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 .
DETAILED ACTION
Election/Restriction
Applicant’s election of Group I, claims 1-8, drawn to a method for improving the differentiation of hepatoblasts into hepatocytes, in the reply filed on 04/13/2026 is acknowledged.
Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.03(a)).
Claims 10, 12, 13 and 15 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Claim Status
Claims 1-8, 10, 12, 13 and 15 are pending.
Claims 10, 12, 13 and 15 are withdrawn.
Claims 1-8 are considered on the merits.
Priority
This application is a 371 of PCT/EP2022/065167 (filed on 06/03/2022), which claims benefit from foreign application EP21305772.2 (filed on 06/07/2021). The priority claim of the instant application has been granted and the earliest benefit date is 06/07/2021 from the application EP21305772.2.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 12/07/2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. The corresponding signed and initialed PTO form 1449 has been mailed with this action.
Specification Objections
The disclosure is objected to because it contains an embedded hyperlink and/or other form of browser-executable code (e.g., p. 32-36). Applicant is required to amend or delete the embedded hyperlink and/or other form of browser-executable code. For example, “https” can be replaced with “hypertext transfer protocol secure” as the URL code. See MPEP § 608.01.
Claim Objections
Claims 1 and 7-8 are objected to because of the following informalities:
Claim 1 recites “hepatocyte medium” in line 2, it is suggested to change to “a hepatocyte medium”.
Furthermore, claims 1, 7 and 8 recite the term “hepatopcyte” (e.g., claim 1, line 4 and line 6, and multiple places in claims 7 and 8), which contains a typographical error. It is suggested to change to “hepatocyte”.
Furthermore, claim 8, the fourth line from the bottom, recites “medium i)”. It seems the term “i)” is accidentally preserved during amendment. It is suggested to delete the “i)” to be consistent with the corresponding citation in claim 7.
Appropriate correction is required.
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 1-8 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 1 lists four steps (i) – (iv) in the last wherein clause. However, there is no conjunction (e.g., and, or) between the steps. Thus, it is unclear whether the entire list is required or only one from the list. For examination purposes the claim is interpreted as all the four steps are required. Claims 2-8 are rejected as being dependent from claim 1 but not resolving the ambiguity.
Claim Rejections - 35 USC § 112(a)
(Written Description)
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 1-8 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 pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
Under the written description guidelines (see MPEP 2163) the Examiner is directed to determine whether one skilled in the art would recognize that the Applicant was in possession of the claimed invention as a whole at the time of filing. The following considerations are critical to this determination.
To satisfy the written description requirement, a patent 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. See, e.g., Moba, B.V. v. Diamond Automation, Inc., 325 F.3d 1306, 1319, 66 USPQ2d 1429, 1438 (Fed. Cir. 2003); Vas-Cath, Inc. v. Mahurkar, 935 F.2d at 1563, 19 USPQ2d at 1116. An original claim may lack written description support when (1) the claim defines the invention in functional language specifying a desired result but the disclosure fails to sufficiently identify how the function is performed or the result is achieved or (2) a broad genus claim is presented but the disclosure only describes a narrow species with no evidence that the genus is contemplated. See Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1349-50 (Fed. Cir. 2010) (en banc). The written description requirement is not necessarily met when the claim language appears in ipsis verbis in the specification. "Even if a claim is supported by the specification, the language of the specification, to the extent possible, must describe the claimed invention so that one skilled in the art can recognize what is claimed. The appearance of mere indistinct words in a specification or a claim, even an original claim, does not necessarily satisfy that requirement." Enzo Biochem, Inc. v. Gen-Probe, Inc., 323 F.3d 956, 968, 63 USPQ2d 1609, 1616 (Fed. Cir. 2002).
Accordingly, 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. Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1562-63, 19 USPQ2d 1111 (Fed. Cir. 1991). See also MPEP 2163.
