Notice of Pre-AIA or AIA Status
The examiner prosecuting the action has changed.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Application Status
The action is written in response to applicant’s correspondence received on 10/01/2025. Claims 1-5, 7-20, 22, and 30 are currently pending in the instant application.
Priority
The instant application claims priority to US provisional application 62/983,173, with an effective filing date of 2/28/2020.
Election/Restriction
Applicant’s election without traverse of the inventions of Group I (drawn to a circularized bispecific aptamer) in the reply filed on 10/1/2025 is acknowledged.
Applicant further elects the following species:
TfR for the second protein recited in claim 1 and 2.
L1CAM for the third protein in response to the TfR election of the second protein.
SEQ ID NO: 57, as recited in claims 20 and 30.
Claims 30 is withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Claims 19 and 22 withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 10/1/2025.
Claims 1-5, 7-18, and 20 are currently under examination on the merits.
Specification
The use of the term Glen Research Corp, ChemGenes, Sigma-Aldrich, Signal Chem, New England Biolabs, Fisher Scientific, Corning, amongst others, which is a trade name or a mark used in commerce, has been noted in this application. The term 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.
Drawings
The drawings filed on 8/3/2022 are objected to because Fig.1 uses the improper terminology of “Figure”. Correct terminology would be the abbreviation “Fig.”.
The drawings 8/3/2022 are objected to because Fig. 40 has listed SEQ ID NOs (SEQ ID NO: 25, 55, and X) that overlaps with Fig. 40D. Therefore, it is unclear what the figure is conveying.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
The drawings filed on 8/3/2022 are objected to under 37 CFR 1.83(a) because they fail to show key details such as sequence nucleotides, legends, or other defining characteristics as described in the specification. The following figures wherein such elements are unclear are Figs. 4, 11, 12, 14, 20B, 33B, 39, 41, 42, 43, and 44. Any structural detail that is essential for a proper understanding of the disclosed invention should be shown in the drawing. MPEP § 608.02(d). Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Color photographs and color drawings are not accepted in utility applications unless a petition filed under 37 CFR 1.84(a)(2) is granted. Any such petition must be accompanied by the appropriate fee set forth in 37 CFR 1.17(h), one set of color drawings or color photographs, as appropriate, if submitted via the USPTO patent electronic filing system or three sets of color drawings or color photographs, as appropriate, if not submitted via the via USPTO patent electronic filing system, and, unless already present, an amendment to include the following language as the first paragraph of the brief description of the drawings section of the specification: colored photographs are found on the supplementary filed drawings submitted on 4/30/2026.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
Color photographs will be accepted if the conditions for accepting color drawings and black and white photographs have been satisfied. See 37 CFR 1.84(b)(2).
Claim Objections
Claims 5 ,11, 12, 14, 15, and 18 are objected to because of the following informalities:
Regarding claims 5 and 18, “Gd+3” is improper as Gd3+ is more often used in the art.
Regarding claim 11 and 14, applicant recites “where the three” and “where all three”, where formal language should read “wherein”.
Regarding claim 12, applicant recites “wherein the second protein are TfR”. “Are” should be replaced with “is”.
Regarding claim 15, applicant recites “the elongated stems” however, claim 14 recites a singular “elongated stem”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
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 11-18 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.
MPEP § 2163.II.A3.(a).(i) states, “whether the specification shows that applicant was in possession of the claimed invention is not a single, simple determination, but rather is a factual determination reached by considering a number of factors. The factors to be considered when analyzing claims for compliance with the written description requirement include: (A) actual reduction to practice; (B) disclosure of drawings or structural chemical formulas; (C) sufficient relevant identifying characteristics (e.g., complete structure, partial structure, physical and/or chemical properties, structure/function correlation); (D) level of skill and knowledge in the art; and (E) predictability in the art.
For claims drawn to a genus, MPEP § 2163.II.A3.(a).(i) states, “written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species” where “representative number of species” means that the species which are adequately described are representative of the entire genus. Thus, when there is a substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus”.
