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 .
Claims Status
Claims 1, 3, 6, 9-10, 12-14, 16, 18-20, 23, 25-27, and 29 are pending and are examined on the merits.
REJECTIONS MAINTAINED
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.
Claims 1, 3, 6, 9-10, 12-13, 18-20, 23, and 25-27 are rejected under 35 U.S.C. 103 as being unpatentable over Zhu et al. 2019 (Cell Stem Cell 25.4 (2019): 542-557.; of record), herein Zhu, in view of Rotolo et al. 2018 (Cancer Cell 34.4 (2018): 596-610.; of record), herein “Rotolo”, Ma et al. 2018 (US 2018/0162939 A1; of record), herein “Ma”, and Canté‑Barrett (BMC research notes, 9(1), 312.; of record), herein “Canté‑Barrett”, and as evidenced by GenBank DQ341448.1 (“J3N.5 T cell receptor alpha chain”; https://www.ncbi.nlm.nih.gov/nuccore/DQ341448.1; deposited 03/17/2006; of record) and GenBank DQ341459.1 (“J3N.5 T cell receptor beta chain”; https://www.ncbi.nlm.nih.gov/nuccore/DQ341459.1; deposited 03/17/2006; of record).
Zhu teaches a lentiviral construct comprising invariant TCRα and TCRβ (Figure 1) for use in the differentiation of invariant natural killer T (iNKT) cells from hematopoietic stem cells (HSC-iNKT) – which solves the problem of the relatively low numbers of naturally occurring iNKT cells (Summary).
Figure 1 demonstrates that the TCRs can be linked with a cleavable linker (F2A) and that additional components can be linked with a P2A linker (e.g., EGFP or the suicide gene sr39TK).
Zhu further proposes that this technology can be combined with CARs in the future (Discussion): “Moreover, recent studies showed promising cancer therapy potential of chimeric antigen receptor (CAR)-engineered iNKT cells; therefore, further engineering HSC-iNKT cells to express CAR to enhance their tumor-targeting effectiveness may represent another attractive approach”.
Regarding Claims 19-20, 23, and 25-27, Zhu further teaches a viral vector comprising a nucleic acid encoding for TCRα and TCRβ (Figure 1), a method of generating an engineered cell comprising transducing a cell with said viral vector (Materials and Methods; “Generation of BLT and BLT-iNKT Humanized mice”), a pharmaceutical composition comprising said engineered cell (Materials and Methods; i.v. injection of 1x107 HSC-iNKT cells in PBS vehicle), and that the engineered cells can be autologous or allogenic (Graphical Abstract).
Zhu teaches that in contrast conventional αβ T cells, mice administered iNKT cells were significantly protected from graft-versus-host disease (GvHD), whereas all control mice eventually died of GvHD (Fig. S2; Pg. 546, § Safety Study of HSC-iNKT Cell Therapy in BLT-iNKT Humanized Mice).
Nucleotide sequences encoding for invariant TCRα and TCRβ chains are 831 bp and 948 bp in length, respectively, as evidenced by GenBank DQ341448.1 and GenBank DQ341459.1, respectively.
Zhu does not teach that the constructs comprise anti-CD19 and anti-CD20 CARs linked to the TCRs nor that TCRα and TCRβ are expressed from separate vectors.
Rotolo teaches a “CAR iNKT” cell comprising both an invariant TCR and an anti-CD19 CAR (“CAR19-iNKT cells”), which resulted in enhanced cytotoxicity against CD19+ leukemia cells relative to conventional CAR19-T cells (Summary). Figure S1 demonstrates that the anti-CD19 CAR can be introduced via lentiviral vectors and can be linked to additional components with a 2A self-cleaving peptide, that the CAR is a conventional “3rd gen” CAR comprising a hinge, a CD28 transmembrane domain, and intracellular CD28 and CD3ζ costimulatory and activating domains. Rotolo further teaches that combining the CAR with iNKT cells preserves iNKT function (Pg 598-599; “Co-operative Activation of CAR19-iNKT Cells”).
