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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 6/8/26 has been entered.
Claims 1-5, 8, 9, 14, 16, 18, 28-31, 34-37, 44, and 48 are pending.
Claims 4-5 remain withdrawn.
Claims 1, 14, 16, and 44 have been amended by Applicant.
Claims 1-3, 8, 9, 14, 16, 18, 28-31, 34-37, 44, and 48 are currently under consideration.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
This Office Action contains New Rejections.
Rejections Withdrawn
All previous rejections are withdrawn.
New Rejections
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 14 and 16 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 14 and 16 are rejected because both claims recite “The bicistronic retroviral vector of claim 12, wherein….” Claim 12 has been canceled. Therefore, the metes and bounds of claims 14 and 16 are unclear because it is unclear which bicistronic retroviral vector the claims are further limiting. Also, there is insufficient antecedent basis for “The bicistronic retroviral vector of claim 12” in the claims.
Claim Rejections - 35 USC § 103
Claim(s) 1-3, 8, 9, 18, 44, and 48 are rejected under 35 U.S.C. 103 as being unpatentable over Png et al (US 2018/0148506 A1; 5/31/2018; 5/5/21 IDS) in view of Kamiya et al (Blood Advances, 2018, 2(5): 517-528; 5/5/21 IDS), Szymczak-Workman et al (Cold Spring Harbor Protoc, 2012, 199-204), Kim et al (PLOSone, 2011, 6(4): e18556), and Yang et al (Gene Therapy, 2008, 15: 1411-1423).
Png et al teaches methods of treating cancer comprising administering anti-CD7-CAR immune cells comprising nucleic acid expressing an anti-CD7 chimeric antigen receptor (anti-CD7-CAR) to patients with cancer ([0024], in particular). Png et al further teaches such immune cells include T cells ([0035], in particular). Png et al further teaches such anti-CD7-CAR immune cells further comprising nucleic acid expressing an anti-CD7 protein expression blocker (anti-CD7 PEBL) that downregulates CD7 and controls fratricide (see Abstract, [0082], [0090], and [0148], in particular). Png et al further teaches vectors include viral expression vectors and teaches polynucleotide vectors carrying both nucleic acids encoding the anti-CD7 PEBL and nucleic acids encoding the anti-CD7-CAR can be generated ([0131], in particular). Png et al further teaches such vectors comprising promoter sequences ([0060], in particular).
Png et al further teaches anti-CD7 PEBL having the structure: CD8a signal peptide- VL-linker-VH-ER-retention domain, wherein the VL-linker-VH is an anti-CD7 scFv (Figure 3E, in particular). At Table 3, Png et al further teaches amino acid sequences for such an anti-CD7-PEBL wherein the CD8a signal peptide comprises SEQ ID NO:7, the VL comprises SEQ ID NO:2, the linker comprises SEQ ID NO:12, the VH comprises SEQ ID NO:1, and the retention/localization domain comprise SEQ ID NO:8. The anti-CD7 PEBL disclosed by the instant specification as SEQ ID NO: 24 is identical to such an anti-CD7 PEBL of Png et al consisting of SEQ ID NOs: 7, 12, 1, and 8.
Png et al further teaches anti-CD7-CAR having the structure anti-CD7 scFv (comprising a VL-linker-VH)-hinge-transmembrane-signaling domains (Figure 17, in particular). At Table 5, Png et al teaches amino acid sequences for such an anti-CD7-CAR wherein the VL of the scFv comprises SEQ ID NO:2, the VH of the scFv comprises SEQ ID NO:1, the hinge-transmembrane comprises SEQ ID NO:10, a 4-1BB intracellular signaling domain comprising SEQ ID NO:3, and a CD3 intracellular signaling domain comprising SEQ ID NO:4. Png et al further teaches (GGGGS)4 as a linker for the scFv of the anti-CD7-CAR ([0109], in particular). Png et al further teaches the anti-CD7-CAR with a CD8a signal peptide comprising SEQ ID NO:7 ([0079], in particular). The anti-CD7 CAR disclosed by the instant specification as SEQ ID NO: 28 is identical to such an anti-CD7 CAR of Png et al consisting of SEQ ID NO:7-SEQ ID NO:2-(GGGGS)4-SEQ ID NO:10-SEQ ID NO:3-SEQ ID NO:4.