SCOPE OF THE INVENTION
Independent claim 1 encompasses a genus of method for improving the differentiation of hepatoblasts into hepatocytes comprising culturing the hepatoblasts in a medium comprising hepatocyte growth factor (HGF), glucocorticoid and oncostatin M, in any concentration, and further adding vitamin K, in any concentration, from the 4th, 5th, 6th or 7th day until the end of culture (it is noted that “the end of culture” is not defined by the specification, thus encompasses any time after the earliest recited date), fluctuating the concentration of glucocorticoid, from any initial concentration, from the 8th or 9th day until any time after the 8th day, tapering oncostatin M, from any initial concentration, from the 9th, 10th or 11th day until any time after the 9th day, and adding a Notch inhibitor and a TGF-β receptor inhibitor, in any form encompassing gene knockout, gene knockdown, or small molecules, directly or indirectly, specifically or nonspecifically, affecting the Notch and TGF-β signaling pathways, from the 9th, 10th or 11th day until any time after the 9th day.
However, the specification only discloses a single species of method for a 2D culture and a single species of method for a 3D culture, wherein the 2D culture method comprises culturing the hepatoblasts in a medium comprising 20 ng/mL HGF, 0.1 nM dexamethasone (Dex) and 20 ng/mL oncostatin M, and further adding 10 ng/mL vitamin K1 from the 7th day, fluctuating the concentration of glucocorticoid between 0.05 nM and 0.1 nM from the 9th day, tapering oncostatin M from 20 ng/mL to complete removal from the 11th day, and adding 0.5 nM of compound E and 5 nM of SB431542 from the 11th day to the 17th day (see p. 21, last 2 para for culture condition, and see p. 25, last para for culture duration, “at day 11, cells were … differentiation into iHBs” (hepatoblasts) and “a total of twenty-eight days in culture” in 2D, thus the culture duration for hepatoblast differentiation is 28-11 = 17 days). The 3D culture method is using the same medium but the culture duration is 34 days (see p. 25, last para for culture duration, “3D configuration allowed extended iHep culture until day 45 (34 days of 3D culture)”. Accordingly, the specification only discloses a single species of 2D culture and a single species of 3D culture for improving the differentiation of hepatoblasts into hepatocytes.
Dependent claims 2-8 encompass the culture format, specific reagents and ranges of concentrations, but even the most limited claim (claim 8) still encompasses the culture duration being any time after the 9th day. However, the specification only discloses a single species of 2D culture with a culture duration of 17 days and a single species of 3D culture with a culture duration of 34 days for improving the differentiation of hepatoblasts into hepatocytes.
ACTUAL REDUCTION TO PRACTICE
Accordingly, Applicant did not demonstrate a reduction to practice a genus of methods for improving the differentiation of hepatoblasts into hepatocytes encompassed by the broad scope as claimed, nor did Applicant adequately set forth in terms of distinguishing identifying characteristics as evidenced by other descriptions of the invention that are sufficiently detailed to show that Applicant was in possession of the claimed genus of method.
DISCLOSURE OF STRUCTURE
The Applicant has provided only one single species of 2D culture and 3D culture methods for improving the differentiation of hepatoblasts into hepatocytes. Although the methods for differentiating hepatoblasts into hepatocytes are being studied in the field, the prior art is silent on a method for improving the differentiation of hepatoblasts into hepatocytes encompassed by the claimed scope, nor indicates a relationship between the structure of the claimed reagents, in any concentration, in any form, for any culture time and the ability to improve the differentiation of hepatoblasts into hepatocytes.
SUFFICIENT RELEVANT IDENTIFYING CHARACTERISTICS
As mentioned in above, methods for differentiating hepatoblasts into hepatocytes are known in the field, and the skilled artisan could choose and try different reagents, in any concentration, in any form, for any culture time.
The breadth of the claims encompasses a genus of method comprising culturing hepatoblasts in a medium comprising HGF, glucocorticoid and oncostatin M in any concentration, and further adding vitamin K in any concentration, fluctuating the concentration of glucocorticoid from any initial concentration, tapering oncostatin M from any initial concentration, and adding any form of Notch inhibitor and TGF-β receptor inhibitor, for any culture duration to differentiate into hepatocytes, yet the present specification only provides a single species of 2D and 3D culture method with specified concentration, reagents and culture duration that would result in differentiation of hepatoblasts into hepatocytes, therefore the skilled artisan would not know what rational approach to take to use the claimed reagents, in any concentration, in any form, for any culture time to obtain any predictable outcome on improving the differentiation of hepatoblasts into hepatocytes. Therefore, it is incumbent on the applicant to provide this nexus between structure and function, in order to be given credit for possession of the claimed genus of methods. Otherwise, the Written Description guidelines suggest that the applicant is entitled to only the species specifically recited as having this activity. Moreover, even when several species are disclosed, these are not necessarily representative of the entire genus. AbbVie Deutschland GMBH v. Janssen Biotech, 111 USPQ2d 1780, 1790 (Fed. Cir. 2014) (“The ’128 and ’485 patents, however, only describe species of structurally similar antibodies that were derived from Joe-9. Although the number of the described species appears high quantitatively, the described species are all of the similar type and do not qualitatively represent other types of antibodies encompassed by the genus.”). Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus to provide a "representative number” of species.