Like Zhu, Rotolo teaches that the endogenous T cell receptor in CAR-modified T cells can lead to GvHD, and that unlike conventional T cells, iNKT cells protect from GvHD – suggesting a dual benefit to CAR-iNKT cells in both the added targeting of CD1d and protection from the risk of GvHD (Introduction).
Ma teaches a “compound CAR” construct comprising an anti-CD19 CAR and anti-CD20 CAR linked by a cleavable P2A element, each CAR comprising a leader peptide, an antigen-specific scFv, a hinge region, a transmembrane domain, a 4-1BB or CD28 costimulatory domain, and a CD3ζ primary signaling domain (Fig. 15, 16A).
Ma teaches that combining a CD19 CAR with a second CAR targeting CD20 safeguards against antigen escape and disease relapse in adoptive cell therapy for B-cell malignancies (¶0464).
Ma acknowledges teaches that with longer gene constructs, expression drops significantly with each 1 kb of additional length (¶1000). Ma teaches that transduction efficiencies with compound CARs are lower than with single CARs and highlights the need to optimize transduction efficiency to achieve the desired killing activity of the CAR T cells (¶1063).
Ma teaches that a nucleotide sequence encoding a pair of CARs is just over 3kb in length (e.g. Ma SEQ ID NO: 167), which is approximately 1.5kb for each CAR.
Ma teaches that GvHD “remains the most important cause of morbitdity and mortality after allogeneic hematopoietic stem cell transplants”, and that the cause of GvHD is the endogenous TCR expressed on the engineered T cells (¶0552).
Canté‑Barrett teaches the optimization of lentiviral transduction in primary hematopoietic stem cells (HSCs) and T cells (Abstract). Like Ma, Canté‑Barrett teaches that vector size has a profound impact on transduction efficiency (Fig. 3), and that this problem is even more pronounced in HSCs, which required a thousand-fold more virus particles than JURKAT cells for smaller vectors but up to 104 times more for larger vectors (Pg. 4, Col. 2). Canté‑Barrett teaches that even a modest reduction in vector size by 600 bp can improve HSC transduction efficiency by more than threefold (§ Discussion).
Given the suggestion by Zhu that the HSC-iNKT technology could be combined with CARs and the reduction to practice of an iNKT cell expressing a CD19 CAR by Rotolo, it would have been obvious to one of ordinary skill in the art to combine the invariant TCRα/TCRβ construct taught by Zhu with the dual CD19-CAR and CD20-CAR construct taught by Ma.
One would have been motivated to do so because Ma teaches that cells comprising both a CD19-CAR and CD20-CAR can mitigate antigen escape and relapse, and Rololo teaches CAR-iNKT cells outperform conventional CAR-T cells. Further, Ma acknowledges the risk of GvHD induced by adoptive CAR-T cells, and both Zhu and Rotolo teach that iNKT cells, unlike conventional T cells, protect from GvHD with the added benefit of targeting CD1d.
There would have been a reasonable expectation of success because Rotolo teaches the feasibility and benefits of expressing a CD19-CAR in iNKT cells, and because Zhu teaches that differentiating iNKT cells from stem cells by forced expression of invariant TCRα and TCRβ chains solves the issue of the limited supply of iNKT cells.
It further would have been obvious to rearrange the expression vectors of Zhu and Ma such that the first vector comprises the first CAR linked to the invariant TCRα chain, and the second vector comprises the second CAR linked to the invariant TCRβ chain. The skilled artisan would have been motivated make this modification to because Ma teaches that large constructs comprising two CARs present a challenge to transduction efficiency, and Canté‑Barrett teaches that the impact of vector size on transduction efficiency is even more pronounced for HSCs.
There would have been a reasonable expectation of success because Canté‑Barrett teaches that even a modest 600bp difference in vector size can improve transduction efficiency in HSCs by more than threefold, and each the TCRα and TCRβ chains are ~600bp smaller than a typical CAR (831/927 bp vs 1.5kb), resulting in a pair of vectors each with a reduced size relative to the dual-CAR constructs of Ma – with the added benefit that both vectors would be closely matched in size (and thus transduction efficiency).
