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 .
Claim Status
Claims 1-3, 5, 8-9, 11, 16, 18, 22-23, 26-27, 29, 31, 33-36, 38, 40-43, 46, 48-49, 51-52, 55-56, 58, 60, 64, 162-163, 290-291, 309-310, 313, 316-317, 321, 325, 330, 334-335, 337-339, 373, 375 and 406 are pending.
Claims 1-3, 5, 8-9, 11, 16, 18, 290-291, 309-310, 313, 316-317, 321, 325, 330, 334-335, and 337-339 are withdrawn.
Claims 22-23, 26-27, 29, 31, 33-36, 38, 40-43, 46, 48-49, 51-52, 55-56, 58, 60, 64, 162-163, 373, 375 and 406 are under examination.
Election/Restrictions
Applicant’s election without traverse of the following invention
Invention
Group II, claims 22-23, 26-27, 29, 31, 33-36, 38, 40-43, 46, 48-49, 51-52, 55-56, 58, 60, 64, 162-163, 373, 375 and 406 drawn to a method comprising: a) providing a source cell; b) differentiating the source cell in vitro in at least one culture medium comprising an agent that increases intracellular cyclic AMP, wherein the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability; and c) recovering the mature hepatocyte-like cell and a method for producing a mature hepatocyte-like cell having enhanced ureagenesis capability comprising: a) providing a source cell; b) differentiating the source cell in vitro in at least one culture medium comprising an agent that increases intracellular cyclic AMP, wherein the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability; and c) recovering the mature hepatocyte-like cell, wherein the differentiating is initially carried out on a first substrate comprising gelatin and fetal bovine serum and transferred to a second substrate comprising laminin and/or collagen on about day 14 of the differentiating, and a method for producing a mature hepatocyte-like cell having enhanced
ureagenesis capability comprising: a) providing a source cell; b) differentiating the source cell in vitro in a three dimensional culture system comprising: i. a fetal bovine serum (FBS) free substrate; and ii. at least one culture medium comprising an agent that increases intracellular cyclic AMP, wherein the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability; and c) recovering the mature hepatocyte-like cell.
in the reply filed on 3rd, November, 2025 is acknowledged.
The requirement is still deemed proper and is therefore made FINAL.
Claims 1-3, 5, 8-9, 11, 16, 18, 290-291, 309-310, 313, 316-317, 321, 325, 330, 334-335, and 337-339 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.
Examiner’s Remark
The Examiner notes that claim 64 was not listed in a group in the previous office action due to a typographical error. Claim 64 is drawn to the subject matter of elected Group II and is under consideration in this office action.
The Examiner notes that claims 373 and 375 have been amended to depend on claim 42, which is part of the elected group and accordingly these claims read on the elected invention.
Claim Objections
Claims 51 and 406 are objected to because of the following informalities:
Claim 51 recites “comprises selected from” which includes two transitional phrases (comprising and “selected from,” and is grammatically improper. It is recommended that Applicant amend to one transitional phrase.
Claim 406 includes periods before the end of the claim (“i.” and “ii.”). Periods are only allowed at the end of a claim. Applicant is directed to MPEP 608.01(m) which states “Each claim begins with a capital letter and ends with a period. Periods may not be used elsewhere in the claims except for abbreviations. See Fressola v. Manbeck, 36 USPQ2d 1211 (D.D.C. 1995). Where a claim sets forth a plurality of elements or steps, each element or step of the claim should be separated by a line indentation, 37 CFR 1.75(i).”
To overcome this objection to claim 406 it is recommended that Applicant amend all instances of periods before the end of the claim to parentheses (for example, “i.” in claim 406 would be amended to “i)” or “(i)”).
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
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 22-23, 26-27, 29, 31, 33-36, 38, 40-43, 46, 48-49, 51-52, 55-56, 58, 60, 64, 162-163, 373, 375 and 406 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.
Claims 22, 162 and 406 recite “enhanced in vitro ureagenesis capability.” The term “enhanced” in this phrase is relative terminology. A claim may be rendered indefinite when a limitation of the claim is defined by reference to an object and the relationship between the limitation and the object is not sufficiently defined. That is, where the elements of a claim have two or more plausible constructions such that the examiner cannot readily ascertain positional relationship of the elements, the claim may be rendered indefinite. See, e.g., Ex parte Miyazaki, 89 USPQ2d 1207 (Bd. Pat. App. & Inter. 2008) (precedential) and Ex parte Brummer, 12 USPQ2d 1653 (Bd. Pat. App. & Inter. 1989). In the instant case “enhanced in vitro ureagenesis capability” is dependent on some reference value of in vitro ureagenesis capability, which is not sufficiently defined (see MPEP 2173.05(b)).
By nature of their ultimate dependency on claim 22, claims 23, 26-27, 29, 31, 33-36, 38, 40-43, 46, 48-49, 51-52, 55-56, 58, 60, 64, 373 and 375 are also rejected because they do not clarify the issue.
By nature of its dependency on claim 162, claim 163 is also rejected because it does not clarify the issue.
Similarly, claim 56 recites “increased RNA expression” and “increased protein expression.” The term “increased” in these phrases is relative terminology which is a limitation of the claim defined by reference to an object and the relationship between the limitation and the object is not sufficiently defined because “increased RNA expression” and “increased protein expression” are dependent on some reference RNA expression and protein expression, which are not sufficiently defined (see MPEP 2173.05(b)).
Similarly, claim 60 recites “increased expression.” The term “increased” in this phrases is relative terminology which is a limitation of the claim defined by reference to an object and the relationship between the limitation and the object is not sufficiently defined because “increased expression” is dependent on some reference expression, which is not sufficiently defined (see MPEP 2173.05(b)).
Claim 33 recites “the differentiating step b) takes place during the differentiation of an immature hepatocyte-like cell to the mature hepatocyte-like cell,” which includes the limitation of “the differentiation of an immature hepatocyte-like cell.” However, claim 22, upon which claim 33 depends, does not recite a step of a differentiation of an immature hepatocyte-like cell. Therefore, there is improper antecedent basis for “the differentiation of an immature hepatocyte-like cell to the mature hepatocyte-like cell,” it is unclear what the scope of “the differentiation of an immature hepatocyte-like cell to the mature hepatocyte-like cell” encompasses and the metes and bounds of the claim are unclear.
Claim 51 recites the open-ended language “comprises” together with the Markush language “selected from the group consisting of” which is closed language. The presence of both an open-ended and a closed transitional phrase makes it unclear whether the scope of the claim is open to including other elements.
Claim 58 recites “the culture medium further comprises hepatocyte growth factor (HGF) and oncostatin-M (OSM), is free of hepatocyte growth factor (HGF), or both.” The scope of the claim is indefinite because it is unclear how the claim can include “both” being “free of hepatocyte growth factor (HGF)” and comprising hepatocyte growth factor (HGF).