Each of the factors (A)-(E) listed above is analyzed below along with interpretations of recited claims:
Regarding claim 1, applicant recites a bi-specific circularized DNA aptamer comprising a first oligonucleotide aptamer that binds to Tau protein and a second oligonucleotide aptamer that binds to a second protein , wherein the first oligonucleotide is ligated to the second oligonucleotide and the DNA aptamer penetrates the blood-brain barrier. Claim 7 is a separate independent claim that broadly recites any DNA aptamer comprising a DNA Tau aptamer and a protein aggregate binding moiety, without further structural limitations. Claim 11 recites a tri-specific circularized DNA aptamer comprising a first, second, and third oligonucleotide. Absent evidence to the contrary, applicant does not have possession of a tri-specific circularized aptamer, as claimed in claim 11.
Actual reduction to practice
For the actual reduction to practice, applicant discloses Example 11 (Neuronal Surface Adhesion Molecule L1CAM with Tau Targeting bispecific Aptamer or with Tau and TfR Trispecific Aptamer Improves Neuronal Cell Uptake of Aptamer), where a trispecific aptamer can cross both BBB and neuron cell membrane barrier, which will be practically applied into the real in vivo models for tauopathy studies (see paragraph 0199). Applicant does not disclose anywhere in the specification where the term trispecific and circularized is used to describe an aptamer structure, absent objective evidence to the contrary.
Disclosure of Drawings or Structural Chemical Formulas
For the disclosure of drawings, applicant presents Fig. 5B, which discloses the Y-shaped trispecific Tau-TfR-L1CAM/GLAST-1/and ACSA-2 aptamer. Applicant does not disclose anywhere in the specification where the term trispecific and circularized is used to describe an aptamer structure, wherein the tri-specific aptamer possess a ring like structure after circularization.
Sufficient Relevant Identifying Characteristics
Applicant discloses Fig.5B wherein a trispecific aptamer was constructed by fusing an TfR-binding aptamer to Tau aptamer and to a L1CAM/GLAST-1/ACSA-2 aptamers, respectively, which creates a y-shape tri-specific aptamer that (i) targets Tau for tauopathy mitigation, (ii) target L1CAM for neuron cell engagement and internalization or GLAST-1/ACSA-2 for astrocyte cell engagement and internalization, and (iii) targets TfR to facilitate brain vascular endothelial cell binding and to pass through the BBB. Applicant does not disclose anywhere in the specification where the term trispecific and circularized is used to describe an aptamer structure, absent objective evidence to the contrary.
The Level of Skill and Knowledge in the Art
The level of skill and knowledge in the art is high. A skilled artisan would need experience in aptamer design as well as understanding aptamer binding across cell-tissue and types.
Predictability in the Art
At the time of filing, the art is very unpredictable regarding tri-specific circularized aptamers. Tan et al. (Programmable Circular Multispecific Aptamer-Drug Engager to Broadly Boost Antitumor Immunity, J. Am. Chem. Soc., Volume 146, Issue 50, pgs. 34311-34323, published 12/4/2024), teaches of a circularized, trispecific DNA aptamer (Fig. 1B) targeting 3 proteins (PD-1, PD-L1, and c-Met), however, this is post filing date art. At the time of filing, the art only teaches bispecific circularized aptamers, as evidenced by Kuai et al. (Circular Bivalent Aptamers Enable in Vivo Stability and Recognition, J Am Chem Soc., Volume 139, Issue 27, pgs. 9128-9131, 7/12/2017).
In view of the foregoing, claims 11-18 are rejected for failing to comply with the written description requirement as claim 11 recites a trispecific circularized DNA aptamer. Based off the effective filing date of 2/28/2020, the art is silent on the use and design of trispecific circularized aptamers. Tan does disclose the use and creation of trispecific circularized DNA aptamers, however, almost 5 years after the EFD of the instant application. Furthermore, absent evidence to the contrary, the specification does not disclose a complete structure, or steps, on how to make or use a trispecific circularized DNA aptamer, only a Y-shaped aptamer.
Indefiniteness
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 8-10, 14 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 8-10, all claims recites “A DNA aptamer of claim 7”, wherein “A” should be “the” to comply with proper antecedent basis.
Regarding claim 9, Claim 9 depends on claim 7 and recites the limitations of claim 1. However, as written, claim 7 is an independent claim that does not recite the limitations of claim 1. Therefore, it is unclear if the limitations of claim 1 are incorporated into the DNA aptamer presented in claim 7.
