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 .
Status of Claims
Claims 1-17 and 19-21 are pending.
Priority
Claims 1-17 and 19-21 have priority to PRO 63/397,908 filed on August 15, 2022
Claim Interpretation
Under the broadest reasonable interpretation (BRI), the transitional phrase “comprising or consisting of” is interpreted as “comprising” in order to give the claims the broadest reasonable scope. Under BRI, “comprising” is an open-ended transition that allows for the inclusion of additional, unrecited elements. Therefore, for purposes of examination, the claims are interpreted as covering at least the recited elements and potentially additional elements.
Claim Objections
Claim 12 is objected to for the following reasons:
Claim 12 recites “wherein the set of factors is delivered” should read “wherein the set of factors are
Double Patenting
A rejection based on double patenting of the “same invention” type finds its support in the language of 35 U.S.C. 101 which states that “whoever invents or discovers any new and useful process... may obtain a patent therefor...” (Emphasis added). Thus, the term “same invention,” in this context, means an invention drawn to identical subject matter. See Miller v. Eagle Mfg. Co., 151 U.S. 186 (1894); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Ockert, 245 F.2d 467, 114 USPQ 330 (CCPA 1957).
A statutory type (35 U.S.C. 101) double patenting rejection can be overcome by canceling or amending the claims that are directed to the same invention so they are no longer coextensive in scope. The filing of a terminal disclaimer cannot overcome a double patenting rejection based upon 35 U.S.C. 101.
Applicant is advised that should claim 1 be found allowable, claim 7 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). As written, Claim 7 is reciting substantially the same limitation as claim 1 “wherein the set of factors comprise…PRDM16, ZBTB16, LIN28, and LIN41”. Thus, despite the slight difference in wording, the claims have substantially the same scope.
Applicant is advised that should claim 15 be found allowable, claim 21 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). As written, Claim 7 is reciting substantially the same limitation as claim 1 “wherein the set of factors comprise…PRDM16, ZBTB16, LIN28, and LIN41”. Thus, despite the slight difference in wording, the claims have substantially the same scope.
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 1-2, 5, 7-14 and 15, 16, 19, and 21 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.
Claim 1 uses the generic phrase “wherein the factors are selected from PRDM16, ZBTB16, LIN28, and LIN41” with respect to a set of factors that are delivered to fibroblasts as a means for producing limb progenitor cells. The same generic scope of “wherein the factors are selected from PRDM16, ZBTB16, LIN28, and LIN41” is present in each of the dependent claims, i.e. Claims 2, 5, 7-14.
Claim 15 uses the generic phrase “set of factors selected from PRDM16, ZBTB16, LIN28, and LIN41” with respect to a composition made up of these factors that may or may not include fibroblasts. The same generic scope of “set of factors selected from PRDM16, ZBTB16, LIN28, and LIN41” is present in each of the dependent claims, i.e. Claims 16, 19, and 21.
The specification provides antecedent basis for producing limb progenitor cells using the factors selected from PRDM16, ZBTB16, LIN28, and LIN41 [Pg. 1 Summary].