An applicant may show that an invention is complete by disclosure of sufficiently detailed, relevant identifying characteristics which provide evidence that applicant was in possession of the claimed invention, i.e., complete or partial structure, other physical and/or chemical properties, functional characteristics when coupled with a known or disclosed correlation between function and structure, or some combination of such characteristics. Enzo Biochem, 323 F.3d at 964, 63 USPQ2d at 1613.
STATE OF THE ART & QUANTITY OF EXPERIMENTATION
The method of using the claimed invention is not well established. Although the method for differentiating hepatoblasts into hepatocytes was known in the state of the art, one of skill in the art would neither expect nor predict the method may result in improving the differentiation of hepatoblasts into hepatocytes produced according to the claimed genus of methods.
Indeed, the instant specification provides data supporting the unpredictability of the claimed method, e.g., in 2D culture that even under culturing with all the specified reagents in the specified concentrations from the specified timing, merely changing the culture duration would impair the differentiation of hepatoblasts into hepatocytes, evidenced in that a shorter culture duration (e.g., 9 days after culture) results in increased AFP expression (which is a marker for hepatoblasts, see p. 4, last para – p. 5, para 1), as recited “However, in 2D samples, the AFP profile showed the typical bell curve already observed in literature in which the highest secretion point was recorded around day 20 of differentiation” (p. 26, lines 10-12, see also Fig 3A. It is noted that Day 11 is the start date of hepatoblasts differentiation, thus day 20 is 9 days after culture).
Consequently, supported by Applicant’s disclosure, there is ample reason to conclude that there would be a high degree of unpredictability in differentiating hepatoblasts into hepatocytes by culturing with a genus of reagents, in any form, in any concentration, and for any culture duration as encompassed by the instant claims. Thus, the method for improving the differentiation of hepatoblasts into hepatocytes is highly unpredictable, and is not well established.
Applicant has claimed a genus of methods, yet the specification has only disclosed a single species of such method, has not set forth in terms of distinguishing identifying characteristics as evidenced by other descriptions of the invention that are sufficiently detailed to show that Applicant was in possession of the claimed genus of method. Furthermore, Applicant’s own disclosure indicated that such method is not well established and would require undue experimentation, and one of skill in the art would neither expect nor predict the claimed outcome of improving the differentiation of hepatoblasts into hepatocytes obtained according to the claimed genus of methods.
CONCLUSION
The Examiner concludes that there is insufficient written description of the instantly claimed genus of methods for improving the differentiation of hepatoblasts into hepatocytes by culturing with a genus of reagents, in any form, in any concentration, and for any culture duration. Specifically, Applicant has only provided one single species of such method with defined reagents in a defined concentration from a defined timing for a defined duration, thus does not provide sufficient number of species to represent the entire scope of the claimed extremely broad genus of methods. Therefore, the Examiner concludes that there is insufficient written description to show that Applicant was in possession of the claimed genus of methods for improving the differentiation of hepatoblasts into hepatocytes by culturing with a genus of reagents, in any form, in any concentration, and for any culture duration.
(Scope of Enablement)
Claims 1-8 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while enabling for a method for improving the differentiation of hepatoblasts into hepatocytes comprising culturing the hepatoblasts in a medium supplemented with 20 ng/mL HGF, 0.1 nM dexamethasone and 20 ng/mL oncostatin M, and further adding 10 ng/mL vitamin K1 from the 7th day, fluctuating the concentration of glucocorticoid between 0.05 nM and 0.1 nM from the 9th day, tapering oncostatin M from 20 ng/mL to complete removal from the 11th day, and adding 0.5 nM of compound E and 5 nM of SB431542 from the 11th day, until the 17th day in a 2D culture or until the 34th day in a 3D culture (see specification, p. 21, last 2 para, and p. 25, last para), does not reasonably provide enablement for a genus of method comprising culturing hepatoblasts in a medium supplemented with HGF, glucocorticoid and oncostatin M in any concentration, and further adding vitamin K in any concentration, fluctuating the concentration of glucocorticoid from any initial concentration, tapering oncostatin M from any initial concentration, and adding any form of Notch inhibitor and TGF-β receptor inhibitor, for any culture duration to differentiate into hepatocytes. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims.
