Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election with traverse of Group II (Claims 10-19; drawn to a method of inducing human induced pluripotent stem cells to form oligodendrocytes) in the reply filed on June 5, 2026, is acknowledged.
Claims 1-9 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention (Groups I), there being no allowable generic or linking claim.
Response to Arguments
Applicant's arguments filed June 5, 2026, are acknowledged.
Applicant argues that independent claim 1 of the non-elected Group I shares the same product features of Group II. Therefore, there is no undue burden to examine Groups I and II (page 9, paragraph 7).
Applicant's arguments have been fully considered and are considered persuasive regarding the previous reasoning for restriction in light of Applicant’s amendments to claims 10-11.
However, Restriction to one of the following inventions is still considered to be required under 35 U.S.C. 121:
Group I, Claims 1-9, drawn to a culture medium combination, classified in C12N5/0018.
Group II, Claims 10-19, drawn to a method of inducing human iPSCs to form oligodendrocytes, classified in C12N5/0622.
The inventions are distinct, each from the other because of the following reasons:
Inventions I and II are related as product and process of use. The inventions can be shown to be distinct if either or both of the following can be shown: (1) the process for using the product as claimed can be practiced with another materially different product or (2) the product as claimed can be used in a materially different process of using that product. See MPEP § 806.05(h). In the instant case, the product as claimed can be used in a materially different process of using the product. Claim 1 refers to four different medium compositions that can be used independently of each other and not solely as part of the four step differentiation method of Group II. For example, the neural induction complete culture medium could be used to generate neural progenitor cells that are then examined and tested or that are further differentiated into neurons instead of oligodendrocytes. Similarly, the OPC mature culture medium could be used to differentiate oligodendrocyte progenitor cells (OPCs) isolated from a patient to assess developmental differences between diseased and healthy OPCs. As such, the medium combination of Group I can be used in materially different processes than that of Group II.
Restriction for examination purposes as indicated is proper because all these inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because at least the following reason(s) apply:
(a) the inventions have acquired a separate status in the art in view of their different classification; (b) the inventions have acquired a separate status in the art due to their recognized divergent subject matter; (c) the inventions require a different field of search (for example, searching different classes/subclasses or electronic resources, or employing different search queries); (d) the prior art applicable to one invention would not likely be applicable to another invention; (e) the inventions are likely to raise different non-prior art issues under 35 U.S.C. 101 and/or 35 U.S.C. 112, first paragraph.
Therefore, the restriction between Groups I and II is maintained.
DETAILED ACTION
The amended claims filed on June 5, 2026, have been acknowledged. Claims 1-11 were amended. Claims 12-19 are new. In light of the Applicant’s elected invention, claims 1-9 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. Claims 10-19 are pending and examined on the merits.
Priority
Acknowledgment is made of Applicant’s claim for foreign priority under 35 U.S.C. 119(a)-(d).The applicant claims foreign priority from CN202110894940.X filed on August 5, 2021. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55, received June 4, 2026. While a certified copy of the foreign patent application CN202110894940.X is provided with the instant application, a certified English translation of said foreign patent application has not been provided.
Specification
The use of the terms TeSR-E8, mTESR1, E8, AmnioMax, Amnio Max II, MesenCult-XF, GlutaMax-I, and B27 which are trade names or marks used in commerce, has been noted in this application. The terms should be accompanied by the generic terminology; furthermore the term should be capitalized wherever it appears or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
Claim Objections
Claims 10-11 and 19 are objected to because of the following informalities:
In claim 10, line 4, the claim uses the abbreviation “OPC”, which has not been spelled out upon first use. Although claims are allowed abbreviations, if an abbreviation is not spellout upon first use in a claim, MPEP §2429 states that Applicant only use abbreviations that are specifically defined in "WIPO Standard ST.25 (1998)" or that are well known and would be clear to someone who had not read the invention description.
