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 .
Claim Status
Claims 1 and 4-6 are currently amended and claims 1-18 have been considered on their merits.
Withdrawn Objections/Rejections
The objections to the specification have been withdrawn due to Applicant’s amendments to the specification.
The claim objection has been withdrawn due to Applicant’s amendments to the claims.
The claim rejections under 35 USC § 112 have been withdrawn due to Applicant’s amendments to the claims. However, a new rejection is set forth below due to Applicant’s amendments to the claims.
The claim rejections under 35 USC § 103 have been withdrawn due to Applicant’s amendments to the claims. However, a new rejection is set forth below due to Applicant’s amendments to the claims.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-18 rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as based on a disclosure which is not enabling.
This is a new rejection necessitated by Applicant’s amendments to the claims.
The disclosure does not enable one of ordinary skill in the art to practice the invention without identifying the step involved with arriving at CAR-T cells, which is/are critical or essential to the practice of the invention but not included in the claim(s). See In re Mayhew, 527 F.2d 1229, 188 USPQ 356 (CCPA 1976).
The factors to be considered in determining whether undue experimentation is required are summarized in In re Wands, 858 F.2d 731, 737, 8 USPQd 1400, 1404 (Fed. Cir. 1988) (a) the breadth of the claims; (b) the nature of the invention; (c) the state of the prior art; (d) the level of one of ordinary skill; (e) the level of predictability in the art; (f) the amount of direction provided by the inventor; (g) the existence of working examples; and (h) the quantity of experimentation needed to make or use the invention based on the content of the disclosure. While all of these factors have been considered, the relevant factors will be addressed below.
Claim 1 is drawn to a perfusion culture method for CAR-T cells which comprises the steps of obtaining and activating T cells from PBMC and infecting said T cells with a lentiviral vector comprising any gene or construct followed by a perfusion culture step which arrives at obtaining and harvesting CAR-T cells. The broadest reasonable interpretation is that the claim at step 4 reads as carrying out perfusion culture of the T cells arrives at CAR-T cells. However, simply carrying out perfusion culture of an activated T cell would not result in a CAR-T cell.
The nature of the invention is that of culturing CAR-T cells, yet the claims do not disclose how one would arrive at CAR-T cells from the activated and isolated T cells from the previous steps. The current language of the claim is written in a way which suggests the perfusion step is what is utilized to obtain CAR T cells and that is considered to be missing a crucial step as the lentivirus is not identified as encoding the CAR and the lentivirus infected T cells are not identified as CAR T cells and it is not clear how the perfusion step converts the lentivirus infected T cells into CAR T cells. Therefore, there is a missing step within the method which is required to connect the steps of infecting the T cells with a lentiviral vector and obtaining CAR-T cells.
The state of the prior art: T. Smith (Methods in Molecular Biology, Chapter 11, published 10 November 2019, of record) on page 161 explains transformation can be accomplished with multiple strains of viral vectors and notes that lentiviral vectors are preferred over other vectors and other nonviral methods, such as electroporation, also exist. T. Smith also notes process development for each user’s specific workflow is required to ensure a robust CAR T cell product.
The instant specification at page 28 states the present disclosure does not limit the lentiviral vectors involved, and the lentiviral vectors containing nucleic acid sequences encoding CAR genes in the prior art can be used in the present disclosure. No other methods of making CAR-T cells are present in the disclosure.
Thus, in view of the teachings of the specification and the prior art regarding the necessity of including a lentiviral vector comprising a CAR gene to obtain a CAR T cell, the skilled artisan would find the claimed method unpredictable as prefusion culture alone is insufficient to arrive at CAR-T cells. Thus, the skilled artisan would require an undue amount of experimentation without a predictable degree of success to make and use the invention as claimed.
It is recommended to include, for example, stating in step 3 of claim 1 infecting the activated T cells with a lentiviral vector encoding a CAR.
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 (i.e., changing from AIA to pre-AIA ) 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.
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.