Generally, when the claims are indefinite, vague or unclear, they cannot be construed without speculation or conjecture; therefore, the indefinite claims are not treated on the merits with respect to prior art. See In re Steele, 305 F.2d 859, 862 (CCPA 1962) (A prior art rejection cannot be sustained if the hypothetical person of ordinary skill in the art would have to make speculative assumptions concerning the meaning of claim language.); see also In re Wilson, 424 F.2d 1382, 1385 (CCPA 1970) ("If no reasonably definite meaning can be ascribed to certain terms in the claim, the subject matter does not become obvious-the claim becomes indefinite."). Notwithstanding Steele, the Office has made every attempt to construe the claims in what the Office believes is the intent of the Applicants in the interest of compact prosecution.
Claim Rejections - 35 USC § 112
Improper Markush
Claims 26 and 29 are rejected on the basis that they contain an improper Markush grouping of alternatives. See In re Harnisch, 631 F.2d 716, 721-22 (CCPA 1980) and Ex parte Hozumi, 3 USPQ2d 1059, 1060 (Bd. Pat. App. & Int. 1984). A Markush grouping is proper if the alternatives defined by the Markush group (i.e., alternatives from which a selection is to be made in the context of a combination or process, or alternative chemical compounds as a whole) share a “single structural similarity” and a common use. A Markush grouping meets these requirements in two situations. First, a Markush grouping is proper if the alternatives are all members of the same recognized physical or chemical class or the same art-recognized class, and are disclosed in the specification or known in the art to be functionally equivalent and have a common use. Second, where a Markush grouping describes alternative chemical compounds, whether by words or chemical formulas, and the alternatives do not belong to a recognized class as set forth above, the members of the Markush grouping may be considered to share a “single structural similarity” and common use where the alternatives share both a substantial structural feature and a common use that flows from the substantial structural feature. See MPEP § 2117.
Regarding claim 26, the Markush grouping of forskolin, glucagon, glucagon-like peptide-I (GLP-1), glucose-dependent insulinotropic peptide (GIP), a phosphodiesterase inhibitor is improper because the alternatives defined by the Markush grouping do not share both a single structural similarity and a common use for the following reasons: The listed alternatives do not share a single structural similarity.
Regarding claim 29, the Markush grouping of carbamoylphosphate synthetase I (CPS 1), omithine transcarbamylase (OTC), argininosuccinic acid synthetase (ASS1), argininosuccinic acid lyase (ASL), arginase (ARG1), N-acetyl glutamate synthetase (NAGS), ornithine translocase (ORNT1), citrin is improper because the alternatives defined by the Markush grouping do not share both a single structural similarity and a common use for the following reasons: The listed alternatives do not share a single structural similarity.
Furthermore, regarding claims 26 and 29, the recitation of “comprises” includes open language and is improper Markush language. Applicant is directed to MPEP 2117 which states claim language defined by a Markush grouping requires selection from a closed group "consisting of" the alternative members. Id. at 1280, 67 USPQ2d at 1196.
To overcome this rejection, Applicant may set forth each alternative (or grouping of patentably indistinct alternatives) within an improper Markush grouping in a series of independent or dependent claims and/or present convincing arguments that the group members recited in the alternative within a single claim in fact share a single structural similarity as well as a common use.
Claim Interpretation
Claims 22, 162, and 406 each require the steps of:
providing a source cell and b) differentiating the source cell under claimed conditions. Because source cells can differentiate into different types and sub-types across a differentiation protocol, the source cell is hereby interpreted to encompass the original cell of a given method, or an intermediate cell type, since that same source cell may change types across the method but is still the same cell in question.
Due to the 112b issues identified above, for the sake of compact prosecution, the claims identified with 112 issues above are being examined against the prior art and double-patenting as follows:
Regarding claims 22, 162 and 406, the phrase “enhanced in vitro ureagenesis capability” is interpreted as an enhancement of all possible amounts, including small amounts, relative to all possible reference points which also includes regular fluctuation in in vitro ureagenesis capability in a given cell.
Regarding claim 56, the phrases “increased RNA expression” and “increased protein expression” are interpreted as an increase of all possible amounts, including small amounts, relative to all possible reference points which also includes regular fluctuation of expression in a given cell.
Regarding claim 60, the term “increased expression” is interpreted as an increase of all possible amounts, including small amounts, relative to all possible reference points which also includes regular fluctuation of expression in a given cell.
Claim Rejections - 35 USC § 102
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 22-23, 26-27, 29, 31, 33-36, 38, 42, 48-49, 56, 58, 60, 64 and 406 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) as evidenced by Nitzahn et al. (Mol Genet Metab. 2020 Oct 10;131(3):289–298.; henceforth “Nitzahn”).
Regarding claim 22, Keller discloses a method comprising:
providing a source cell (“pluripotent stem cells”; hESCs or hiPSCs; abstract; para. [0001-0002, 0006, 0021, 0023, 0027, 0050, 0068, 0081-0082, 0084-0085, 0096, 00151-00154, 00177, 00180, 00183, 00223-00228, 00230, 00319-00321]; Figures 7, 9; Example 9; Claims 4-5, 10, 15, 25)
differentiating the source cell in vitro in at least one culture medium comprising an agent that increases intracellular cyclic AMP (“cAMP and/or a cAMP analog” para. [0014] see also “Inducing maturation of cell aggregates with cAMP treatment” Example 5 and Example 1; abstract; para. [0015, 0017, 0024, 0027, 0031-0032, 0034, 0048-0050, 0052, 0056, 0068, 00102-00105, 00107-00108, 00110, 00119, 00127, 00152-00153, 00157-00158, 00161, 00164, 00168, 00170, 00174, 00176, 00177, 00178, 00183, 00210-00213, 00216-00219, 00262-00263, 00311-00318, 00320, 00322-00323, 00326-003312, 00335, 00351-00352, 00357, 00367, 00369-00370, 00375]; Figures 1, 5-7, 9, 11 ; claims 9-12 and 15), wherein the source cell differentiates into a mature hepatocyte-like cell (“mature hepatocytes” para. [0005]; see also abstract; para. [0013-0015, 0021, 0023-0024, 0027-0028, 0032, 0034, 0044, 0047-0048, 0052, 0054-0056, 0068-0071, 0093, 0096, 00100-00110, 00113, 00115-00116, 00118, 00120, 00128, 00151, 00153, 00157, 00161, 00164, 00166, 00168-00169, 00172, 00174, 00177-00179, 00183, 00189, 00210, 00214-00217, 00220, 00222, 00243-00245, 00259, 00261, 00297, 00309, 00311, 00316-00317, 00323-00332, 00353, 00392,
Figures 1, 4, 5, 9, 11-13; Examples 1, 5, 7, 8; claims 1,3 ,5, 9-12, 14-15, 19, 23, 26 and 24) and
recovering (“enriching or isolating” para. [0039]; see also para. [0039-0040, 00237-00239, 00243, 00247, 00266-00267, 00288, 00291, 00294]) the mature hepatocyte-like cell.