Png et al does not specifically teach a bicistronic retroviral vector comprising polynucleotides encoding anti-CD7 PEBL of Png et al and anti-CD7-CAR of Png et al. Further Png et al does not specifically teach the bicistronic retroviral vector comprising a polynucleotide comprising an open reading frame encoding a self-cleaving 2A peptide flanked by the sequences encoding the protein constructs of Png et al is a lentiviral vector or that expression of the open reading frame is driven by a MSCV promoter. However, these deficiencies are made up in the teachings of Kamiya et al, and Szymczak-Workman et al, Kim et al, and Yang et al.
Kamiya et al teaches a PEBL gene can be combined with a CAR gene on a bicistronic construct (left column on page 525, in particular) and teaches generating T cells expressing CAR and corresponding PEBL constructs wherein the constructs are expressed on retroviral vector comprising a sequence encoding a self-cleaving 2A peptide flanking the CAR and PEBL (right column on page 518, in particular). Kamiya et al cites Szymczak-Workman et al as teaching how said CAR and corresponding PEBL constructs were generated (right column on page 518, in particular).
Szymczak-Workman et al teaches self-cleaving 2A peptides include F2A, E2A, P2A, and T2A (Figure 1, in particular). Szymczak-Workman et al further teaches use of such self-cleaving 2A peptides with multicistronic vectors wherein the self-cleaving 2A peptides cloned between genes of a single open reading frame (“operatively linked”) allows for efficient production of discrete protein constructs within a single vector through a novel cleavage event within the 2A peptide sequence (Abstract, in particular).
Kim et al teaches a known problem with IRES bicistronic constructs is that translation efficiency of a gene placed after an IRES sequence is much lower than that of a gene located before IRES and that this problem is overcome by using a P2A self-cleaving peptide (page 1, in particular).
Yang et al teaches using bicistronic retroviral lentiviral vectors comprising a MSCV promoter driving expression of a polynucleotide comprising an open reading frame encoding a self-cleaving 2A peptide flanked by two different protein sequences (Figure 1, in particular). Yang et al further teaches advantages of lentiviral vectors include the ability to transduce nondividing cells, resistance to gene silencing, and potentially safer integration site profile (Abstract, in particular).
One of ordinary skill in the art would have been motivated, with a reasonable expectation of success, to generate and treat subjects with cancer by performing a combined method comprising administering anti-CD7-CAR T cells that also express anti-CD7 PEBL of Png et al wherein the T cells express both anti-CD7-CAR of Png and anti-CD7 PEBL of Png using a bicistronic retroviral vector comprising a polynucleotide comprising an open reading frame encoding just any self-cleaving 2A peptide of Szymczak-Workman et al flanked by polynucleotides encoding CD7-CAR of Png and anti-CD7 PEBL of Png because Png et al teaches methods of treating cancer comprising administering anti-CD7-CAR immune cells, such as T cells, comprising nucleic acid expressing an anti-CD7 chimeric antigen receptor, Png et al teaches fratricide of such anti-CD7-CAR immune cells can be controlled by also expressing nucleic acids encoding an anti-CD7 protein expression blocker (anti-CD7 PEBL) to downregulate in CD7 said cells, Kamiya et al teaches such a PEBL gene can be combined with a CAR gene on a bicistronic construct and teaches generating T cells expressing CAR and corresponding PEBL constructs wherein the constructs are expressed on retroviral vector comprising a sequence encoding a self-cleaving 2A peptide flanking the CAR and PEBL that (as taught by Szymczak-Workman et al) allows for efficient production of discrete protein constructs within a single vector through a novel cleavage event within the 2A peptide sequence. This is an example of some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art references or to combine prior art reference teachings to arrive at the claimed invention.
In particular regards to claim 9, one of skill in the art (in view of Figure 27 of the instant specification) would recognize polynucleotides of the bicistronic retroviral vectors of the combined method (ones where the self-cleaving 2A peptide is P2A of Szymczak-Workman et al) include sequences having at least 90% sequence identity to instant SEQ ID NO:13.
