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 .
Application Status
The preliminary amendment filed 09/12/2024 has been acknowledged and entered. Claims 2-3 5-6, 9, 11, 13-16, 18, 22-23 are amended. Claims 7-8, 12, 19-21, 24-32, and 34-42 are canceled. Claims 43-44 are newly added. Claims 1-6, 9-11, 13-18, 22-23, 33 and 43-44 are pending and being examined on the merits.
Priority
The application is a 371 PCT of CA2022/051521 filed 10/14/2022 which claims priority to application 63/262,523 filed 10/14/2021.
Information Disclosure Statement
The information disclosure statements filed 4/12/2024, 06/27/2024, and 10/24/2025 have been considered.
Specification
The disclosure is objected to because of the following informalities:
Cell signaling on page 21 is misspelled.
Biorad should be amended to Bio-Rad.
Appropriate correction is required.
The use of the term Adobe, Oxford Instruments, Zeiss, Fisher Scientific, Abcam, Bio-rad, Invitrogen, Gibco, and Lonza 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.
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 1-6, 9-11, 13-18, 22-23, 33 and 43-44 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 1-2, 6, 10-11, 15, 17-18, 23, and 43 recite “e.g.” in parenthesis. This language renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 4 recites that the lipid component comprises “a molar ratio of between 30 to 70, 35 to 65, 40 to 60, 47 to 57, 45 to 55%, or about 35, 40, 45, 50, 55, 60, 65, or 70% of the ionizable cationic unsaturated lipid.” The claim fails to identify the components forming the recited molar ratio. Furthermore, the numerical ranges are expressed inconsistently, with some ranges lacking percentage units and others expressly reciting percentages. It is therefore unclear whether the claim requires a molar ratio between the ionizable lipid and another lipid component, a mole percentage of the ionizable lipid relative to total lipid, or another compositional relationship. Although the specification describes corresponding compositional ranges [Specification, p. 7], the claim does not distinctly identify the intended quantitative relationship.
Regarding claim 6, the term “suitable volumes” is a relative term which renders the claim indefinite. The term “suitable volumes” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
Claim 13 recites the limitation "the subject" in line 3. There is insufficient antecedent basis for this limitation in the claim.
Claim 33 recites a method of “producing or modifying a glioblastoma test or a test for detecting glioblastoma,” wherein the method comprises “adding or integrating into said test quantifying a panel of metabolites in a biological sample.” The recitation fails to clearly define the operations required to perform the claimed method. Specifically, the phrase “adding or integrating into said test quantifying” does not clearly identify what is being added or integrated into the test. It is unclear whether the claim requires incorporating a metabolite-quantification procedure into an existing glioblastoma test, physically adding a metabolite-quantification component to a diagnostic test, actually performing quantification of metabolites in a biological sample, or some combination of these activities. These interpretations impose materially different requirements. Although the specification describes incorporating metabolite quantification into a glioblastoma testing program, the claim does not clearly distinguish the act of modifying a test from the act of performing the resulting test. Consequently, a person of ordinary skill in the art cannot determine with reasonable certainty which acts constitute performance of the claimed method. Furthermore, the expression “a glioblastoma test or a test for detecting glioblastoma” does not clarify whether the claim encompasses any test associated with glioblastoma, including a prognostic or monitoring test, or is restricted to a test for detecting the presence of glioblastoma. This ambiguity affects the scope of the method because the required purpose and nature of the test are not clearly identified. Accordingly, the scope of claim 33 is unclear, and the claim fails to particularly point out and distinctly claim the subject matter regarded as the invention. Applicant is required to amend the claim to clearly identify the test being produced or modified and the specific method steps required to produce or modify that test.
Those claims identified in the statement of rejection but not explicitly referenced in the rejection are also rejected for depending from a rejected claim but failing to remedy the indefiniteness therein.
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 22, 23, and 44 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for the demonstrated nanoparticle-preparation and in vitro delivery embodiments, does not reasonably provide enablement for the full scope of the claimed invention. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the invention commensurate in scope with these claims.