(see also Figure 1A, 4; para. [0044, 0047, 00107, 0309-0310]).
Regarding claim 22, concerning the limitation that the mature hepatocyte-like cell has “enhanced in vitro ureagenesis capability,” first this limitation is part of a wherein clause which does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited. Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) ("A 'whereby' clause that merely states the result of the limitations in the claim adds nothing to the patentability or substance of the claim."). See also Minton v. National Assoc. of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003) ("A whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited."). See also MPEP 2111.04 that a “Claim scope is not limited by claim language that suggests or makes optional but does not require steps to be performed, or by claim language that does not limit a claim to a particular structure” and a “whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Furthermore, Keller discloses the active method steps of the instantly claimed method and therefore “enhanced in vitro ureagenesis capability” would inherently follow the recitation of the taught steps.
Additionally, regarding claim 22, concerning the limitation that the mature hepatocyte-like cell has “enhanced in vitro ureagenesis capability,” as discussed above, this encompasses all possible enhancements of in vitro ureagenesis capability including regulator fluctuation in in vitro ureagenesis capability which would also inherently be met by the mature hepatocyte obtained by the method disclosed by Keller.
Regarding claim 23, further to the discussion of claim 22 above, Keller discloses the source cell is a stem cell (“pluripotent stem cells”; hESCs or hiPSCs; abstract; para. [0001-0002, 0006, 0021, 0023, 0027, 0050, 0068, 0081-0082, 0084-0085, 0096, 00151-00154, 00177, 00180, 00183, 00223-00228, 00230, 00319-00321]; Figures 7, 9; Example 9; Claims 4-5, 10, 15, 25)) or a fibroblast (since the iPSCS can be obtained from fibroblasts; para. [00280]).
Regarding claim 26, further to the discussion of claim 22 above, Keller discloses the agent comprises forskolin (para. [00104, 00212]) or IBMX, which is a phosphodiesterase inhibitor (para. [00104]).
Regarding claim 27, further to the discussion of claim 22 and 26 above, as stated above (see claim 26 rejection above) Keller discloses the agent comprises forskolin (para. [00104, 00212]).
Regarding claim 29, further to the discussion of claim 22 above, as stated above, (see claims 22 rejection above), Keller discloses the agent increases intracellular cyclic AMP (“cAMP and/or a cAMP analog” para. [0014] see also “Inducing maturation of cell aggregates with cAMP treatment” Example 5 and Example 1; abstract; para. [0015, 0017, 0024, 0027, 0031-0032, 0034, 0048-0050, 0052, 0056, 0068, 00102-00105, 00107-00108, 00110, 00119, 00127, 00152-00153, 00157-00158, 00161, 00164, 00168, 00170, 00174, 00176, 00177, 00178, 00183, 00210-00213, 00216-00219, 00262-00263, 00311-00318, 00320, 00322-00323, 00326-003312, 00335, 00351-00352, 00357, 00367, 00369-00370, 00375]; Figures 1, 5-7, 9, 11 ; claims 9-12 and 15), and Keller discloses specific agents (see also para. [00104]). Nitzahn evidences increased cAMP increases the expression of the urea cycle pathway enzyme CPS 1 (“Glucagon signaling via cAMP also increases the expression of PGC1α, which rapidly induces increased Sirt5 expression to deacetylate, and thus activate, CPS1” pg. 4).
Regarding claim 31, further to the discussion of claim 22 above, Keller discloses the differentiating step b) takes place after the source cell differentiates into a progenitor hepatocyte-like cell (see Figure 1A, the step with the cAMP activator “cAMP” of ““Hepatic Maturation B” occurs after “Hepatic Specification” and “Hepatic Maturation A” in which the source cell differentiates into a progenitor hepatocyte-like cell).
Regarding claim 33, further to the discussion of claim 22 above, Keller discloses the differentiating step b) takes place during the differentiation of an immature hepatocyte-like cell to the mature hepatocyte-like cell (see “Hepatic Maturation B”; Figure 1A).
Regarding claim 34, further to the discussion of claim 22 above, Keller discloses the differentiating step b) takes places in a two-dimensional (2D) culture system (“plated” para. [0044]; see also para. [0047]; Figures 1A, 4; see also Figure 13 and para [0056] where cells were cultured in 7 days in liquid in hepatocyte culture medium supplemented VEGF and bFGF and followed by 12 days of culture in the same medium supplemented with cAMP). The Examiner notes that the liquid culture medium on a plate represents a 2D culture system.
Regarding claim 35, further to the discussion of claims 22 and 34 above, Keller discloses the two-dimensional culture system comprises a substrate comprising an extracellular matrix (ECM) component or a soft hydrogel substrate (“culture on several different extra- cellular matrix (ECM)” including Gelatin, Matrigel, Laminin, Fibronectin and Collagen type 1 all comprise ECM components and Matrigel is a “soft hydrogel substrate “ as claimed; para. [00353] and Figure 9f).
Regarding claim 36, further to the discussion of claims 22 and 34-35 above, as stated above (see claim 35 rejection above), Keller discloses the ECM component comprises Gelatin (comprises collagen), Matrigel (comprises collagen and Laminin), Laminin, and Collagen type 1 (para. [00353] and Figure 9f).
Regarding claim 38, further to the discussion of claims 22 and 34-35 above, as stated above (see claim 35 rejection above), Keller discloses the ECM component comprises Gelatin, Matrigel, Laminin, Fibronectin or Collogen type 1 (para. [00353] and Figure 9f). Gelatin, Matrigel, Laminin, Fibronectin or Collagen type 1 do not comprise FBS and therefore the substrate disclosed by Keller is fetal bovine serum (FBS) free. Additionally, Keller is silent to the presence of FBS and therefore FBS is not present in the media or substrate.
Regarding claim 42, further to the discussion of claim 22 above, Keller discloses the differentiating step b) takes places in a three-dimensional culture system (see para. [0056] and Figure 13 “To test the effects of collagen on maturation, day 32 chimeric aggregates were embedded in a Collagen type 1 gel and cultured in the presence of cAMP, PD0325901 and XAV939 for 12 days”). The examiner notes that “embedded in a Collagen type 1 gel” represents a 3D culturing condition because it allows cells to grow in 3 dimensions as opposed to culturing “on” a coated plate which is also disclosed above, and is a 2D culture condition.