Regarding claim 14, applicant recites “a 3’ end of the oligonucleotide aptamer” and where ligation occurs to “a 5’ end of one other oligonucleotide aptamer”. Claim 14 depends on claim 11 which recites 3 separate and distinct aptamers. It is unclear if the ligation formation of the Y-shape applies to a single aptamer or all aptamers recited.
Improper Markush Group
Claim 20 is rejected on the basis that it contains an improper Markush grouping of alternatives. See In re Harnisch, 631 F.2d 716, 721-22 (CCPA 1980) and Ex parte Hozumi, 3 USPQ2d 1059, 1060 (Bd. Pat. App. & Int. 1984). A Markush grouping is proper if the alternatives defined by the Markush group (i.e., alternatives from which a selection is to be made in the context of a combination or process, or alternative chemical compounds as a whole) share a “single structural similarity” and a common use. A Markush grouping meets these requirements in two situations. First, a Markush grouping is proper if the alternatives are all members of the same recognized physical or chemical class or the same art-recognized class, and are disclosed in the specification or known in the art to be functionally equivalent and have a common use. Second, where a Markush grouping describes alternative chemical compounds, whether by words or chemical formulas, and the alternatives do not belong to a recognized class as set forth above, the members of the Markush grouping may be considered to share a “single structural similarity” and common use where the alternatives share both a substantial structural feature and a common use that flows from the substantial structural feature. See MPEP § 2117.
The Markush grouping of claim 20 is improper because the alternatives defined by the Markush grouping do not share both a single structural similarity and a common use for the following reasons: The SEQ ID NOs: 1-15, 25-44, and 55-57 do not share structurally distinct or a core nucleotide sequences. A brief exemplary alignment of SEQ ID NO: 1 and 57 are shown below with low query score and 10 mismatches.
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231
727
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To overcome this rejection, Applicant may set forth each alternative (or grouping of patentably indistinct alternatives) within an improper Markush grouping in a series of independent or dependent claims and/or present convincing arguments that the group members recited in the alternative within a single claim in fact share a single structural similarity as well as a common use.
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.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Son et al. (US 2021/0332363 A1, published 10/28/2021, which claims priority to KR10-2018-0102941, filed on 8/30/2018) in view of Kuai et al. (Circular Bivalent Aptamers Enable in Vivo Stability and Recognition, J Am Chem Soc., Volume 139, Issue 27, pgs. 9128-9131, 7/12/2017), Xu et al. (A smart magnetic resonance imaging contrast agent responsive to adenosine based on a DNA aptamer-conjugated gadolinium complex, Chem. Commun., Volume 47, Issue 17, pgs. 4998-5000, published 3/22/2011), and MacDonald et al. (Development of a Bifunctional Aptamer Targeting the Transferrin Receptor and Epithelial Cell Adhesion molecule (EpCAM) for the Treatment of Brain Cancer Metastases, ASC Chemical Neuroscience, Volume 8, Issue 4, pgs. 777-784, published 12/23/2016).
Regarding claim 1, Son teaches an aptamer that penetrates the blood-brain barrier (BBB) and relates to an application of such an aptamer to complex combined with a substance that selectively binds to a target substance present in the brain (see abstract), wherein the aptamer can be bi-specific (see paragraph 0024). The “substance” of Son that selectively binds to a target substance in the brain can be a drug, chemical substance, aptamer, siRNA, ASO, miRNA…(see paragraph 0017), therefore suggesting two aptamers can complex together. Son teaches where the target substance present in the brain is …tau (see claim 5). Son further teaches where the substance that selectively binds a target in the brain and the aptamer passing through the BBB are preferably connected by a linker, but it is not limited thereto (see paragraph 0017).
Regarding claim 2, Son teaches where receptors known to transfer substances to the brain parenchyma through transcytosis include transferring receptor (see paragraph 0006).
Regarding claim 3, Son teaches the substance that selectively binds to the target substance present in the brain is labeled with a radioactive isotope (see claim 7). In another example, Son teaches where the bi-specific aptamer is labeled with a fluorescent substance on the side corresponding to the blood vessel (see paragraph 0054).
Regarding claim 4, Son teaches where the bi-specific aptamer is prepared and used as a positron emission tomography (PET) radiation contrast agent (aptamer-based radiotracer) to prevent aggregation of the target material to diagnose, prevent and treat Alzheimer’s disease or Parkinson’s disease at an early stage (see paragraph 0024).