Nature and Breadth of the claimed invention
Claim 22 is directed to a method for increasing delivery of an RNA payload across the blood-brain barrier (BBB) of a subject. The method comprises providing a biocompatible lipid nanoparticle composition containing an encapsulated RNA payload and intravenously administering the composition in combination with a cadherin-binding peptide that transiently increases BBB permeability. Claim 22 does not restrict the RNA payload to SAT1 siRNA, the nanoparticle to a particular lipid formulation or particle size, or the cadherin-binding peptide. The claim therefore encompasses numerous combinations of RNA payloads, lipid nanoparticle formulations, and cadherin-binding peptides that must achieve the recited increase in delivery following intravenous administration. Claim 23 further limits the nanoparticle composition to the recited lipid-component classes, but does not restrict the composition to the experimentally tested formulation. Claim 44 limits the peptide to the recited peptide alternatives, but likewise does not require the tested nanoparticle formulation or RNA payload.
Guidance from the Specification
The specification describes biocompatible lipid nanoparticles containing encapsulated RNA payloads, including SAT1 siRNA, and identifies ionizable lipids, PEGylated lipids, sterols, and phospholipids suitable for preparing the nanoparticles [pp. 5–8]. The specification further identifies cadherin-binding peptides, including ADTC5 and HAVN1, for increasing BBB permeability [pp. 9–11]. Example 1 provides a procedure for preparing SAT1 siRNA-containing nanoparticles using DODAP, DSPC, cholesterol, and DSPE-PEG2000. Example 5 evaluates the delivery of SAT1 siRNA-containing nanoparticles across an in vitro BBB coculture model comprising hCMEC/D3 endothelial cells and U251 glioblastoma cells. The specification reports increased nanoparticle permeability in the presence of ADTC5 and a corresponding reduction in SAT1 expression in recipient U251 cells [pp. 22 and 25–26; Fig. 10]. Example 6 evaluates selected cadherin-binding peptides and nanoparticle formulations of different sizes. The specification reports increased permeability of certain formulations using ADTC5 and HAVN1 [pp. 26–27; Figs. 11–13]. However, the specification does not report intravenous administration of an RNA-loaded nanoparticle–peptide combination to an animal or human subject or demonstrate increased RNA delivery across an intact BBB following such administration. The specification therefore demonstrates preparation of particular RNA-loaded nanoparticles and increased permeability of selected formulations in an in vitro BBB model, but does not experimentally demonstrate the intravenous method required by claim 22.
State of the Art
Yokel (Yokel et al. Nanomedicine 15.4 (2020): 409-432) explains that in vitro BBB models do not fully reproduce the cellular composition, interactions, spatial organization, and transport resistance of the intact BBB. Yokel further distinguishes nanoparticle association with cerebral blood vessels from actual entry into brain parenchyma [section entitled “Level of demonstration of NP brain or brain parenchymal entry & critical review of study claims”]. Pardridge (Pardridge et al. Frontiers in Medical Technology 2 (2020): 602236) likewise discusses limitations of in vitro BBB models, including differences between cultured endothelial cells and the intact BBB, and identifies examples in which apparent in vitro transport did not translate into successful in vivo BBB delivery [section entitled “In Vitro BBB Models”]. These references establish that increased permeability in a cultured BBB model cannot, without further evidence, be treated as a reliable demonstration of increased delivery across the intact BBB following systemic administration.
Ulapane (Ulapane et al. Pharmaceutics 11.11 (2019): 568) evaluated the effects of cadherin-binding peptides on delivery of proteins of different molecular weights into mouse brains. ADTC5 enhanced delivery of 15-kDa lysozyme, 65-kDa albumin, and 150-kDa IgG, but did not significantly enhance delivery of 220-kDa fibronectin. HAV6 enhanced delivery of lysozyme but did not significantly enhance delivery of albumin or IgG [Abstract]. These findings demonstrate that peptide-mediated BBB delivery varies with both peptide identity and cargo characteristics.
Experimentation Required
The required experimentation is not limited to routine preparation of a known formulation or confirmation of a previously demonstrated in vivo result. The skilled artisan would need to identify nanoparticle–peptide combinations that retain the required delivery activity following intravenous administration, despite the differences between the disclosed in vitro model and the intact BBB. This would require evaluating the effects of nanoparticle composition, particle size, surface characteristics, peptide identity, administration conditions, and systemic biological interactions on the claimed delivery result. Consequently, the skilled artisan could not simply apply the disclosed in vitro results to all encompassed intravenous combinations with a reasonable expectation that the claimed functional result would be achieved. Instead, the skilled artisan would need to identify effective combinations through additional experimentation involving systemic administration and assessment of BBB delivery.