The factors to be considered in determining whether undue experimentation is required are summarized In re Wands 858 F.2d 731, 8 USPQ2nd 1400 (Fed. Cir, 1988). The Court in Wands states: “Enablement is not precluded by the necessity for some 'experimentation.'” Clearly, enablement of a claimed invention cannot be predicated on the basis of quantity of experimentation required to make or use the invention. “Whether undue experimentation is needed is not a single simple factual determination, but rather is a conclusion reached by weighing many factual considerations.” (Wands, 8 USPQ2d 1404). The factors to be considered in determining whether undue experimentation is required include: (1) the quantity of experimentation necessary, (2) the amount or direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims. While all of these factors are considered, a sufficient amount for a prima facie case is discussed below.
The office has analyzed the specification in direct accordance to the factors outlined in In re Wands. MPEP 2164.04 states: "[W]hile the analysis and conclusion of a lack of enablement are based on factors discussed in MPEP 2164.01(a) and the evidence as whole, it is not necessary to discuss each factor in written enablement rejection." These factors will be analyzed, in turn, to demonstrate that one of ordinary skill in the art would have had to perform "undue experimentation" to make and/or use the invention and therefore, Applicant's claims are not enabled commensurate with the scope of the invention.
SCOPE OF THE INVENTION
Independent claim 1 encompasses a genus of method for improving the differentiation of hepatoblasts into hepatocytes comprising culturing the hepatoblasts in a medium comprising hepatocyte growth factor (HGF), glucocorticoid and oncostatin M, in any concentration, and further adding vitamin K, in any concentration, from the 4th, 5th, 6th or 7th day until the end of culture (it is noted that “the end of culture” is not defined by the specification, thus encompasses any time after the earliest recited date), fluctuating the concentration of glucocorticoid, from any initial concentration, from the 8th or 9th day until any time after the 8th day, tapering oncostatin M, from any initial concentration, from the 9th, 10th or 11th day until any time after the 9th day, and adding a Notch inhibitor and a TGF-β receptor inhibitor, in any form encompassing gene knockout, gene knockdown, or small molecules, directly or indirectly, specifically or nonspecifically, affecting the Notch and TGF-β signaling pathways, from the 9th, 10th or 11th day until any time after the 9th day.
However, the specification only discloses a single species of method for a 2D culture and a single species of method for a 3D culture, wherein the 2D culture method comprises culturing the hepatoblasts in a medium comprising 20 ng/mL HGF, 0.1 nM dexamethasone (Dex) and 20 ng/mL oncostatin M, and further adding 10 ng/mL vitamin K1 from the 7th day, fluctuating the concentration of glucocorticoid between 0.05 nM and 0.1 nM from the 9th day, tapering oncostatin M from 20 ng/mL to complete removal from the 11th day, and adding 0.5 nM of compound E and 5 nM of SB431542 from the 11th day to the 17th day (see p. 21, last 2 para for culture condition, and see p. 25, last para for culture duration, “at day 11, cells were … differentiation into iHBs” (hepatoblasts) and “a total of twenty-eight days in culture” in 2D, thus the culture duration for hepatoblast differentiation is 28-11 = 17 days). The 3D culture method is using the same medium but the culture duration is 34 days (see p. 25, last para for culture duration, “3D configuration allowed extended iHep culture until day 45 (34 days of 3D culture)”. Accordingly, the specification only discloses a single species of 2D culture and a single species of 3D culture for improving the differentiation of hepatoblasts into hepatocytes.
Dependent claims 2-8 encompass the culture format, specific reagents and ranges of concentrations, but even the most limited claim (claim 8) still encompasses the culture duration being any time after the 9th day. However, the specification only discloses a single species of 2D culture with a culture duration of 17 days and a single species of 3D culture with a culture duration of 34 days for improving the differentiation of hepatoblasts into hepatocytes.
