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 .
Election/Restrictions
Applicant’s election without traverse of Group 1, claims 1-10, 12, 14, 16, 18-20, and 31 in the reply filed on 11 February 2026 is acknowledged.
Claims 25, 29, and 33 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 11 February 2026.
Claim Status
Claims 3-8, 10, 12, 14, 16, 18-20, 25, 29, 31, and 33 were previously amended, claims 11, 13, 15, 17, 21-24, 26-28, 30, 32, and 34-36 were previously canceled, claims 25, 29, and 33 have been withdrawn, and claims 1-10, 12, 14, 16, 18-20, and 31 have been considered on their merits.
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 1-10, 12, 14, 16, 18-20, and 31 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 applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 and its dependent claims, broadly discloses an in vitro method for inducing differentiation of stem cells, comprising contacting the stem cells with any inhibitor of SMAD signaling, any inhibitor of WNT signaling, and any inhibitor of Notch signaling to arrive at a cell comprising at least one cortical excitatory neuron marker.
The scope of the required inhibitors is extensive including multiple classes of molecule, such as, any small molecule, secreted protein ligand antagonist, protein fragments, siRNA, antisense nucleic acid, aptamer, antibody, and dominant negative mutants.
Claims 9, 12, 14, and 16 disclose more specific inhibitors, yet also include multiple classes of compounds and/or “derivatives thereof”, which encompasses inhibitors including anything yet to be discovered through trial and error experimentation.
The instant specification only discloses one example of differentiating stem cells to cortical excitatory neurons, the method comprising specific inhibitors SB431542, LDN193189, XAV939, and DAPT, which are all small-molecule signaling pathway modulators. However, considering the broad scope of any signal inhibitor, it is not predictable that any signal inhibitor would produce the same outcome, i.e., inducing differentiation of stem cells, as described. The instant specification does not provide sufficient written description to support the entire scope of any signal inhibitor or derivatives thereof.
M.P.E.P. §2163 recites, “The written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice, reduction to drawings, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus…when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. For inventions in an unpredictable art, adequate written description of a genus which embraces widely variant species cannot be achieved by disclosing only one species within the genus.”
Considering the broad scope of the claimed invention with regard to any SMAD, WNT, and Notch signal inhibitor, and limited disclosure of the method of differentiating stem cells to cortical excitatory neurons with specific small molecules and lack of additional disclosure, it is concluded that the inventors did not have possession on the subject matter commensurate with the entire scope of the claimed invention.
It is recommended to include the specific species of molecule to be utilized as signal inhibitors in claim 1.
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 2 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.
Claim 2 recites “…wherein the cells the initial contact of the cells…” in the first line of the claim. The scope of this statement is unclear and thus indefinite. The language of a claim must make it clear what subject matter the claim encompasses to adequately delineate its "metes and bounds". See, e.g., the following decisions: In re Hammack, 427 F 2d. 1378, 1382, 166 USPQ 204, 208 (CCPA 1970); In re Venezia 530 F 2d. 956, 958, 189 USPQ 149, 151 (CCPA 1976); In re Goffe, 526 F 2d. 1393, 1397, 188 USPQ 131, 135 (CCPA 1975); In re Watson, 517 F 2d. 465, 477, 186 USPQ 11, 20 (CCPA 1975); In re Knowlton 481 F 2d. 1357, 1366, 178 USPQ 486, 492 (CCPA 1973).
For examination purposes the claim will be interpreted as this statement meaning “wherein the initial contact of the cells…” in the first line of the claim.
Appropriate correction is required.
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.
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 1-10, 12, 14, 16, 18-20, and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Studer et al. (US 2016/0115448 A1, published 28 April 2016, IDS ref.) in view of Hansen et al. (Neuron 70, May 26, 2011, IDS ref.) and Eiraku et al. (Cell Stem Cell 3, 519-532, November 6, 2008).
