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 .
Priority
The instant application is a national stage entry under 35 U.S.C. § 371 of PCT/US22/78377 (filed 10/19/2022). Acknowledgement is made of Applicants’ claim for benefit of Provisional U.S. Application No. 63/257,479 (filed 10/19/2021).
Election/Restrictions
Applicant’s election of Group I in the reply filed on 06/29/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claims 1-3, 5, 9-10, 12-16, 18-26, 29, and 33-36 are pending; claims 20-26, 29, and 33-36 are withdrawn. Claims 1-3, 5, 9-10, 12-16, and 18-19 read on the elected invention and are examined on the merits herein.
Claim Interpretation
Regarding claim 5: This claim is directed to the lentiviral packaging composition of claim 3, wherein the heterologous nucleic acid is 4-8 kb, at least 4-7.5 kb, or at least 4-5 kb. The broadest reasonable interpretation of the at least 4-7.5 kb and at least 4-5 kb limitations is at least 4 kb.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-3, 5, 9-10, 12-16, and 18-19 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 1: This claim recites the limitation, “…wherein the transfer plasmid comprises a heterologous nucleic acid greater than 2 kb.” The issue at present is the lack of clarity surround the term heterologous nucleic acid. Lacking a clear definition or guidance from the instant specification – heterologous to what exactly? heterologous to the lentivirus? heterologous to the target cell and/or subject? – a person having ordinary skill in the art would not immediately ascertain which component of the instant invention the nucleic acid is heterologous thereto. Thus, the metes and bounds are not clearly or precisely defined, rendering claim 1 indefinite.
For the purposes of examination, and under broadest reasonable interpretation, the term heterologous nucleic acid is interpreted as heterologous to the target cell and/or subject; i.e., the nucleic acid which encodes the transfer plasmid is interpreted as the heterologous nucleic acid.
Claims 2-3, 5, 9-10, 12-16, and 18-19 depend from claim 1, inherit its deficiencies, and are likewise rejected as indefinite.
Regarding claims 14, 16: Claim 14 contains the trademarks/trade names Opti-MEM®, Opti-Plex™, Freestyle®, and LV-MAX®; claim 16 contains the trademarks/trade names PEIpro® and PEI-MAX®.
Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph. See Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case: the trademarks/trade names recited in claim 14 are used to identify/describe media which support the formation of a plasmid DNA complex in solution; the trademarks/trade names recited in claim 16 are used to identify/describe transfection reagents. Accordingly, the identification/description is indefinite.
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.
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 1-3, 5, 9-10, 12-15, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Frost, et al. (US 2017/0356010) in view of Storck, et al. (BioTechniques. 2017).
Frost, et al. teaches methods for genetically modifying lymphocytes, as well as recombinant retroviral particles and packaging cell lines (Abstract).
Storck, et al. teaches recombinant lentivirus production (Abstract).
Regarding claims 1-3, 5, 9, 12-14, 18: Frost, et al. teaches a composition comprising plasmid DNA diluted in Opti-MEM, to obtain lentiviral particles pseudotyped with VSV-G, wherein the plasmid DNA comprises a mixture of 4 plasmids with the following molar ratios: 2x genomic plasmid (F1-0-03), 1x Rev-containing plasmid, 1x VSV-G containing plasmid, and 1x gag/pol-containing plasmid (par. 0852); the genomic plasmid F1-0-03 encodes GFP and an anti-CD19 chimeric antigen receptor (par. 0851; Fig. 20). As seen in Fig. 20, the 5’ long terminal repeat (LTR) is truncated; i.e., lacks a wild-type, or full-length, 5’ LTR. Additionally, this genomic plasmid is approximately 10 kb in size (Fig. 20). Thus, the composition of Frost, et al. reads on:
the lentiviral plasmid packaging composition comprising a gag/pol plasmid, a rev plasmid, an envelope plasmid, and a transfer plasmid, wherein the plasmid packaging composition lacks a wild-type lentiviral 5' long terminal repeat (LTR) promoter, and wherein the transfer plasmid comprises a heterologous nucleic acid greater than 2 kb limitations recited in claim 1;
the wherein the envelope plasmid comprises a coding region for vesicular stomatitis virus G protein (VSV-G) limitation recited in claim 2;
the wherein the heterologous nucleic acid is at least 4 kb, at least 5kb, or at least 8 kb limitations recited in claim 3;
the wherein the heterologous nucleic acid is at least 4-7.5 kb or at least 4-5 kb limitations recited in claim 5;
the wherein the heterologous nucleic acid encodes a T-cell receptor, a chimeric antigen receptor, or a multi-gene complex limitations recited in claim 9;
the lentiviral plasmid packaging composition of claim 1 that lacks a lentiviral tat gene limitation recited in claim 12;
the lentiviral plasmid packaging composition of claim 1 further comprising a complexation solution limitation recited in claim 13; and
the wherein the complexation solution is OPTI-MEM® limitation recited in claim 14.