Therefore, the experimentation would involve more than routine optimization of a demonstrated intravenous embodiment. It would require determining which of the numerous encompassed combinations achieve the claimed result in the first instance. In view of the breadth of the claims, the limited in vivo guidance, and the demonstrated variability in BBB delivery, the specification does not enable the full claimed scope without undue experimentation.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 9 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 11 is dependent from claim 9 which already incorporates the composition of claim 1, including all four lipid classes. Therefore, claim 11 fails to limit the subject matter of the claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-4 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Jayaraman (Jayaraman et al. Angew. Chem. Int. Ed. 2012, 51:8529–8533).
Regarding claim 1 and 3, Jayaraman teaches a biocompatible lipid nanoparticle composition comprising an siRNA encapsulated in a lipid component. Specifically, Jayaraman teaches lipid nanoparticles containing ionizable amino lipids that self-assemble with polyanionic oligonucleotides to form nanoparticles encapsulating siRNA. Jayaraman further teaches that the ionizable amino lipid facilitates nanoparticle assembly and intracellular delivery of the encapsulated siRNA [p. 8529, col. 1-2]. Jayaraman teaches that the lipid component comprises a mixture of an ionizable cationic lipid, a PEGylated lipid, a sterol, and a phospholipid. Specifically, Jayaraman discloses an optimized lipid nanoparticle formulation comprising DLin-MC3-DMA (lipid 16), DSPC, cholesterol, and PEG-lipid at a molar ratio of 50:10:38.5:1.5, respectively [p. 8533, left column, third paragraph; Fig. 7]. Thus, DLin-MC3-DMA corresponds to the ionizable cationic lipid, PEG-lipid corresponds to the PEGylated lipid, cholesterol corresponds to the sterol, and DSPC corresponds to the phospholipid required. Jayaraman further teaches that DLin-MC3-DMA comprises a polar dimethylamino head group and has a reported pKa of 6.44, which is below the claimed upper limit of 7 [p. 8530, right column, final paragraph; p. 8531, Table 1, lipid 16; p. 8532, Fig. 4]. Jayaraman additionally teaches that the optimized composition is suitable for biological administration and functional siRNA delivery. Specifically, Jayaraman reports that the formulation achieves Factor VII gene silencing in mice and transthyretin gene silencing in cynomolgus monkeys following intravenous administration [p. 8533, left column, third paragraph; Fig. 7]. These experimental results provide evidence supporting the biocompatibility of the disclosed formulation for the demonstrated uses [p. 8533, Fig. 7].
Regarding claim 2, Jayaraman further teaches lipid nanoparticles having a particle-size distribution of 70–90 nm. Specifically, Jayaraman teaches that the nanoparticles were extruded up to three times through 80-nm membranes to obtain a particle-size distribution within the range of 70–90 nm [p. 8530, left column, first paragraph]. Jayaraman additionally reports a polydispersity index of 0.11 ± 0.04 for these nanoparticles [p. 8530, left column, first paragraph].
Regarding claim 4, Jayaraman's optimized formulation contains 50 mol% DLin-MC3-DMA [p. 8533, left column, third paragraph].
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.
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 5, 9–11, 16-18, and 43 are rejected under 35 U.S.C. 103 as being unpatentable over Jayaraman (Jayaraman et al. Angew. Chem. Int. Ed. 2012, 51:8529–8533) in view of Brett-Morris (Brett-Morris et al. Cancer research 74.23 (2014): 6925-6934) and Thakur (Thakur et al. Oncogene 38.41 (2019): 6794-6800).
The teachings of Jayaraman are discussed above as applied to claim 1.
Regarding claims 5 and 9-11, Jayaraman teaches lipid nanoparticles encapsulating siRNA and comprising DLin-MC3-DMA, DSPC, cholesterol, and PEG-lipid at a molar ratio of 50:10:38.5:1.5 [p. 8533, left column, third paragraph]. Jayaraman therefore teaches the lipid-nanoparticle delivery platform recited in claim 1.