Regarding claim 1, Studer teaches methods of deriving neuronal cells from stem cells via inhibiting SMAD and Wnt signaling pathways (Abstract). Studer teaches markers for the derived neuronal cells include one or more of FOXG1, MAP2, and CTIP2 (cortical excitatory neuron markers) (para. [0023]). Studer teaches contacting with SMAD inhibitors and/or contacting with Wnt signaling antagonists can be carried out simultaneously or can be carried out sequentially for a duration from about 5 days to about 30 days (para. [0033]). Studer teaches Wnt antagonists can be initiated from 0 days to about 5 days after contacting the cells with a SMAD signal inhibitor and/or Wnt signal antagonist (para. [0033]). Studer teaches with the addition of a wither DKK1 or XAV939 to the dual SMAD inhibition protocol resulted in a significant increase in the percentage of FOXG1+ cells (para. [0055] and Fig. 1B). Studer teaches with the addition of DKK1 about 80% of the cells expressed FOXG1 and with the addition of XAV939 up to about 95% of the cells expressed FOXG1 (Fig. 1B).
Studer does not teach contacting the cells with a Notch signaling inhibitor.
However, Hansen teaches approaches to generate specific subtypes of excitatory cortical neurons from pluripotent stem cells (Abstract). Hansen teaches different subtypes of cortical excitatory neurons, the layers from which they derive, and associated markers (Table 1). Hansen teaches aggregate culture techniques wherein the cells were treated with inhibitors of Wnt and Nodal signaling during the initial period of neural specification (p. 647, Aggregate Cultures). Hansen teaches Production of layer I neurons (Reelin+) occurred first, subcortical projection neurons (Tbr1+, Ctip2+) second, and callosal projection neurons (Brn2+, Satb2+, Cux1+) third (p. 648, Aggregate Cultures). Hansen teaches alternative approaches are needed to achieve single neuron subtype production, wherein timed application of the Notch pathway inhibitor DAPT has been used to force the differentiation of all progenitor cells at a given time (p. 652, 2nd column). Hansen teaches it may be possible to overload the cells with Notch ligand to prevent neurogenesis while the cells’ neurogenic competence advances, wherein, at the desired time, DAPT can be added to drive differentiation to the desired laminar subtype (p. 653, 1st column). Hansen teaches SFEBq aggregates appear to autonomously produce the right factors in the right combination and levels to mimic the developing cortical neuroepithelium (p. 653, 2nd column).
Hansen does not specify the timing of the addition of the Notch signal inhibitor, but suggests the timed application of DAPT to direct differentiation to specific neuron subtypes.
Eiraku teaches the in vivo-mimicking birth order of distinct cortical neurons permits the selective generation of particular layer-specific neurons by timed induction of cell-cycle exit (Abstract). Eiraku teaches spatial and temporal aspects of early corticogenesis can be manipulated in ESC culture (Abstract). Eiraku teaches serum-free suspension culture of embryoid body-like aggregates (SFEB)-culture mESCs differentiate into Bf1 (FoxG1)+ telencephalic progenitors at a moderately high frequency (p. 519, Introduction). Eiraku teaches dissociated mESCs were cultured in low cell-adhesion plates, wherein, the cells reaggregated quickly and the majority (89%; day 10) of the FoxG1+ progenitors generated in the modified SFEB culture (SFEBq) coexpressed the bona fide cortical marker Emx1 (p. 519, Results). Eiraku teaches in vivo development of the cortical hem and choroid plexus requires Wnt and BMP signals (p. 523, 1st column), which suggests inhibiting these signals would promote development of cortical neurons.
Eiraku teaches early-born Reelin+ neurons and early CP neurons (Ctip2+) can be preferentially generated by timed control of neuronal induction in SFEBq culture (p. 524). Eiraku teaches ESCs were cultured in SFEBq, followed by suspension culture in the presence of the Notch inhibitor DAPT, which promotes neuronal differentiation from mitotic progenitors (p. 525, 1st column). Eiraku teaches the birth of Reelin+ (layer I), Tbr1+/FoxG1+ (layer VI), Ctip2+/Emx1+ (layer V), and Brn2+/Tuj1+ (layer II/III) neurons peaked on days 8-10, 9-10, 10-11, and 12-13, respectively (p. 523, 2nd column). Eiraku teaches cortical neuronal differentiation occurred slightly more slowly in ESCs and Ctip2+ expressing appeared about 0.5 to 1 day later than in the wild-type ESCs (p. 525, 1st column). Eiraku teaches administration of DAPT at days 9 and 12 (Fig. 5J), wherein the percentage of Reelin+ cells was between 53 and 60% (Fig. 5N). The initial administration of DAPT on day 9 reads as at least about 10 days, as the instant specification defines the term “about” as a range of up to 20%, which would be 8-12 days (section 5.1. Definitions, p. 6). Eiraku teaches Notch may provide one of the key signals which supports the maintenance of neuroepithelia, given the acceleration of the disappearance of the rosette structure being accelerated by DAPT treatment during days 8-10 (p. 529, 1st column). Eiraku demonstrates the timing involved with the development of neuronal cells, however, does not teach the administration of SMAD or Wnt signaling inhibitors, yet suggests their role in the development of cortical neurons.