Claims 14, 16, and 29 are rejected under 35 U.S.C. 103 as being unpatentable over Zhu et al. 2019 (Cell Stem Cell 25.4 (2019): 542-557.; of record), herein Zhu, in view of Rotolo et al. 2018 (Cancer Cell 34.4 (2018): 596-610.; of record), herein “Rotolo”, Ma et al. 2018 (US 2018/0162939 A1; of record), herein “Ma”, and Canté‑Barrett (BMC research notes, 9(1), 312.; of record), herein “Canté‑Barrett”, as applied to claims 1, 9, and 13 above, further in view of Perez et al. 2020 (WO 2020/123691 A2; Published 06/18/2020; of record), herein “Perez”, and as evidenced by GenBank ADM64594.1 (“FMC63-28Z receptor protein”; https://www.ncbi.nlm.nih.gov/protein/ADM64594.1/; deposited 06/11/2012; of record).
The teachings of Zhu, Rotolo, Ma, and Canté‑Barrett are described above.
Regarding claims 14, 16, and 29, Rotolo further teaches that the CD19-CAR comprises the FMC63 scFv (Figure S1A). The sequence of FMC63 (as evidenced by GenBank: ADM64594.1) comprises 100% of both VH and VL of instant SEQ ID NOs: 221 and 232, including the CDRs of SEQ ID NOs: 224, 227, 230, 235, 238, and 241. See alignment below, CDRs are highlighted:
Heavy Chain Alignment; FMC63 and SEQ ID NO: 221 (SEQ 221)
FMC63 148 EVKLQESGPGLVAPSQSLSVTCTVSGVSLPDYGVSWIRQPPRKGLEWLGVIWGSETTYYN 207
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SEQ 221 1 EVKLQESGPGLVAPSQSLSVTCTVSGVSLPDYGVSWIRQPPRKGLEWLGVIWGSETTYYN 60
FMC63 208 SALKSRLTIIKDNSKSQVFLKMNSLQTDDTAIYYCAKHYYYGGSYAMDYWGQGTSVTVSS 267
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SEQ 221 61 SALKSRLTIIKDNSKSQVFLKMNSLQTDDTAIYYCAKHYYYGGSYAMDYWGQGTSVTVSS 120
Light Chain Alignmnet; FMC63 and SEQ ID NO: 232 (SEQ 232)
FMC63 23 DIQMTQTTSSLSASLGDRVTISCRASQDISKYLNWYQQKPDGTVKLLIYHTSRLHSGVPS 82
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SEQ 232 1 DIQMTQTTSSLSASLGDRVTISCRASQDISKYLNWYQQKPDGTVKLLIYHTSRLHSGVPS 60
FMC63 83 RFSGSGSGTDYSLTISNLEQEDIATYFCQQGNTLPYTFGGGTKLEIT 129
|||||||||||||||||||||||||||||||||||||||||||||||
SEQ 232 61 RFSGSGSGTDYSLTISNLEQEDIATYFCQQGNTLPYTFGGGTKLEIT 107
Although the combined teachings of Zhu, Rotolo, Ma, and Canté‑Barrett teach combining anti-CD19 CARs with anti-CD20 CARs, they do not teach the specific CD20 CAR of Claims 14, 16, and 29. This deficiency is cured by Perez.