Therefore, the specification fails to describe the genus of methods. Instead, the specification has only disclosed a single species of the claimed genus of methods.
ACTUAL REDUCTION TO PRACTICE
Accordingly, Applicant did not demonstrate a reduction to practice a genus of methods for improving the differentiation of hepatoblasts into hepatocytes encompassed by the broad scope as claimed, nor did Applicant adequately set forth in terms of distinguishing identifying characteristics as evidenced by other descriptions of the invention that are sufficiently detailed to show that Applicant was in possession of the claimed genus of method. The specification has only disclosed a single species of the claimed genus of methods. Therefore, the specification does not provide sufficient guidance on how to make and use the claimed genus of methods.
STATE OF THE ART & QUANTITY OF EXPERIMENTATION
The method of using the claimed invention is not well established. Although the method for differentiating hepatoblasts into hepatocytes was known in the state of the art, one of skill in the art would neither expect nor predict the method may result in improving the differentiation of hepatoblasts into hepatocytes produced according to the claimed genus of methods. Since prior or post art did not provide guidance for methods for improving the differentiation of hepatoblasts into hepatocytes as broad as being encompassed by the instant invention, it is incumbent upon the instant specification to do so. As stated supra, Applicant has only disclosed a single species of such method.
Furthermore, the instant specification provides data supporting the unpredictability of the claimed method, e.g., in 2D culture that even under culturing with all the specified reagents in the specified concentrations from the specified timing, merely changing the culture duration would impair the differentiation of hepatoblasts into hepatocytes, evidenced in that a shorter culture duration (e.g., 9 days after culture) results in increased AFP expression (which is a marker for hepatoblasts, see p. 4, last para – p. 5, para 1), as recited “However, in 2D samples, the AFP profile showed the typical bell curve already observed in literature in which the highest secretion point was recorded around day 20 of differentiation” (p. 26, lines 10-12, see also Fig 3A. It is noted that Day 11 is the start date of hepatoblasts differentiation, thus day 20 is 9 days after culture).
Consequently, supported by Applicant’s disclosure, there is ample reason to conclude that there would be a high degree of unpredictability in differentiating hepatoblasts into hepatocytes by culturing with a genus of reagents, in any form, in any concentration, and for any culture duration as encompassed by the instant claims. Thus, the method for improving the differentiation of hepatoblasts into hepatocytes is highly unpredictable, and is not well established.
The physiological art is recognized as unpredictable (MPEP 2164.03). As set forth in In re Fisher, 166 USPQ 18 (CCPA 1970), compliance with 35 USC 112, first paragraph requires: “That scope of claims must bear a reasonable correlation to scope of enablement provided by specification to persons of ordinary skill in the art; … in cases involving unpredictable factors, such as most chemical reactions and physiological activity, scope of enablement varies inversely with degree of unpredictability of factors involved.” Moreover, the courts have also stated that reasonable correlation must exist between scope of exclusive right to patent application and scope of enablement set forth in the patent application (27 USPQ2d 1662 Ex parte Maize!.). In view of the foregoing, due to the lack of sufficient guidance provided by the specification regarding the issues set forth above, the state of the relevant art, and the breadth of the claims, it would have required undue experimentation for one skilled in the art to use the instant broadly claimed invention.
CONCLUSION
In conclusion, since Applicant’s own disclosure teaches that the method for improving the differentiation of hepatoblasts into hepatocytes with any reagents, in any form, in any concentration, and for any culture duration, is highly unpredictable, and the specification does not provide ample guidance with respect to how to choose the reagents, concentrations and culture durations, one would be burdened with undue experimentation to use the claimed invention for improving the differentiation of hepatoblasts into hepatocytes.
In conclusion, given the breadth of the claims and the limited scope of the specification, an undue quantity of experimentation is required to use the invention.
Examiner’s comment
Based on the limited genus of method disclosed by Applicant’s specification to have the claimed function of improving the differentiation of hepatoblasts into hepatocytes, the prior art have been applied below to make obvious this limited genus of method for improving the differentiation of hepatoblasts into hepatocytes.
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.