Frost, et al. does not teach the plasmid mass ratios recited in claim 1.
Storck, et al. teaches in the development of a lentivirus production system, the transfection reagent-to-DNA ratio is a critical parameter of efficient nucleic acid delivery, wherein the positively charged transfection reagent must be supplied in sufficient quantities to effectively condense and coat the negatively charged plasmid DNA; this ratio affects the virus titers (“Reagent-to-DNA Ratio”; pg. 136). Additionally, the order of addition, composition, and stoichiometry of the individual plasmids in the development of a lentivirus production system greatly influences the titers obtained (pg. 137; col. 1, par. 1). Storck, et al. teaches a recommended starting ratio for the individual plasmids (pg. 137; col. 1, par. 1), but emphasizes the systematic optimization of the experimental variables surrounding recombinant lentivirus production, including plasmid ratios and packaging premixes thereof, as well as transfection reagent-to-DNA ratio; the differences in the transfection reagent and transfer and packaging plasmid variables can lead to a 100-fold difference in titers in head-to-head comparisons ("Conclusions"; pg. 138).
Therefore, it would have been prima facie obvious for a person having ordinary skill in the art to have modified the composition of Frost, et al. by optimizing (1) the ratio of the individual plasmids diluted in Opti-MEM, and (2) the ratio of total plasmid DNA to transfection reagent. This conclusion of obviousness is based on the ‘teaching, suggestion, or motivation rationale’; one would be motivated to do so in order to determine the ideal ratios for optimal virus titer, as taught by Storck, et al. Specifically, the skilled artisan would be motivated to optimize the individual plasmid ratios of (1) to determine the ideal the order of addition, composition, and stoichiometry thereof for optimal virus titer; the skilled artisan would also be motivated to optimize the transfection reagent-to-DNA ratio of (2) to determine the sufficient quantity of positively charged transfection reagent to effectively condense and coat the negatively charged plasmid DNA for optimal virus titer (pgs. 136-137). Further, as evidenced by the Storck, et al. disclosure, such optimization is routine and well known in the art; thus, one of ordinary skill in the art would have more than a reasonable expectation of success in doing so.
For clarity of record, while Frost, et al. teaches the ratio of the plasmids as a molar ratio, optimization thereof would necessarily optimize the mass ratio, as well. Therefore, the modified composition of Storck, et al. renders obvious:
the remaining wherein the plasmids are present in a mass ratio of 1.1 gag/pol plasmid : 1 rev plasmid : 1.1 envelope plasmid : 3.2 transfer plasmid limitation recited in claim 1; and
the wherein the mass of total plasmid and the mass of transfection reagent are present in a ratio between 1 total plasmid mass : 1.0 transfection reagent mass and 1 total plasmid mass : 3.0 transfection reagent mass limitations recited in claim 18.
