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 .
Election/Restrictions
Claims 13-14, 16-18, 20-21, and 28 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 20 October 2025.
Claim Status
Claims 2 and 14 are currently amended, claims 6, 15, 19, and 22-27 are cancelled, claims 13-14, 16-18, 20-21, and 28 are withdrawn from further consideration, and claims 1-5 and 7-12 have been considered on their merits.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 4-5, and 7-12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chen et al. (Biology of Reproduction, 2017, IDS ref).
Regarding claim 1, Chen et al. teach induction of human primordial germ cell-like cell (PGCLCs) through incipient mesoderm-like cells from primed hESCs (pluripotent stem cell population), wherein, hESCs were dissociated into single cells and plated at 200,000 cells/well in 2 mL/well of incipient mesoderm-like cell (iMeLC) media, comprising knockout serum replacement (KSR), Activin A (TGFβ agonist), and CHIR99021 (WNT agonist) (p. 852, bottom of the 1st column). Chen et al. teach the iMeLCs were dissociated into single cells after 24 hours of incubation at the density of 3,000 cells/well in 200 µL/well of PGCLC media comprising KSR, human LIF, human bone morphogenetic protein 4 (BMP4), human epidermal growth factor (EGF), Stem Cell Factor (SCF), and Dickkopf Wnt Signaling Pathway Inhibitor 1 (DKK1) (WNT inhibitor) (p. 852, top of the 2nd column). Since incipient mesoderm-like cells are a cell state that arises from posterior epiblast cells as they differentiate and gain competency for mesoderm formation, therefore, the posterior epiblast cells would have been present in the method of Chen et al. as these cells are a precursor to the iMeLCs.
Regarding claim 4, Chen et al. teach all ITGA6/EPCAM double positive putative PGCLCs at day 4 of differentiation were positive for TNAP, wherein TNAP was used as a positive control as ITGA6 and EPCAM can be used to sort human PGCs from the prenatal embryonic ovary and testis (p. 854, Results, 1st and 2nd column). Since the differentiated cells of Chen et al. were positive for genes expressed in PGCs at day 4 of differentiation, this reads as said PGC is formed within 4 days.
Regarding claim 5, Chen et al. teach dissociating the hESCs after 24 hours of incubation in iMeLC media, as discussed in the rejection of claim 1, this reads as contacting of step (i) comprises expanding said pluripotent stem cell population as plating cells in a growth medium would necessarily lead to the expansion of said cells.
Regarding claims 7 and 8, Chen et al. teach the iMeLCs were dissociated into single cells after 24 hours of incubation at the density of 3,000 cells/well in 200 µL/well of PGCLC media comprising knockout serum replacement (KSR), human bone morphogenetic protein 4 (BMP4), human epidermal growth factor (EGF), Stem Cell Factor (SCF), and Dickkopf Wnt Signaling Pathway Inhibitor 1 (DKK1) (WNT inhibitor) (p. 852, top of the 2nd column) (claim 7). The teachings of Chen et al. read as the above named factors contacted the cells simultaneously (claim 8).
Regarding claim 9, Chen et al. teach hESCs were dissociated into single cells and plated onto Human Plasma Fibronectin-coated 12-well plate at the density of 200,000 cells/well (p. 852 bottom of 1st column). Fibronectin is well-known in the art to be used in cell culture monolayers to promote cell attachment, spreading, and proliferation by providing an adhesive substrate. Therefore, the teachings of Chen et al. read as the hESCs (pluripotent stem cells) form a monolayer in a cell culture container.
Regarding claim 10, Chen et al. teach, in the steps corresponding to steps (i) and (ii), the medium comprises KSR, which is a well-known serum replacement, therefore, Chen et al. teach steps (i) and (ii) occur in serum-free medium (p. 852, section bridging 1st and 2nd column).
Regarding claim 11, the limitations recited in this claim read as intended results of the process step positively recited, therefore, are not considered limiting since the cell marker genes would necessarily be present as a result of following the steps of claim 1. However, if this limitation were considered limiting, Chen et al. teach do determine which primitive streak genes were associated with hESCs, RNA-seq was performed on the hESCs and iMeLCs (p. 856, 1st column). Chen et al. teach seven genes, EOMES, T, GATA6, MIXL1, GATA4, WLS, and LHX1, which are associated with primitive streak formation and are known to be induced by NODAL/ACTIVIN A (TGFβ) and WNT, were found to be expressed in the iMeLCs (p. 856, 1st column). Chen et al. teach, by means of immunofluorescence, and identified nuclear accumulation of phosphorylated SMAD2/3 (pSMAD2/3) (Figure 3A) and β-CATENIN (Figure 3B) in both iMeLCs and hESCs, indicating that these cells are capable of responding to both signaling path ways (p. 856, 2nd column). β-CATENIN is a marker associated with pluripotency.
Regarding claim 12, Chen et al. teach the pluripotent stem cells are human embryonic stem cells (p. 852, section bridging 1st and 2nd column).