Jayaraman does not teach selecting an siRNA targeting SAT1 for inhibiting glioblastoma-cell growth.
Brett-Morris teaches that SAT1 is overexpressed in brain tumors and that SAT1 knockdown using shRNA and siRNA sensitizes glioblastoma cells to radiation and decreases tumorigenesis [Abstract]. Brett-Morris teaches transfecting cells with siSAT1 [p. 6926, left column, “shRNA screen/knockdown”] and administering siRNA packaged in the lipid material ECO directly into established U87MG tumors [p. 6926, right column, “Tumor formation assay”].
Thakur additionally teaches that SAT1 is elevated in aggressive brain tumors and promotes resistance to radiotherapy [Abstract]. Thakur teaches that SAT1 knockdown alters genes involved in cell-cycle regulation and DNA repair [p. 6795, Results, “SAT1 regulates gene programs controlling cell cycle and DNA dynamics”] and significantly reduces neurosphere formation in GBM821 and GBM913 cells [p. 6797, Fig. 3G–H].
It would have been obvious to a person of ordinary skill in the art to encapsulate SAT1-targeting siRNA, as taught by Brett-Morris, in the established siRNA-LNP formulation of Jayaraman to provide a delivery vehicle for inhibiting SAT1 expression in glioblastoma cells. Thakur provides additional motivation by demonstrating that SAT1 promotes glioblastoma aggressiveness and that its depletion reduces glioblastoma neurosphere formation. The skilled artisan would have had a reasonable expectation that an appropriately formulated SAT1 siRNA could reduce SAT1 expression after successful delivery to the target cells, given Brett-Morris's experimental demonstration of SAT1 siRNA-mediated knockdown.
Regarding claim 16, Brett-Morris teaches that SAT1 knockdown sensitizes glioblastoma cells to ionizing radiation and describes intratumoral administration of lipid-packaged siRNA followed by irradiation of half the tumors 48 hours later [p. 6926, “Tumor formation assay”]. Thakur independently teaches that SAT1 promotes radiation resistance and identifies SAT1 as a therapeutic target [Abstract; p. 6795, Introduction].
Regarding claims 17 and 18, Brett-Morris teaches that standard glioblastoma treatment includes radiotherapy and temozolomide [p. 6925, Introduction]. Thakur likewise discusses the relationship between SAT1 expression and response to radiotherapy/temozolomide [p. 6795, Introduction].
It would have been obvious to combine the SAT1-targeting siRNA treatment taught by Brett-Morris with radiation therapy and temozolomide because Brett-Morris experimentally demonstrates radiosensitization following SAT1 knockdown. The skilled artisan would have had a reasonable expectation of obtaining a radiosensitizing effect upon successful delivery and inhibition of SAT1 of which the combination of both radiation and chemotherapy could provide better treatment. A skilled artisan would have a reasonable expectation of success because of the identification of SAT1 as a mediator of glioblastoma treatment resistance and temozolomide as an established treatment.
Regarding claim 43, the teachings of Jayaraman are discussed above as applied to claim 2.
Claim 6 is rejected under 35 U.S.C. §103 as being unpatentable over Jayaraman (Jayaraman et al. Angew. Chem. Int. Ed. 2012, 51:8529–8533) as applied to claim 1 and in view of Leung (Leung et al. Nanomaterials and interfaces 116.34 (2012): 18440).
The teachings of Jayaraman are discussed above as applied to claim 1 and similarly
apply to claim 6. Jayaraman does not expressly disclose all of the particular microfluidic preparation conditions taught by Leung.