Regarding claim 5, Son teaches broadly discloses wherein the labeling moiety is a “radioactive isotope” (see claim 7).
Regarding claim 1, Son does not teach where the bispecific aptamer is circularized.
Regarding claim 2, Son discloses that the most effective way to deliver substances through the BBB is through receptor binding, wherein the receptor targeted in many studies is Transferrin receptor (TfR). This is exemplified in the art by MacDonald, wherein MacDonald teaches a bifunctional aptamer in which a TfR-targeting arm drives receptor-mediated transport across the BBB endothelium and a second arm engages a second target (see results and discussion of MacDonald).
Regarding claim 5, Son does not teach where the signaling moiety is dodecane tetraacetic acid (DOTA).
Regarding claim 1, Kuai teaches circularization of bivalent aptamers which can improve thermal stability, nuclease resistance, and binding affinity (see abstract).
Regarding claim 5, Xu teaches a general strategy for developing a smart MRI contrast agent for sensing of small molecules such as adenosine based on a DNA aptamer that is conjugated to a Gd compound and a protein streptavidin (see abstract). Xu teaches new methods to couple aptamers to gadolinium-tetraazacyclododecanetetraacetic acid (DOTA-Gd) (see Fig. 1).
It would have been obvious to one skilled in the art, before the effective filing date of the claimed invention, to modify the teaching of Son, a bispecific DNA aptamer binding Tau and a second aptamer wherein the aptamer comprises a radio isotope, with the teachings of Kuai and Xu, to arrive at the instantly claimed inventions.
One would expect a reasonable chance of success as Kuai teaches the circularization of bivalent DNA aptamers formed by ligating two aptamer domains into a closed construct (see abstract and introduction/entire document). Therefore, Kuai teaches the method, reduced to practice, on a DNA aptamer, wherein the result of a nuclease-resistant bispecific aptamer retaining both binding functions is predictable (See MPEP § 2143(I)(C)). MacDonald teaches where an aptamer comprise a TfR-targeting arm that drives receptor-mediated transport across the BBB. Furthermore, Xu teaches a DNA aptamer-based magnetic resonance imaging contrast agent in which DOTA-Gd is covalently conjugated and used as a contrasting agent. It would have been obvious for a skilled artisan to employ DOTA or DOTA-Gd as the signaling moiety construct in Son as Son broadly discloses a radioisotope labeling for PET, but no chelation chemistry. A radiometal cannot be employed without a chelator, and a skilled artisan practicing Son’s disclosed imaging embodiment would need to select from a small set of macrocyclic chelators available for oligonucleotide conjugation. Xu established DOTA-Gd conjugation to DNA by amine coupling was routine and effective as an applicable method. The selection of DOTA or DOTA-Gd as the signal moiety is the application of a known technique to a known device or composition ready for improvement to yield predictable results, and presents a finite number of identified, predictable solutions. See MPEP § 2143(I)(C) and (E). KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007).
One would be motivated to do so as Kuai teaches circularization of DNA aptamers stabilizes bivalent aptamer constructs against nuclease degradation without post-selection chemical modification (see abstract of Kuai). The teachings of MacDonald allows for the DNA aptamer construct to efficiently cross the BBB and the use of the DOTA-Gd signaling moiety would allow a practicing artisan to image aggregate distribution in the brain, wherein Son teaches abnormally aggregated proteins cause apoptosis of nerve cells and cause disease (see paragraph 0002 of Son).
In view of the foregoing, claims 1-5 are rejected under 35 U.S.C. 103 as being prima facie obvious, before the effective filing date.
Claims 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Son et al. (US 2021/0332363 A1, published 10/28/2021, which claims priority to KR10-2018-0102941, filed on 8/30/2018) in view of Kuai et al. (Circular Bivalent Aptamers Enable in Vivo Stability and Recognition, J Am Chem Soc., Volume 139, Issue 27, pgs. 9128-9131, 7/12/2017), MacDonald et al. (Development of a Bifunctional Aptamer Targeting the Transferrin Receptor and Epithelial Cell Adhesion molecule (EpCAM) for the Treatment of Brain Cancer Metastases, ASC Chemical Neuroscience, Volume 8, Issue 4, pgs. 777-784, published 12/23/2016), Teng et al. (Identification and Characterization of DNA Aptamers Specific for Phosphorylation Epitopes of Tau Protein, J. Am. Chem. Soc., Volume 140, Issue 43, pgs. 14314-14323, published 10/16/2018), Wischik et al. (Selected inhibition of Alzheimer disease-like tau aggregation by phenothiazines, PNAS, Volume 93, Issue 20, pgs. 11213-11218, published 10/1/1996), and Pheeney et al. (DNA Electrochemistry with Tethered Methylene Blue, Langmuir, Volume 28, Issue 17, pgs. 7063-7070, published 5/1/2012).
