DETAILED ACTION
This action is in reply to papers filed 10/27/2025.
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 .
Examiner’s Note
All paragraph numbers throughout this office action, unless otherwise noted, are from the US PGPub of this application US20240400984A1, Published 12/5/2024.
Election/Restrictions
Applicant’s election without traverse of claims 1 and 3-10 (Invention III), drawn to a method for converting non-neuronal cells into neurons or neural progenitor cells, characterized in that the method comprises reducing the expression or activity of a cell trans-differentiation factor, wherein the non-neuronal cells are terminally differentiated cells in the reply filed on 10/27/2025 is acknowledged.
Invention I (claims 1-2, 5-7, 10), drawn to a method for converting non-neuronal cells into neurons or neural progenitor cells, Invention II (claims 1, 5-7, 10), drawn to a method for converting non-neuronal cells into neurons or neural progenitor cells, Invention IV (claims 11-16), drawn to a method for the prevention or treatment of disease associated with neuronal dysfunction or death, Invention V (claims 17-19 and 21-23), drawn to a pharmaceutical composition or kit or reagent kit comprising the inhibitor according to claim 11 and Invention VI (claim 20), drawn to a pharmaceutical composition or kit according to claim 17, are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 10/27/2025.
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, 3- 10 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.
Regarding claims 1, 7 and 9, the phrase "such as" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Similarly, claims 1 and 3-10 each recite the phrase “preferably”. These claims are held indefinite as it is unclear the limitations following the phrase are part of the claimed invention. Per MPEP 2173.05 (c), description of examples and preferences is properly set forth in the specification rather than in a single claim.
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.
Claims 1 and 3-10 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 enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Enablement is considered in view of the Wands factors (MPEP 2164.01 (a)). The court in Wands states that “Enablement is not precluded by the necessity for some experimentation such as routine screening. However, experimentation needed to practice the invention must not be undue experimentation. The key word is ‘undue.’ Not ‘experimentation;” (Wands, 8 USPQ2d 104). 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 weighting many factual considerations.” (Wands, 8 USPQ2d 1404). The factors to be considered when determining whether there is sufficient evidence to support a determination that a disclosure does not satisfy the enablement requirement and whether any necessary experimentation required is “undue” include, but are not limited to:
• (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
Furthermore, the USPTO does not have laboratory facilities to test if an invention will function as claimed when working examples are not disclosed in the specification. Therefore, enablement issues are raised and discussed based on the state of knowledge pertinent to an art at the time of the invention. And thus, skepticism raised in the enablement rejections are those raised in the art by artisans of expertise.
All of the Wands factors have been considered with regard to the instant claims, with the most relevant factors discussed below.
The Nature of the Invention: The inventive concept in the instant application is a method of converting terminally differentiated cells into neuronal cells.
Amount of Direction Provided by Inventor/Working Examples: At para. 181, the specification discloses that in order to screen for neural conversion factors, the authors first constructed a CAG-LSL-CasRx mouse embryonic stem cell line (CasRx-mESCs), and further constructed a Tubb3-EGFP-CasRx-mESC cell line by knocking in an EGFP fluorescent reporting system at the Tubb3 locus. When Tubb3- EGFP-CasRx-mESCs differentiate into neurons, Tubb3 activates EGFP expression. By analyzing factors that are highly expressed in glial cells but low in neurons, we designed three gRNAs for each gene and constructed them into the Lenti-Cre backbone vector, which is the target lentiviral library Lenti-gRNAs-Cre. The Lenti-gRNAs-Cre library were then used to infect Tubb3-EGFP- CasRx-mESC cells and induced differentiation in induction medium, and enriched factors that promote mESCs differentiation into neurons through flow sorting (FIG. 1A). Each factor was then individually constructed into a lentiviral vector and used to infect Tubb3-EGFP-CasRx-mESC cell lines and induce differentiation (FIG. 1B). Flow cytometry analysis results showed that in the control group that did not target any sequence, the average percentage of Tubb3-EGFP-positive cells was approximately 2.96%, while in the groups containing gRNAs targeting different factors, the percentage of Tubb3-EGFP-positive cells increased significantly. Among them, the Tubb3-EGFP- positive cell proportion of the group targeting Plpp7, Fam126a, Gprc5c, Tmed4, Tlc6, Psmd5, Mastl, Ccdc8, Adck1, Gjb2, Smad9, Nr2el, Atp10b, Nid1, Tmcc3, Rad21, Amigo1, Rbm 10, Hnrnpa3, and other factor groups exceeded 12% (FIG. 1C).
