims and absence of a strong showing by Applicant, in the way of specific guidance and direction, and/or working examples demonstrating the same, such invention as claimed by Applicant is not enabled commensurate with full scope. An artisan of skill would have required undue experimentation to practice the invention without reasonable expectation of success.
Claim Rejections - 35 USC § 103
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 1, 2, 5, 8, 13, 15, 17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS).
Proetzel et al. teach developing a series of humanized transgenic mouse models designed to study the pharmacokinetics (PK) of human Fc-based compounds (P149, right column). Mouse lines are transgenic for human FCGRT (the FcRn gene to form FcRn α chain) and in addition engineered for a deletion in mouse Fcgrt, i.e. they do not express mouse FcRn, but express human FcRn protein (p149, right column).
Regarding claim 1, Proetzel et al. teach the long serum half-life of immunoglobulin G’s (IgGs) and Fc domains are due to their rescue and recycling by the neonatal Fc receptor (FcRn) (Abstract). FcRn forms a heterodimer consisting of the alpha-chain and beta-2-microglobulin (B2M) light chain (p149, left column). Proetzel et al. teach Tg32/hB2M mice lack mouse FcRn expression (FcRn-null), while expressing human FcRn, human B2M and mouse B2M (p151, right column). This teaching reads on a genetically-modified mice expressing B2M and FcRn (i.e., human B2M and FcRn). Proetzel et al. do not teach the B2M and FcRn is expressed as a fusion protein. However, this was disclosed by Feng et al. at the time of instant invention.
Feng et al. teach a new method to express in mammalian cells soluble human FcRn (sFcRn) as a single-chain soluble fusion protein (abstract).
Regarding claim 1, Feng et al. teach the single fusion protein human sFcRn for expression in mammalian cells, the highly hydrophilic beta 2 microglobulin was joined with the hydrophobic heavy chain via a 15 amino acid linker (Abstract and p67, figure 1). This teaching reads on a fusion protein comprises human B2M and FcRn. Feng et al. further teach this (fusion protein) design should also be valid for producing soluble mouse FcRn protein (p69, right column), indicates that the fusion protein also can be a fusion protein of mouse B2M and FcRn.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn (i.e., human B2M and FcRn) in the form of heterodimer, and use a single-chain fusion protein comprising B2M and FcRn as taught by Feng et al.. The skilled artisan would have been motivated to have genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the genetically- modified mice expressing a B2M and a FcRn (i.e., human B2M and FcRn) are designed as tools for studying pharmacokinetics (PK) of Fc-containing compounds (see Abstract), and Feng et al. teach the single-chain fusion protein comprising B2M and FcRn is fully functional (p67, left column) and has an improved expression level of the heavy chain which are generally low (Abstract), therefore is beneficial for the PK analysis of Fc-containing compounds. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column) and Feng et al. teach the design of fusion protein (p67, right column).
Regarding claim 2, following the discussion above, Proetzel et al. teach generating a humanized FcRn mouse: the mouse FcRn gene was inactivated using gene targeting in the mouse embryonic stem (ES) cell line ESV/J-1182 derived from the mouse strain 129X1/SvJ. Heterozygous offspring carrying the targeted allele were backcrossed to B6 for 11 generation, and then intercrossed to generate homozygous FcRn-null mice (p150, left column). To generate the Tg32 mouse strain, a human 33 kb cosmid clone encoding the complete human FCGRT gene and including an approximately 10 kb of 50 flanking sequences and 10 kb of 30 flanking sequences was microinjected into fertilized B6 mouse oocytes. Resulting offspring were screened for expression of the human FCGRT gene, and selected strains were backcrossed to the B6 congenic FcRn-null mice, and homozygosed for the FcRn-null deletion plus the human FCGRT transgene (p150, left column). This teaching indicates the mice have been genetically modified, which has at least one chromosome modified with the human FCGRT gene. Feng et al. teach a fusion protein comprising human FcRn and B2M, which can also be introduced to at least one chromosome by the same method.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s method of generating genetically- modified mice by introducing human FCGRT gene into at least one chromosome, and use the same method to introduce genes encoding a single-chain fusion protein comprising B2M and FcRn as taught by Feng et al. into at least one chromosome. The skilled artisan would have been motivated to introduce a single-chain fusion protein comprising B2M and FcRn into at least one chromosome of mice, since Proetzel et al. teach the genetically- modified mice expressing a B2M and a FcRn (i.e., human B2M and FcRn) are designed as tools for studying pharmacokinetics (PK) of Fc-containing compounds (see Abstract), and Feng et al. teach the single-chain fusion protein comprising B2M and FcRn is fully functional (p67, left column) and has an improved expression level of the heavy chain which are generally low (Abstract), therefore is beneficial for the PK analysis of Fc-containing compounds. There would be a reasonable expectation of success of introducing a single-chain fusion protein comprising B2M and FcRn to at least one chromosome of mice, since Proetzel et al. teach the gene modification method (see p150, left column) and Feng et al. teach the design of the fusion protein (p67, right column).