In claim 10, line 29, claim 11, line 25, and claim 19, line 6, the term “purerarin” should be spelled “puerarin” as used in paragraph 0063 of the specification.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 10-19 are rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as based on a disclosure which is not enabling. The disclosure does not enable one of ordinary skill in the art to practice the invention without identifying cells used in the individual culture steps in the step-wise differentiation of pluripotent stem cells into oligodendrocytes and the final differentiation steps to generate oligodendrocytes from oligodendrocyte progenitor cells (OPCs), which is/are critical or essential to the practice of the invention but not included in the claim(s). See In re Mayhew, 527 F.2d 1229, 188 USPQ 356 (CCPA 1976).
The factors to be weighed to evaluate whether a disclosure satisfies the enablement requirement and whether any necessary experimentation is undue are set forth in MPEP 2164.01(a).
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
Although all the factors have been considered, the relevant factors will be addressed below.
Breadth of the claims: Claim 10 recites the following claim language, “A method for inducing human induced pluripotent stem cells to form oligodendrocytes, wherein a culture medium combination consisting of a neural induction complete culture medium, a N2 culture medium, a B27 culture medium and an OPC mature culture medium is used in the method, and the method comprises: culturing on days 0-7 using the neural induction complete culture medium, culturing on days 8-11 using the N2 culture medium, culturing on days 12-19 using the B27 culture medium, and culturing on days 20-30 using the OPC mature culture medium”. The broadest reasonable interpretation is that this method could be done with any starting cell type at day 0 as long as that cell type is a induced pluripotent stem cell (iPSC)or is derived from a pluripotent stem cell as there is no positively recited step of adding any specific cell to the culture media of each step.
Similarly, claim 11 recites the following claim language, “An application of a culture medium combination in inducing human induced pluripotent stem cells to form oligodendrocytes, wherein the culture medium combination consists of a neural induction complete culture medium, a N2 culture medium, a B27 culture medium and an OPC mature culture medium”. The broadest reasonable interpretation is that this method could be done with any culturing steps and starting cell type at day 0 as long as that cell type is a induced pluripotent stem cell (iPSC)or is derived from a pluripotent stem cell as there are no positively recited culturing steps and no positively recited step of adding any specific cell to any of the defined the culture media.
Nature of the invention: The subject matter of the invention relates to a method to differentiate pluripotent stem cells into oligodendrocytes using the medium compositions recited in claims 10 and 11.
State of the prior art: The prior art teaches that a multi-step procedure is required for generating oligodendrocytes from induced pluripotent stem cells and that the type of cell being cultured is an important consideration for achieving differentiation of stem cells to oligodendrocytes, as identified by World Intellectual Property Organization Patent Application No. 2020243618 (Fossati).
Fossati teaches a method of differentiating oligodendrocytes from iPSCs comprising culturing iPSCs in neural induction media containing the small molecules SB431542 10 μM (Stemgent) and LDN193189 250 nM and 100 nM all-trans-RA where DMEM/F12 with the addition of about 25 μg/ml insulin could be used as the base media from 0-7 days.
On day 8, the cultured cells express Pax6 (a neural cell marker) and the media was switched to N2 medium comprising glutamax, non-essential amino acids, β-mercaptoethanol, penicillin-streptomycin, N2 supplement, 100 nM retinoic acid, and 1 μM SAG. The cells were cultured with this medium composition through day 11.
On day 12, overconfluent cells were piling up and 3D structures were clearly visible and this is an important checkpoint before proceeding with the differentiation. Cells expressed OLIG2 and NKX2.2. Cells were re-plated into Ultra-low attachment plates in N2B27 Medium (glutamax, non-essential amino acids, β-mercaptoethanol, penicillin-streptomycin, N2 supplement, B27 supplement) containing 1 μM SAG, changing it every other day until day 20.