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 1-9 and 11-18 are rejected under 35 U.S.C. 103 as being unpatentable over T. Smith (Methods in Molecular Biology, Chapter 11, published 10 November 2019, of record) in view of Smith et al. (Clinical & Translational Immunology, 2015, IDS ref., of record) as evidenced by Tao et al. (Biotechnol. Prog., 2011, of record) and Sartorius (Biostat RM Bioreactor product datasheet, 2026, of record).
This is a new rejection, necessitated by Applicant’s amendments to the claims. A response to Applicant’s traversal follows the rejection below.
Regarding claim 1, T. Smith teaches CAR-T cell expansion in a Xuri cell expansion system W25, a wave bioreactor (Abstract). T. Smith teaches in CAR-T cell therapy workflows, the Cellbag bioreactor is installed on the rocking Base Unit, wherein the bag is filled with an appropriate gas mixture (e.g., 5% CO2), partially filled with completed culture medium with or without serum, and inoculated with cells (p. 152). T. Smith teaches gas transfer and culture mixing is accomplished by wave-induced agitation, performed by the rocking Base Unit (p. 152). T. Smith teaches perfusion cycles, where waste media is withdrawn and fresh complete medium is added, can be scheduled manually or using an automated protocol (p. 152). T. Smith does not specifically teach the AIM-V (3-9%) Immune cell serum replacement (ISR), however, T. Smith notes serum-independent media formulations are commercially available for use in the Xuri Cell Expansion System W25 and these media still typically require completion with rHu IL-2 (Notes, 4). AIM-V with ISR is a commercially available serum free media.
T. Smith teaches in step 1 of T cell culture initiation, activation, and transformation, start with fresh isolated human peripheral blood mononuclear cells (PBMCs) and in step 2, enrich CD3+ T cells to >90% purity, as assessed by flow cytometry (claim 1, step 1) (p. 155, Section 3.1). T. Smith teaches determine the volume of ImmunoCult Human CD3/CD28/CD2 T Cell Activator, or equivalent, required followed by aliquoting cel culture into appropriate static culture vessel with activators and lentiviral vector (claim 1, step 3) (p. 154, Section 2.2, Step 3 and p. 155, Section 3.1, steps 3-5). CD3/CD28 stimulation via magnetic beads is considered a well-known technique for activating T cells and would have an equivalent effect as the ImmunoCult Human CD3/CD28/CD2 T Cell activator of T. Smith (claim 1, step 2).
T. Smith teaches recommended perfusion schedule based on cell density, wherein the cell density is from 2-10 x 106 (2 x 106 is in the range of 1.1-2 x 106) the perfusion rate is 500 mL/day and wherein the cell density is from 10-15 x 106 (reads as greater than 2 x 106) the perfusion rate is 750 mL/day (Table 1). The suggested perfusion schedule of T. Smith reads as the second and third stage of claim 1, the cell density from 2-10 x 106 reads on the range of 1.1-2 x 106 and the cell density from 10-15 x 106 reads on >2 x 106. The suggested perfusion rates 500:750 read on the rate ratio of the second and third stage of 2:2.5 since 750 is 1.5 times 500.
Regarding the use of AIM-V with ISR and activation with the CD3/CD28 magnetic beads. Smith teaches T cells were cultured in CTS OpTmizer T-cell Expansion SFM supplemented titrated amounts of CTS Immune Cell SR, at a range of 0, 2, 5 or 10% (p. 2, Results). Smith teaches T cells supplemented with 5% SR displayed the highest average fold expansion (Fig. 1). Smith teaches polyclonal T cells were activated according to the rapid expansion protocol and cultured in XVIVO15, OpTmizer or CTS AIM-V supplemented with SR (p. 2, Results, 2nd column). Smith teaches the different culture medium formulations supplemented with CTS Immune Cell SR consistently expanded polyclonal and virus-specific T cells (p. 7, Discussion) which suggests XVIVO15, OpTmizer, and AIM-V are equivalent culture mediums. Smith teaches ex vivo expansion of T cells isolated and activated from PMBC with CTS Dynabeads (magnetic beads) CD3/CD28 is a commonly used protocol for production of T cell products for cell therapy (p. 2, Results and Fig. 1).