To further study the function of these factors in promoting non-neuronal cells to produce neurons, the authors at para. 181 teach targeted genes such as Amigo1, Fam126a, Gjb2, and Gprc5c with Lenti-gRNA-Cre and imaged them under a fluorescence microscope. In the control group, only a very small number of green fluorescent cells were found, while in the experimental groups targeting Amigol, Fam126a, Gjb2, and Gprc5c, mESCs clearly underwent differentiation. Compared with the control group, the number of EGFP-positive cells increased significantly; and most of these EGFP-positive cells had typical neuronal morphological characteristics (FIG. 2 ). The authors conclude that above results indicate that these factors can promote non-neuronal cells to produce neurons.
At para. 182, the authors investigated whether the screened factors can promote the generation of mature neurons from non-neuronal cells (mESCs) using the mature neuronal protein marker (MAP2) for immunofluorescence staining. The results showed that after targeting Amigol and Gprc5c with CasRx and inducing differentiation, there were many cells expressing green fluorescence, and MAP2 staining also showed that most of these cells expressed MAP2 (FIG. 3A and 3B). The authors conclude that this indicates that the factors screened out through the Lenti-gRNAs-Cre library in the Tubb3- EGFP-CasRx-mESCs system can efficiently promote the generation of neurons from non-neuronal cells (mESCs), and can partially mature into MAP2-positive neurons.
Relevant to the pending claims, in Example 3 (starting at para. 185), the authors further investigated whether the factors selected in this study can induce glial cells to differentiate into neurons in vivo. In this experiment, the authors constructed an AAV-U6-gRNA-GFAP-CasRx system targeting the factors obtained from the screening. However, note that no results were provided for this experiment. In fact, no experimental results were provided for the transdifferentiation of any terminally differentiated cell into a neuron. This is problematic.
The State of the Prior Art: Carter et al. (Front Genome Ed. 2020 Sep 4:2:7.) teach canonical reprogramming strategies have focused on developing induced neurons (iNs) from donor cells of the ectoderm, such as mouse embryonic, tail-tip fibroblasts or human neonatal, and adult fibroblasts. However, a study co-expressed Brn2, Ascl1, Myt1l (BAM factors) in primary mouse hepatocytes to further investigate the feasibility of reprogramming cells derived from the endodermal lineage to iNs. The transcriptomic analysis performed in this study suggests that reprogramming across germ layers, or at least to a neuronal fate, is more challenging than fibroblasts to neurons. Indeed, Carter teaches single-cell transcriptomic analysis of primary neurons and hepatocyte-derived iN revealed similar expression of liver markers in hepatocyte-derived iN, suggesting these markers are transcriptional noise. Carter adds that in order for iN to provide accurate modeling systems for therapeutic drug discovery, it is critical for the donor cell's transcriptional network to be silenced or the impact retention has on neuronal function must be investigated (paragraph bridging Pg. 4-5). Huang et al. (Biosci Rep. 2024 Jan 25;44(1):BSR20231717) cautions that reprogramming fibroblasts into neurons requires transdifferentiation across lineages, which increases the difficulty of reprogramming. Additionally, fibroblast-transformed neurons must be transplanted into the brain, facing the obstacle of immune rejection. Therefore, scientists have targeted the widespread distribution of astrocytes in the CNS, which share a common origin with neurons originating from radial glial cells (Pg. 2, para. 1)