Under the broadest reasonable interpretation, Claims 1 encompasses delivering any combination of the four listed factors, i.e. any one, two, three, or all four, to fibroblasts to produce limb progenitor cells. Citing MPEP § 2161.01(I), Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1340, 94 USPQ2d 1161, 1167 (Fed. Cir. 2010) (en banc), to satisfy the written description requirement, the 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 at the time of filing. However, the specification discloses that from the initial pool of 142 factors, 15 were more than two-fold overexpressed in the limb as compared to the neck, and 16 were more than two-fold overexpressed compared to the flank [pg. 18 Ln 30-34]. The specification further states that redundant or compartment-specific factors were excluded, e.g. Lhx9 and Hoxa6 for their redundancy to Lhx2 and Hox genes. Lmx1b was excluded because it only specifies the dorsal compartment of the limb field [pg. 19 1-10]. The specification goes on to identify LIN28a, a conserved RNA-binding protein that suppresses let-7 microRNA biogenesis, as a key factor because of its increased expression in limb buds compared to flank lateral plate mesoderm. In Example 4, Applicant states that PRDM16, ZBTB16, and LIN28 were responsible for induction of limb progenitor marker genes, i.e. PrxGFP and Sall4. The specification further states that Applicant conducted 7-1 and 7-2 assay analysis in order to determine which combination of one or two factors contributed more to GFP induction. In both instances, LIN28 was shown to be necessary to yield high GFP scores [pg. 20 Ln. 20-25]. Applicant’s specification then described a LIN28 plus one analysis where combinations of LIN28 and PRDM16 or ZBTB16 were combined that resulted in higher GFP scores. The specification defined these three factors as “core factors” [pg. 19 ln. 30-33]. Additionally, Example 6 discusses the introduction of LIN41, which aided in the repression of Egr1, for the purpose of accelerating proliferation of the recombinant limb progenitor cells [pg. 22 Example 6]. However, LIN41 is described as an enhancer, not as a factor essential for induction of limb progenitors. Furthermore, Atsuta et al., also discussing direct reprogramming of non-limb fibroblasts, discloses that LIN41 is used to potentiate the proliferation of the reprogrammed cells [Abstract, Direct reprogramming of non-limb fibroblasts to cells with properties of limb progenitors, Developmental Cell, 2024]. Atsuta et al. also states that LIN41 was co-expressed with PRDM16, ZBTB16 and LIN28, but that the reprogrammed cells expressed the same limb progenitor markers as cells reprogrammed with only the core factors of PRDM16, ZBTB16, and LIN28. Additionally the specification does not describe or provide any data indicating that combinations lacking LIN28 would be successful in inducing fibroblasts into limb progenitors. The disclosure consistently teaches that LIN28 is required as a component for reprogramming and that LIN41 functions only to enhance proliferation, and does not participate in inducing reprogramming [pg. 22 Example 6]. Based on this, a person of ordinary skill would not understand that the disclosure supports combinations that do not include LIN28.
Based on this and the generic scope of “set of factors (are) selected from PRDM16, ZBTB16, LIN28, and LIN41”, and the absence of teachings of what combinations that do not include LIN28 that would also induce fibroblasts into limb progenitor cells, the Artisan would not understand Applicant to be in possession of the generic scope of “set of factors (are) selected from PRDM16, ZBTB16, LIN28, and LIN41” with respect to inducing fibroblasts into limb progenitor cells given the claims broadest reasonable interpretation.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 8, 13, and 14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 8 recites the broad recitation “about embryonic day 10 (E10) to about embryonic day 15 (E15), and the claim also recites “preferably about E13.5” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 13 recites the broad recitation “at least 7 days”, and the claim also recites “at least 14 days, or at least 21 weeks” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 14 recites the broad recitation “about 7 days to about 21 days”, and the claim also recites “optionally about 14 days” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-14 are rejected under 35 U.S.C. §103 as being unpatentable over Yokoyama et al. [Dynamic gene expression of Lin28 during embryonic development in mouse and chicken, Gene Expression Ptterns, 2008], in view of Plikus et al. [Fibroblasts: origins, definitions, and functions in health and disease, Cell, 2021], in view of Tsialikas & Seibert (Hereinafter Seibert) [Lin28: roles & regulation in development and beyond, Development, 2015], in view of Biferali et al. [Prdm16-mediated H3K9 methylation controls fibro-adipogenic progenitors identity during skeletal muscle repair, Science Advances, 2021], in view of Liu et al. [Concise review: balancing stem cell self-renewal and differentiation with PLZF, Stem Cells, 2015], in view of StemCell Technologies [CHIR99021: wnt pathway activator, inhibits GSK3 , https://www.stemcell.com/chir99021.html, Dec. 2021: Internet Archive Wayback Machine], in view of Nedunchezian et al. [Generating adipose stem cell laden hyaluronic acid based scaffolds using 3D bioprinting via the double crosslinking strategy for chondrogenesis, Materials Science & Engineering: C, May 2021], in view of Anson [The use of retroviral vectors for gene therapy – what are the risks? A review of retroviral pathogenesis and its relevance to retroviral-mediated gene delivery, Genet Vaccines Ther., 2004], in view of Chen et al. [Generation of iPSC-derived limb progenitor-like cells for stimulating phalange regeneration in the adult mouse, Cell Discovery, 2017].