Regarding claim 5, following the discussion above, Feng et al. teach the design of the fusion protein comprising B2M and FcRn should also be valid for producing soluble mouse FcRn protein and MHC I molecules (see p69, right column).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn (i.e., human FcRn as well as human or mouse B2M) in the form of heterodimer, and use a single-chain fusion protein comprising mouse B2M and FcRn as taught by Feng et al.. The skilled artisan would have been motivated to generate genetically modified mice which express a single chain fusion protein comprising endogenous B2M and FcRn for the purposes such as studying or comparing pharmacokinetics (PK) of Fc-containing compounds in mice. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column) and Feng et al. teach the design concept of the fusion protein (p67, right column).
Regarding claim 8, following the discussion above, Feng et al. teach the design of the fusion protein: for the single fusion FcRn protein expression vector, the N-terminal sequence for the signal peptide of B2M was not amplified. Similarly, the coding sequence for the heavy chain excluding the signal peptide and transmembrane domain was amplified (p67, left column and figure 1). This teaching reads on the fusion protein has (b) an B2M (i.e., an endogenous or humanized B2M) without a signal peptide. Feng et al. also teach the mammalian expression vector used, pSec-Tag2A, has Ig kappa chain leader peptide as the signal peptide to direct protein secretion, and this leader peptide to be sufficiently strong to direct the secretion of most proteins. Therefore, the original signal peptides of the two subunits were not included in the design of the recombinant FcRn (p68, right column). This teaching indicates that the signal peptide of FcRn can be included in the fusion protein, as recited in (a) and (c) in instant claim, in the situation that the expression vector does not have a signal peptide.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn (i.e., human FcRn as well as human or mouse B2M) in the form of heterodimer, and use a single-chain fusion protein comprising mouse B2M and FcRn which include a signal peptide of an endogenous FcRn, an endogenous B2M and the endogenous FcRn without the signal peptide following Feng et al.’s design concept. The skilled artisan would have been motivated to have genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn which include a signal peptide of an endogenous FcRn, an endogenous B2M and the endogenous FcRn without the signal peptide, since Proetzel et al. teach the genetically- modified mice expressing a B2M and a FcRn (i.e., human B2M and FcRn) are designed as tools for studying pharmacokinetics (PK) of Fc-containing compounds (see Abstract), and Feng et al. teach the single-chain fusion protein comprising B2M and FcRn is fully functional (p67, left column), and has an improved expression level of the heavy chain which are generally low (Abstract), therefore is beneficial for the PK analysis of Fc-containing compounds. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column) and Feng et al. teach the design concept of the fusion protein (p67, right column).
Regarding claims 13 and 15, Proetzel et al. teach transgenic for human FCGRT and in addition carry a deletion in mouse Fcgrt, i.e. they do not express mouse FcRn, but only express human FcRn. Proetzel et al. teach to generate the Tg32 mouse strain, a human 33 kb cosmid clone encoding the complete human FCGRT gene and including an approximately 10 kb of 50 flanking sequences and 10 kb of 30 flanking sequences was microinjected into fertilized B6 mouse oocytes. Resulting offspring were screened for expression of the human FCGRT gene (p150, left column). This teaching indicates the mice are heterozygous for expressing human FCGRT gene. Proetzel et al. teach selected strains (heterozygous mice) were backcrossed to the B6 congenic FcRn-null mice, and homozygosed for the FcRn-null deletion plus the human FCGRT transgene (p150, left column). This teaching indicates the mice are homozygous for expressing human FCGRT gene. Feng et al. teach using fusion protein expressing FcRn and B2M, therefore the mice may be generated as heterozygous or homozygous mice same way as Proetzel et al. teach with respect to the sequence encoding the fusion protein.