Regarding claims 48-49, further to the discussion of claim 22 above, Keller discloses the
differentiating step b) is carried out at “a 5% CO2 ambient air environment” (“Aggregation cultures were maintained in a 5% CO2 ambient air environment” para. [00332]), which is an oxygen condition (instant claim 48), and is a normoxic condition (instant claim 49).
Regarding claim 56, further to the discussion of claims 22 and 29 above, the wherein clause does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited (e.g. “the mature hepatocyte-like cell has increased RNA expression of the one or more urea cycle pathway enzymes and increased protein expression of the one or more urea cycle pathway enzymes”) . Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) ("A 'whereby' clause that merely states the result of the limitations in the claim adds nothing to the patentability or substance of the claim."). See also Minton v. National Assoc. of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003) ("A whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited."). See also MPEP 2111.04 that a “Claim scope is not limited by claim language that suggests or makes optional but does not require steps to be performed, or by claim language that does not limit a claim to a particular structure” and a “whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Additionally, because Keller discloses all the active method steps of the instantly claimed method, the result of “the mature hepatocyte-like cell has increased RNA expression of the one or more urea cycle pathway enzymes and increased protein expression of the one or more urea cycle pathway enzymes” would inherently follow the recitation of the disclosed steps. Additionally, as discussed above (see claim interpretation above), instant claims encompass small increases including those that occur with regular fluctuation in expression and are therefore met by Keller.
Regarding claim 58, further to the discussion of claim 22 above, Keller discloses the culture medium does not comprise and is therefore free of HGF (see figure 1a “Hepatic Maturation B” which does not include HGF).
Regarding claim 60, further to the discussion of claim 22 above, the wherein clause does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited. Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) (See also MPEP 2111.04). Additionally, because Keller discloses all the active method steps of the instantly claimed method, the result of the mature hepatocyte (i) having increase expression of ALB, ASGR1, ASGR2, AFP, G6PC, HNF4a, KRT18, SOX9, SERPINA1, CYP1A1, CYP1A2, CYP2Cl9, CYP2B6, CYP2D6, CYP3A4 , CYP3A7, or any combination thereof, (ii) secretes albumin or and/or α-1 antitrypsin (A1AT), and (iii) has cytochrome p450 activity, wherein the cytochrome p450 activity comprises activity of one or more cytochrome p450 family members comprising CYP1A1, CYP1A2, CYP2Cl9, CYP2B6, CYP2D6, CYP3A4, CYP3A7, or any combination thereof would inherently follow the recitation of the disclosed steps. Additionally, as discussed above (see claim interpretation above), instant claims encompass small increases including those that occur with regular fluctuation in expression and are therefore met by Keller. Lastly, it is noted that Keller specifically discloses the hepatocytes express (i) (ALB) albumin, therefore would secrete albumin (ii), and have increased the expression of several cytochrome P450 genes including CYP3A7 and CYP3A4 (i) and therefore have cytochrome p450 activity (iii) (para. [00309]).
Regarding claim 64, further to the discussion of claim 22 above, the wherein clause does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited. Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) (See also MPEP 2111.04). Additionally, because Keller discloses all the active method steps of the instantly claimed method, the result of “the mature hepatocyte-like cell has glycogen synthesis capability and/or storage capability, low density lipoprotein (LDL) uptake and/or storage capability, lipid storage capability, indocyanine green (ICG) uptake and/or clearance capability, gamma-glutamyl transpeptidase activity, or any combination thereof” would inherently follow the recitation of the disclosed steps.
Regarding claim 406, as stated above (see claim 22 rejection above), Keller discloses a method comprising:
providing a source cell (“pluripotent stem cells”; hESCs or hiPSCs; abstract; para. [0001-0002, 0006, 0021, 0023, 0027, 0050, 0068, 0081-0082, 0084-0085, 0096, 00151-00154, 00177, 00180, 00183, 00223-00228, 00230, 00319-00321]; Figures 7, 9; Example 9; Claims 4-5, 10, 15, 25 or day 32 chimeric aggregates para. [0056])
b) differentiating the source cell in vitro in a three dimensional culture system (see para. [0056] and Figure 13 “To test the effects of collagen on maturation, day 32 chimeric aggregates were embedded in a Collagen type 1 gel and cultured in the presence of cAMP, PD0325901 and XAV939 for 12 days”) comprising:
i. a fetal bovine serum (FBS) free substrate (Collagen type 1 gel which does not include FBS because Keller is silent to including FBS); and
ii. at least one culture medium comprising an agent that increases intracellular cyclic AMP (cAMP para. [0056]; see also “cAMP and/or a cAMP analog” para. [0014] see also “Inducing maturation of cell aggregates with cAMP treatment” Example 5 and Example 1; abstract; para. [0015, 0017, 0024, 0027, 0031-0032, 0034, 0048-0050, 0052, 0056, 0068, 00102-00105, 00107-00108, 00110, 00119, 00127, 00152-00153, 00157-00158, 00161, 00164, 00168, 00170, 00174, 00176, 00177, 00178, 00183, 00210-00213, 00216-00219, 00262-00263, 00311-00318, 00320, 00322-00323, 00326-003312, 00335, 00351-00352, 00357, 00367, 00369-00370, 00375]; Figures 1, 5-7, 9, 11 ; claims 9-12 and 15), wherein the source cell differentiates into a mature hepatocyte-like cell (“mature hepatocytes” para. [0005]; see also abstract; para. [0013-0015, 0021, 0023-0024, 0027-0028, 0032, 0034, 0044, 0047-0048, 0052, 0054-0056, 0068-0071, 0093, 0096, 00100-00110, 00113, 00115-00116, 00118, 00120, 00128, 00151, 00153, 00157, 00161, 00164, 00166, 00168-00169, 00172, 00174, 00177-00179, 00183, 00189, 00210, 00214-00217, 00220, 00222, 00243-00245, 00259, 00261, 00297, 00309, 00311, 00316-00317, 00323-00332, 00353, 00392, Figures 1, 4, 5, 9, 11-13; Examples 1, 5, 7, 8; claims 1,3 ,5, 9-12, 14-15, 19, 23, 26 and 24); and
c) recovering the mature hepatocyte-like cell (“enriching or isolating” para. [0039]; see also para. [0039-0040, 00237-00239, 00243, 00247, 00266-00267, 00288, 00291, 00294]) the mature hepatocyte-like cell.
(see also Figure 1A, 4; para. [0044, 0047, 00107, 0309-0310]).