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 1-4 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Guirevich et al., (WO 2020/227711 A1, cited in IDS 12/07/2023) in view of Kaserman et al., (Methods Mol Biol. 2017:1639:151-160) and Paganelli et al., (WO 2019/222853 A1, cited in IDS 12/07/2023).
With respect to claim 1, Guirevich teaches a method for the production of hepatocytes from induced pluripotent stem cells (see e.g., abstract), which comprises a step of differentiating the hepatoblasts to hepatocytes (see e.g., Summary [0005], step (d)), thus teaches the preamble of claim 1.
In regard to the culture medium, Guirevich teaches the hepatoblasts are cultured in Hepatocyte Differentiation Media (Stage 2) (see p. 21, last section, [0090]), that the medium comprises HGF (e.g, about 50-200 ng/mL, particularly about 100 ng/mL), Oncostatin M (OSM) (e.g., about 10-30 ng/mL, particularly about 20 ng/mL), and dexamethasone (e.g., about 0.01-1 µM, particularly about 0.1 µM) (see [0090]), thus teaches the method comprises culturing the hepatoblasts in a hepatocyte medium (e.g., the Stage 2 Hepatocyte Differentiation Media) supplemented with HGF, glucocorticoid (i.e., dexamethasone) and oncostatin M. Guirevich teaches the Stage 2 medium is “fed every other day” (e.g., [00144]), thus teaches the hepatocyte medium is used and refreshed every other day. Although Guirevich does not specifically teach the medium is refreshed every day, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method to have refreshed the medium every day as claimed with a reasonable expectation of success. One of ordinary skill in the art would have had a reason to do so in order to provide fresh growth factors and cytokines to improve the differentiation of hepatoblasts.
In regard to (i) adding vitamin K, however, Guirevich does not specifically teach the medium is supplemented with vitamin K.
Kaserman teaches a protocol for directed differentiation of human iPSCs to a hepatic cells (e.g., abstract). Kaserman teaches hepatic progenitors (i.e., hepatoblasts) are generated on Day 13 and hepatic cells (i.e., hepatocytes) are generated on Day 25 (see p. 156, Fig 2. Thus, Kaserman’s Day 13-25 is corresponding to the method for differentiating hepatoblasts into hepatocytes as instantly claimed). Kaserman teaches the day 13-18 medium and day 19-25 medium both comprise vitamin K 6 μg/mL (see p. 158, para 4 and 5).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method for differentiating hepatoblasts into hepatocytes disclosed by Guirevich, by combining vitamin K as a supplement in the medium as suggested by Kaserman with a reasonable expectation of success. Since Kaserman reduces to practice a differentiation medium (i.e., both the day 13-18 medium and day 19-25 medium) comprising vitamin K in combination with HGF, oncostatin M and dexamethasone for successfully differentiating hepatoblasts into hepatocytes (see p. 158, para 4 and 5), one of ordinary skill in the art would have had a reason to add vitamin K in the medium of Guirevich in order to obtain successful differentiation of the hepatoblasts into hepatocytes. Furthermore, it would have been obvious for one of ordinary skill in the art to have tried the date of starting vitamin K so as to arrive at the claimed date (e.g., from the seventh day until the end of culture recited in claims 1 and 7-8) with a reasonable expectation of success. One of ordinary skill in the art would have had a reason to do so since this date of starting vitamin K is the result of “routine optimization”. See MPEP 2144.05(II)(A).
In regard to claim 1 (ii) and claim 8 fluctuating the concentration of glucocorticoid from the ninth day until the end of the culture, as stated supra, Guirevich teaches a Stage 2 Hepatocyte Differentiation Medium comprising dexamethasone (e.g., about 0.01-1 µM, particularly about 0.1 µM) and being used for 8 days (see [0090]), and further teaches a Hepatocyte Maturation Media (Stage 3) comprising dexamethasone (e.g, about 0.01-1 μM, particularly about 0.1 μM) and being used for another 7-10 days (see e.g., [0091]), thus teaches glucocorticoid (i.e., dexamethasone) is administered to the culture from the ninth day until the end of the culture (i.e., in the Stage 3 Hepatocyte Maturation Media).
However, Guirevich does not specifically teach the concentration is decreased by half and reverts to the initial concentration every other day.