Therefore, it would have been obvious to one of ordinary skill in the art to include the Notch pathway inhibitor of Hansen and Eiraku with the method of Studer with a reasonable expectation of success because Studer, Hansen, and Eiraku all teach differentiation of stem cells into neurons. One would be motivated to include the Notch pathway inhibitor of Hansen and Eiraku with the method of Studer because Hansen teaches timed application of DAPT can control the laminar subtype which would facilitate the production of the desired neuron subtype. Additionally, the teachings of Hansen in view of Eiraku suggest the addition of the Notch signal inhibitor at about 10 days from the initial contact of the cells with at least one SMAD signal inhibitor would result in the development of cortical neurons comprising cortical excitatory neuron markers.
Regarding claim 2, it is noted that none of the references specifically teach contacting the cells with a Notch signal inhibitor about 20 days from the initial contact of the cells with a SMAD signal inhibitor. However, the timing of the administration of the inhibitors would have been readily optimizable by one having ordinary skill in the art by routine experimentation in order to achieve the desired cells expressing cortical excitatory neuron markers. 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.
Additionally, Hansen teaches there are multiple differences between human and mouse cortical development which contribute to the difficulty of deriving cortical neurons from human pluripotent cells, not the least of which is the hugely protracted time course of human development compared to the mouse (p. 656, Conclusion), which highlights the differences in timing regarding initial cell type. Therefore, optimizing the time periods is critical to controlling the outcome of the contacted cells.
Regarding claim 3, Eiraku teaches administration of DAPT at days 9 and 12 (Fig. 5J), wherein the percentage of Reelin+ cells was between 53 and 60% (Fig. 5N). The teachings of Eiraku read as the cells are contacted with DAPT, the Notch signal inhibitor, for at least 3 days, thus read as at least 1 day as required by the claim.
Regarding claims 4-5, it is noted that none of the references specify the length of time in which the cells are contacted with the Notch signal inhibitor. However, the timing of the administration of the inhibitors would have been readily optimizable by one having ordinary skill in the art by routine experimentation in order to achieve the desired cells expressing cortical excitatory neuron markers. 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. Additionally, Hansen teaches it may be possible to overload the cells with Notch ligand to prevent neurogenesis while the cells’ neurogenic competence advances, wherein, at the desired time, DAPT can be added to drive differentiation to the desired laminar subtype (p. 653, 1st column). Therefore, depending on the type of cell being differentiated and the desired marker expression profile, through routine experimentation, would arrive at contacting the cells with the Notch signal inhibitor for about 10 days (claim 5) and/or up to about 20 days (claim 4).
Regarding claim 6, Studer teaches contacting with SMAD inhibitors and/or contacting with Wnt signaling antagonists can be carried out simultaneously or can be carried out sequentially for a duration from about 5 days to about 30 days (para. [0033]). Contacting the cells with at least one SMAD signaling inhibitor for about 10 days falls within the range disclosed by Studer. 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). See MPEP 2144.05.
Regarding claim 7, Studer teaches Wnt antagonists can be initiated from 0 days to about 5 days after contacting the cells with a SMAD signal inhibitor and/or Wnt signal antagonist (para. [0033]).