Regarding claim 7, Son teaches where the bispecific aptamer can comprise a substance targeting moiety (which can be Tau according to claim 5) (see paragraph 0017 and 0024) and example 1, where aptamers that specifically bind α-synuclein monomer/oligomer are treated. The degree of aggregation and decomposition of α-synuclein was confirmed through western blot (see paragraph 0034). An oligomer that binds to α-synuclein which aggregates reads on a protein aggregate binding moiety. Furthermore, Son identifies aggregating proteins including α-synuclein, superoxide dismutase (SOD1), or amyloid beta as target substances (see claim 5).
Regarding claim 9, the combined teachings of Son, Kuai, and MacDonald teach a bispecific aptamer according to claim 1 (see claim 1).
Regarding claim 7 and 8, Son does not teach where the aptamer is expressly a DNA aptamer (but does suggest it as the aptamers were designed using SELEX technology using ssDNA), or where the DNA Tau aptamer is IT2a.
Regarding claim 10, Son does not teach wherein the protein aggregate binding moiety is methylene blue.
Regarding claim 7 and 8, Teng teaches tau epitope-specific aptamers, specifically DNA aptamers, and IT2a (see section titled “Sequence Truncation of the Selected Aptamers” and Determination of Binding Kinetics/Affinities of the Selected Aptamers”).
Regarding claim 10, Wischik discloses methylene blue binds tau through the repeat domain and blocks tau-tau binding interaction responsible for paired helical filament assembly and blocks the tau-tau binding interaction that drives PHF assembly, and reverses the proteolytic stability of already formed filaments (see abstract). Thus, Wischik teaches methylene blue is a known protein aggregate binding moiety directed to Tau. Pheeney teaches methylene blue covalently attached to DNA through a flexible C12 alkyl linker, which provides a sensitive redox reporter in DNA electrochemistry measurements. Thus, Pheeney teaches a stable conjugate in which methylene blue remains functionally accessible (see abstract and introduction of Pheeney).
It would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to modify the teachings of Son with the teachings of Kuai, MacDonald, Teng, Wischik, and Pheeney, to arrive at the instantly claimed invention.
One would expect a reasonable chance of success as Son teaches a bispecific aptamer that can bind Tau and the structure of the bispecific aptamer is rendered obvious by the teachings of Kuai and MacDonald, as described above. Teng teaches where I2Ta is a DNA Tau aptamer that binds to Tau441 almost 50 times faster than IT2 (see section titled “Determination of Binding Kinetics/Affinities of the Selected Aptamers), and a skilled artisan would recognize that IT2a as a DNA Tau aptamer would be a substitution of the generic Tau aptamer disclosed by Son, wherein the simple substitution of a known structure with the same function would yield predictable results (see MPEP § 2143(I)(B)).
Furthermore, Wischik teaches that methylene blue is a known protein aggregate binding moiety directed to Tau (see above). One of ordinary skill would have had a reasonable expectation of success because Pheeney demonstrates routine covalent conjugation of methylene blue to DNA oligonucleotides, and the combination amounts to the use of a known compound for its known purpose to achieve a predictable result (see MPEP § 2144.07)
One would be motivated to do so as since Son discloses that the second component of the complex described binds protein aggregates, but does not restrict the component to an aptamer and contemplates the binding substance may be selected from several classes of molecules (see paragraph 0016), therefore Son invites an artisan to select from the known art any moiety that has aggregate-binding activity against the desired target. Therefore, the combined teachings would allow a complex to bind Tau through IT2a with much higher efficiency and the use of methylene blue as an aggregate-binding moiety would block the tau-tau binding interaction and reverse the proteolytic stability of protease-resistant filaments, potentially allowing for the breakdown of such aggregates.