Regarding claim 10: Following the above discussion, Frost, et al. teaches the total plasmid DNA diluted in Opti-MEM is at a concentration of 1 µg/mL (par. 0852); this reads on the wherein the total DNA concentration of gag/pol plasmid, rev plasmid, envelope plasmid, and transfer plasmid is 0.25-2.5 µg/ml or 1.0-2.0 µg/ml limitations recited in claim 10.
Regarding claim 15: Following the above discussion, Frost, et al. teaches transfection reagent PEI diluted in Opti-MEM prior to being mixed with the plasmid solution (par. 0852); the solution comprising both the plasmid DNA and the PEI after mixing the two solutions together reads on the lentiviral plasmid packaging composition of claim 1 further comprising a transfection reagent limitation recited in claim 15.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Frost, et al. (US 2017/0356010) in view of Storck, et al. (BioTechniques. 2017).
The teachings of Frost, et al. and Storck, et al. are set forth above.
Marceau, et al. teaches the production of recombinant lentiviral vectors (Abstract).
Regarding claim 16: Following the above discussion, Frost, et al. does not teach the transfection reagents recited in the instant claim.
However, Marceau, et al. teaches the use of transfection reagent PEIpro® in the production of lentiviral packaging systems (par. 0033).
Therefore, it would have been prima facie obvious to a person having ordinary skill in the art to have substituted the PEI of Frost, et al. with the PEIpro® of Marceau, et al. This conclusion of obviousness is based on the ‘substitution rationale’. The use of PEIpro® in place of the PEI is a predictable use of prior art elements according to their established functions as polyethylenimine-based transfection reagents, leading to the predictable result of introduction of genetic material into a target cell. This rationale aligns with the principle of a simple substitution of one known element for another to obtain predictable results; see MPEP 2143(I)(B).
This renders obvious the wherein the transfection reagent is PEIpro limitation recited in claim 16.
Claims 1-3, 5, 10, 12-13, 15-16, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Marceau, et al. (US 2019/0211360) in view of Bartlett, et al. (US 2021/0238632), as evidenced by Kalidasan, et al. (Sci Rep. 2021).
The teachings of Marceau, et al. are set forth above.
Bartlett, et al. teaches viral vector production (Abstract).
Regarding claims 1, 3, 5, 12: Marceau, et al. teaches a lentiviral packaging system comprising an envelope (Env) plasmid, a Gag-Pol plasmid, a Rev plasmid, and a transgene of interest plasmid (pars. 0015, 0020, 0070). Disclosed is an embodiment wherein the transgene of interest plasmid encodes the Wiskott-Aldrich protein, wherein the total size of the plasmid is 9.78 kb (par. 0102). Thus, the lentiviral packaging system reads on:
the lentiviral plasmid packaging composition comprising a gag/pol plasmid, a rev plasmid, an envelope plasmid, and a transfer plasmid, wherein the transfer plasmid comprises a heterologous nucleic acid greater than 2 kb limitations recited in claim 1;
the wherein the heterologous nucleic acid is at least 4 kb, at least 5kb, or at least 8 kb limitations recited in claim 3;
the wherein the heterologous nucleic acid is at least 4-7.5 kb or at least 4-5 kb limitations recited in claim 5; and
the lentiviral plasmid packaging composition of claim 1 that lacks a lentiviral tat gene limitation recited in claim 12.