At day 20, medium was switched to PDGF Medium (glutamax, non-essential amino acids, β-mercaptoethanol, penicillin-streptomycin, N2 supplement, B27 supplement, PDGF, IGF-1, HGF, NT3, Insulin, Biotin, cAMP, and T3), and 2/3 media changes were performed every other day until day 30.
At day 30, spheres were plated onto plates coated with poly-L-ornithine hydrobromide (50μg/mL) and Laminin (20μg/ml) at a density of 2 spheres/cm2 (about 20 spheres per well in a 6-vvell plate). This density was optimized to allow cells to migrate out from the sphere, proliferate and spread to the entire dish by the end of the protocol without the need for passaging. A p200 pipette was used to pick aggregates that were round, golden/brown with a dark center, having a diameter between 300 and 800μm. Spheres that were completely transparent were avoided, as these do not differentiate to oligodendrocytes. At this stage, plated spheres were cultured in a medium containing mitogen (Option A) or in a medium without any mitogen (Option B). Option A was optimized to obtain the highest yield of O4+ cells, while Option B was developed to provide a shorter and less costly version of the protocol. O4+ staining occurred at day 75 in option A and day 55 in option B. Additionally, 34 ± 4% of O4+ OPCs differentiated into MBP+ mature oligodendrocytes after growth-factor withdrawal from the medium for at least two weeks (paragraphs 0098-0129 and Table 2).
As such, the prior art shows that a specific cell type are used for each stage of differentiation: iPSCs in stage 1, Pax6+ cells in stage 2, OLIG2+ and NKX2.2+ cells with 3D structures at stages 3-4, round, golden/brown OPC cell aggregates with a dark center at stage 5, O4+ mature OPCs cells for stage 6 differentiation of OPCs into oligodendrocytes. Furthermore, Fossati clearly identifies multiple important considerations for proper differentiation of the iPSCs into oligodendrocytes as 3D structures are important to see before proceeding with stages 3-4; OPC spheres with golden/brown with a dark center are important as spheres that were completely transparent were avoided, as these do not differentiate to oligodendrocytes; and O4+ cells are important for differentiating OPCs into oligodendrocytes. Therefore, careful consideration of the cells associated with each differentiation step is important for successful differentiation of stem cells into oligodendrocytes.
Level of predictability in the art: The prior art has successfully reduced to practice that a multistep differentiation protocol with refined control of concentration, time and duration of treatment with the defined growth and differentiation factors is required to generate oligodendrocyte cells from pluripotent stem cells. As such, this results in unpredictability about how someone can use this method to differentiate induced pluripotent stem cells into oligodendrocytes without defining the cell types used with each media composition and respective induction times associated with each step of the multistep differentiation protocol of claim 1 and without identifying how the resulting OPCs of the four stage process of claim 10 are further differentiated into oligodendrocytes.
Amount of direction provided by the inventor and existence of working examples: The Applicant discloses that they used a defined protocol for differentiating induced pluripotent stem cell types into oligodendrocyte progenitor cells.
Started from day 0, iPSC media was replaced with neural induction complete medium from E8 complete medium. Neural induction complete medium: 98% DMEM/F-12 medium, 1% non-essential amino acid, 1% GlutaMAX-I, 0.1 mM 2-Mercaptotothanol, 10 μM SB431542, 0.25 μM LDN193189 and 100 μM Vitamin A acid, 25 μg/ml insulin. From the 1st to 7th day thereafter, changed the fluid daily.
Started from day 8, the complete neural induction medium was replaced with N2 medium. N2 medium: 97% DMEM/F-12 medium, 1% non-essential amino acid, 1% GlutaMAX-I, 0.1mM 2-Mercaptoethano, 1% N2 supplement, 1% μM SAG and 100 μM Vitamin A acid. From the 8th to 11th day thereafter, changed the fluid daily.