Regarding claim 17, following the discussion above, Feng et al. teach the expression of soluble FcRn in mammalian cells in a single fusion protein format. The method of producing human FcRn allows the 1:1 molar ratio of the heavy chain and B2M when expressed, and it is fully functional (p67, left column).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn (i.e., human FcRn as well as human or mouse B2M) in the form of heterodimer, and use a single-chain fusion protein comprising B2M and FcRn as taught by Feng et al. to generate heterozygous or homozygous mice expressing the functional fusion protein. The skilled artisan would have been motivated to have heterozygous or homozygous genetically- modified mice expressing a functional single-chain fusion protein comprising B2M and FcRn since Proetzel et al. teach the genetically- modified mice expressing a B2M and a FcRn (i.e., human FcRn as well as human or mouse B2M) are designed as tools for studying pharmacokinetics (PK) of Fc-containing compounds (see Abstract), and Feng et al. teach the single-chain fusion protein comprising B2M and FcRn is fully functional (p67, left column) and has an improved expression level of the heavy chain which are generally low (Abstract), therefore is beneficial for the PK analysis of Fc-containing compounds. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column) to generate heterozygous or homozygous mice, and Feng et al. teach the design of fusion protein (p67, right column).
Regarding claim 19, Proetzel et al. teach genetically modified mice expressing human FCRGT gene (see p149, right column).
Regarding claim 20, Proetzel et al. teach three immunodeficient variants have been developed: Tg276-Rag1-null mice, Tg276-SCID and Tg32-SCID mice (Table 1). These immunodeficient hFcRn mouse models can be used directly in xenograft studies and for the testing of anti-tumor activities of the mAbs in vivo (p151, right column).
Claims 1, 2, 3, 5, 8, 13, 15, 17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS), as applied to claims 1, 2, 5, 8, 13, 15, 17, 19 and 20 above, further in view of Sander et al. (Nat Biotechnol. 2014 Apr;32(4):347-55).
The teaching of Proetzel et al. and Feng et al. is set forth above.
Regarding claim 3, Proetzel et al. teach transgenic lines express human FcRn either under the control of a ubiquitous CAG promoter or human FCGRT regulatory elements (p150, left column), but do not teach the gene modifying is at an endogenous FcRn gene locus or an endogenous B2M locus. However, such precise gene editing at the endogenous gene locus was disclosed by Sander et al. at the time of instant invention.
Sander et al. review CRISPR-Cas systems for editing, regulating and targeting genomes, describe how this RNA-guided system works and how it has been applied to perform genome editing across a wide variety of cell types and whole organisms (p347, right column).
Regarding claim 3, Sander et al. teach CRISPR-Cas gene editing at desired DNA target sites (i.e., see p351, figure 4).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s method of generating genetically- modified mice expressing a B2M and a FcRn (i.e., human B2M and FcRn) in the form of heterodimer, use a single-chain fusion protein comprising B2M and FcRn as taught by Feng et al., and further introduce the gene which encoding the fusion protein to the desired position (i.e., endogenous FcRn gene locus or an endogenous B2M locus) by gene editing technology such as CRISPR as taught by Sander et al.. The skilled artisan would have been motivated to use gene editing technology such as CRISPR to guide the transgene precisely to the desired gene locus. There would be a reasonable expectation of success of using gene editing technology such as CRISPR to precisely introduce transgene to the desired gene locus since such technology is well known in the art and Sander et al. teach how this RNA-guided system works and how it has been applied to perform genome editing across a wide variety of cell types and whole organisms (p347, right column).
Claims 1, 2, 5, 8, 9, 13, 15, 17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS), as applied to claims 1, 2, 5, 8, 13, 15, 17, 19 and 20 above, further in view of Seidel, III et al. (US 2018/0282392 A).
The teaching of Proetzel et al. and Feng et al. is set forth above.
Regarding claim 9, Proetzel et al. and Feng et al. do not teach the B2M comprises an amino acid sequence that is at least 70% identical to amino acids 21-119 of SEQ ID NO: 2. However, this was disclosed by Seidel, III et al. at the time of instant invention.
Seidel, III et al. teach methods and compositions for clonally inhibiting or clonally stimulating T - cells (Abstract).