Regarding claim 406, concerning the preamble “for producing a mature hepatocyte-like cell having enhanced ureagenesis capability,” the preamble merely states, the purpose or intended use of the invention, rather than any distinct definition of any of the claimed invention’s limitations, and therefore the preamble is not considered a limitation and is of no significance to claim construction (see MPEP 2111.02) See also Rowe v. Dror, 112 F.3d 473, 478, 42 USPQ2d 1550, 1553 (Fed. Cir. 1997) ("where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation"). Furthermore, Keller discloses the active method steps of the instantly claimed method and therefore “producing a mature hepatocyte-like cell having enhanced ureagenesis capability” would inherently follow the recitation of the taught steps.
Regarding claim 406, concerning the limitation that the mature hepatocyte-like cell has “wherein the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability,” this limitation is part of a wherein clause which does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited. Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) ("A 'whereby' clause that merely states the result of the limitations in the claim adds nothing to the patentability or substance of the claim."). See also Minton v. National Assoc. of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003) ("A whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited."). See also MPEP 2111.04 that a “Claim scope is not limited by claim language that suggests or makes optional but does not require steps to be performed, or by claim language that does not limit a claim to a particular structure” and a “whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Furthermore, Keller discloses the active method steps of the instantly claimed method and therefore the result of “the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability” would inherently follow the recitation of the taught steps.
Additionally, regarding claim 406, concerning the limitation that the mature hepatocyte-like cell has “enhanced in vitro ureagenesis capability,” as discussed above, this encompasses all possible enhancements of in vitro ureagenesis capability including regulator fluctuation in in vitro ureagenesis capability which would also inherently be met by the mature hepatocyte disclosed by Keller.
Accordingly, Keller anticipates instant claims.
Claim Rejections - 35 USC § 102/103
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.
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.
Claim 40 is rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) as evidenced by Soofi et al. (J Struct Biol. 2009 Sep;167(3):216-9. Epub 2009 May 27.; henceforth “Soofi”). The teachings of Keller above are hereby incorporated in their entirety.
Regarding claim 40, further to the discussion of claims 22 and 34-35 above, as stated above (see claim 35 rejection above), Keller discloses the soft hydrogel substrate comprises Matrigel (para. [00353] and Figure 9f).
Regarding claim 40, although Keller is silent to the elastic modulus of Matrigel, Soofi evidences the elastic modulus of Matrigel of approximately 450 Pa (abstract), which is “about 1kPA” of the instantly claimed range of “about 1 kPa to about 8 kPa.”
Accordingly, by teaching all the limitations of claims 40, as evidenced by Soofi, Keller anticipates instant claims.
Alternatively, regarding claim 40, if the method is not directly anticipated because the Matrigel disclosed by Keller has an elastic modulus of Matrigel of “about 1kPA” (approximately 450 Pa; abstract), then the method is still prima facie obvious because the range of approximately 450 Pa overlaps with the instantly claimed range of “about 1 kPa to about 8 kPa.” In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists and It is routine procedure to optimize component amounts to arrive at an optimal product that is superior for its intended use. See M.P.E.P. §2144.05.
Furthermore, regarding claim 40, if the method is not directly anticipated because the Matrigel disclosed by Keller has an elastic modulus of Matrigel of “about 1kPA” (approximately 450 Pa; abstract), then the method is still prima facie obvious because the values of “approximately 450 Pa” is close to the value of “about 1kPA” of instant claims and one of ordinary skill would have expected them to have the same properties. Applicant is directed to MPEP section 2144.05 which states a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties.").
Finally, regarding claim 40, Applicant is reminded that generally, differences in concentration will not support patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical (MPEP 2144.05 II).
Hence, the claimed invention as a whole was prima facie obvious.
Claim Rejections - 35 USC § 103
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 43 is rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Shirahama et al. (J Vis Exp. 2016 Aug 27:(114):54331.; see IDS filed 14th, July, 2023; henceforth “Shirahama”). The teachings of Keller above are hereby incorporated in their entirety.
Regarding claim 43, further to the discussion of claims 22 and 42 above, although Keller teaches a 3D culture system that comprises ECM components (collagen type 1 gel), Keller is silent to a 3D culture system that comprises an inverse colloidal crystal scaffold, wherein the inverse colloidal crystal scaffold is coated with an extracellular matrix (ECM) component.
Nevertheless, regarding claim 43, Shirahama teaches a 3D culture system that comprises an inverse colloidal crystal scaffold, wherein the inverse colloidal crystal scaffold (ICC cell culture platform) is coated with an extracellular matrix (ECM) component for liver tissue culture (abstract). Shirahama teaches the ICC cell culture platform addresses the void in the art for a scaffold with controlled porosity and high spatial organization (pg. 9 last para.). Shirahama also teaches that the further collagen coating enhances cell behavior (pg. 9 last para.).
Therefore, regarding claim 43, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Keller, and simply substitute the known prior art element of the ICC cell culture platform of Shirahama, which comprises an inverse colloidal crystal scaffold that is coated with an ECM component to obtain the predictable result of a method for culturing hepatocytes in 3D culture. One of ordinary skill would have been motivated to do so as taught by Shirahama to control porosity, have high spatial organization, and enhance cell behavior (pg. 9 last para.). Regarding the reasonable expectation of success, Shirahama evidences culturing hepatocytes in a 3D culture system with the ICC cell culture platform and a collagen coating (pg. 3 “3. Huh-7.5 Cell Culture and Seeding”).
Hence, the claimed invention as a whole was prima facie obvious.
Claims 373 and 375 are rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Shirahama et al. (J Vis Exp. 2016 Aug 27:(114):54331.; see IDS filed 14th, July, 2023; henceforth “Shirahama”) and Lee et al. (Acta Biomater. 2017 Dec:64:67-79. Epub 2017 Sep 28.; henceforth “Lee”).
The teachings of Keller and Shirahama above are hereby incorporated in their entirety.
Regarding claims 373 and 375, further to the discussion of claim 42 above, as stated above (see claim 43 rejection above), Shirahama teaches and makes obvious an ICC cell culture platform which comprises an inverse colloidal crystal scaffold that is coated with an ECM component. The ICC cell culture platform of Shirahama comprises a soft hydrogel substrate (instant claim 373), which is poly(ethylene glycol) (PEG) (instant claim 375) (abstract) (pg. 1 introduction 2nd para.; pg. 2 1st-2nd para.; Protocol “2. Preparing bare and ECM-coated PEGDA scaffolds”).
However, regarding claims 373 and 375, although Shirahama teaches preparation of the ICC cell culture platform which comprises the soft hydrogel substrate comprising PEG, Shirahama is silent to the elastic modulus of the substrate.