Perez teaches an anti-CD20 binding domain comprising a VH and VL comprising 100% sequence identity to SEQ ID NOs: 1 and 12, respectively – including the CDRs of SEQ ID NOs: 4, 7, 10, 15, 18, and 21 (Perez claims 1, 3, and 6). See alignment below, CDRs are highlighted:
VH; Instant SEQ ID NO: 1 (SEQ1) and Perez SEQ ID NO: 1 (Perez1)
SEQ1 1 QVQLQQWGAGLLKPSETLSLTCAVYGGSFSGYYWSWIRQPPGKGLEWIGEIDHSGSTNYN 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Perez1 1 QVQLQQWGAGLLKPSETLSLTCAVYGGSFSGYYWSWIRQPPGKGLEWIGEIDHSGSTNYN 60
SEQ1 61 PSLKSRVTISVDTSKNQFSLKLSSVTAADTAVYYCARGGGSWYSNWFDPWGQGTMVTVSS 120
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Perez1 61 PSLKSRVTISVDTSKNQFSLKLSSVTAADTAVYYCARGGGSWYSNWFDPWGQGTMVTVSS 120
VL; Instant SEQ ID NO: 12 (SEQ12) and Perez SEQ ID NO: 12 (Perez12)
SEQ12 1 DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQKPGKAPKLLIYDASSLESGVPS 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Perez12 1 DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQKPGKAPKLLIYDASSLESGVPS 60
SEQ12 61 RFSGSGSGTEFTLTISSLQPDDFATYYCQQDRSLPPTFGGGTKVEIK 107
|||||||||||||||||||||||||||||||||||||||||||||||
Perez12 61 RFSGSGSGTEFTLTISSLQPDDFATYYCQQDRSLPPTFGGGTKVEIK 107
Additionally, Perez teaches a CAR comprising the aforementioned CD20 binding domain (Perez claims 16-17) and further teaches a second polypeptide comprising a CD19-CAR (Perez claims 18, 20) with a CD19-binding domain which comprises the same heavy and light chain CDRs as the instant claims and FMC63 (Perez SEQ ID NOs: 224, 227, 230, 235, 238, and 241 are identical to instant SEQ ID NOs: 224, 227, 230, 235, 238, and 241; see alignment below as well as previously presented FMC63 alignment). Perez teaches that the CD20 and CD19 CARs can be expressed in a bi-cistronic vector and cells expressing these CARs together possess cytotoxicity to Raji cells (Table 21).
HCDRs; FMC63 and Perez SEQ ID NOs: 224, 227, 230
FMC63 HCDR1 DYGVS HCDR2 VIWGSETTYYNSALKS HCDR3 HYYYGGSYAMDY
||||| |||||||||||||||| ||||||||||||
Perez HCDR1 DYGVS HCDR2 VIWGSETTYYNSALKS HCDR3 HYYYGGSYAMDY
LCDRs; FMC63 and Perez SEQ ID NOs: 235, 238, 241
FMC63 LCDR1 RASQDISKYLN LCDR2 HTSRLHS LCDR3 QQGNTLPYT
||||||||||| ||||||| |||||||||
Perez LCDR1 RASQDISKYLN LCDR2 HTSRLHS LCDR3 QQGNTLPYT
It therefore would have been prima facie obvious to one of ordinary skill in the art at the time of filing to make an antigen binding system comprising a first construct comprising TCRα linked to CD19-CAR by a 2A peptide and a second construct comprising TCRβ linked to CD20-CAR by a 2A peptide wherein the CD19-CAR comprised the CD19 binding domain of FMC63 as taught by the combination of Zhu, Rotolo, Ma, and Canté‑Barrett and the CD20-CAR comprised the CD20 binding domain of SEQ ID NOs: 1 and 12 as taught by Perez. One would be motivated to do so because FMC63 is well-proven CD19 binding domain common in the art and Perez teaches that the CD20 binding domains of SEQ ID NOs: 1 and 12 binds cells expressing CD20 (Table 15). One would have had a reasonable expectation of success because Perez teaches the combination of these two CD19 and CD20 CARs in a bi-cistronic vector and demonstrates cytotoxicity against cancer cell lines.
Response to Arguments
Applicant's arguments filed 12/23/2025 have been fully considered but they are not persuasive.
Applicant has made no amendments to the claims in response to the previous office action. Instead, Applicant’s arguments focus largely on the purpose/intended use of the instantly claimed constructs: “the current office action fails to consider that a purpose of the system of claim 1 requires both constructs to function for selection for double-positive cells” (Remarks, Pg. 8). Applicant notes that only cells receiving both constructs will differentiate into iNKT cells, thereby obviating the need for a second selection process for cells having both of the two CAR constructs (as all iNKT cells will necessarily have received all CARs). While plausible, the instant disclosure provides no working examples of such an expression system or selection process. Moreover, this intended use is neither recited by the claims nor would it convey or require additional structure to the claimed constructs. See MPEP 2111.02(II).
