DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s amendment filed on 10/14/2025 is acknowledged.
Applicant’s election without traverse of Invention I, Claims 1-10 and 14-15 in the reply filed on 6/27/2025 is acknowledged.
The requirement is still deemed proper and is therefore made FINAL.
Claims 11-13 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 6/27/2025.
Claims 1-10 and 14-15 are under examination on the merits.
Response to Arguments
Applicant’s arguments, see p. 1, filed 10/14/2025, with respect to claim objections and claim rejections under 35 U.S.C. §112(b) have been fully considered and are persuasive. The claim objections and claim rejections under 35 U.S.C. §112(b) have been withdrawn.
Applicant's arguments filed 10/14/2025 have been fully considered but they are not persuasive. See below.
Withdrawn Objections and Rejections
The following objections and rejections are hereby withdrawn due to Applicant’s amendment filed 10/14/2025:
Claim objection: claim 1.
Rejection under 35 U.S.C. §112(b): claim 15.
Maintained Rejections
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.
(Previous Rejection Maintained) Claims 1-10 and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Mineno et al. (WO 2015053387 A1, published 4/16/2015; hereinafter referred to as “Mineno”) in further view of Okamoto et al. (WO 2012157742 A1, published 11/22/2012; hereinafter referred to as “Okamoto”).
The claimed invention encompasses a nucleic acid construct for expressing a gene of interest, comprising in order from the 5’ end to 3’ end, (a) a 5’ LTR (Long Terminal Repeat) sequence derived from a retrovirus, (b) a packaging signal sequence (ψ) derived from a retrovirus, (c) a sequence of the gene of interest or a multiple cloning site, (d) a posttranscriptional regulatory element (PRE), (e) a siRNA-producing sequence which is transcribed into an RNA that forms at least one stem-loop structure and induces RNA interference in a mammalian cell, and (f) a 3’ LTR sequence derived from a retrovirus, as recited in claim 1. In another embodiment, the PRE is a PRE derived from Woodchuck hepatitis virus (WPRE), as recited in claim 2. Alternatively, the nucleic acid construct further comprises a foreign promoter sequence on the 5’ side of the gene of interest sequence, as recited in claim 3. In a different embodiment, the gene of interest is a gene encoding a T cell receptor (TCR) or a chimeric antigen receptor (CAR), as recited in claim 4, or more specifically a gene encoding a TCR α chain and a TCR β chain linked with a 2A peptide, as recited in claim 5. In another embodiment, the siRNA-producing sequence is a sequence for producing siRNA that acts on an mRNA encoding a constant region of a wild-type TCR to suppress its expression, as recited in claim 6, or more specifically wherein the gene of interest is a gene encoding a mutated TCR in which a mutation is introduced into a nucleotide sequence of the constant region, and expression of the mutated TCR is not suppressed by the siRNA, as recited in claim 7. Alternatively, the siRNA-producing sequence is a sequence for producing siRNA that acts on an mRNA encoding a molecule that suppresses an activity of an immune cell to suppress its expression, as recited in claim 8.
Another embodiment of the claimed invention encompasses a retroviral vector comprising a transcript from the nucleic acid construct a nucleic acid construct for expressing a gene of interest, comprising in order from the 5’ end to 3’ end, (a) a 5’ LTR (Long Terminal Repeat) sequence derived from a retrovirus, (b) a packaging signal sequence (ψ) derived from a retrovirus, (c) a sequence of the gene of interest or a multiple cloning site, (d) a posttranscriptional regulatory element (PRE), (e) an siRNA-producing sequence which is transcribed into an RNA that forms at least one stem-loop structure and induces RNA interference in a mammalian cell, and (f) a 3’ LTR sequence derived from a retrovirus, as recited in claim 9. In a more specific embodiment, the retroviral vector comprises a 5’ LTR derived from an oncoretrovirus or a lentivirus, a packaging signal sequence derived from an oncoretrovirus or a lentivirus, and a 3’ LTR derived from an oncoretrovirus or a lentivirus, as recited in claim 10.