Nevertheless, regarding claims 373 and 375, Lee teaches elastic modulus values for PEG hydrogel substrates that are suitable for culturing hepatocyte. Specifically, Lee teaches a microenvironment affording low mechanical compliance (from 0.4 to 2 kPa range) is considered suitable to enhance hepatocyte function and differentiation (pg. 68 col. 1 2nd para.).
Therefore, regarding claims 373 and 375, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method as suggested by Keller in view of Shirahama, and combine the known prior art element of the elastic modulus range of from 0.4 to 2 kPa to obtain the predicable result of a method for culturing hepatocytes. One of ordinary kill would have been motivated to do so as taught by Lee because the microenvironment affording low mechanical compliance (from 0.4 to 2 kPa range) is considered suitable to enhance hepatocyte function and differentiation (pg. 68 col. 1 2nd para.). Regarding the reasonable expectation of success, Lee evidences preparation of hydrogels with elastic moduli and methods of culturing cells using the hydrogels (see Figures 3-4 and of 74 “3.5. Optimal 3D microenvironment enhances drug-metabolizing enzyme induction, Alb secretion, and drug metabolism” ; see also Materials and Methods pg. 68-69).
Additionally, regarding claims 373 and 375, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). It is routine procedure to optimize component amounts to arrive at an optimal product that is superior for its intended use, since it has been held where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See M.P.E.P. §2144.05. In the instant case, the elastic modulus range of from 0.4 to 2 kPa range suggested by Lee above overlaps with the instantly claimed range of from about 1 kPa to about 8 kPa and thereby makes it obvious.
Hence, the claimed invention as a whole was prima facie obvious.
Claim 41 is rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Schmitt et al. (Adv Healthc Mater. 2015 May 20;4(10):1555–1564.; henceforth “Schmitt”).
The teachings of Keller above are hereby incorporated in their entirety.
Regarding claim 41, further to the discussion of claims 22 and 34-35 above, although, as stated above (see claim 35 rejection above), Keller discloses the substrate comprises the soft hydrogel substrate of Matrigel (para. [00353] and Figure 9f) for coated plates, Keller is silent to using a soft hydrogel substrate comprising poly(ethylene glycol) (PEG) coated plates with the method.
Nevertheless, regarding claim 41, Schmitt teaches poly(ethylene glycol) (PEG) coated plates for cell culture (abstract). Schmitt teaches PEG coated plates provide a “blank slate” background to cells and prevent nonspecific protein adsorption (Introduction; pg. 2 1st para.). Schmitt teaches PEG is relatively easy to functionalize with biomolecules using a number of different chemistries (Introduction; pg. 2 1st para.). Schmitt teaches a specific coating comprising PEG for chemically defined culture of adult and pluripotent stem cells which met multiple design criteria including simple application to multiple substrate types, compatibility with large area plastic substrates, ability to undergo rapid peptide attachment in aqueous solution at low peptide concentrations, and long-term stability in cell culture condition (pg. 3 1st para.).
Therefore, regarding claim 41, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Keller, and simply substitute the PEGMEMA coating, which contains PEG, for the coated plates of Keller to obtain the predictable result of a method for culturing hepatocytes. One of ordinary skill would have been motivated to do so as taught by Schmitt because the PEGMEMA coating would allow for simple application to multiple substrate types, compatibility with large area plastic substrates, ability to undergo rapid peptide attachment in aqueous solution at low peptide concentrations, and long-term stability in cell culture condition (pg. 3 1st para.). Regarding the reasonable expectation of success, Schmitt evidences culturing cells on the PEG coated plates (pg. 11-12 “Cell Culture”; see also Figures 6 and 8).
Hence, the claimed invention as a whole was prima facie obvious.
Claim 46 is rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Wang et al. (Toxicol Res (Camb). 2017 Sep 28;7(1):13–21.; henceforth “Wang”).
The teachings of Keller above are hereby incorporated in their entirety.
Regarding claim 46, further to the discussion of claim 22 above, although Keller discloses the
differentiating in the presence of an endothelial cells (Example 8), and Keller teaches co-culturing with endothelial cells results in an increased level of CYP3A4 (Example 89; p pg. 77 1st para.), Keller is silent to using HUVEC with the method.
Nevertheless, regarding claim 46, Wang teaches a method for culturing hepatocytes comprising co-culturing hepatocytes with HUVECs (pg. 12 col. 2 3rd para. “The co-culture of hiHeps and HUVECs on paper”). Wang teaches the hiHeps co-cultured with HUVECs exhibited a 3D like morphology and maintained the liver specific functions of producing albumin and urea, maintained a higher expression of cytochrome P450 gene, revealing a marked enhancement of hepatic functions in the 3D liver co-culture model and exhibited near physiological hepatotoxic responses (abstract). Wang teaches that by integrating valid human hepatocyte lineages with other non-parenchymal cells, the established low-cost and simple paper-based array could serve as in vitro tissue/organ models and provide great opportunities for developing further flexible platforms for evaluating drug induced cytotoxicity more accurately (Conclusion; pg. 19 col. 1 2nd para.).
Therefore, regarding claim 46, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Keller, and combine the known prior art element of co-culturing with HUVECs of Keller to obtain the predictable result of a method of culturing hepatocytes. One of ordinary skill would have been motivated to do so as taught by Wang to enhance hepatocyte functions, such as producing albumin and urea, to maintain a higher expression of cytochrome P450 gene, and to develop further flexible platforms for evaluating drug induced cytotoxicity more accurately (Abstract; Conclusion; pg. 19 col. 1 2nd para.). One of ordinary skill would have been specifically motivated to perform the co-culture during the differentiation step because Keller teaches co-culture with endothelial cells during differentiation resulted in hepatocytes which expressed substantially higher levels of CYP3A4 (pg. 77 1st para.). Regarding the reasonable expectation of success, Wang evidences a method for culturing hepatocytes comprising co-culturing hepatocytes with HUVECs (pg. 12 col. 2 3rd para. “The co-culture of hiHeps and HUVECs on paper”).
Claim 51 is rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Yishai et al. (Hepatology. 2015 Jul;62(1):265-78. Epub 2015 Apr 22.; henceforth “Yishai”).
The teachings of Keller above are hereby incorporated in their entirety.
Regarding claim 51, further to the discussion of claim 22 above, although Keller teaches the cell culture mediums may contain vitamins (para. [00138]), Keller does not discloses the mature hepatocyte-like cell is contacted with vitamin K wherein the vitamin K is Vitamin K2.