Regarding claim 9, Seidel, III et al. teach amino acid sequence alignment of beta - 2 microglobulin (B2M) precursors (i.e., including the leader sequence) from Mus musculus (NP 033865.2; SEQ ID NO: 82) (parag 0064). The amino acids 21-119 of SEQ ID NO: 2 in instant claim is 100% identical to the SEQ ID NO: 82.
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It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn in the form of heterodimer, and use a single-chain fusion protein comprising B2M and FcRn (human or mice B2M and FcRn) as taught by Feng et al., and further have the mouse B2M as taught by Seidel, III et al.. The skilled artisan would have been motivated to generate genetically modified mice which express a single chain fusion protein comprising endogenous B2M and FcRn for the purposes such as studying or comparing pharmacokinetics (PK) of Fc-containing compounds in mice. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column), Feng et al. teach the design concept of the fusion protein (p67, right column), and Seidel, III et al. teach the sequence of mouse B2M.
Claims 1, 2, 5, 8, 10, 12, 13, 15, 17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS), as applied to claims 1, 2, 5, 8, 13, 15, 17, 19 and 20 above, further in view of Cameron et al. (US 2019/0113519 A1).
The teaching of Proetzel et al. and Feng et al. is set forth above.
Regarding claims 10 and 12 , Proetzel et al. and Feng et al. do not teach the FcRn comprises an amino acid sequence that is at least 70% identical to amino acids 22-365 of SEQ ID NO: 4, or the fusion protein comprises an amino acid sequence that is at least 70% identical to SEQ ID NO: 6. However, this was disclosed by Cameron et al. at the time of instant claim.
Cameron et al. teach a method of assessing pharmacokinetic properties of a variant of human serum albumin using a non - primate animal species where the native albumin of the animal provides minimal competition for HSA binding to the FcRn receptor in said animal (Abstract).
Regarding claim 10, Cameron et al. teach mouse mature FcRn sequence SEQ ID NO:13 (see parag 0067). The amino acids 22-365 of SEQ ID NO: 4 in instant claim is 100% identical to the SEQ ID NO: 13.
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Regarding claim 12, Cameron et al. teach mouse mature FcRn sequence SEQ ID NO:13 (see parag 0067). Which is 73.1% identical to SEQ ID NO: 6 in instant claim.
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It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mouse expressing a B2M and a FcRn in the form of heterodimer, use a single-chain fusion protein comprising B2M and FcRn (human or mice B2M and FcRn) as taught by Feng et al., and further have the mouse FcRn and the fusion protein comprising mouse B2M and FcRn as taught by Cameron et al.. The skilled artisan would have been motivated to generate genetically modified mice which express a single chain fusion protein comprising endogenous B2M and FcRn for the purposes such as studying or comparing pharmacokinetics (PK) of Fc-containing compounds in mice. There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn, since Proetzel et al. teach the gene modification method (see p150, left column), Feng et al. teach the design concept of the fusion protein (p67, right column), and Cameron et al. teach the sequence of mouse FcRn.
Claims 1, 2, 5, 8, 13, 15, 17, 19, 20 and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS), as applied to claims 1, 2, 5, 8, 13, 15, 17, 19 and 20 above, further in view of Brehm et al. (FASEB J. 2019 Mar;33(3):3137-3151).
The teaching of Proetzel et al. and Feng et al. is set forth above.
Regarding claim 22, Proetzel et al. teach using SCID ((severe combined immunodeficiency) mice (see p149, right column), but do not specifically teach the genome of the animal comprises a disruption in the animal's endogenous CD132 gene (which is also known as IL2RG). However, this was disclosed by Brehm et al. at the time of instant claim.
Brehm et al. created 2 NOD-scid IL-2 receptor subunit Ƴ (IL2rg)null (NSG) strains that lack murine MHC class I and II [NSG–b-2-microglobulin (B2M)null (IA IE)null and NSG-(Kb Db)null (IAnull)], observed rapid human IgG clearance in NSG-B2Mnull (IA IE)null mice whereas clearance inNSG-(KbDb)null (IAnull)mice and NSG mice was comparable. Injection of human PBMCs into both strains enabled long-term engraftment of human CD4+ and CD8+ T cells without acute GVHD (Abstract).
