DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
This application is a continuation of PCT application PCT/EP2022/075292, filed 03/07/2024. Acknowledgment is made of applicant's claim for priority under 35 U.S.C. 119(a)-(d) or (f), 365(a) or (b), or 386(a) based upon an application filed in Europe on 09/10/2021. The claim for priority cannot be based on said application because the subsequent nonprovisional or international application designating the United States was filed more than twelve months thereafter and no petition under 37 CFR 1.55 or request under PCT Rule 26bis.3 to restore the right of priority has been granted.
Applicant may wish to file a petition under 37 CFR 1.55(c) to restore the right of priority if the subsequent application was filed within two months from the expiration of the twelve-month period and the delay was unintentional. A petition to restore the right of priority must include: (1) the priority claim under 35 U.S.C. 119(a)-(d) or (f), 365(a) or (b), or 386(a) in an application data sheet, identifying the foreign application to which priority is claimed, by specifying the application number, country (or intellectual property authority), day, month, and year of its filing (unless previously submitted); (2) the petition fee set forth in 37 CFR 1.17(m)(3); and (3) a statement that the delay in filing the subsequent application within the twelve-month period was unintentional. The petition to restore the right of priority must be filed in the subsequent application, or in the earliest nonprovisional application claiming benefit under 35 U.S.C. 120, 121, 365(c), or 386(c) to the subsequent application, if such subsequent application is not a nonprovisional application. The Director may require additional information where there is a question whether the delay was unintentional. The petition should be addressed to: Mail Stop Petition, Commissioner for Patents, P.O. Box 1450, Alexandria, Virginia 22313-1450.
Election/Restrictions
Applicant’s election without traverse of group I, claims 1-18, drawn to a method of producing hepatocytes from iPSCs, in the reply filed on 06/08/2026 is acknowledged. Accordingly, claims 1-18 have been considered on the merits. Claims 19-21, 23 and 26-27 are withdrawn from consideration pursuant 37 CFR 1.142(b).
Specification
The disclosure is objected to because it contains an embedded hyperlink and/or other form of browser-executable code (see p29, L8). Applicant is required to delete the embedded hyperlink and/or other form of browser-executable code; references to websites should be limited to the top-level domain name without any prefix such as http:// or other browser-executable code. See MPEP § 608.01.
Claim Objections
Claim 1 is objected to because of the following informalities:
Claim 1 recites Roman numerals (i)-(iii) to separate the steps of the method, also recites same Roman numerals (i)-(ii) to list the different combinations of transcription factors. To enhance the clarity of claim language, different types of numerals need to be used (i.e., using (a)-(c) and (i)-(ii) respectively).
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.
Claim 8 is 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.
The terms “suitable” and “sufficient” in claim 8 are relative terms which render the claim indefinite. The terms “suitable” and “sufficient” are not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. In instant case, it is not clear what conditions are considered as “suitable conditions”, and what period of time is considered as “a sufficient period of time” for the displaying of the hepatocyte phenotype, therefore the scope of instant claim is indefinite.
Claim Interpretation
As noted above, claim 8 is indefinite. For purposes of compact prosecution, the claim is interpreted as the population of cells is cultured under any conditions and for any period of time to allow one or more cells to display a hepatocyte phenotype.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-17 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (WO 2015/164228 A1) in view of Rombaut et al. (J Hepatol. 2021 Sep;75(3):690-705, as cited in IDS) and Du et al. (Cell Stem Cell. 2014 Mar 6;14(3):394-403, as cited in IDS).
Yu et al. teach methods comprising both genetic and chemical means for the production of hepatocytes from a variety of cell sources, particularly pluripotent stem cells (Abstract).
Regarding claim 1, Yu et al. teach a method of providing hepatocytes by genetic and chemical forward programming of a variety of cell types, including somatic cells or stem cells (parag 0005). Forward programming may include programming of a multipotent or pluripotent cell by artificially
increasing the expression of one or more specific lineage-determining genes in a multipotent or pluripotent cell (parag0007). Yu et al. teach by effecting expression of a combination of transcription factors in Table 1, forward programming into hepatocytes from pluripotent stem cells may bypass most, if not all, normal developmental stages (parag 00126). Table 1 shows a list of candidate genes for direct programming of human ESC/iPSCs to hepatocytes (p31), includes HNF1A, FOXA3 and RORc. Yu et al. teach the hepatocyte-enriched transcription factors also include hepatocyte nuclear factor HNF-6 (parag 00127). Yu et al. do teach test and use HNF-6 for the programming of human ESC/iPSCs to hepatocytes. However, HNF-6 is a transcriptional factor regulating reprograming to hepatocytes was disclosed by Rombaut et al. at the time of instant invention.