With respect to Claim 1 where a method of producing limb progenitor cells comprises delivering a set of factors that include LIN28, Yokohama et al., discussing in situ hybridization of LIN28 in the developing mouse and chick limb bud, teaches that LIN28 exhibits dynamic expression during embryonic development in mouse and chicken, including in tissues that contribute to limb development [Abstract], suggesting that LIN28 plays an active role in regulating early limb patterning stages [Results and Discussion ¶ 6]. Seibert, also discussing the roles and regulation of LIN28, discloses further that LIN28 functions as a key developmental regulator that influences cell proliferation, tissue patterning, and maintenance of progenitor states by modulating let-7 miRNA pathway as well as other regulatory mechanisms [LIN28 in pluripotent stem cells ¶ 1].
With respect to claim 1 where Applicant delivers a set of factors to fibroblasts, Plikus et al., discussing the versatility of fibroblast mesenchymal cells, discloses that fibroblasts are heterogenous, lineage-flexible mesenchymal cells capable of adopting alternatice fates under reprogramming or injury induced conditions [Myofibroblasts: contraction and coordination of tissue repair ¶ 1, 4, 6]. Additionally, fibroblasts are readily available, easy to culture, and are commonly used as starting cells for direct lineage conversion due to their responsiveness to developmental signaling cues.
With respect to claim 1 where one of the set of factors is PRDM16, Biferali et al. teaches that PRDM16 functions as an epigenetic regulator that is capable of enforcing a progenitor cell transcriptional program while repressing alternative lineages [Abstract].
With respect to claim 1 where one of the set of factors being delivered to fibroblasts is ZBTB16, Liu et al., discussing PLZF, i.e. ZBTB16, displaying tight regulation in cell-type specific and stage specific expression patterns, teaches that ZBTB16 plays a central role in balancing stem cell self-renewal and differentiation where it acts as a lineage-specific repressor/organizer of transcriptional programs capable of preserving progenitor states that helps to prevent premature differentiation [Abstract]. Liu et al. further discloses that during limb bud development, ZBTB16 represses Hoxd, and regulates BMPs to regulate limb patterning [Fig. 1]. It was also shown that ZBTB16 cooperates with Gli3 establishing correct temporal and spatial distribution of chondrogenitors during proximal limb patterning. This is required for all proximal cartilage condensations at very early stages of limb development [Limb bud development ¶ 1].
With respect to claim 1 where LIN41 was also included, Seibert further discloses that LIN41 functions as an RNA-binding E3 ubiquitin ligase regulated downstream of LIN28 and the let-7 miRNA pathway. This allows it to play a role in maintaining stem and progenitor cell identity by repressing differentiation-associated transcripts and promoting proliferation during embryonic development [Lin-28 plays two roles in C. elegans larval development ¶ 2 and Fig. 3]
Here, it is prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Yokoyama et al. and Seibert where it was discussed that LIN28 is dynamically expressed during embryonic development and is a key regulator of progenitor cell maintenance through the suppression of the let-7 miRNA pathway. Given its known role in reprogramming somatic cells toward undifferentiated, progenitor-like states, an artisan would have recognized that LIN28 could be used as a factor in inducing fibroblasts. Additionally, Plikus et al. discusses fibroblasts as a lineage-plastic mesenchymal stem cell that can be reprogrammed or induced to acquire developmental progenitor phenotypes, making fibroblasts a practical somatic cell for use as a starting cell. Biferali et al. further disclosed that PRDM16 regulates fibro-adipgenic progenitor identity in skeletal muscle via H3K9 methylation, thereby controlling lineage fate and maintaining progenitor characteristics that are relevant to limb progenitor cell types. Likewise, Liu et al. disclosed that ZBTB16 is capable of maintaining stem cell self-renewal and is active in limb bud patterning. Lastly, Seibert et al. discusses LIN41 as a downstream effector of LIN28 that suppresses differentiation genes through post transcriptional repression and is capable of maintaining developmental plasticity in embryonic lineages. Given this, there is a reasonable expectation of success that a person skilled in the art would recognize the combinations of LIN28, PRDM16, ZBTB16, and LIN41 as factors that could be introduced into progenitors via transfection, or some other known method of expression, into fibroblasts that would in turn activate transcriptional and epigenetic programs that resemble limb progenitor cells.