Thus, the reference anticipates the subject matter of claims 1, 4-5, and 7-12.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5, and 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (Biology of Reproduction, 2017, IDS ref) as applied to claims 1, 4-5, and 7-12 above, and further in view of Mitsunaga et al. (PNAS, 2017, IDS ref) and Loh et al. (US 2018/0030410, published 2018, IDS ref).
Chen et al. anticipate the subject matter of claims 1, 4-5, and 7-12, and thus, also render them obvious.
Regarding claim 2, Chen et al. teach SOX17 has emerged as a new critical regulator in primates, which is distinct from that of mouse embryos, displaying the transcriptional network required for PGC specification within the mammalian class appears to have diversified (p. 851, Introduction). Chen et al. teach ITGA6 and EPCAM can be used to isolate human PGCs from embryonic ovaries and TNAP/cKIT can be used to sort PGCs from both embryonic ovary and testis (p. 854, Results).
However, while Chen et al. does teach isolating PGCs, Chen et al. is silent to separating a CXCR4+/PDGFRα-/GARP- cell from said cell population comprising a PGC.
Mitsunaga et al. teach human primordial germ cell-like cells (hPGCLCs) generated from pluripotent stem cells in vitro, with broad applications for studies of human germline cells (p. E9913, Significance). Mitsunaga et al. teach hPGCLCs generated using several distinct protocols are transcriptomally comparable and that primed pluripotency human iPSCs gain competence to generate hPGCLCs after only 72 hours of reprogramming toward ERK-independent state-naïve pluripotency (p. E9913, Significance). Mitsunaga et al. teach hPGCLCs were localized in the outermost surface layer of embryoid bodies and strongly expressed CXCR4 (p. E9913, Significance).
Chen et al. in view of Mitsunaga et al. are silent to the markers PDGRFα and GARP.
However, Loh et al. teach PDGRFα is a marker for sclerotome cells (para. [0150]), and GARP is a marker for cardiac mesoderm cells (para. [0152]). Loh et al. teach hESCs and hiPSCs are negative for both PDGRFα and GARP, however, one differentiation begins, both anterior primitive streak and mid primitive streak cells are positive for PDGRFα (fig. 7A). Loh et al. teach the differentiated cells become GARP positive once they become cardiac mesoderm cells (fig. 7A).
Therefore, it would have been obvious to one of ordinary skill in the art to utilize the teachings of Chen et al. in view of Mitsunaga et al. and Loh et al. for separating CXCR4+/PDGRFα-/GARP- cells from a cell population with a reasonable expectation of success because Mitsunaga et al. teach CXCR4 is a marker used to identify induced hPGCLCs from pluripotent stem cells and both Chen et al. and Mitsunaga et al. teach methods of forming PGCs in vitro from pluripotent stem cells. One would be motivated to utilize the teachings of Chen et al. in view of Mitsunaga et al. and Loh et al. for separating CXCR4+/PDGRFα-/GARP- cells from a cell population because Loh et al. teach PDGRFα and GARP are both markers for cells which differentiate from the mesoderm. Additionally, Loh et al. identifies CXCR4 as a cell surface marker for paraxial mesoderm (para. [0149]). Which suggests a cell with CXCR4+ PDGRFα- GARP- markers would be distinct from other cells with a paraxial mesoderm lineage as Loh et al. teach the paraxial mesoderm would also be positive for PDGRFα. Thus, utilizing the teachings of Chen et al. in view of Mitsunaga et al. and Loh et al. to separate CXCR4+/PDGRFα-/GARP- cells from a cell population.
Regarding claim 3, Chen et al. teach the iMeLCs were dissociated into single cells after 24 hours of incubation (p. 852, top of the 2nd column), however, Chen et al. does not teach the time frame of less than 12 hours for the step of contacting a pluripotent stem cell population with a WNT agonist and a TGFβ agonist, thereby forming a posterior epiblast cell population. Since incipient mesoderm-like cells (iMeLCs) are a cell state that arises from posterior epiblast cells as they differentiate and gain competency for mesoderm formation, therefore, the posterior epiblast cells would have been present in the method of Chen et al. as these cells are a precursor to the iMeLCs.
However, because Chen et al. does not specifically identify the time required to achieve the formation of posterior epiblast cell population does not necessarily mean these cells were not present in the “less than 12 hours” time period. Therefore, absent evidence to the contrary, since Chen et al teach the same steps as the claimed method, the formation of the posterior epiblast cell population would be expected to be less than 12 hours as the method requires.
Additionally, M.P.E.P. § 2144.05(II)(A) states a prima facie case of obviousness exists "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, the time frame required to culture the cells would have been a result effective variable amenable to routine optimization and experimentation on the part of the artisan of ordinary skill, said artisan recognizing the time required to culture cells depends on the quantity of cells and the desired cells being produced. A holding of obviousness over the cited claims is therefore clearly required. The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages. See Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382.; See also M.P.E.P. § 2144.05 (II)(A).
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
Conclusion
No claims are allowed.
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/N.A.H./
Examiner, Art Unit 1631
/LAURA SCHUBERG/Primary Examiner, Art Unit 1631