Started from the 12th day, the N2 medium was replaced with B27 medium, and the cells were converted from adherent culture to suspension culture. B27 medium: 95% DMEM/F-12 medium, 1% non-essential amino acid, 1% GlutaMAX-I, 0.1mM 2-Mercaptotothanol, 1% N2 supplement, 2% B27 supplement, and 1 μM SAG and 100 μM vitamin A Acid, 25 μg/ml insulin. On the 12th to 19th days thereafter, changed the fluid every other day. On the 16th day, immunofluorescence detection was performed using the general method, and the results are shown in Figure 1: There are both Olg2+(green, OPC marker) and NKX2.2+(red, neural stem cell marker) cells present in the cells, but there are no cells expressing both Olg2+(green) and NKX2.2+(red), indicating that there are no mature OPC cells yet
Started from the 20th day, replaced B27 medium with OPC mature medium-without puerarin, and the cells will be converted from adherent culture to suspension culture. OPC mature medium - containing puerarin: 95% DMEM/F-12 medium, 1% non-essential amino acid, 1% GlutaMAX-I, 0.1mM 2-mercaptoethanol, 1% N2 supplement, 2% B27 supplement, 10 ng/mL PDGF-AA, 10 ng/mL IGF-1, 5 ng/mL HGF, 10 ng/mL NT3, 60 ng/mL T3, 100 ng/mL Biotin, 1 μM cAMP, 25 μM Puerarin, 25 μg/ml insulin. On the 20th to 30th day thereafter, changed the fluid every other day.
Performed immunofluorescence testing according to the general method on the 33rd day; The results showed in Figure 2 that Olig2 and Nkx2.2 were co expressed in cells after inducing day 33, indicating a successful induction of OPC.
On the 37th day of cultivation, the percentage of oligodendrocytes in all cells was quantitatively counted, as shown in Figure 3. Immunofluorescence analysis was performed, and the results are shown in Figure 4. Using OPC mature culture medium without puerarin as the control group, the control group was able to produce about 21% oligodendrocytes, and adding puerarin could produce about 36% oligodendrocytes. Proving that adding puerarin to OPC mature culture medium is beneficial for the production of oligodendrocytes (Examples 1-2).
As can be seen in Applicant’s examples, the differentiation protocol follows a specific differentiation procedure beginning with iPSCs being cultured with the neural induction medium and proceeding from there. Furthermore, Applicant’s examples identify that they generated oligodendrocyte progenitor cells that required further induction to generate oligodendrocytes (The results showed in Figure 2 that Olig2 and Nkx2.2 were co expressed in cells after inducing day 33, indicating a successful induction of OPC) but does not show that they generated MBP+ oligodendrocytes until day 37 of cultivation.
As such, the method of differentiating pluripotent stem cells into oligodendrocytes of the instant application requires a defined step-wise differentiation protocol that is not disclosed in claim 1.
Quantity of experimentation needed: In light of the above factors, the prior art and the Applicant disclose closely related multi-step differentiation protocols and that the cell type being added, the media composition, and the timing of each step is an important consideration for each step of the differentiation protocol. Therefore, a defined differentiation protocol is necessary to generate oligodendrocyte cells from pluripotent stem cells. As such, these essential steps are considered to be missing from claim 1. There would be undue experimentation related to any culturing method that does not have a defined multistep differentiation protocol in line with the prior art and the Applicant’s specification to practice the full scope of the claim.
Claims 12-19 are also rejected because of their dependency on claim 10.
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 10-19 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 10-11 and 18-19 contains the trademark/trade name B27 and claims 14 and 16-19 contains the trademark/trade name Glutamax-I. Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph. See Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case, the trademarks/trade names are used to identify/describe neuronal culture supplement (in the case of B27) and a an L-alanyl-L-glutamine dipeptide supplement (in the case of Glutamax-I) and, accordingly, the identification/description is indefinite.
Claims 12-19 are also rejected because of their dependence on claim 10.
Conclusion
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/KEENAN A BATES/Examiner, Art Unit 1631
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