For claim 2 where the set of factors comprise or consist of two or more of the same factors as claim 1, as discussed in claim 1, the prior art teaches LIN28, PRDM16, ZBTB16, and LIN41 each independently regulate progenitor or stem-like states during embryonic and mesenchymal development. Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipgenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning. Lastly, Seibert identifies LIN41 as a downstream effector of LIN28 that reinforces progenitor states through translational repression.
For claim 3 where the factors comprise or consist of LIN28 and PRDM16, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity.
For claim 4 where the factors comprise or consist of LIN28 and ZBTB16, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning.
For claim 5 where the two or more factors comprise or consist of three or more factors, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning.
For claim 6 where the three or more factors comprise or consist of LIN28, PRDM16, and ZBTB16, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning.
For Claim 7 where the factors comprise or consist of the four factors, the prior art teaches LIN28, PRDM16, ZBTB16, and LIN41 each independently regulate progenitor or stem-like states during embryonic and mesenchymal development. Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipgenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning. Lastly, Seibert identifies LIN41 as a downstream effector of LIN28 that reinforces progenitor states through translational repression.
Here, it is prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Yokoyama et al. and Seibert where it was discussed that LIN28 is dynamically expressed during embryonic development and is a key regulator of progenitor cell maintenance through the suppression of the let-7 miRNA pathway. Given its known role in reprogramming somatic cells toward undifferentiated, progenitor-like states, an artisan would have recognized that LIN28 could be used as a factor in inducing fibroblasts. Biferali et al. further disclosed that PRDM16 regulates fibro-adipogenic progenitor identity in skeletal muscle via H3K9 methylation, thereby controlling lineage fate and maintaining progenitor characteristics that are relevant to limb progenitor cell types. Likewise, Liu et al. disclosed that ZBTB16 is capable of maintaining stem cell self-renewal and is active in limb bud patterning. Lastly, Seibert et al. discusses LIN41 as a downstream effector of LIN28 that suppresses differentiation genes through post transcriptional repression and is capable of maintaining developmental plasticity in embryonic lineages. Given this, there is a reasonable expectation of success that a person skilled in the art would recognize the combinations of LIN28, PRDM16, ZBTB16, and LIN41 as factors that could be introduced into progenitors via transfection, or some other known method of expression, into fibroblasts that would in turn activate transcriptional and epigenetic programs that resemble limb progenitor cells.
Claim 8 where the method of claim 1 fibroblasts or mouse fibroblasts and are obtained from mouse embryos, Yokohama et al. teaches the isolation and characterization of mouse embryonic fibroblasts and demonstrate that these fibroblasts are readily obtained from mouse embryos and maintained in culture through development [Abstract, Para starting with Yang and Moss revealed that”]. Plikus et al. further discloses that fibroblasts, including embryonic fibroblasts, are lineage flexible mesenchymal cells suitable as starting material for reprogramming into progenitor like cell states [Summary]. Yokohama et al. further discloses that embryonic embryos at different developing stages, i.e. day 10, etc., showed LIN28 expression peaked at around E9.5 [Para starting with “Although Lin-28 was ubiquitously”].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Yokoyama et al. and Seibert where it was discussed that LIN28 is dynamically expressed during embryonic development and is a key regulator of progenitor cell maintenance through the suppression of the let-7 miRNA pathway. Given its known role in reprogramming somatic cells toward undifferentiated, progenitor-like states, an artisan would have recognized that LIN28 could be used as a factor in inducing fibroblasts. Additionally, Plikus et al. discusses fibroblasts as a lineage-plastic mesenchymal stem cell that can be reprogrammed or induced to acquire developmental progenitor phenotypes, making fibroblasts a practical somatic cell for use as a starting cell. Biferali et al. further disclosed that PRDM16 regulates fibro-adipgenic progenitor identity in skeletal muscle via H3K9 methylation, thereby controlling lineage fate and maintaining progenitor characteristics that are