In contrast, the rationale used to reject the instant claims relies on known challenges in the art regarding vector size and transduction efficiency. The action asserts that 1) it would have been obvious to combine the HSC-iNKT differentiation technology of Zhu with CARs such as the “compound CAR” taught by Ma owing to the proof of concept CAR iNKT cells taught by Rotolo and the express suggestions by Zhu that addition of CARs to the HSC-iNKT cells would be an “attractive approach” to increasing tumor targeting; and 2) the particular arrangement of the required components across two vectors as described in the instant claims would have been obvious because it minimizes vector size – following the rationale taught by Ma and Canté‑Barrett.
Motivated by the desire to reduce vector size and optimize transduction efficiency, the skilled artisan would arrive at the instantly claimed invention without needing to consider the intended use of selecting for double positive cells as argued by Applicant. The fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Applicant’s further asserts that the P2A/T2A linkers of the prior art are used “for a completely different purpose”. Examiner disagrees. Each of the prior art references demonstrates that constructs containing 2A linkers effectively supports independent expression of either a TCR chain or a CAR alongside a second protein under control of the same promoter. This use is the same as instantly claimed – namely expression of two independent protein products from the same expression cassette. Although the exact arrangement and components comprised within the constructs of the prior art differ from the instant claims, 2A linkers are extraordinarily common in the art. Their utility in constructing expression cassettes comprising multiple discrete protein products would have been well understood by one of ordinary skill in the art, and the prior art demonstrates that both CARs and TCR chains can and have been effectively used in conjunction with such linkers.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1, 3, 6, 9-10, 12-14, 16, 18-20, 23, 25-27, and 29 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 8-16 of U.S. Patent No. 11,793,834 in view of Zhu et al. 2019 (Cell Stem Cell 25.4 (2019): 542-55I 7.; of record), herein Zhu, Rotolo et al. 2018 (Cancer Cell 34.4 (2018): 596-610.; of record), herein “Rotolo”, Ma et al. 2018 (US 2018/0162939 A1; of record), herein “Ma”, and Canté‑Barrett (BMC research notes, 9(1), 312.; of record), herein “Canté‑Barrett”, and as evidenced by GenBank DQ341448.1 (“J3N.5 T cell receptor alpha chain”; https://www.ncbi.nlm.nih.gov/nuccore/DQ341448.1; deposited 03/17/2006; of record) and GenBank DQ341459.1 (“J3N.5 T cell receptor beta chain”; https://www.ncbi.nlm.nih.gov/nuccore/DQ341459.1; deposited 03/17/2006; of record).
‘834 claims 8-13 are drawn to a cell comprising a first anti-CD20 CAR comprising an anti-CD20 binding domain with a HCDRs 1-3 of SEQ ID NOs: 4, 7, and 10, respectively, and LCDRs 1-3 of SEQ ID NOs: 15, 18, and 21, respectively, and a second CAR comprising a CD19 comprising a VH and VL comprising SEQ ID NOs: 221 and 232, respectively, wherein the second CAR comprises a transmembrane domain, a hinge (CD8α), activating domain (CD3ζ), and costimulatory domain (CD28). Claim 13 is further drawn to a CD19-CAR further comprising “an alpha chain of a T cell receptor” and “a beta chain of a T cell receptor”. The anti-CD20 HCDRs/LCDRs and anti-CD19 VH/VL are identical to those of the instant claims (Instant SEQ ID NOs: 4, 7, 10, 15, 18, 21, 221, 224, 227, 230, 232, 235, 238, and 241; see alignments presented in the previous U.S.C. 103 rejections above).