Studer does not specify contacting the cells with a Wnt signal inhibitor for up to about 3 days (claim 7). However, the timing of the administration of the inhibitors would have been readily optimizable by one having ordinary skill in the art by routine experimentation in order to achieve the desired cells expressing cortical excitatory neuron markers. 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. Therefore, depending on the type of cell being differentiated and the desired marker expression profile, through routine experimentation, one would arrive at contacting the cells with the Wnt signal inhibitor for up to about 3 days. Additionally, as indicated in the teachings of Studer, Eiraku, and Hansen; the timing of the inhibitors would be determined based on the type of neuron being developed.
Regarding claims 8-9, Hansen teaches the inhibitor of Notch signaling is DAPT (claim 9) (p. 652, 2nd column), a γ-secretase inhibitor (claim 8).
Regarding claims 10, 12, and 14, Studer teaches SMAD inhibitors (claim 10) can be selected from the group consisting of SB431542 (claim 12), LDN-193189, Noggin, and Dorsomophin (claim 14) (para. [0034]). Studer teaches two or more SMAD signaling inhibitors can comprise dual-SMAD inhibitors SB431542 and LDN-193189 (para. [0034]).
Regarding claim 16, Studer teaches Wnt signaling antagonists can be selected from the group consisting of XAV939, DKK1, IWP2, IWR1, Wnt-059, and IWP-L6 (para. [0035]).
Regarding claim 18, Studer teaches markers for the derived neuronal cells include one or more of FOXG1, MAP2, and CTIP2 (para. [0023]).
Regarding claim 19, Hansen teaches cortical excitatory neurons comprise derived from pluripotent stem cells comprise different markers depending on which layer neuron is represented, such as, layer V derived neurons express Ctip2, layer VI derived neurons express Tbr1, and layer II-IV express Satb2 (Table 1). Therefore, depending on the desired cell type, the derived neurons would not express either Ctip2 and/or Satb2.
Regarding claim 20, Studer teaches neurons can be efficiently induced in vitro by contacting totipotent, pluripotent, and/or multipotent cells; as an example, human embryonic stem cells (para. [0016]).
Regarding claim 31, Studer teaches compositions comprising one and preferably two or more SMAD inhibitors (claim 31a) and one or more Wnt antagonists (claim 31b) and compositions and formulations, including pharmaceutically appropriate compositions and formulations, comprising one or more activators of SHH signaling as well as kits comprising one, two, or more SMAD inhibitors, and one or more Wnt antagonists, and optionally instructions for use to prepare one or more neurons of the foregoing type or precursors thereof (claim 31d) (para. [0017]).
Studer does not teach the at least one Notch signal inhibitor.
However, Hansen teaches approaches to generate specific subtypes of excitatory cortical neurons from pluripotent stem cells (Abstract). Hansen teaches different subtypes of cortical excitatory neurons, the layers from which they derive, and associated markers (Table 1). Hansen teaches aggregate culture techniques wherein the cells were treated with inhibitors of Wnt and Nodal signaling during the initial period of neural specification (p. 647, Aggregate Cultures). Hansen teaches Production of layer I neurons (Reelin+) occurred first, subcortical projection neurons (Tbr1+, Ctip2+) second, and callosal projection neurons (Brn2+, Satb2+, Cux1+) third (p. 648, Aggregate Cultures). Hansen teaches alternative approaches are needed to achieve single neuron subtype production, wherein timed application of the Notch pathway inhibitor DAPT has been used to force the differentiation of all progenitor cells at a given time (claim 31c) (p. 652, 2nd column). Hansen teaches it may be possible to overload the cells with Notch ligand to prevent neurogenesis while the cells’ neurogenic competence advances, wherein, at the desired time, DAPT can be added to drive differentiation to the desired laminar subtype (p. 653, 1st column).
Therefore, it would have been obvious to one of ordinary skill in the art to include the Notch pathway inhibitor of Hansen with the kit of Studer with a reasonable expectation of success because Studer and Hansen both teach differentiation of stem cells into neurons. One would be motivated to include the Notch pathway inhibitor of Hansen with the kit of Studer because Hansen teaches timed application of DAPT can control the laminar subtype which would facilitate the production of the desired neuron subtype.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
Conclusion
No claims are allowed.
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/N.A.H./Examiner, Art Unit 1631
/LAURA SCHUBERG/Primary Examiner, Art Unit 1631
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