Nevertheless, regarding claim 51, Yishai teaches contacting a mature hepatocyte-like cell with Vitamin K2 (menaquinone-4 (MK4)) (pg. 267 col. 1 2nd para.; pg. 267 col. 2 1st para.; pg. 270; Figures 2-3) to drive expression of liver-specific genes, including urea cycle enzymes, such as ASS and ARG1, as
well as A1AT and CYP1A2 (Figure 3). Yishai teaches hepatocytes treated with Vitamin K2 MK4 exhibit higher CYP450 activity (Figure 5). Yishai teaches hepatocytes treated with Vitamin K2 MK4 produce
CYP450-inducible cells that show an exceptional ability to predict TC50 values of a diverse group of hepatotoxic compounds (Figs. 5 and 6; Discussion pg. 276 col. 1 3rd. para.).
Therefore, regarding claim 51, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Keller, and combine the known prior art element of contacting the hepatocytes with Vitamin K2 of Yishai to obtain the predictable result of a method for culturing hepatocytes. One of ordinary skill would have been motivated to do so as taught by Yishai to drive expression of liver-specific genes, including urea cycle enzymes, such as ASS and ARG1, as well as A1AT and CYP1A2 (Figure 3) and to produce
CYP450-inducible cells that show an exceptional ability to predict TC50 values of a diverse group of hepatotoxic compounds (Figs. 5 and 6; Discussion pg. 276 col. 1 3rd. para.). Regarding the reasonable expectation of success, Yishai evidences methods of culturing hepatocytes comprising contacting the hepatocytes with Vitamin K2 (menaquinone-4 (MK4)) (pg. 267 col. 1 2nd para.; pg. 267 col. 2 1st para.; pg. 270; Figures 2-3).
Hence, the claimed invention as a whole was prima facie obvious.
Claims 52 and 55 are rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”) in view of Blackford et al. (Stem Cells Transl Med. 2019 Feb;8(2):124-137. Epub 2018 Nov 19.; see IDS filed 14th, July, 2023; henceforth “Blackford”).
The teachings of Keller above are hereby incorporated in their entirety.
Regarding claims 52 and 55, further to the discussion of claim 22 above, Keller is silent to a step d) encapsulating the mature hepatocyte-like cell in a polymer matrix, wherein the polymer matrix comprises a matrix component, wherein the matrix component comprises alginate (instant claim 52), and Keller is silent to culturing the mature hepatocyte-like cell into a spheroid (instant claim 53).
Nevertheless, regarding claims 52 and 55, Blackford teaches a method comprising the step of d) encapsulating a mature hepatocyte-like cell in a polymer matrix comprising an alginate matrix component (“Alginate Encapsulation of hPSC-Derived Hepatocyte Spheroids” pg. 126 col 2 last para and pg. 127 col. 1 1st para.) where the mature hepatocyte-like cell is cultured into a spheroid (“hPSC-Derived Hepatocyte Spheroids” pg. 126 col 2 last para and pg. 127 col. 1 1st para.; see also Figure 1 and “Alginate microencapsulated hepatocyte spheroids” pg. 127 col. 1 3rd para.). Blackford teaches encapsulating into the alginate matrix component for transplantation (pg. 127 col. 1 3rd para.). Blackford teaches hepatocytes remained viable after transplantation into the immune-privileged material alginate and remained viable as well as functional upon transplantation into immune competent mice (abstract), and that the alginate encapsulated hepatocyte spheroids were suitable for acute liver failure bridging therapy (Figure 6).
Therefore, regarding claims 52 and 55, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Keller and combine the known prior art elements of encapsulating the mature hepatocyte-like cell in a polymer matrix, wherein the polymer matrix comprises a matrix component, wherein the matrix component comprises alginate (instant claim 52), and culturing the mature hepatocyte-like cell into a spheroid (instant claim 53) of Blackford to obtain the predictable result of a method for culturing alginate encapsulated hepatocyte spheroids. One of ordinary skill would have been motivated to do so as taught by Blackford to create alginate encapsulated hepatocyte spheroids suitable for acute liver failure bridging therapy that included viable as well as functional hepatocytes (pg. 127 col. 1 3rd para.; Figure 6). Regarding the reasonable expectation of success, Blackford evidences a method comprising the step of d) encapsulating a mature hepatocyte-like cell in a polymer matrix comprising an alginate matrix component (“Alginate Encapsulation of hPSC-Derived Hepatocyte Spheroids” pg. 126 col 2 last para and pg. 127 col. 1 1st para.) where the mature hepatocyte-like cell is cultured into a spheroid (“hPSC-Derived Hepatocyte Spheroids” pg. 126 col 2 last para and pg. 127 col. 1 1st para.; see also Figure 1 and “Alginate microencapsulated hepatocyte spheroids” pg. 127 col. 1 3rd para.).
Hence, the claimed invention as a whole was prima facie obvious.
Claims 162-163 are rejected under 35 U.S.C. 103 as being unpatentable over Blackford et al. (Stem Cells Transl Med. 2019 Feb;8(2):124-137. Epub 2018 Nov 19.; henceforth “Blackford”) in view of Keller et al. (WO-2014/124527-A1; see IDS filed 14th, July, 2023; henceforth “Keller”), Liu et al. (J Biosci Bioeng. 2019 Apr;127(4):506-514. Epub 2018 Oct 12.; henceforth “Liu”) and Cellseco (accessed at : https://web.archive.org/web/20190918095637/https://www.cellseco.com/product-category/cell-culture/fetalbovineserum/ on 3rd, February, 2026; Date 18th, September, 2019)
Regarding claim 162, Blackford discloses a method for producing a mature hepatocyte-like cell providing a source cell (human pluripotent stem cells);
differentiating the source cell in vitro in at least one culture medium (defined four-step hepatic differentiation protocol);and
recovering the mature hepatocyte-like cell,
wherein the differentiating is initially carried out on a first substrate (pg. 127 col. 2 “Differentiation of cGMP-Compliant Stem Cells Toward hPSC-Derived Hepatocytes” to obtain hPSC-Heps) comprising gelatin (“gelatin coated tissue culture dishes”) and transferred to a second substrate comprising collagen (day 21 hPSC-heps “We first seeded the day 21 hPSC-Heps onto collagen- 1 coated tissue culture plastic” pg. 130 col. 1 1st para.; day 21 is encompassed by the instantly claimed “about day 14”)) (see also Figure 1; Materials and Methods pg. 125-127)
However, regarding claim 162, Blackford does not disclose differentiating includes at least one culture medium comprising an agent that increases intracellular cyclic AMP.