Rombaut et al. provide an overview of the state-of-the-art reprogramming cocktails and techniques, as well as their corresponding conversion efficiencies. Special attention is paid to the role of liver-enriched transcription factors as hepatogenic reprogramming tools and small molecules as facilitators of hepatic transdifferentiation (Abstract).
Du et al. generate functional human hepatocytes from fibroblasts by ectopically expressing hepatic fate conversion factors together with maturation factors (p395, left column).
Regarding claim 1, Rombaut et al. teach state-of-the-art direct hepatic reprogramming cocktails and reprogramming techniques to generate induced hepatocytes (iHeps, Table 1, p692-696). Rombaut et al. teach combinations of transcription factors including HNF1A, HNF6, FOXA3 and other transcription factors for reprograming cells such as mouse mesenchymal stem cell, mouse embryonic fibroblasts, as well as human neonatal and adult fibroblasts for programming cells to hepatocytes. Du et al. teach a pool of transcription factors which are expressed in human hepatocytes and are crucial to the determination of hepatic cell fate (p395, left column, also Table S1), wherein the pool of transcription factors includes HNF6.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Yu et al.’s method of using a combination of transcription factors to forward programming human PSCs into hepatocytes, and use a different set of transcription factors choosing from the transcription factors as taught by Rombaut et al. and Du et al.. The only difference between instant claim and Yu et al.’s method of using a combination of transcription factors to forward programming human PSCs into hepatocytes is instant claim uses a different set of transcription factors including the set of HNF1A, HNF6, FOXA3 and RORc, or the set of HNF1A, HNF6, FOXA3, RORc and ERα. Given that there is a pool of well-known transcription factors which are likely to regulate the reprograming cells to hepatocytes as taught by Rombaut et al. and Du et al., one of ordinary skill in the art would have tested and optimized the combination of the different transcription factors to obtain best results of forward programming human PSCs into hepatocytes. This simple substitution of one known element (use a combination of transcription factors such as the set of HNF1A, HNF6, FOXA3 and RORc) for another combination of transcription factors is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 — 97 (2007) (see MPEP § 2143, B.).
Regarding claim 2, Yu et al. teach Table 1 shows a list of candidate genes for direct programming of human ESC/iPSCs to hepatocytes (p31), which includes NR1I3.
Regarding claim 3, Yu et al. do not teach the set of transcription factors consists of (i) HNF1A, HNF6, FOXA3, and RORc; or (ii) HNF1A, HNF6, FOXA3, RORc, and ERα. However, as stated above, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Yu et al.’s method of using a combination of transcription factors to forward programming human PSCs into hepatocytes, and use a different set of transcription factors choosing from the transcription factors as taught by Rombaut et al. and Du et al.. The only difference between instant claim and Yu et al.’s method of using a combination of transcription factors to forward programming human PSCs into hepatocytes is instant claim uses a different set of transcription factors including the set of consist of HNF1A, HNF6, FOXA3 and RORc, or the set consist of HNF1A, HNF6, FOXA3, RORc and ERα. Given that there is a pool of well-known transcription factors which are likely to regulate the reprograming cells to hepatocytes as taught by Rombaut et al. and Du et al., one of ordinary skill in the art would have tested and optimized the combination of the different transcription factors to obtain best results of forward programming human PSCs into hepatocytes. This simple substitution of one known element (use a combination of transcription factors consist of the set of HNF1A, HNF6, FOXA3 and RORc) for another combination of transcription factors is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 — 97 (2007) (see MPEP § 2143, B.).
Regarding claim 4, Yu et al. teach the hepatocytes produced have all characteristics of hepatocytes as determined by morphology, marker expression, and in vitro and in vivo functional assays (parag 0080). Yu et al. teach fully functional hepatocytes, could be induced directly from human ESC/iPSCs via expression of a combination of transcription factors important for hepatocyte differentiation/function, similar to the generation of iPSCs, bypassing most, if not all, normal developmental stages (parag 0085, and figure 1).
Regarding claims 5 and 6 , Yu et al. teach the pluripotent stem cell may be an induced pluripotent stem cell (iPSCs), an embryonic stem cell (ESCs), or a pluripotent stem cell derived by nuclear transfer or cell fusion (parag 0029). Yu et al. teach candidate genes for direct programming of human ESC/iPSCs to hepatocytes (p31, Table 1).
Regarding claim 7, Yu et al. teach table 1 shows a list of candidate genes for direct programming of human ESC/iPSCs to hepatocytes (p31, Table 1).
Regarding claim 8, Yu et al. teach the reprogramed hepatocytes show i.e., expression of one or more hepatocyte markers including glucose-6-phosphatase, albumin (ALB) , a-1-antitrypsin (AAT), cytokeratin 8 (CK8), cytokeratin 18 (CK18), asialoglycoprotein receptor (ASGR), alcohol dehydrogenase 1, arginase Type I, cytochrome p450 3A4 (CYP3A4), liver-specific organic anion transporter (LST-1 ), or a combination thereof (see p89, claim 12). Yu et al. teach kinetics of ALB expression Following day 11, the %ALB-expressing cells remained constant. This suggested that the transition from non-hepatic cells to hepatocyte-like cells was complete at about day 11 post-plating with their protocol (parag 00266).