Another embodiment of the claimed invention encompasses a cell containing the nucleic acid construct for expressing a gene of interest, comprising in order from the 5’ end to 3’ end, (a) a 5’ LTR (Long Terminal Repeat) sequence derived from a retrovirus, (b) a packaging signal sequence (ψ) derived from a retrovirus, (c) a sequence of the gene of interest or a multiple cloning site, (d) a posttranscriptional regulatory element (PRE), (e) a siRNA-producing sequence which is transcribed into an RNA that forms at least one stem-loop structure and induces RNA interference in a mammalian cell, and (f) a 3’ LTR sequence derived from a retrovirus, as recited in claim 14. In another embodiment, the cell is a T cell, a cell capable of differentiating into a T cell, or a cell population containing the T cell or the cell capable of differentiating into a T cell, as recited in claim 15.
The Prior Art
Mineno teaches retroviral vectors for gene transfer into a cell, comprising from 5’ end to 3’ end: (a) a 5’ LTR derived from a retrovirus, (b) a packaging signal sequence derived from a retrovirus, c) a desired gene or multiple cloning site, d) a posttransciptional regulatory element (PRE) including WPRE, and f) a 3’ LTR sequence derived from a retrovirus, (Abstract; Description; Fig. 6; p. 4, paras. 1-6, translation; p. 5, para. 4; Examples 2 & 4). Mineno further describes embodiments where exogenous promoters derived from other than the virus from which the LTR sequence is derived can also be used in the present invention, a virus or mammal-derived sequence can be used, and a constitutive, inducible, or tissue-specific promoter can be used (translation, p. 4, para. 6). Mineno further discloses that the desired gene can encode an antigen receptor, such as a T cell receptor, including polycistronicly linked genes encoding two polypeptides constituting a TCR heterodimer, the two genes connected via a self-cleaving peptide sequence (such as 2A peptide), wherein the gene encodes a TCR α chain and a TCR β chain (translation, p. 6, paras. 2-4). Minenos’s nucleotide sequence of a desired gene may be a siRNA (short interfering RNA; translation, p. 5, para. 4). Additionally, the retrovirus may be a lentivirus, and that retroviruses include subclasses of oncoretrovirus and lentivirus; and sequences from any class of virus can be used in the present invention (claims 4, 9; translation, p. 4, para. 2). Further, Mineno teaches gene-transferred cells into which the retroviral vectors are introduced (claim 11). Mineno also indicates that an exogenous TCR may be introduced into a T cell (translation, p. 7, para. 6). However, Mineno does not specifically teach an siRNA-producing sequence which is transcribed into an RNA that forms at least one stem-loop structure and induces RNA interference in a mammalian cell.
Okamoto teaches retroviral vectors for introducing into and expressing an exogenous gene, and further suppresses expression of a specific endogenous gene by transcription of RNA which induces RNA interference in the cell, wherein the RNA interference is achieved by an siRNA generating sequence which forms at least one stem-loop structure and in which RNA is transcribed which induces RNA interference in mammalian cells (Abstract). The exogenous gene can encode an antigen receptor, such as a T cell receptor, including polycistronicly linked sequences encoding two polypeptides constituting a TCR heterodimer, the two genes connected via a self-cleaving peptide sequence (such as 2A peptide), wherein the gene encodes a TCR α chain and a TCR β chain (translation, p. 6, paras. 4-5; p. 7, paras 1-3). Okamoto also specifically teaches a retroviral vector with an siRNA generating sequence that is a sequence that generates siRNA that suppresses expression by acting on mRNA encoding the constant region of wild type TCR, and the desired gene is a gene encoding TCR in which a mutation is introduced into the base sequence of the constant region (translation, p. 13, claims).
It would have been obvious to one of ordinary skill in the art to modify the retroviral vector configurations taught by Mineno to incorporate the exogenous gene and siRNA generating sequence taught by Okamoto. Okamoto teaches retroviral constructs comprising an exogenous gene encoding two polypeptides constituting a TCR heterodimer, the two genes connected via a self-cleaving peptide sequence (such as 2A peptide), wherein the gene encodes a TCR α chain and a TCR β chain, while also encoding an siRNA-producing sequence which is transcribed into an RNA that forms a stem-loop structure and induces RNA interference in a mammalian cell. One of ordinary skill in the art would have been motivated to suppress expression of the native TCR while simultaneously expressing the transgenic TCR. There would be a reasonable expectation of success because Mineno teaches the configuration of the retroviral vector backbone and Okamoto teaches retroviral vectors that suppress native TCR expression by siRNA-mediated RNA interference while simultaneously expressing transgenic TCR that is not susceptible to the siRNA-mediated RNA interference. Therefore, claims 1-10 and 14-15 were prima facie obvious to one of ordinary skill in the art before the priority date of the instant invention.