Nevertheless, regarding claim 162, Keller teaches a method for producing a mature hepatocyte-like cell comprising culturing in a differentiation medium comprising an agent that increases intracellular cyclic AMP (“cAMP and/or a cAMP analog” para. [0014] see also “Inducing maturation of cell aggregates with cAMP treatment” Example 5 and Example 1; abstract; para. [0015, 0017, 0024, 0027, 0031-0032, 0034, 0048-0050, 0052, 0056, 0068, 00102-00105, 00107-00108, 00110, 00119, 00127, 00152-00153, 00157-00158, 00161, 00164, 00168, 00170, 00174, 00176, 00177, 00178, 00183, 00210-00213, 00216-00219, 00262-00263, 00311-00318, 00320, 00322-00323, 00326-003312, 00335, 00351-00352, 00357, 00367, 00369-00370, 00375]; Figures 1, 5-7, 9, 11 ; claims 9-12 and 15), wherein the source cell differentiates into a mature hepatocyte-like cell (“mature hepatocytes” para. [0005]; see also abstract; para. [0013-0015, 0021, 0023-0024, 0027-0028, 0032, 0034, 0044, 0047-0048, 0052, 0054-0056, 0068-0071, 0093, 0096, 00100-00110, 00113, 00115-00116, 00118, 00120, 00128, 00151, 00153, 00157, 00161, 00164, 00166, 00168-00169, 00172, 00174, 00177-00179, 00183, 00189, 00210, 00214-00217, 00220, 00222, 00243-00245, 00259, 00261, 00297, 00309, 00311, 00316-00317, 00323-00332, 00353, 00392) Figures 1, 4, 5, 9, 11-13; Examples 1, 5, 7, 8; claims 1,3 ,5, 9-12, 14-15, 19, 23, 26 and 24). Keller teaches activating the cAMP pathway induces maturation of the hepatocytes (para. [0024, 0048]; Figure 5), increase the proportion of Albumin positive cells (para.[0048]) and increases metabolic enzyme activity (para. [0049]; Figure 6).
Therefore, regarding claim 162, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Blackford, and combine the known prior art element of culturing in a maturation medium comprising a cAMP activator of Keller to obtain the predicable result of a method for culturing hepatocytes. One of ordinary skill would have been motivated to do so as taught by Keller to induces maturation of the hepatocytes (para. [0024, 0048]; Figure 5), increase the proportion of Albumin positive cells (para.[0048]) and increases metabolic enzyme activity (para. [0049]; Figure 6). Regarding the reasonable expectation of success, Keller evidences a method for culturing hepatocytes comprising culturing in a maturation medium with a cAMP activator (see Figure 1a; Examples).
However, regarding claims 162-163, Blackford and Keller are silent to including FBS in the medias.
Nevertheless, regarding claims 162-163, Liu teaches a method of culturing hepatocytes comprising culturing in mediums with FBS (abstract; pg. 507 col. 2; pg. 501 col. 1 1-2nd para.; pg. 509; pg. 510 col. 1; pg. 513 col. 1).
Additionally, regarding claims 162-163, Cellseco teaches the most common type of serum used for cell growth is foetal bovine serum (FBS)(pg. 1 1st para.). Cellseco teaches using FBS helps to ensure high quality and consistency essential for successful cell culture (Title). Cellseco teaches in cell culture, serum provides a wide variety of macromolecular proteins, low molecular weight nutrients, carrier proteins for water - insoluble components, and other compounds necessary for in vitro growth of cells, such as hormones and attachment factor and also adds buffering capacity to the medium and binds or neutralises components that may be toxic (pg. 1 2nd para.). Cellseco teaches FBS promotes steady, healthy cell growth in culture (pg. 3).
Therefore, regarding claims 162-163, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to practice the method as suggested by Blackford in view of Keller, and combine the known prior art element of the FBS of Liu and Cellseco to both substrates taught by Blackford obtain the predictable result of a method of culturing hepatocytes. One of ordinary skill would have been motivated to do so as taught by Cellseco to ensure high quality and consistency essential for successful cell culture (Title), to provide a wide variety of macromolecular proteins, low molecular weight nutrients, carrier proteins for water - insoluble components, and other compounds necessary for in vitro growth of cells, such as hormones and attachment factor, to add buffering capacity to the medium and binds or neutralize components that may be toxic (pg. 1 2nd para.), and to promote steady, healthy cell growth in culture (pg. 3). Regarding the reasonable expectation of success, Liu evidences methods of culturing hepatocytes with FBS and Liu evidences optimization of FBS amounts for hepatocyte culture (abstract; pg. 507 col. 2; pg. 501 col. 1 1-2nd para.; pg. 509; pg. 510 col. 1; pg. 513 col. 1).
Regarding claim 162, concerning the preamble “for producing a mature hepatocyte-like cell having enhanced ureagenesis capability,” the preamble merely states, the purpose or intended use of the invention, rather than any distinct definition of any of the claimed invention’s limitations, and therefore the preamble is not considered a limitation and is of no significance to claim construction (see MPEP 2111.02) See also Rowe v. Dror, 112 F.3d 473, 478, 42 USPQ2d 1550, 1553 (Fed. Cir. 1997) ("where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation"). Furthermore, Blackford in view of Keller, Liu and Cellseco suggest the active method steps of the instantly claimed method and therefore “producing a mature hepatocyte-like cell having enhanced ureagenesis capability” would naturally follow the recitation of the taught steps.
Regarding claim 162, concerning the limitation “wherein the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability,” this limitation is part of a wherein clause which does not recite any additional active method steps, but simply state a characterization or conclusion of the results of process step positively recited. Therefore, the "wherein" clause is not considered to further limit the method defined by the claim and has not been given weight in construing the claims. See Texas Instruments, Inc. v. International Trade Comm., 988 F.2d 1165, 1171,26 USPQ2d 1018, 1023 (Fed Cir. 1993) ("A 'whereby' clause that merely states the result of the limitations in the claim adds nothing to the patentability or substance of the claim."). See also Minton v. National Assoc. of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003) ("A whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited."). See also MPEP 2111.04 that a “Claim scope is not limited by claim language that suggests or makes optional but does not require steps to be performed, or by claim language that does not limit a claim to a particular structure” and a “whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Furthermore, Blackford in view of Keller, Liu and Cellseco suggest the active method steps of the instantly claimed method and therefore the result of “the source cell differentiates into a mature hepatocyte-like cell having enhanced in vitro ureagenesis capability” would naturally follow the recitation of the taught steps.
Additionally, regarding claim 162, concerning the limitation that the mature hepatocyte-like cell has “enhanced in vitro ureagenesis capability,” as discussed above, this encompasses all possible enhancements of in vitro ureagenesis capability including regulator fluctuation in in vitro ureagenesis capability which would also naturally be met by the mature hepatocyte made by the method suggested by Blackford in view of Keller, Liu, and Cellseco above.
Hence, the claimed invention as a whole was prima facie obvious.
Conclusion
No claim is allowable.
Correspondence
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/BRIANA N EBBINGHAUS/Examiner, Art Unit 1632
/PETER PARAS JR/Supervisory Patent Examiner, Art Unit 1632