‘834 claims 14-17 are drawn to a nucleic acid encoding the CD20 antigen binding domain, a vector comprising said nucleic acid, and a method of generating an engineered cell comprising transducing a cell with said nucleic acid. Although claims 14-17 do not require the CD19 CAR taught by claims 8-13, it would have been obvious to one of ordinary skill in the art that the nucleic acids, vectors, and method of generating an engineered cell of claims 14-17 could further comprise the CD19 CAR required by other embodiments of the invention.
The claims of ‘834 are not drawn to the CD20-CAR further comprising an TCRα or TCRβ chain nor are the claims drawn to constructs wherein the CD19- or CD20-CAR is linked to a TCRα or TCRβ by cleavable T2A linkers. The claims of ‘834 are further silent on whether the cells are autologous or allogenic or of the cells are comprised in a pharmaceutical composition. These deficiencies are cured by Zhu, Rotolo, Ma, and Canté‑Barrett.
Zhu teaches a lentiviral construct comprising invariant TCRα and TCRβ (Figure 1) for use in the differentiation of invariant natural killer T (iNKT) cells from hematopoietic stem cells (HSC-iNKT) – which solves the problem of the relatively low numbers of naturally occurring iNKT cells (Summary).
Figure 1 demonstrates that the TCRs can be linked with a cleavable linker (F2A) and that additional components can be linked with a P2A linker (e.g., EGFP or the suicide gene sr39TK).
Zhu further proposes that this technology can be combined with CARs in the future (Discussion): “Moreover, recent studies showed promising cancer therapy potential of chimeric antigen receptor (CAR)-engineered iNKT cells; therefore, further engineering HSC-iNKT cells to express CAR to enhance their tumor-targeting effectiveness may represent another attractive approach”.
Regarding Claims 19-20, 23, and 25-27, Zhu further teaches a viral vector comprising a nucleic acid encoding for TCRα and TCRβ (Figure 1), a method of generating an engineered cell comprising transducing a cell with said viral vector (Materials and Methods; “Generation of BLT and BLT-iNKT Humanized mice”), a pharmaceutical composition comprising said engineered cell (Materials and Methods; i.v. injection of 1x107 HSC-iNKT cells in PBS vehicle), and that the engineered cells can be autologous or allogenic (Graphical Abstract).
Zhu teaches that in contrast conventional αβ T cells, mice administered iNKT cells were significantly protected from graft-versus-host disease (GvHD), whereas all control mice eventually died of GvHD (Fig. S2; Pg. 546, § Safety Study of HSC-iNKT Cell Therapy in BLT-iNKT Humanized Mice).
Nucleotide sequences encoding for invariant TCRα and TCRβ chains are 831 bp and 948 bp in length, respectively, as evidenced by GenBank DQ341448.1 and GenBank DQ341459.1, respectively.
Rotolo teaches a “CAR iNKT” cell comprising both an invariant TCR and an anti-CD19 CAR (“CAR19-iNKT cells”), which resulted in enhanced cytotoxicity against CD19+ leukemia cells relative to conventional CAR19-T cells (Summary). Figure S1 demonstrates that the anti-CD19 CAR can be introduced via lentiviral vectors and can be linked to additional components with a 2A self-cleaving peptide, that the CAR is a conventional “3rd gen” CAR comprising a hinge, a CD28 transmembrane domain, and intracellular CD28 and CD3ζ costimulatory and activating domains. Rotolo further teaches that combining the CAR with iNKT cells preserves iNKT function (Pg 598-599; “Co-operative Activation of CAR19-iNKT Cells”).
Like Zhu, Rotolo teaches that the endogenous T cell receptor in CAR-modified T cells can lead to GvHD, and that unlike conventional T cells, iNKT cells protect from GvHD – suggesting a dual benefit to CAR-iNKT cells in both the added targeting of CD1d and protection from the risk of GvHD (Introduction).
Ma teaches a “compound CAR” construct comprising an anti-CD19 CAR and anti-CD20 CAR linked by a cleavable P2A element, each CAR comprising a leader peptide, an antigen-specific scFv, a hinge region, a transmembrane domain, a 4-1BB or CD28 costimulatory domain, and a CD3ζ primary signaling domain (Fig. 15, 16A).