Regarding claim 22, Brehm et al. teach 2 NOD-scid IL-2 receptor subunit Ƴ (IL2rg)null (NSG) strains that lack murine MHC class I and II [NSG–b-2-microglobulin (B2M)null (IA IE)null and NSG-(Kb Db)null (IAnull)], which has a disruption in CD132 (IL-2 receptor subunit Ƴ).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically-modified SCID mice such as Tg32-SCID (backcrossing Tg276 mice to B6.CB17-Prkdc<scid>/SzJ mice, see p149, right column) mice expressing a B2M and a FcRn in the form of heterodimer, and use another immunodeficient mice such as NOD-scid IL-2 receptor subunit Ƴ (IL2rg)null (NSG) strains that lack murine MHC class I and II as taught by Brehm et al. to express a fusion protein comprising B2M and FcRn as taught by Feng et al.. The difference between instant claim and genetically-modified SCID mice such as Tg32-SCID mice is instant claim has mice with disruption in the endogenous CD132 gene (IL-2 receptor subunit Ƴ). Given that Proetzel et al. teach these mice (including Tg32-SCID mice) can be readily used in the area of xenograft and cancer studies (p152, right column), which is known to require immunodeficient mice, and Brehm et al. teach NOD-scid IL-2 receptor subunit Ƴ (IL2rg)null (NSG) strains that lack murine MHC class I and II (Abstract), one of ordinary skill in the art would have substituted Proetzel et al.'s SCID (Prkdc<scid>) mice expressing B2M and FcRn, and use another immunodeficient mice NOD-scid IL-2 receptor subunit Ƴ (IL2rg)null (NSG) strains that lack murine MHC class I and II depends on their research interest. This simple substitution of one known element (immunodeficient mice with disruption in the endogenous CD132 gene) for another known element (immunodeficient Prkdc<scid> mice) is likely to be obvious when predictable results are achieved. See KSR International Co. V. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143, B.).
Claims 1, 2, 5, 8, 13, 15, 17, 19, 20 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Proetzel et al. (Methods. 2014 Jan 1;65(1):148-53, cited in IDS) in view of Feng et al. (Protein Expr Purif. 2011 Sep;79(1):66-71, cited in IDS), as applied to claims 1, 2, 5, 8, 13, 15, 17, 19 and 20 above, further in view of Viuff et al. (J Control Release. 2016 Feb 10;223:22-30).
The teaching of Proetzel et al. and Feng et al. is set forth above.
Regarding claim 24, Proetzel et al. do not teach the animal further comprises a sequence encoding an additional human or chimeric protein. However, this was disclosed by Viuff et al. at the time of instant invention.
Viuff et al. teach a novel mouse model that better mimics the human physiological conditions and, thus, has potential wide applications in the development of albumin-linked drugs or conventional drugswhose action is influenced by reversible binding to endogenous HAS (Abstract).
Regarding claim 24, Zhu et al. teach a double transgenic humanized FcRnα-chain and albumin
(hFcRn+/+, hAlb+/+) mouse that offers a more physiologically relevant model for the preclinical study of HSA-based drugs (p23, left column).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Proetzel et al.'s genetically- modified mice expressing a B2M and a FcRn in the form of heterodimer, and use a single-chain fusion protein comprising B2M and FcRn (human or mice B2M and FcRn) as taught by Feng et al., and further have the mice comprising a sequence encoding an additional human protein such as human albumin (hAlb) as taught by Viuff et al.. The skilled artisan would have been motivated to generate genetically modified mice which express a single chain fusion protein comprising B2M and FcRn, as well as an additional human protein such as human albumin (hAlb), since Viuff et al. teach double transgenic humanized FcRnα-chain and albumin (hFcRn+/+, hAlb+/+) mouse that offers a more physiologically relevant model for the preclinical study of HSA-based drugs, which is beneficial for investigation and optimization of FcRn-dependent pharmacokinetics (see p23, left column). There would be a reasonable expectation of success of having genetically- modified mice expressing a single-chain fusion protein comprising B2M and FcRn as well as an additional human protein such as human albumin (hAlb), since Proetzel et al. teach the gene modification method (see p150, left column), Feng et al. teach the design concept of the fusion protein (p67, right column), and Viuff et al. teach the method of introducing human albumin gene (p23, left column).
Conclusion
No claim is allowed.
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/Q.G./Examiner, Art Unit 1633
/FEREYDOUN G SAJJADI/Supervisory Patent Examiner, Art Unit 1699