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 .
Status of Application/Amendments/Claims/RCE 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1.114 and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 7/22/2026 has been entered.
Claim 59 has been amended. Claims 59, 61-75 and 81-87 are pending. Claims 65-80 and 88-93 are currently withdrawn from further consideration pursuant to 37 CFR 1.142 (b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Claims 59, 61-64 and 81-87 are the subject of the present Official Action. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Priority
Applicant’s claim for the benefit of a prior-filed application PRO 62/315,480 and PCT/US17/24951 filed on 3/30/2016 and 3/30/2017, respectively, under 35 U.S.C 119(e) or under 35 U.S.C 120, 121 or 365(c) is acknowledged.
Accordingly, the effective priority date of the instant application is granted as 3/30/2016.
Withdrawn Rejections
The 35 U.S.C. 112(a) rejection of claims 59, 61-64 and 82-87 is withdrawn in light of applicants claim amendments deleting the functional language describing the therapeutic protein which corrects a genetic defect by alleviating a symptom resulting from an insufficient amount of the protein in a cell.
The 35 U.S.C. 112(b) rejection of claims 59, 61-64 and 81-87 is withdrawn in light of applicants claim amendments that specify that the HEK cell lines produce rAAV vector particles having packaged therein the first heterologous nucleic acid sequence which encodes for the protein or nucleic acid sequence.
The 35 U.S.C. 103 rejections of claims 59, 61-64 and 81-87 over Liu in view of XL Liu, Collingwood and Jantz has been withdrawn to address applicants’ amendments that specify that the HEK cell lines produce rAAV vector particles having packaged therein the first heterologous nucleic acid sequence which encodes for the protein or nucleic acid sequence.
Claim Interpretation
Claim 59 describes an AAV vector genome comprising a first heterologous nucleic acid sequence encoding a protein OR nucleic acid sequence and selectable marker. It is emphasized that the OR conjunction indicates that the heterologous nucleic acid sequence either codes for a protein or selectable marker, and not both.
New Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 59, 61-64 and 82-87 are newly rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. US 2010/0129869A1, published 5/27/2010 (hereinafter Liu, reference of record) in view of Lebkowski et al. US 5,589,377, published 12/31/1996 (hereinafter Lebkowski). This rejection is newly applied to address applicants claim amendments submitted on 7/22/2026. A response to applicant’s traversal is found below.
Claim 59: Liu describes methods and compositions for inactivating glutamine synthetase (GS) and dihydrofolate reductase (DHFR) in human embryonic kidney (HEK) cells) using fusion proteins comprising a zinc finger protein (ZFN) and a cleavage domain (Liu, abstract). Liu specifically lists HEK293 as a cell line which the methods described in the patent can be applied (Liu, para 19). Liu presents a detailed example for generating GS-DHFR double knockout CHO cell lines in Example 4 (Liu, para 153-161) and states that ZFNs can stack multiple knockouts in a single mammalian cell line and that the results are not dependent on the type of cell (Liu, para 177). Liu describes GS-specific ZFNs and methods for generating GS knockout HEK293 cells (Liu, para 175-176). Liu explains that DHFR deficient cells have long been used for the production of recombinant proteins since they will only grow in media supplemented by certain factors involved in folate metabolisms or if DHFR is provided to the cell as a transgene (Liu, para 6). Similarly, GS can also be used in conjunction with DHFR as a selection marker gene in HEK cell based recombinant protein expression systems (Liu, para 4-9). Liu describes the use of viral vectors to deliver the transgene to GS-DHFR deficient HEK cell lines including AAV vectors with two ITRs that flank the 5’ and/or 3’ ends of the heterologous nucleic acid sequence as well as AAV rep sequences (Liu, para 113-120 and 125-127). Liu describes the use of inhibitors such as methotrexate (MTX) to amplify the DHFR gene copy number (Liu, para 6). Liu describes the integration of the therapeutic gene into the target cell to provide permanent transgene expression with a therapeutic effect (Liu, para 18 and 113). Liu does not specifically describe the stable or transient transfection of the HEK cell line to produce rAAV vectors having packaged therein the first heterologous nucleic and or nucleic acid sequence/selectable marker as described in newly amended claim 59.
Claims 61: Liu describes stable transgene delivery due to efficient gene transfer via rAAV delivery (Liu, para 117).
Claim 82: Liu does not describe selection markers that provide resistance to antibiotics.
Claims 83-85: Liu explains that DHFR deficient cells have long been used for the production of recombinant proteins since they will only grow in media supplemented by certain factors involved in folate metabolisms or if DHFR is provided to the cell as a transgene (Liu, para 6). Similarly, GS can also be used in conjunction with DHFR as a selection marker gene in HEK cell based recombinant protein expression systems (Liu, para 4-9).
Claims 86: Liu provides preferred embodiments to HEK293 cell lines (Liu, para 19).
Claim 87: Liu describes the use of various culturing medium formulations for cell growth and long-term storage (Liu, examples 2-4).
Claims 59 and 62-64: Lebkowski describes a HEK 293 permanent packaging cell lines which are used as a rAAV production host (Lebkowski, examples 2-4 and 7). Lebkowski describes transiently or stably transfecting HEK cell linkes using an AAV vector that carries an ITR-flanked rAAV genome with a heterologous nucleic acid sequence encoding a protein (apoA1 or neo) and a selectable marker (Lebkowski, summary and examples 1-3).