Regarding claim 9, Yu et al. teach figure 1, which shows the forward programing directly transfects hESC/iPSC to mature hepatocyte, and skip the stages of definitive endoderm, hepatic specification and immature hepatocyte.
Regarding claims 10-13, Yu et al. teach a method of producing hepatocytes by forward programming of stem cells, comprising transfecting the stem cells with at least one exogenous expression cassette comprising the hepatocyte programming factor genes. The expression cassette may comprise an externally controllable transcriptional regulatory element, such as an inducible promoter (p88, claims 1 and 3). Yu et al. teach vectors for delivery of nucleic acids encoding hepatic lineage programming or differentiation factors could be constructed to express these factors in cells (parag 00140). Vectors include but are not limited to, plasmids, cosmids, viruses (bacteriophage, animal viruses, and plant viruses), and artificial chromosomes (e.g., YACs), such as retroviral vectors, lentiviral vectors, adenoviral (Ad) vectors (parag 0142).
Regarding claim 14, Yu et al. teach a method of producing hepatocytes by forward programming of stem cells, comprising transfecting the stem cells with at least one exogenous expression cassette comprising the hepatocyte programming factor genes, and obtaining the hepatocytes less than or about 10 days after culturing in said conditions (p89, claims 16-17), wherein “less than or about 10 days” overlaps the range of at least 7 days. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(I).
Regarding claim 15, Yu et al. teach i.e., figure 11, which is the percentage of ALB (~80%), ALB is a hepatocyte marker (parag 0021). Yu et al. teach Hepatocytes may be at least, about, or up to 1 %, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 85%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.9% (or any intermediate ranges) of the cell population (parag 0030), indicates i.e., at least 5% or 10% or more population of PSCs are forward programmed into hepatocytes, as recited in instant claim.
Regarding claims 16 and 17, Yu et al. teach the mature hepatocytes may be selected or enriched by using a screenable or selectable reporter expression cassette comprising a mature hepatocyte-specific transcriptional regulatory element operably linked to a reporter gene, or magnetic cell sorting using an antibody against a hepatocyte-specific cell surface antigen, such as ASGR, or by assessing characteristics specific for mature hepatocytes as known in the art (parag 0023), wherein the “selecting” reads on “isolating and/or purifying” as recited in instant claim 16, and the “enrich” reads on “expand” as recited in instant claim 17. Regarding “expanding the hepatocytes”, Yu et al. also teach production of more mature hepatocytes, the starting cell population may be cultured in a medium comprising one or more growth factors such as Oncostain M (OSM), or further comprising hepatocyte growth factor (HGF) (parag 0024).
Claims 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (WO 2015/164228 A1) in view of Rombaut et al. (J Hepatol. 2021 Sep;75(3):690-705, as cited in IDS) and Du et al. (Cell Stem Cell. 2014 Mar 6;14(3):394-403, as cited in IDS), as applied to claims 1-17 above, and further in view of Whaley et al. (Cell Transplant. 2021 Jan-Dec;30:963689721999617, published in March, 2021).
The teaching of Yu et al. in view of Rombaut et al. and Du et al. is set forth above.
Regarding claim 18, Yu et al. in view of Rombaut et al. and Du et al. do not teach storing the hepatocytes. However, this was disclosed by Whaley et al. at the time of instant invention.
Whaley et al. teach the history and basic physical principles of cryopreservation, including: permeating, and nonpermeating cryoprotecting agents, vitrification mixtures, and cooling and thawing rates (p1, left column).
Regarding claim 18, Whaley et al. teach cryopreservation of hepatocytes (p5).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Yu et al.’s method of using transcription factors to forward programming human PSCs into hepatocytes, and store these hepatocytes by cryopreservation for future use as taught by Whaley et al.. The skilled artisan would have been motivated to cryopreserve these hepatocytes since Whaley et al. teach hepatocyte cryopreservation is a critical step for the hepatocyte transplantation (p5, left column) and a good cryopreservation enhances hepatocyte yield and viability (p5, right column). There would be a reasonable expectation of success of storing these hepatocytes by cryopreservation since Whaley et al. teach the method of cryopreserve hepatocyte (p5).
Conclusion
No claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to QINHUA GU whose telephone number is (703)756-1176. The examiner can normally be reached M-F: 9:00 - 5:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Christopher Babic can be reached at (571)272-8507. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Q.G./Examiner, Art Unit 1633
/FEREYDOUN G SAJJADI/Supervisory Patent Examiner, Art Unit 1699
Prosecution Insights