Regarding the change of concentration, MPEP states “generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical” and “where 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”. See MPEP 2144.05(II)(A). In the instant case, Guirevich teaches glucocorticoid (i.e., dexamethasone) is administered to the culture from the ninth day until the end of the culture. Therefore, it would have been obvious for one ordinary skill in the art before the effective filing date of the claimed invention to apply the claimed scheme of decreasing the concentration by half and reverting to the initial concentration every other day because it is the result of “routine optimization”. Applicant is invited to provide or specifically point to factually supported objective evidence to demonstrate the criticality of such changing scheme.
In regard to (iii) tapering the concentration of oncostatin M until its complete removal, however, Guirevich does not specifically teach removal of oncostatin M.
Paganelli teaches a method for differentiating an hepatic progenitor cell into an hepatocyte-like cell (e.g., abstract). Paganelli teaches “For the final stage of differentiation, OSM was removed (since after birth, hematopoiesis no longer occurs in the liver)” (e.g., p. 61, lines 10-12). It is noted that this final stage comprises contacting the immature hepatocyte-like cells with a fifth culture medium excluding cytokines such as oncostatin M to obtain the mature hepatocyte-like cells (e.g., p. 3, lines 12-14). Thus, Paganelli suggests removing oncostatin M from the hepatocyte maturation medium (which corresponds to Guirevich’s Stage 3 Hepatocyte Maturation Media from the ninth day until the end of the culture, e.g., Guirevich [0090], [0091]).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method for differentiating hepatoblasts into hepatocytes disclosed by Guirevich, by substituting with removing oncostatin M from the hepatocyte maturation medium from the ninth day until the end of the culture as suggested by Paganelli with a reasonable expectation of success. Since Paganelli reduces to practice removing oncostatin M in the hepatocyte maturation medium “since after birth, hematopoiesis no longer occurs in the liver” (e.g., p. 61, lines 10-12), one of ordinary skill in the art would have had a reason to remove oncostatin M from the hepatocyte maturation medium of Guirevich from the ninth day in order to facilitate the differentiation of hepatocytes (see Paganelli, p. 32, lines 2-7). Furthermore, regarding the scheme of decreasing oncostatin M concentration by half every other day until complete removal, it would have been obvious for one ordinary skill in the art before the effective filing date of the claimed invention to apply the claimed scheme of decreasing oncostatin M concentration by half every other day until complete removal because it is the result of “routine optimization”. See MPEP 2144.05(II)(A). Applicant is invited to provide or specifically point to factually supported objective evidence to demonstrate the criticality of such tapering scheme.
In regard to claim 1 (iv) and claims 7-8 from the ninth day of culture until the end of the culture a Notch inhibitor and a TGFβ receptor inhibitor are added to the culture, Guirevich teaches using a Hepatocyte Maturation Media (Stage 3) from the ninth day of culturing hepatoblasts (hepatoblasts are cultured in Stage 2 Hepatocyte Differentiation Medium for 8 days, see [0090]), which further comprise a TGFβ inhibitor and γ-secretase inhibitor, such as SB431542 (e.g., about 1-20 μM, particularly about 10 μM) and DAPT (e.g., about 1-5 μM, particularly about 2 μM) (see e.g., [0091]). It is noted that γ-secretase inhibitor is a Notch inhibitor. Thus, Guirevich teaches from the ninth day of culture until the end of the culture, a Notch inhibitor and a TGFβ receptor inhibitor are added to the culture.
With respect to claim 2 directed to 2D or 3D culture, Guirevich teaches the step of hepatocyte differentiation can be performed in a 2D or 3D format (e.g., [0090]).
With respect to claim 3 directed to the glucocorticoid being dexamethasone, as stated supra, Guirevich teaches the stage 2 Hepatocyte Differentiation Media and the stage 3 Hepatocyte Maturation Media both comprise dexamethasone (see e.g., [0090], [0091]).
With respect to claim 4 directed to the vitamin K being vitamin K1, as stated supra, Kaserman makes obvious adding vitamin K as a supplement in the medium, and teaches the vitamin K is obtained from Invitrogen (see p. 154, para 2.2 “Differentiation Components”, Item #17). One of ordinary skill in the art would have immediately acknowledged that the vitamin K from Invitrogen (now under Thermo Fisher Scientific) would have been vitamin K1.
With respect to claim 6 directed to the TGFβ receptor inhibitor being SB431542, Guirevich teaches the TGFβ inhibitor is SB431542 (e.g., [0091]).