relevant to limb progenitor cell types. Likewise, Liu et al. disclosed that ZBTB16 is capable of maintaining stem cell self-renewal and is active in limb bud patterning. Lastly, Seibert et al. discusses LIN41 as a downstream effector of LIN28 that suppresses differentiation genes through post transcriptional repression and is capable of maintaining developmental plasticity in embryonic lineages. Given this, there is a reasonable expectation of success that a person skilled in the art would recognize the combinations of LIN28, PRDM16, ZBTB16, and LIN41 as factors that could be introduced into progenitors via transfection, or some other known method of expression, into fibroblasts that would in turn activate transcriptional and epigenetic programs that resemble limb progenitor cells. Lastly, there would have a been a reasonable expectation of success that an artisan would have selected fibroblasts derived from mouse embryos at around E10 given that based on the teachings of Yokohama et al., strong LIN28 expression was observed with a tapering off around day 10.5.
For claim 9 where the fibroblasts are human fibroblasts, Plikus et al. discusses human fibroblasts and the characteristic markers of human fibroblasts [Table 1, Cross organ commonalities in fibroblasts biology ¶ 1].
For claim 10 where the fibroblasts are cultured in a hydrogel that contains a high molecular weight hyaluronic acid and adipic acid dihydrazide crosslinkers, Nedunchezian et al., discussing hyaluronic acid-based scaffolds using 3D bioprinting, teaches the use of hydrogel system fabrication that includes a high molecular weight hyaluronic acid along with a adipic dihydrazide [2.1.2 Synthesis of HA-ADH]. Given this, there is a reasonable expectation of success that a person of ordinary skill in the art would have found it prima facie obvious to culture fibroblasts in a high molecular weight hyaluronic acid and adipic didydrazide crosslinker hydrogel given the hydrogel provides a supportive matrix that promotes cell adhesion, proliferation, and differentiation and would facilitate the maintenance and enhancement of progenitor-like characteristics in fibroblasts.
For claim 11 where fibroblasts are cultured in the presence of CHIR99021, StemCell Technologies discloses that CHIR99021 is an aminopyridimine derivative that is extremely potent GSK3 inhibitor [Overview] and enables reprogramming of mouse embryonic fibroblasts [Id.].
For claim 12 where the set of factors are delivered using retrovirus or pooled retroviruses, Anson, discussing the role of retroviruses in vector-mediated gene delivery, discusses the use of retroviruses and their inherent advantage given their ability to transform their single stranded RNA genome into a double stranded DNA molecule that stably integrates into the target cell genome [Abstract]. This allows the retroviral vector to permanently modify the host cell nuclear genome [Id.].
Claims 13 and 14, respectively, are directed to where the fibroblasts are cultured for at least or about 7 days or longer, Chen et al., discussing generation of iPSC-derived limb progenitor-like cells, cultured fibroblasts for 14 days [Fig. 3]. Therefore, there is a reasonable expectation of success that an artisan would combine the teachings of Chen et al. with the teachings of Nedunchezian et al. and Plikus et al. to create a culture media system that promotes/maintains fibroblasts while priming the fibroblasts in a reprogrammable state through a combination of culture conditions and supportive microenvironment that maintain plasticity and proliferative capacity. Additionally, the use of CHIR99021 modulates intracellular pathway signaling, including Wnt/Beta-catenin, which also promotes progenitor-like characteristics and prevents premature differentiation. This, plus the high molecular weight hyaluronic acid hydrogel crosslinked with adipic acid dihrydrozide provides a three-dimensional extracellular matrix-like environment supporting adhesion, cell survival, and proliferation.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 15-17 and 19-21 are rejected under 35 U.S.C. §103 as being unpatentable in view of Yokoyama et al. [Dynamic gene expression of Lin28 during embryonic development in mouse and chicken, Gene Expression Ptterns, 2008], in view of Plikus et al. [Fibroblasts: origins, definitions, and functions in health and disease, Cell, 2021], in view of Tsialikas & Seibert (Hereinafter Seibert) [Lin28: roles & regulation in development and beyond, Development, 2015], in view of Biferali et al. [Prdm16-mediated H3K9 methylation controls fibro-adipogenic progenitors identity during skeletal muscle repair, Science Advances, 2021], in view of Liu et al. [Concise review: balancing stem cell self-renewal and differentiation with PLZF, Stem Cells, 2015].