Further, one of ordinary skill in the art would have been motivated, with a reasonable expectation of success, to perform the combined method wherein the bicistronic retroviral vector comprising a polynucleotide comprising an open reading frame encoding a self-cleaving 2A peptide flanked by the sequences encoding the protein constructs of Png et al is a lentiviral vector and expression of the open reading frame is driven by a MSCV promoter of the vector, resulting in a vector comprising 3’ to 5’ an MSCV promoter operably linked to a polynucleotide encoding CD7-CAR of Png which is operably linked to a polynucleotide encoding P2A of Szymczak-Workman et al which is operably linked to a polynucleotide encoding anti-CD7 PEBL of Png because Yang et al teaches using bicistronic retroviral lentiviral vectors comprising a MSCV promoter driving expression of a polynucleotide comprising an open reading frame encoding a self-cleaving 2A peptide flanked by two different protein sequences and Yang et al teaches advantages of lentiviral vectors include the ability to transduce nondividing cells, resistance to gene silencing, and potentially safer integration site profile. This is an example of some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art references or to combine prior art reference teachings to arrive at the claimed invention. Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, absent unexpected results.
Response to Arguments
In the Reply of 6/8/26, Applicant cites Png as disclosing expression of PEBL and CAR by sequential retroviral transduction produced powerful cytotoxicity against patient-derived T-ALL cells and argues, based on the teachings of Png, there is no motivation to replace sequential transduction with claimed bicistronic retroviral vector. Applicant further argues a skilled artisan would not have recognized technical benefits of a 2A self-cleaving peptide, a skilled artisan would have no reason to replace methods with transduction using a bicistronic construct, and cited references do not provide a skilled artisan with any motivation to use a 2A self-cleaving peptide over sequential transduction. Applicant further cites Figure 1A of Kamiya as showing 87% of cells transduced with PEBL-IRES-GFP were CD3- and Supplementary Figure 5 of Kamiya as showing only 65% of cells transduced with CAR-2A-PEBL5 were CD3-/CAR+, which Applicant argues is an indication a bicistronic architecture comprising a 2A self-cleaving peptide was not Kamiya’s preferred embodiment and was not viewed by Kamiya as a predictable success. Applicant further cites instant Fig. 1a and Fig. 6 and argues disclosed P2A bicistronic constructs having better transduction efficiencies than disclosed IRES bicistronic constructs is unexpected based on Supplementary Figure 5 of Kamiya teaching P2A bicistronic constructs having worse (65%) downregulation efficiency than Kamiya’s IRES bicistronic constructs of Figure 1A (87%), and such teachings of Kamiya indicate switching from an IRES to a 2A peptide would either not improve performance or might even reduce it. Applicant further cites various teachings of Yang optimizing 2A peptide constructs in primary T cells (using a spacer, furin cleavage site, and a tag) and argues, based on Yang, a skilled artisan would have understood that a bare 2A bicistronic configuration recited in the pending claims would not be expected to function in primary T cells.
The amendments to the claims and the arguments found in the Reply of 6/8/26 have been carefully considered, but are not deemed persuasive. In regard to the arguments that there is no motivation to replace sequential transduction of Png with claimed bicistronic retroviral vector and a skilled artisan would have no reason to replace methods with transduction using a bicistronic construct, benefits of bicistronic vectors are self-evident. One of skill in the art would recognize that bicistronic vectors, as compared to separate expression vectors, have benefits that include the ability of a single vector to express two constructs in a transduced cell. Further, Kamiya et al teaches: because a PEBL gene can be combined with a CAR gene in a single bicistronic construct, “an allogeneic CAR-T cell product can be obtained after a single transduction procedure” (left column on page 525, in particular).
In regard to the arguments that a skilled artisan would not have recognized technical benefits of a 2A self-cleaving peptide and cited references do not provide a skilled artisan with any motivation to use a 2A self-cleaving peptide over sequential transduction, the examiner disagrees. Again, benefits of bicistronic vectors are self-evident. One of skill in the art would recognize that bicistronic vectors, as compared to separate expression vectors, have benefits that include the ability of a single vector to express two constructs in a transduced cell. Further, Kamiya et al teaches: because a PEBL gene can be combined with a CAR gene in a single bicistronic construct, “an allogeneic CAR-T cell product can be obtained after a single transduction procedure” (left column on page 525, in particular). Further, Kamiya et al teaches a PEBL gene can be combined with a CAR gene on a bicistronic construct (left column on page 525, in particular) and teaches generating T cells expressing CAR and corresponding PEBL constructs wherein the constructs are expressed on retroviral vector comprising a sequence encoding a self-cleaving 2A peptide flanking the CAR and PEBL (right column on page 518, in particular). Kamiya et al cites Szymczak-Workman et al as teaching how said CAR and corresponding PEBL constructs were generated (right column on page 518, in particular). Szymczak-Workman et al teaches self-cleaving 2A peptides include F2A, E2A, P2A, and T2A (Figure 1, in particular). Szymczak-Workman et al further teaches use of such self-cleaving 2A peptides with multicistronic vectors wherein the self-cleaving 2A peptides cloned between genes of a single open reading frame (“operatively linked”) allows for efficient production of discrete protein constructs within a single vector through a novel cleavage event within the 2A peptide sequence (Abstract, in particular). Further, Kim et al recognizes technical benefits of P2A, as Kim et al teaches a known problem with IRES bicistronic constructs is that translation efficiency of a gene placed after an IRES sequence is much lower than that of a gene located before IRES and that this problem is overcome by using a P2A self-cleaving peptide (page 1, in particular).