Applicant’s arguments have been carefully considered but are found unpersuasive.
Applicant presents the following arguments:
Claim recites elements (a) to (f), “in order from the 5’ end to 3’ end.” In the nucleic acid construct of claim 1 of the present application, “(e) an siRNA producing sequence” is positioned downstream of “(c) a sequence of the gene of interest or a multiple cloning site”. An embodiment corresponding to the nucleic acid construct of claim 1 is vector D prepared in Example 2 of the specification of the present application (see FIG. 1). Further, Example 4 of the specification demonstrates that vector D has a higher expression efficiency of exogenous TCR than vector C, which, like vector D, contains an siRNA-producing sequence positioned downstream of the TCR coding region (see FIG. 3, paragraph [0072] of the specification). Thus, Example 4 shows that the configuration of vector D, in which an siRNA-producing sequence is positioned downstream of a WPRE sequence and upstream of a 3’ LTR, is highly effective.
In contrast, Okamoto teaches a vector containing an siRNA expression cassette (i.e., an siRNA-producing sequence) placed at a position different from the present invention, specifically between an SD sequence and an SA sequence (see vector D in FIG. 8 of Okamoto), and that such a vector has a higher expression efficiency of exogenous TCR than a vector containing an siRNA-producing sequence positioned downstream of the TCR coding region (see vector B in FIG. 8 of Okamoto and FIG. 9 and Example 9 of Okamoto).
One of ordinary skill in the art might consider placing an siRNA-producing sequence between SD/SA sequences in the vector taught by Mineno in view of Okamoto. However, one of ordinary skill in the art would not have had a reasonable expectation of success by placing an siRNA-producing sequence downstream of a posttranscriptional regulatory element (PRE) in the vector taught by Mineno in view of Okamoto. Further, one of ordinary skill in the art who read Okamoto would never be motivated to choose the less effective configuration of vector B, i.e., the configuration in which the siRNA-producing sequence is positioned downstream of the TCR coding region.
Given the combined teachings of the cited references, it would not be obvious to one of ordinary skill in the art to place an siRNA producing sequence downstream of a TCR coding region and downstream of a WPRE sequence and upstream of a 3’ LTR.
Applicant’s arguments are not persuasive because:
Okamoto presents several different vectors with the siRNA cassette at different positions (Fig. 8). Among the vector configurations disclosed by Okamoto are the siRNA cassette being in the region of the SD/SA sequences, as mentioned by Applicant, as well as the siRNA cassette being at the end of the vector, next to the 3’ LTR (Fig. 8). Notably, Okamoto also discloses that each of these orientations resulted in expression of the transgene, with levels being similar (Fig. 9). However, Okamoto also tested expression vectors where the TCR-beta chain preceded the TCR-alpha chain (Figs. 8-15), and it appears that, in certain circumstances, the presence of the TCR-beta chain being 5’ resulted in higher expression (Figs. 8-15).
Notably, Mineno discloses that PREs increase stability of mRNA, and the PRE is generally present to the 3’ direction of the desired gene (pp. 2-3).
The claimed vector configuration would be obvious to one of ordinary skill in the art upon reading Mineno and Okamoto for the reasons described above in the rejection under 35 U.S.C. §103. Mineno describes vectors that have a PRE in the 3’ direction of a gene of interest, and Okamoto describes constructs wherein siRNA sequences are after a gene of interest but are next to the 3’ LTR. Applicant’s results are not unexpected, as vectors B and C of the instant application still exhibit expression of both TCRα and TCRβ chains, with apparently small differences in the TCRβ chain in particular (instant Fig. 3). One of ordinary skill in the art would have a reasonable expectation of success given that Okamoto demonstrates expression of a gene of interest with each configuration of the vector elements (i.e., siRNA near SD and SA sequences or wherein the siRNA cassette is immediately prior to the 3’LTR.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JEFFREY MARK SIFFORD/Examiner, Art Unit 1671 /BENJAMIN P BLUMEL/Primary Examiner, Art Unit 1671