Claim 15 is directed to a composition comprising PRDM16, ZBTB16, LIN28, and LIN41, where as Yokohama et al. and Seibert teach LIN28 with Seibert further teaching LIN41. However these two references do not teach PRDM16 or ZBTB16.
For the Claim 15 limitation related to a composition the comprises LIN28, Yokohama et al., discussing in situ hybridization of LIN28 in the developing mouse and chick limb bud, teaches that LIN28 exhibits dynamic expression during embryonic development in mouse and chicken, including in tissues that contribute to limb development [Abstract], suggesting that LIN28 plays an active role in regulating early limb patterning stages [Results and Discussion ¶ 6]. Seibert, also discussing the roles and regulation of LIN28, discloses further that LIN28 functions as a key developmental regulator that influences cell proliferation, tissue patterning, and maintenance of progenitor states by modulating let-7 miRNA pathway as well as other regulatory mechanisms [LIN28 in pluripotent stem cells ¶ 1].
With respect to claim 15 where one of the set of factors is PRDM16, Biferali et al. teaches that PRDM16 functions as an epigenetic regulator that is capable of enforcing a progenitor cell transcriptional program while repressing alternative lineages [Abstract].
With respect to claim 15 where one of the set of factors is ZBTB16, Liu et al., discussing PLZF, i.e. ZBTB16, displaying tight regulation in cell-type specific and stage specific expression patterns, teaches that ZBTB16 plays a central role in balancing stem cell self-renewal and differentiation where it acts as a lineage-specific repressor/organizer of transcriptional programs capable of preserving progenitor states that helps to prevent premature differentiation [Abstract]. Liu et al. further discloses that during limb bud development, ZBTB16 represses Hoxd, and regulates BMPs to regulate limb patterning [Fig. 1]. It was also shown that ZBTB16 cooperates with Gli3 establishing correct temporal and spatial distribution of chondrogenitors during proximal limb patterning. This is required for all proximal cartilage condensations at very early stages of limb development [Limb bud development ¶ 1].
With respect to claim 15 where LIN41 was also included in the composition, Seibert further discloses that LIN41 functions as an RNA-binding E3 ubiquitin ligase regulated downstream of LIN28 and the let-7 miRNA pathway. This allows it to play a role in maintaining stem and progenitor cell identity by repressing differentiation-associated transcripts and promoting proliferation during embryonic development [Lin-28 plays two roles in C. elegans larval development ¶ 2 and Fig. 3].
Here, it is prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Yokoyama et al. and Seibert where it was discussed that LIN28 is dynamically expressed during embryonic development and is a key regulator of progenitor cell maintenance through the suppression of the let-7 miRNA pathway. Given its known role in reprogramming somatic cells toward undifferentiated, progenitor-like states, an artisan would have recognized that LIN28 could be used as a factor in inducing fibroblasts. Biferali et al. further disclosed that PRDM16 regulates fibro-adipgenic progenitor identity in skeletal muscle via H3K9 methylation, thereby controlling lineage fate and maintaining progenitor characteristics that are relevant to limb progenitor cell types. Likewise, Liu et al. disclosed that ZBTB16 is capable of maintaining stem cell self-renewal and is active in limb bud patterning. Lastly, Seibert et al. discusses LIN41 as a downstream effector of LIN28 that suppresses differentiation genes through post transcriptional repression and is capable of maintaining developmental plasticity in embryonic lineages. Given this, there is a reasonable expectation of success that a person skilled in the art would recognize the combinations of LIN28, PRDM16, ZBTB16, and LIN41 as factors that could be introduced into fibroblasts via transfection, or some other known method of expression, that would in turn activate transcriptional and epigenetic programs that resemble limb progenitor cells.