Regarding the plasmid mass ratio:
Marceau, et al. teaches the molar ratio of the plasmids as 1 gag/pol : 2 rev : 1 env : 1 transfer (par. 0037), but does not teach the mass ratio recited in claim 1. However, the disclosure does teach (emphasis added):
The molar ratio between the different plasmids used for producing a lentivirus can also be adapted for optimizing the scale-up of this production. Thanks to the results provided herein, the person skilled in the art is able to adapt this parameter to the specific plasmids he uses for producing the lentivirus of interest. For example, the present inventors here show that a ratio of 1: 1: 2: 1 (Env plasmid: Gag - Pol plasmid: Rev plasmid: TOI plasmid) leads to a more robust transfection and satisfying lentivirus production with respect to the lentiviruses shown in the examples. Of course, the person skilled in the art is able to adapt this ratio to the specific lentiviruses whose production is sought. The ratio can easily be adapted for each new situation (e. g., with respect to each specific plasmid vector used for the transfection) based on the teaching of the present invention (see the examples below) and common general knowledge in the field of recombinant lentivirus production. (par. 0037)
Thus, Marceau, et al. clearly teaches the plasmids are provided at a ratio effective to achieve a robust and satisfying lentivirus production. That means the conditions necessary to achieve said production were result effective variables. Result effective variables would be optimized by routine experimentation by one having ordinary skill in the art. See MPEP 2144.05(II)(A). Further, in view of such explicit disclosure, it is reasonable to conclude Marceau, et al. discloses the ratio of plasmids not merely as a variable which can be optimized, but as a variable which should be optimized for each specific lentivirus; i.e., different transgenes of interest will have different optimal plasmid ratios.
For clarity of record, while Marceau, et al. teaches the ratio of the plasmids as a molar ratio, optimization thereof would necessarily optimize the mass ratio, as well. This renders obvious the wherein the plasmids are present in a mass ratio of 1.1 gag/pol plasmid : 1 rev plasmid : 1.1 envelope plasmid : 3.2 transfer plasmid limitation recited in claim 1.
Regarding the 5’ LTR promoter:
Bartlett, et al. teaches a lentiviral packaging system wherein the U3 region of the 5’ LTR is replaced with a heterologous promoter as a safety enhancement (par. 0095).
Therefore, it would have been prima facie obvious to a person having ordinary skill in the art to have further modified the lentiviral packaging system of Marceau, et al. by replacing the U3 region of the 5’ LTR with a heterologous promoter, as taught by Bartlett, et al. This conclusion of obviousness is based on the ‘teaching, suggestion, or motivation rationale’; the skilled artisan would have been motivated to do so for the enhanced safety, as taught by Bartlett, et al. Further, as both disclosures teach lentiviral packaging systems, and as the use of a heterologous promoter is a well-known technique in the art (as evidenced by the Bartlett, et al. disclosure), the skilled artisan would have more than a reasonable expectation of success.
This renders obvious the remaining wherein the plasmid packaging composition lacks a wild-type lentiviral 5' long terminal repeat (LTR) promoter limitation recited in claim 1.
Regarding claim 2: Following the above discussion, Marceau, et al. teaches an embodiment wherein the envelope plasmid encodes a VSV-G Env protein (par. 0023); this reads on the wherein the envelope plasmid comprises a coding region for vesicular stomatitis virus G protein (VSV-G) limitation recited in claim 2.
Regarding claim 10: Following the above discussion, Marceau, et al. teaches an embodiment wherein host cells are used at a cell density between 0.8 and 1.3 x 106 cells/mL (par. 0030); further disclosed is an embodiment wherein the total DNA of the plasmids is 1.5 µg/106 cells (par. 0038). Thus, Marceau, et al. teaches an embodiment wherein the total plasmid DNA concentration is 1.2 to 1.95 µg/mL; this reads on the wherein the total DNA concentration of gag/pol plasmid, rev plasmid, envelope plasmid, and transfer plasmid is 0.25-2.5 µg/ml or 1.0-2.0 µg/ml limitation recited in claim 10.
Regarding claim 13: Following the above discussion, Marceau, et al. teaches the use of OPTIPROSFM for the generation of the plasmid transfection complex (par. 0056); this reads on the lentiviral plasmid packaging composition of claim 1 further comprising a complexation solution limitation recited in claim 13.
Regarding claims 15-16: Following the above discussion, Marceau, et al. teaches an embodiment wherein PEIpro® is used as the transfection reagent for the plasmid transfection complex (pars. 0033). This reads on:
the lentiviral plasmid packaging composition of claim 1 further comprising a transfection reagent limitation recited in claim 15; and
the wherein the transfection reagent is PEIpro limitation recited in claim 16.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Marceau, et al. (US 2019/0211360) in view of Bartlett, et al. (US 2021/0238632), further in view of Frost, et al. (US 2017/0356010), and as evidenced by Kalidasan, et al. (Sci Rep. 2021).