In view of the foregoing, claims 7-10 is rejected under 35 U.S.C. 103 as being prima facie obvious, before the effective filing date.
Claims 11-18 are rejected under 35 U.S.C. 103 as being unpatentable over Son et al. (US 2021/0332363 A1, published 10/28/2021, which claims priority to KR10-2018-0102941, filed on 8/30/2018) in view of Kuai et al. (Circular Bivalent Aptamers Enable in Vivo Stability and Recognition, J Am Chem Soc., Volume 139, Issue 27, pgs. 9128-9131, 7/12/2017), MacDonald et al. (Development of a Bifunctional Aptamer Targeting the Transferrin Receptor and Epithelial Cell Adhesion molecule (EpCAM) for the Treatment of Brain Cancer Metastases, ASC Chemical Neuroscience, Volume 8, Issue 4, pgs. 777-784, published 12/23/2016), Xu et al. (A smart magnetic resonance imaging contrast agent responsive to adenosine based on a DNA aptamer-conjugated gadolinium complex, Chem. Commun., Volume 47, Issue 17, pgs. 4998-5000, published 3/22/2011), Wang et al. (Imaging of Neurite Network with an Anti-L1CAM Aptamer Generated by Neurite-SELEX, J. Am. Chem. Soc., Volume 140, Issue 51, pgs. 18066-18073, published 12/26/2018), and Cansiz et al. (DNA Aptamer Based Nanodrugs: Molecular Engineering for Efficiency, Chem Asian J., Volume 10, Issue 10, pgs. 2084-2094, published 10/1/2016).
Regarding claim 11, the combined teachings of Son, Kuai, Xu, and MacDonald teach a circularized bispecific DNA aptamer wherein the first oligonucleotide aptamer binds to Tau protein, the second oligonucleotide aptamer binds to a second protein, and where the aptamer is capable of penetrating the blood brain barrier (see the rejection above).
Regarding claim 12, MacDonald teaches a bifunctional aptamer in which a TfR-targeting arm drives receptor-mediated transport across the BBB endothelium and a second arm engages a second target (see results and discussion of MacDonald) and Son further discloses the use of TfR receptor binding aptamers to cross the BBB (see paragraph 0006).
Regarding claim 16, Son teaches the substance that selectively binds to the target substance present in the brain is labeled with a radioactive isotope (see claim 7). In another example, Son teaches where the bi-specific aptamer is labeled with a fluorescent substance on the side corresponding to the blood vessel (see paragraph 0054).
Regarding claim 17, Son teaches where the bi-specific aptamer is prepared and used as a positron emission tomography (PET) radiation contrast agent (aptamer-based radiotracer) to prevent aggregation of the target material to diagnose, prevent and treat Alzheimer’s disease or Parkinson’s disease at an early stage (see paragraph 0024).
Regarding claim 18, Xu teaches a general strategy for developing a smart MRI contrast agent for sensing of small molecules such as adenosine based on a DNA aptamer that is conjugated to a Gd compound and a protein streptavidin (see abstract). Xu teaches new methods to couple aptamers to gadolinium-tetraazacyclododecanetetraacetic acid (DOTA-Gd) (see Fig. 1).
Regarding claim 11, Son, Kuai, Xu and MacDonald does not teach where the DNA aptamer is tri-specific circularized DNA aptamer comprising a third oligonucleotide aptamer that binds to a third protein, where the three oligonucleotide aptamers are ligated and annealed to each other to form a Y-shape.
Regarding claim 13, Son, Kuai, and MacDonald does not teach where the third protein comprises L1CAM, GLAST-1, or ACSA-2.
Regarding claim 14, Son, Kuai, and MacDonald does not teach wherein the 3’ end of the oligonucleotide aptamer contains an elongated stem that is ligated to a 5’ end of one other oligonucleotide aptamer for formation of the y-shaped where all three oligonucleotide aptamers are bound together.
Regarding claim 15, Son, Kuai, and MacDonald does not teach wherein the elongated stems have complementary sequences that hybridizes for formation of the y-shape.
Regarding claim 11, 14 and 15, Wu teaches a trivalent, multifunctional aptamer-based DNA nanoassembly (AptNA) that employes various Y-shaped functional DNA domains through predesigned base pair hybridization, including targeting aptamers, anticancer drugs, and therapeutic antisense oligonucleotides (see abstract). Such domains are assembled through hybridization with complementary connector strands.