Leung teaches preparing siRNA-containing lipid nanoparticles by mixing lipid stock solutions in ethanol with an aqueous phase containing siRNA duplexes using a microfluidic micromixer [p. 18441, 2.3]. Specifically, Leung teaches dissolving siRNA in 25 mM sodium acetate at pH 4.0, combining equal volumes of the ethanolic lipid solution and aqueous siRNA solution using a herringbone micromixer, and operating the mixer at a combined flow rate of 2 mL/min [p. 18441, 2.3]. Leung further teaches diluting the resulting mixture with sodium acetate buffer and subsequently dialyzing the formulation against buffer at pH 6.7, followed by PBS at pH 7.4 [p. 18441, 2.3]. Leung also teaches that its siRNA nanoparticles comprise an ionizable cationic lipid, DSPC, cholesterol, and PEG-lipid. In particular, Leung discloses a formulation comprising 40 mol% DLinKC2-DMA, 11.5 mol% DSPC, 47.5 mol% cholesterol, and 1 mol% PEG-c-DMA [p. 18441, 2.5]. Leung reports that the microfluidic preparation method produced nanoparticles having a mean diameter of 41.3 ± 14.9 nm [p. 18441, 2.3].
It would have been obvious to a person of ordinary skill in the art at the time of the invention to prepare the siRNA-containing lipid nanoparticles of Jayaraman using the microfluidic mixing process taught by Leung. Both references concern the preparation of siRNA-containing lipid nanoparticles using ionizable lipids, phospholipids, cholesterol, and PEG-lipids. Leung provides an established method for combining an ethanolic lipid phase with an aqueous siRNA phase to form nanoparticles that encapsulate siRNA. A skilled artisan would have been motivated to employ this process to obtain reproducibly prepared siRNA-loaded nanoparticles, with a reasonable expectation of successfully forming nanoparticles containing the lipid components and siRNA taught by Jayaraman.
Claims 13-15, 22-23, and 44 are rejected under 35 U.S.C. §103 as being unpatentable over Jayaraman (Jayaraman et al. Angew. Chem. Int. Ed. 2012, 51:8529–8533) in view of Brett-Morris (Brett-Morris et al. Cancer research 74.23 (2014): 6925-6934) and Thakur (Thakur et al. Oncogene 38.41 (2019): 6794-6800) as applied to claims 1 and 9, and further in view of Ulapane (Ulapane et al. Pharmaceutics 11.11 (2019): 568) and Zabel (Zabel et al. Methods and Protocols. New York, NY: Springer New York, 2019. 389-403).
The teachings of Jayaraman, Brett-Morris and Thakur are discussed above as applied to claims 1 and 9 and similarly apply to claims 13-15, 22-23, and 44. Jayaraman, Brett-Morris and Thakur do not teach administering the composition to the brain of a subject intravenously in combination with a blood-brain barrier (BBB) permeabilizing agent.
Ulapane teaches that the BBB presents an obstacle to delivery of therapeutics for brain diseases, including glioblastoma, and that cadherin peptides can modulate intercellular junctions to increase brain delivery [Abstract; Introduction]. Ulapane expressly demonstrates that intravenous coadministration of ADTC5 with a fluorescently labeled IgG monoclonal antibody significantly increases antibody accumulation in mouse brains relative to antibody alone [p. 6, 2.3; p. 7, 3.2; Fig. 5].
Zabel additionally teaches intravenous administration of lipid-formulated siRNA to mice and reports delivery of siRNA to the CNS [Abstract; p. 6, 3.2]. Zabel demonstrates brain-associated siRNA following intravenous administration and reduced brain PrP protein expression following treatment with lipid-formulated siRNA [p. 14, Fig. 2; p. 16, Fig. 4].
Regarding claims 13-14, it would have been obvious to a person of ordinary skill in the art to formulate SAT1-targeting siRNA, as taught by Brett-Morris, in the established lipid nanoparticle delivery system of Jayaraman and administer the formulation intravenously with a BBB-permeabilizing peptide, such as ADTC5, as taught by Ulapane. One or ordinary skill would be motivated to make the modification to address the recognized obstacle posed by the BBB to systemic delivery of therapeutic agents to glioblastoma cells. Zabel provides additional evidence that intravenous administration of lipid-formulated siRNA can result in brain delivery and a biological effect, while Ulapane demonstrates that ADTC5 can increase brain delivery of a large biomolecule. The combination would have provided a reason to investigate systemic SAT1-siRNA delivery using a BBB-permeabilizing agent. The evidence supports a reasonable expectation of increased BBB permeability and the feasibility of CNS delivery of lipid-formulated siRNA.