Hence, the claimed invention as a whole was prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention in the absence of evidence to the contrary.
Claims 5 and 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Guirevich et al., (WO 2020/227711 A1, cited in IDS 12/07/2023) in view of Kaserman et al., (Methods Mol Biol. 2017:1639:151-160) and Paganelli et al., (WO 2019/222853 A1, cited in IDS 12/07/2023), as applied to claims 1 and 6 above, and further in view of Touboul et al., (J Hepatol. 2016;64(6):1315-26).
Claims 5 and 7-8 are directed to the notch inhibitor being compound E.
However, Guirevich exemplifies DAPT as a γ-secretase inhibitor which is a Notch inhibitor (e.g., [0091]), but is silent on using compound E as a notch inhibitor.
Touboul teaches a method of differentiating hESCs into hepatocytes with a 5-stage protocol in which the 5th stage comprises differentiating hepatoblasts into hepatocytes (e.g., abstract). Touboul teaches dual inhibition of TGF-β and NOTCH signaling efficiently differentiate hepatoblasts into hepatocytes in the 5th stage (e.g., abstract and p. 1320, para 1, also see Figs 1A and 5A). Touboul teaches Compound-E (CE, 0.5 µM) is used as the inhibitor of NOTCH signaling (p. 1320, para 1, also see Figs 1A and 5A).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method for differentiating hepatoblasts into hepatocytes suggested by Guirevich in view of Kaserman and Paganelli, by substituting the DAPT with Compound-E as a Notch inhibitor as suggested by Touboul with a reasonable expectation of success. Since Touboul reduces to practice Compound-E as the inhibitor of NOTCH signaling and teaches it efficiently improves the differentiation of hepatoblasts into hepatocytes (e.g., p. 1320, para 1, Fig 5A), one of ordinary skill in the art would have had a reason to substitute with Compound E in order to efficiently improves the differentiation of hepatoblasts into hepatocytes as suggested by Touboul. Furthermore, since Touboul's Compound E and Guirevich’s DAPT are for the same purpose (i.e., being used as a Notch inhibitor), these chemicals are art-recognized obvious equivalents to each other. Therefore, it would have been obvious for one of ordinary skill in the art to have substituted Touboul's Compound E for Guirevich’s DAPT. See MPEP 2144.06.
In regard to the timings of addition of components and changing of dexamethasone concentration recited in claim 7 and claim 8, these limitations are rejected in the same way as those in claim 1 (see above).
In regard to the concentrations of components recited in claim 7 and claim 8, as stated supra, Guirevich (see [0090]) teaches the medium comprises HGF (e.g, about 50-200 ng/mL, particularly about 100 ng/mL), which overlaps with or is close to the claimed range, dexamethasone (e.g., about 0.01-1 µM, particularly about 0.1 µM), which is close to the claimed range, Oncostatin M (OSM) (e.g., about 10-30 ng/mL, particularly about 20 ng/mL), which overlaps with the claimed range. Kaserman makes obvious supplementing vitamin K1 at 6 μg/mL (see p. 158, para 4 and 5), which is within or close to the claimed range. Touboul makes obvious Compound-E (CE, 0.5 µM) is used as the inhibitor of NOTCH signaling (p. 1320, para 1, also see Figs 1A and 5A), which is close to the claimed range. Guirevich teaches a TGFβ inhibitor SB431542 (e.g., about 1-20 μM, particularly about 10 μM) (see e.g., [0091]), which is close to the claimed range.
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method for differentiating hepatoblasts into hepatocytes by choosing the claimed concentrations of components as suggested by Guirevich, Kaserman and Touboul with a reasonable expectation of success. One of ordinary skill in the art would have had a reason to do so because 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), and in addition, MPEP 2144.05(I) teaches “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, 227 USPQ 773 (Fed. Cir. 1985).” Thus, “approaching, similar or close range” is obvious in the absence of any showing of unexpected results or criticality. Furthermore, MPEP states “generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical” and “where 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”. See MPEP 2144.05(II)(A).
Hence, the claimed invention as a whole was prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention in the absence of evidence to the contrary.
Conclusion
No claims are allowed.
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/JIANJIAN ZHU/Examiner, Art Unit 1631
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