In regard to Applicant’s argument that Figure 1A of Kamiya showing 87% of cells transduced with PEBL-IRES-GFP were CD3- and Supplementary Figure 5 of Kamiya showing only 65% of cells transduced with CAR-2A-PEBL5 were CD3-/CAR+ is an indication a bicistronic architecture comprising a 2A self-cleaving peptide was not Kamiya’s preferred embodiment and was not viewed by Kamiya as a predictable success, the examiner disagrees. Supplementary Figure 5 of Kamiya shows 65% of cells transduced with CAR-2A-PEBL5 were initially CD3-/CAR+, though Kamiya teaches 95% of cells transduced with CAR-2A-PEBL5 were CD3-/CAR+ after PEBL5 of the transduced construct depleted CD3. Kamiya further describes CAR-2A-PEBL5 as “effectively” achieving downregulation of CD3 with CAR expression (right column on page 522, in particular), indicating Kamiya viewed CAR-2A-PEBL5 (a bicistronic architecture comprising a 2A self-cleaving peptide) as a success. Supplementary Figure 5 is shown below:
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In regards to the citation of instant Fig. 1a and Fig. 6 and arguments disclosed P2A bicistronic constructs having better transduction efficiencies than disclosed IRES bicistronic constructs is unexpected based on Supplementary Figure 5 of Kamiya teaching P2A bicistronic constructs having worse (65%) downregulation efficiency than Kamiya’s IRES bicistronic constructs of Figure 1A (87%) and such teachings of Kamiya indicate switching from an IRES to a 2A peptide would either not improve performance or might even reduce it, the examiner disagrees. Supplementary Figure 5 of Kamiya shows 65% of cells transduced with CAR-2A-PEBL5 were initially CD3-/CAR+, though Kamiya teaches 95% of cells transduced with CAR-2A-PEBL5 were CD3-/CAR+ after PEBL5 of the transduced construct depleted CD3. Therefore, transduction efficiency of the P2A bicistronic construct of Kamiya (95%) appears to be better than that of the IRES construct of Kamiya (85%). Kamiya further describes CAR-2A-PEBL5 as “effectively” achieving downregulation of CD3 with CAR expression (right column on page 522, in particular), indicating Kamiya viewed CAR-2A-PEBL5 (a bicistronic architecture comprising a 2A self-cleaving peptide) as a success and provides no indication switching from an IRES to a 2A peptide would either not improve performance or might even reduce it. Supplementary Figure 5 is shown above. Further, transduction efficacy is predictably better in P2A bicistronic constructs than IRES bicistronic constructs because Kim et al teaches a known problem with IRES bicistronic constructs is that translation efficiency of a gene placed after an IRES sequence is much lower than that of a gene located before IRES and that this problem is overcome by using a P2A self-cleaving peptide (page 1, in particular).
In regards to citation of teachings of Yang optimizing 2A peptide constructs in primary T cells (using a spacer, furin cleavage site, and a tag) and argument, based on Yang, a skilled artisan would have understood that a bare 2A bicistronic configuration recited in the pending claims would not be expected to function in primary T cells, the examiner disagrees. First, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Second, the instant “comprising” claims encompass constructs comprising a spacer, furin cleavage site, and/or a tag of Yang et al. Third, it is noted Kamiya et al (Supplemental Fig. 5) also teaches a 2A bicistronic construct comprising the “GSG” spacer used by Yang et al effectively functioning in primary T cells (see Supplemental Fig. 5 above).
Allowable Subject Matter
Claims 28-31 and 34-37 are allowed.
Conclusion
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/SEAN E AEDER/Primary Examiner, Art Unit 1642
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