Regarding claim 15, Jayaraman, Brett-Morris and Thakur do not teach wherein the blood-brain barrier permeabilizing agent is a cadherin binding peptide. Ulapane expressly teaches ADTC5 and identifies it as a cadherin-derived peptide capable of modulating BBB permeability [Introduction]. Table 1 identifies ADTC5 as cyclo(1,7)Ac-CDTPPVC-NH₂, HAVN1, HAVN2, and HAV6 [p. 3, Table 1]. Ulapane further demonstrates that intravenous administration of ADTC5, HAVN1, or HAVN2 with an IgG monoclonal antibody significantly increased brain delivery relative to administration of the antibody alone [p. 7, 3.2; p. 8, Fig. 5]. It would have been obvious to select ADTC5, HAVN1, or HAVN2 as the BBB-permeabilizing agent in the method because Ulapane expressly identifies ADTC5, HAVN1, or HAVN2 as a BBB-modulating cadherin peptide and experimentally demonstrates increased brain delivery of a large biomolecule following its administration.
Regarding claim 22, Jayaraman, Brett-Morris and Thakur do not teach a method for increasing the delivery of an RNA payload across the blood-brain barrier of a subject by administering the composition in combination with a cadherin-binding peptide that transiently increases BBB permeability.
Zabel teaches intravenous administration of lipid-formulated siRNA for delivery to the central nervous system. Specifically, Zabel describes peptide-addressed liposome-encapsulated therapeutic siRNA (PALETS), in which siRNA is encapsulated within liposomes and a neuronal-targeting peptide is associated with the liposome surface [p. 3, Introduction; p. 5, §3.1.2]. Zabel further teaches administering the siRNA-containing formulations intravenously through the tail vein and demonstrates brain-associated siRNA following administration [p. 6, §3.2; p. 14, Fig. 2]. Zabel therefore establishes that intravenous administration of lipid-formulated siRNA was a known approach for delivering an RNA payload to the central nervous system. However, Zabel does not expressly teach coadministration of a cadherin-binding peptide that transiently increases BBB permeability.
Norouzi teaches that the BBB limits delivery of therapeutic agents to glioblastoma and investigates increasing nanoparticle penetration across an experimental BBB model using the cadherin-binding peptide ADTC5 [Abstract; p. 10, Results and Discussion]. Norouzi teaches that ADTC5 transiently modulates BBB permeability by interfering with cadherin-mediated intercellular interactions [p. 10, Results and Discussion]. Norouzi further demonstrates that administration of ADTC5 increased penetration of doxorubicin-loaded iron oxide nanoparticles across an MDCK-MDR1/U251 glioblastoma co-culture barrier model from approximately 5.2% to 6.2%, while administration of ADTC5 in combination with an external magnetic field increased penetration to approximately 8.5% [p. 10, Results and Discussion; p. 11, Fig. 11(c)].
It would have been obvious to a person of ordinary skill in the art to administer the siRNA-containing lipid nanoparticles of Jayaraman intravenously in combination with ADTC5, as taught by Norouzi, to increase delivery of the encapsulated RNA payload across the BBB. Jayaraman teaches an established system for encapsulating and systemically administering siRNA, while Zabel demonstrates that lipid-formulated siRNA can reach the CNS following intravenous administration. Norouzi identifies the BBB as an obstacle to nanoparticle-mediated treatment of brain tumors and teaches using ADTC5 to transiently increase BBB permeability and enhance nanoparticle penetration. The skilled artisan would therefore have been motivated to combine the established siRNA-LNP delivery system with ADTC5 to improve brain-directed RNA delivery, with a reasonable expectation of increasing BBB permeability and facilitating delivery based on the demonstrated effects of ADTC5 and the known feasibility of CNS delivery of lipid-formulated siRNA.
Regarding claim 23, the teachings of Jayaraman are discussed above as applied to claim 1.
Regarding claim 44, the teachings of Ulapane are discussed above as applied to claim 15.
Claim 33 is rejected under 35 U.S.C. §103 as being unpatentable over Maksymiuk (Maksymiuk et al. Future science OA 4.10 (2018): FSO345) in view of Brett-Morris (Brett-Morris et al. Cancer research 74.23 (2014): 6925-6934).