The teachings of Marceau, et al., Bartlett, et al., and Frost, et al. are set forth above.
Regarding claim 14: Following the above discussion, Marceau, et al. does not teach the limitations recited in the instant claim.
However, Frost, et al. teaches the use of Opti-MEM® in the generation of a plasmid transfection complex (par. 0852).
Therefore, it would have been prima facie obvious to a person having ordinary skill in the art to have further modified the plasmid transfection complex of Marceau, et al. by substituting the OPTIPROSFM with the Opti-MEM® of Frost, et al. This conclusion of obviousness is based on the ‘substitution rationale’. The use of Opti-MEM® in place of the OPTIPROSFM is a predictable use of prior art elements according to their established functions as media which support the formation of a plasmid DNA complex in solution, leading to the predictable result of formation of a plasmid transfection complex. This rationale aligns with the principle of a simple substitution of one known element for another to obtain predictable results; see MPEP 2143(I)(B).
This renders obvious the wherein the complexation solution is OPTI-MEM limitation recited in claim 14.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Marceau, et al. (US 2019/0211360) in view of Bartlett, et al. (US 2021/0238632), further in view of Storck, et al. (BioTechniques. 2017), and as evidenced by Kalidasan, et al. (Sci Rep. 2021).
The teachings of Marceau, et al., Bartlett, et al., and Storck, et al. are set forth above.
Regarding claim 18: Following the above discussion, Marceau, et al. does not teach the limitation recited in the instant claim.
However, Storck, et al. teaches the transfection reagent-to-DNA ratio is a critical parameter of efficient nucleic acid delivery, wherein the positively charged transfection reagent must be supplied in sufficient quantities to effectively condense and coat the negatively charged plasmid DNA; this ratio affects the virus titers ("Reagent-to-DNA Ratio"; pg. 136).
Therefore, it would have been prima facie obvious to a person having ordinary skill in the art to have further modified the lentiviral packaging system of Marceau, et al. by optimizing the transfection reagent-to-DNA ratio, as taught by Storck, et al. This conclusion of obviousness is based on the ‘teaching, suggestion, and motivation rationale’. One would be motivated to do so in order to determine the sufficient quantity of positively charged transfection reagent to effectively condense and coat the negatively charged plasmid DNA for optimal virus titer, as taught by Storck, et al. (pg. 136); further, as the same disclosure evidences such optimization is routine and well known in the art, the skilled artisan would have more than a reasonable expectation of success in doing so.
This renders obvious the wherein the mass of total plasmid and the mass of transfection reagent are present in a ratio between 1 total plasmid mass : 1.0 transfection reagent mass and 1 total plasmid mass : 3.0 transfection reagent mass limitation recited in claim 18.
Claim Objections
Claims 3 and 19 are objected to because of the following minor informalities:
Line 2 of claim 3 recites “…at least 5kb…”; this should read “…at least 5 kb…” for consistency with the other size limitations recited in the same claim. Appropriate correction is required.
Claim 19 is presumed to contain typographical errors, as it recites “…the sequence set forth at SEQ ID NO…” prior to the recitation of each SEQ ID NO. This should read, “…the sequence set forth [[at]]as SEQ ID NO…”; or, alternatively, “…the sequence set forth [[at]]in SEQ ID NO…”.
Claim 19 is further objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. SEQ ID NOs: 1, 4, and 7 are free from the prior art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to GINA PRONZATI whose telephone number is (571)270-5725. The examiner can normally be reached Monday - Friday 9:00a - 5:00p ET.
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/GINA PRONZATI/Examiner, Art Unit 1633
/ALLISON M FOX/Primary Examiner, Art Unit 1633
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