For claim 16 where the set of factors comprise or consist of two or more of the same factors as claim 1, as discussed in claim 1, the prior art teaches LIN28, PRDM16, ZBTB16, and LIN41 each independently regulate progenitor or stem-like states during embryonic and mesenchymal development. Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipgenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning. Lastly, Seibert identifies LIN41 as a downstream effector of LIN28 that reinforces progenitor states through translational repression.
For claim 17 where the factors comprise or consist of LIN28 and PRDM16, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity.
For claim 19 where the two or more factors comprise or consist of three or more factors, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning.
For claim 20 where the three or more factors comprise or consist of LIN28, PRDM16, and ZBTB16, Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Additionally, Seibert teaches that LIN28 is associated with developing limb bud tissue where progenitor cells remain undifferentiated [Introduction ¶ 2] and has been identified as one of several factors that can participate in the reprogramming of mammalian cells to pluripotent cells [Id.]. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipogenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning.
For Claim 7 where the factors comprise or consist of the four factors, the prior art teaches LIN28, PRDM16, ZBTB16, and LIN41 each independently regulate progenitor or stem-like states during embryonic and mesenchymal development. Yokohama et al. and Seibert teach LIN28 and how it regulates progenitor cell identity and suppresses differentiation via the let-7 pathway. Biferali et al. teaches that PRDM16 is a transcriptional regulator maintaining fibro-adipgenic progenitor identity. Liu et al. shows that ZBTB16 (PLZF) maintains stem cell self-renewal and contributes to limb bud patterning. Lastly, Seibert identifies LIN41 as a downstream effector of LIN28 that reinforces progenitor states through translational repression.
Here, it is prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Yokoyama et al. and Seibert where it was discussed that LIN28 is dynamically expressed during embryonic development and is a key regulator of progenitor cell maintenance through the suppression of the let-7 miRNA pathway. Given its known role in reprogramming somatic cells toward undifferentiated, progenitor-like states, an artisan would have recognized that LIN28 could be used as a factor in inducing fibroblasts. Biferali et al. further disclosed that PRDM16 regulates fibro-adipogenic progenitor identity in skeletal muscle via H3K9 methylation, thereby controlling lineage fate and maintaining progenitor characteristics that are relevant to limb progenitor cell types. Likewise, Liu et al. disclosed that ZBTB16 is capable of maintaining stem cell self-renewal and is active in limb bud patterning. Lastly, Seibert et al. discusses LIN41 as a downstream effector of LIN28 that suppresses differentiation genes through post transcriptional repression and is capable of maintaining developmental plasticity in embryonic lineages. Given this, there is a reasonable expectation of success that a person skilled in the art would recognize the combinations of LIN28, PRDM16, ZBTB16, and LIN41 as factors that could be introduced into progenitors via transfection, or some other known method of expression, into fibroblasts that would in turn activate transcriptional and epigenetic programs that resemble limb progenitor cells.
The Supreme court has acknowledged:
When a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one. If a person of ordinary skill can implement a predictable varition..103 likely bars its patentability…if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond that person’s skill. A court must ask whether the improvement is more than the predictable use of prior-art elements according to their established functions…
…the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results (see KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 U.S. 2007) emphasis added.
In KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), the Supreme Court reaffirmed "the conclusion that when a patent 'simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." Id. at 417 (quoting Sakraida v. Ag Pro, Inc., 425 U.S. 273,282 (1976)). The Supreme Court also emphasized a flexible approach to the obviousness question, stating that the analysis under 35 U.S.C. § 103 "need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ." Id. at 418; see also id. at 421 ("A person of ordinary skill is... a person of ordinary creativity, not an automaton.").
From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary.
Conclusion
No claims allowed.
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/JOHN DAVID MOORE/Examiner, Art Unit 1638
/ROBERT M KELLY/Primary Examiner, Art Unit 1638