Ma teaches that combining a CD19 CAR with a second CAR targeting CD20 safeguards against antigen escape and disease relapse in adoptive cell therapy for B-cell malignancies (¶0464).
Ma acknowledges teaches that with longer gene constructs, expression drops significantly with each 1 kb of additional length (¶1000). Ma teaches that transduction efficiencies with compound CARs are lower than with single CARs and highlights the need to optimize transduction efficiency to achieve the desired killing activity of the CAR T cells (¶1063).
Ma teaches that a nucleotide sequence encoding a pair of CARs is just over 3kb in length (e.g. Ma SEQ ID NO: 167), which is approximately 1.5kb for each CAR.
Ma teaches that GvHD “remains the most important cause of morbitdity and mortality after allogeneic hematopoietic stem cell transplants”, and that the cause of GvHD is the endogenous TCR expressed on the engineered T cells (¶0552).
Canté‑Barrett teaches the optimization of lentiviral transduction in primary hematopoietic stem cells (HSCs) and T cells (Abstract). Like Ma, Canté‑Barrett teaches that vector size has a profound impact on transduction efficiency (Fig. 3), and that this problem is even more pronounced in HSCs, which required a thousand-fold more virus particles than JURKAT cells for smaller vectors but up to 104 times more for larger vectors (Pg. 4, Col. 2). Canté‑Barrett teaches that even a modest reduction in vector size by 600 bp can improve HSC transduction efficiency by more than threefold (§ Discussion).
Given the suggestion by Zhu that the HSC-iNKT technology could be combined with CARs and the reduction to practice of an iNKT cell expressing a CD19 CAR by Rotolo, it would have been obvious to one of ordinary skill in the art to combine the invariant TCRα/TCRβ construct taught by Zhu with the CD19-CAR and CD20-CAR of patent ‘834.
One would have been motivated to do so because and Rotolo teaches CAR-iNKT cells outperform conventional CAR-T cells. Further, Ma acknowledges the risk of GvHD induced by adoptive CAR-T cells, and both Zhu and Rotolo teach that iNKT cells, unlike conventional T cells, protect from GvHD with the added benefit of targeting CD1d.
There would have been a reasonable expectation of success because Rotolo teaches the feasibility and benefits of expressing a CD19-CAR in iNKT cells, and because Zhu teaches that differentiating iNKT cells from stem cells by forced expression of invariant TCRα and TCRβ chains solves the issue of the limited supply of iNKT cells.
It further would have been obvious to distribute the TCR chains and CARs across two separate expression vectors such that the first vector comprises the first CAR linked to the invariant TCRα chain by a 2A element, and the second vector comprises the second CAR linked to the invariant TCRβ chain by a 2A element. The skilled artisan would have been motivated arrange the vectors in this way because Ma teaches that large constructs comprising two CARs present a challenge to transduction efficiency, and Canté‑Barrett teaches that the impact of vector size on transduction efficiency is even more pronounced for HSCs.
There would have been a reasonable expectation of success because Zhu and Ma teach the use of self-cleaving 2A peptides to express multiple proteins (including TCRs or CARs) from a single construct, Canté‑Barrett teaches that even a modest 600bp difference in vector size can improve transduction efficiency in HSCs by more than threefold, and each the TCRα and TCRβ chains are ~600bp smaller than a typical CAR (831/927 bp vs 1.5kb), resulting in a pair of vectors each with a reduced size relative to the dual-CAR constructs of Ma – with the added benefit that both vectors would be closely matched in size (and thus transduction efficiency).
Response to Arguments
Applicant's arguments filed 12/23/2025 have been fully considered but they are not persuasive.
Regarding the double patenting rejection, Applicant does not present separate arguments, but instead refers to the arguments made against the 35 USC § 103 obviousness rejections. Accordingly, the response is the same as stated above. Briefly, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Conclusion
No claim is allowed.
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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/BRYAN WILLIAM HECK/Examiner, Art Unit 1643
/JULIE WU/Supervisory Patent Examiner, Art Unit 1643