It would have been prima facie obvious to one of ordinary skill in the art to stably or transiently transfect the GS-DHFR double knockout HEK cells described by Liu as the rAAV host in the methods for generating rAAV particles as described in Lebkowski. It would have been a matter of simply substituting the HEK cell lines in Lebkowski for the GS-DHFR double knockout HEK cells described in Liu. One of ordinary skill would be motivated to make this substitution since selecting for two separately introduced constructs requires two non-overlapping selection systems. Lebkowski teaches this need through its two-marker design and the separate rep/cap markers. However, using GS and DHFR together provides a similar approach but also allows copy-number amplification (MSX for GS and MTX for DHFR). One would have a reasonable expectation of successes given that Liu presents a detailed example for generating GS-DHFR double knockout CHO cell lines in Example 4 (Liu, para 153-161) and states that ZFNs can stack multiple knockouts in a single mammalian cell line and that the results are not dependent on the type of cell and can thus be readily applied to HEK cells (Liu, para 177). Accordingly, in the absence of evidence to the contrary, one of ordinary skill in the art would have considered claims 59, 61-64 and 82-87 to have been prima facie obvious to at the time the invention was made.
Response to Traversal
Although the rejection is newly applied, some of applicant’s arguments are still relevant and are addressed below.
Applicant traverses the instant rejection by arguing that the claimed subject matter meets a long-felt but unmet need in the art by providing a stable producer of clones for rAAV production that exhibit increased rAAV yields, easy to scale up, safer production, production of rAAV vectors with low amount of empty capsids and achieves a high copy number of rAAC genomes. Specifically, applicant describes that there was a persistent long-felt need in the art and acknowledged by XL Liu who describes large scale manufacturing of rAAVs as difficult. Applicant argues that efforts were made to solve the long-felt need and were unlikely to be feasible for clinical scale manufacturing and cites XL Liu showing that a distinct approach was used employing a hybrid recombinant adenovirus.
These arguments have been fully considered, but are not found persuasive since establishing long-felt need requires objective evidence that an art recognized problem existed in the art for a long period of time without solution. The relevance of long-felt need and the failure of others to the issue of obviousness depends on several factors. First, the need must have been a persistent one that was recognized by those of ordinary skill in the art. Second, the long-felt need must not have been satisfied by another before the invention by the inventor. Although applicant has argued that the stable production of clones of AAVs that exhibit increased rAAV yields and is easy to scale up was an unmet need in the art, applicant has not provided a showing that others of ordinary skill in the art were working on the problem and if so, for how long. In addition, there is no evidence that if persons skilled in the art who were presumably working on the problem knew of the teachings of the above cited references, they would still be unable to solve the problem, see MPEP 716.04.
Claims 59, 61-64 and 81-87 are rejected under 35 U.S.C. 103 as being unpatentable over Liu (supra) and Lebkowski (supra) as applied to claims 59, 61-64 and 82-87 above in further view of Jantz et al. US 2014/0179005, published 6/26/2014 (hereinafter Jantz, reference of record). This rejection is newly applied to address applicants claim amendments submitted on 7/22/2026.
A description of Liu and Lebkowski can be found above. Neither Liu nor Lebkowski describes a first and/or second heterologous nucleic acid sequence encoding for a protein useful for correction of in born errors including factor VIII as recited in claim 81. It is noted that factor VIII is the elected heterologous nucleic acid sequence.
Claims 43-44: However, predictable methods exist for inserting an exogenous transgene proximal to an endogenous selectable gene in an amplifiable locus which does not inhibit amplification of the endogenous selectable gene and can be co-amplified (Jantz, para 12). For example, Jantz describes such methods for mammalian cell lines including HEK cell lines (Jantz, para 5, 127). Jantz describes techniques using both GS and DHFR as selectable markers (Jantz, para 129, 130, 135 and example 2). Jantz also describes the use of selectable genes in combination with selection agents like MTX and MSX (Jantz, para 17). Furthermore, Jantz provides embodiments for transgenes encoding therapeutic proteins like factor VIII (Jantz, para 131).
It would have been prima facie obvious to one of ordinary skill in the art to select factor VIII as the therapeutic transgene as disclosed by Jantz in the GS-DHFR double knockout HEK cell line described by Liu. Both Jantz and Liu have a clear appreciation for the use of GS and DHFR as selectable markers for amplifying HEK cells expressing therapeutic transgenes. Although Liu does not list factor VIII as a therapeutic transgene of interest, Jantz provides preferred embodiments towards the use of factor VIII, which is a well-known blood clotting agent useful in treating disorders like hemophilia A. Thus, it would have been a matter of simple substitution for one therapeutic transgene for another to obtain predictable results. One would have been motivated to make this substitution given the clinical importance of factor VIII as a therapeutic in treating diseases like hemophilia A. Thus, one of ordinary skill would naturally look to use cell lines like the GS-DHFR double knockout HEK cell line described by Liu to produce large quantities of factor VIII given the efficiency of this amplification strategy. One would have a reasonable expectation of successes given that predictable methods exist for inserting exogenous transgenes proximal to endogenous selectable genes. Furthermore, both authors show that HEK cell lines are readily attainable and can be modified using gene editing techniques like ZFN. Accordingly, in the absence of evidence to the contrary, one of ordinary skill in the art would have considered the claimed invention to have been prima facie obvious to at the time the invention was made.
Conclusion
No claims allowed.
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Alexander Nicol
Patent Examiner
Art Unit 1634
/ALEXANDER W NICOL/Examiner, Art Unit 1634
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