And although the specification provides a prophetic example of transdifferentiation of glial cells into neurons, Peng et al. (Front Aging Neurosci. 2022 May 19;14:885707.) provides a cautionary note. Indeed, Peng notes that while previous studies stating that knocking down of the gene Ptbp1 readily converted glial cells into neurons in young mice, such was difficult to achieve in older mice. In fact, one study critically showed that Ptbp1 deletion does not induce trans-differentiation of astrocytes into neurons in adult mouse retina and brain. Peng notes that controversies in this field have not yet been definitively resolved, suggesting that more rigorous genetic tools in the future to validate the report on the glial-to-neuron reprogramming (Pg. 9 ‘Conclusion and Perspective’). Rao et al. (Neuron. 2021 Dec 15;109(24):4094-4108.e5.) teach a previous study suggested that the ectopic expression of NeuroD1 could induce microglia-to-neuron conversion. However, Rao and colleagues unexpectedly found that NeuroD1 cannot convert microglia to neurons in mice. Instead, NeuroD1 expression induces microglial cell death (Abstract). In agreement with Peng’s teachings of unpredictability, Huang et al. adds that regional heterogeneity in astrocytes is critical in the determining the type of neuron that is transdifferentiated. For example, Huang teaches Ascl1 mainly induces GABAergic neurons, whereas Ngn2 mainly induces glutamatergic neurons. Furthermore, Ngn2-induced neurons in the neocortex exhibit glutamatergic properties, whereas neurons in the striatum are mainly striatal projection neurons. Further complicating matters, Huang teaches the combination of Ngn2 and Nurr1 results in efficient astrocyte reprogramming in the gray matter, yet no astrocyte transdifferentiation is observed in the white matter. Even further, Huang teaches the effectiveness of reprogramming varies depending on the environment. For example, in the AD model, reactive astrocytes are reprogrammed more effectively in older than in younger AD mice , indicating that reprogramming is influenced by both intrinsic cellular mechanisms and particular environmental cues (Pg. 12, para. 1). Thus, Huang concludes that there is an evident need for a better understanding of the cellular and molecular mechanisms by which the local environment directs glial-to-neuronal transdifferentiation.
In 2020, Qian et al. (Nature. 2020 Jun;582(7813):550-556.) showed that the knock down of the RNA-binding protein PTB in the midbrain of PD model mice could directly reprogram astrocytes in mice and humans into induced neurons (Abstract). However, as elaborated upon above, questions remain regarding the validity of this study. Nevertheless, an extensive review of the art by the Examiner shows that no other group since 2020 has shown that reducing the expression or activity of any non-PTB gene- including the genes set forth in the claims- directly reprograms any terminally differentiated cell into a neuron. Applicant’s lack of a working example, in this regard, only further exacerbates an unpredictability art.
Conclusion: In essence, the specification merely presents an idea of, and leaves it entirely up to the practitioner to determine whether the reduction of expression or activity of the at least one gene recited in claim 1 would produce the claimed effect (i.e. transdifferentiation of a terminally differentiated cell into a neuron). It has been established by legal decision that a patent is not a hunting license. It is not a reward for the search, but compensation for its successful conclusion. Tossing out the germ of an idea does not constitute an enabling disclosure. While every aspect of a generic claim need not have been carried out by an inventor, or exemplified in the specification, reasonable detail must be provided in order to enable the skilled artisan to understand and carry out the invention. It is true that a specification need not disclose what is well known in the art. However, that general, oft-repeated statement is merely a rule of supplementation, not a substitute for a basic enabling disclosure. It means that the omission of minor details does not cause a specification to fail to meet the enablement requirement under 35 USC 112, first paragraph.
Authorization to Initiate Electronic Communications
The examiner may not initiate communications via electronic mail unless and until applicants authorize such communications in writing within the official record of the patent application. See M.P.E.P. § 502.03, part II. If not already provided, Applicants may wish to consider supplying such written authorization in response to this Office action, as negotiations toward allowability are more easily conducted via e-mail than by facsimile transmission (the PTO's default electronic-communication method). A sample authorization is available at § 502.03, part II.
Conclusion
No claim is allowed.
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/TITILAYO MOLOYE/ Primary Examiner, Art Unit 1632