Claim 33 recites “A method for producing or modifying a glioblastoma test or a test for detecting glioblastoma, the method comprising adding or integrating into said test quantifying a panel of metabolites in a biological sample from a subject having or suspected of having glioblastoma, the panel comprising one or more corresponding metabolites of substrates of Spermidine/spermine N1-acetyltransferase 1 (SAT1)” . For purposes of this rejection, claim 33 is interpreted as encompassing a method of modifying a glioblastoma testing procedure by incorporating quantification of at least one metabolite corresponding to a substrate of SAT1. This interpretation is consistent with the specification's description of incorporating SAT1-related metabolite quantification into a glioblastoma testing program. It does not require that the test actually be performed, that a diagnosis be rendered, or that any specified diagnostic accuracy be achieved. The claim remains indefinite for the separate reasons above. MPEP §2173.06 permits an art rejection based on an expressly identified reasonable interpretation when the uncertainty is not so extensive that the rejection would depend on speculation.
Maksymiuk teaches the use of SAT1 activity as a potential biomarker for cancer screening. Specifically, Maksymiuk teaches that amantadine is a substrate of SAT1 and that SAT1-mediated acetylation produces acetylamantadine, which can be quantified to assess SAT1 activity [p. 2, Introduction]. Maksymiuk further teaches administering amantadine to human subjects, collecting urine samples, and quantifying acetylamantadine using liquid chromatography–tandem mass spectrometry (LC-MS/MS) [pp. 2–3, Materials and Methods]. Maksymiuk reports that urinary acetylamantadine measurements differed between cancer patients and healthy control subjects and investigates the utility of acetylamantadine quantification as a cancer-screening biomarker [p. 1, Abstract; pp. 5–6, Results and Discussion]. Thus, Maksymiuk teaches incorporating quantification of a metabolite corresponding to a SAT1 substrate into a cancer-testing procedure. Maksymiuk does not expressly identify glioblastoma as the particular cancer for which the assay is to be incorporated into a testing procedure.
Brett-Morris teaches that SAT1 is associated with glioblastoma. Specifically, Brett-Morris analyzes publicly available brain-tumor datasets and reports that SAT1 was overexpressed in glioblastoma samples by factors of 3.11, 3.33, and 2.28 relative to normal tissue in three separate datasets [p. 6928, Results; Fig. 1C]. Brett-Morris further teaches that elevated SAT1 expression was associated with reduced survival across a broader glioma cohort and could distinguish the glioma patients having the poorest prognoses, including glioblastoma patients, from other glioma patients [p. 6928, Results; Fig. 1D]. Brett-Morris therefore identifies SAT1 as a molecular characteristic associated with glioblastoma. Brett-Morris does not expressly teach incorporating acetylamantadine quantification into a glioblastoma diagnostic test. However, Brett-Morris supplies a glioblastoma-specific reason to investigate SAT1 as a measurable molecular characteristic in a glioblastoma testing procedure.
It would have been obvious to a person of ordinary skill in the art to modify a glioblastoma testing procedure to incorporate the SAT1-activity assay taught by Maksymiuk in view of Brett-Morris's identification of elevated SAT1 expression in glioblastoma. Maksymiuk establishes that quantifying acetylamantadine in a biological sample provides a measurable indicator of SAT1 activity and proposes the measurement for cancer screening. Brett-Morris identifies glioblastoma as a cancer characterized by elevated SAT1 expression. A skilled artisan seeking additional molecular measurements for a glioblastoma testing procedure would therefore have had reason to incorporate Maksymiuk's established SAT1-activity measurement into that procedure to assess a molecular characteristic associated with glioblastoma.
The skilled artisan would have had a reasonable expectation of successfully incorporating the quantification procedure because Maksymiuk demonstrates actual measurement of acetylamantadine in human urine using LC-MS/MS. The proposed modification requires incorporating an established analytical measurement into a testing procedure, rather than demonstrating that the resulting test achieves a particular sensitivity, specificity, or clinical diagnostic accuracy.
Conclusion
No claims allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TIFFANY N GROOMS whose telephone number is (571)272-3771. The examiner can normally be reached M-F 830-530.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Dunston can be reached at 571-272-2916. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/TIFFANY NICOLE GROOMS/Examiner, Art Unit 1637
Prosecution Insights