Regarding claim 13, Wang teaches a neurite-SELEX strategy for generating a DNA aptamer, which strong binds neurites, and the molecular target was identified as L1CAM (see abstract).
It would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to modify the bispecifc aptamer taught by the combination of Son, Kuai, MacDonald, and Xu with the teachings of Wu and Wang, to arrive at the instantly claimed invention, or a trispecific circular DNA aptamer, wherein the aptamer binds Tau, TfR1, and L1CAM.
One would expect a reasonable chance of success as Son contemplates that the brain-target-binding component may be an aptamer and where the target substance can be directed to tau (see claim 5). MacDonald teaches where aptamers targeting TfR can be used to transport aptamers across the BBB (which is also briefly mentioned in Son) and Wang teaches where L1CAM is another molecular target of DNA aptamers, wherein the target is in the brain, specifically neurites. Wu reduces to practice a trivalent Y-shaped aptamer with functionalized DNA domains and Kuai teaches circularization of bivalent DNA aptamer constructs with retention of binding function. Each modification has been separately demonstrated on DNA aptamer constructs and the combination yields the predictable result of a nuclease-resistant three-armed construct retaining the binding function of each arm. See MPEP § 2143(I)(A) and (C).
While Wang discloses the Y-shaped structure, Wang does not use the terminology “elongated stems”, as recited in the instant claims. However, a Y-shaped junction assembled from three oligonucleotide aptamers requires a junction-forming duplex sequence at the point of convergence, as evidenced by Wang. An artisan constructing a junction from three aptamers faces a limited number of identified, predictable ways of supplying the sequence, whether it is extending the aptamer termini so the aptamers themselves form the junction, or introducing a separate connector strands to which the aptamers hybridize. Selection among a small and finite set of known design options with predictable outcomes is obvious, wherein a skilled artisan would play with aptamer length and structure for the formation of the Y-shape as it would be “obvious to try”, KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007); MPEP § 2143(I)(E). Extending the terminal region of an oligonucleotide to a length sufficient for stable duplex formation is a change in dimension of a known structure, and absent evidence showing that the recited elongation is critical, such a change does not confer patentability. See MPEP § 2144.04. Though Wang is directed towards delivery cancer therapeutics, the composition presented by Wang relates to DNA aptamer binding targeting specific domains, which is well-covered in the art and wherein the simple substitution or improvement of the composition of Son would yield predictable results.
Furthermore, Xu teaches a DNA aptamer-based magnetic resonance imaging contrast agent in which DOTA-Gd is covalently conjugated and used as a contrasting agent. It would have been obvious for a skilled artisan to employ DOTA or DOTA-Gd as the signaling moiety construct in Son as Son broadly discloses a radioisotope labeling for PET, but no chelation chemistry. A radiometal cannot be employed without a chelator, and a skilled artisan practicing Son’s disclosed imaging embodiment would need to select from a small set of macrocyclic chelators available for oligonucleotide conjugation. Xu established DOTA-Gd conjugation to DNA by amine coupling was routine and effective as an applicable method. The selection of DOTA or DOTA-Gd as the signal moiety is the application of a known technique to a known device or composition ready for improvement to yield predictable results, and presents a finite number of identified, predictable solutions. See MPEP § 2143(I)(C) and (E). KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007).
One would be motivated to do so as the combined teachings would result in trispecific circularized DNA aptamer where Son and MacDonald disclose TfR allows for the DNA aptamer to pass the BBB and to target Tau. Circularization of the aptamer would result in nuclease resistance, as taught by Kuai, and the trispecific structure, taught by Wu would allow for 1) an easy, modular design, 2) integrated multifunctionality, 3) high programmability, 4) good biostability, and 5) excellent biocompatibility, wherein the third aptamer targeting L1CAM, as disclosed by Wang (see conclusion), would allow the DNA aptamer to have further specificity in targeting neurons once the aptamer passes the BBB.
In view of the foregoing, claims 11-18 are rejected under 35 U.S.C. 103 as being prima facie obvious, before the effective filing date.
Conclusion
No claims are allowed.
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/D.T.Y./Examiner, Art Unit 1635
/RAM R SHUKLA/Supervisory Patent Examiner, Art Unit 1635