Therefore, it would have been obvious to utilize the AIV-V with 5% ISR and the CD3/CD28 magnetic beads of Smith in the method of T. Smith with a reasonable expectation of success because T. Smith teaches serum-independent media formulations are commercially available for use in the Xuri Cell Expansion System W25 and ImmunoCult Human CD3/CD28/CD2 T Cell Activator, or equivalent, can be used as a T cell activator. One would be motivated to utilize the AIV-V with 5% ISR and the CD3/CD28 magnetic beads of Smith in the method of T. Smith because Smith teaches ex vivo expansion of T cells isolated and activated from PMBC with CTS Dynabeads (magnetic beads) CD3/CD28 is a commonly used protocol for production of T cell products for cell therapy and Smith teaches T cells supplemented with 5% SR displayed the highest average fold expansion wherein AIM-V with SR was one of the basal media. The teachings of Smith highlight the availability of AIM-V with 5% ISR.
Regarding claim 2, T. Smith in view of Smith teach the serum-free culture medium is 5% AIM-V with 5% ISR, as discussed in the rejection of claim 1 above.
Regarding claim 3, T. Smith teaches perfusion is initiated only after the culture has reached a minimum viable cell density of 2x106 cells/mL in 1 L volume (p. 158). T. Smith teaches wherein the cell density is from 2-10 x 106 (2 x 106 is in the range of 1.1-2 x 106) the perfusion rate is 500 mL/day and wherein the cell density is from 10-15 x 106 (reads as greater than 2 x 106) the perfusion rate is 750 mL/day or at > 15x106 cells the perfusion rate is 1000 mL/day (Table 1). Therefore, the perfusion rate of T. Smith reads as A2 is 0.5/day and A3 is either .75 or 1.0/day.
T. Smith does not teach the 0.8/day perfusion rate for A2.
However, perfusion rates are known to be considered an optimizable result-effective variable as evidenced by Tao (p. 827, 1st column and Fig. 5). Tao teaches the culture perfusion rate (volume of fresh medium/working volume of reactor/day, vvd) was increased daily according to the integral cell growth (ICG) of the culture and a cell specific perfusion rate (CSPR) using the following equation; Perfusion rate (vvd) = CSPR x ICG where CSPR (nL/cell/day) represents the volume of the medium provided to one cell in one day and ICG (106 cells/mL x day) is determined from the area under the viable cell curve of current viable cell density and predicted viable cell density in 24h interval, which is estimated by the specific cell growth of the cell line (p. 825, 1st column). Therefore, the optimization of the perfusion rates to arrive at those recited in claim 3 would have been a matter of routine experimentation motivated by the cell density and viability. A person of ordinary skill would have been motivated to optimize the perfusion rate because Tao teaches and suggests the beneficial optimization of media perfusion rate to support exponential growth of cells (p. 827, 1st column).
Regarding claims 4 and 12-14, T. Smith teaches the perfusion schedule starts only after the culture has reached a minimum viable cell density of 2 x 106 cells/mL, a preset value, in 1 L volume (p. 158, Section 3.5). Claim 4 requires the perfusion culture to initiate when the cell density is greater than or equal to a preset value, in this instance T. Smith teaches the preset value is 2 x 106 cells/mL, which is greater than 0.3-1.2x106 cells/mL (claim 12), 0.4-1.0x106 cells/mL (claim 13), and 0.5x106 cells/mL (claim 14).
Regarding claims 5 and 6, T. Smith teaches Xuri cell expansion system (a wave bioreactor) (claim 6) for expanding CAR-T cells (p. 151, Introduction). T. Smith teaches the initial minimum culture volume of 300 mL and initial minimum viable cell density of 0.5 x 106 cells/mL (p. 161). T. Smith teaches culturing conditions will vary from workflow to workflow; however, typical settings include 10 rocks per minute (RPM), 37°C, and 5% CO2 (claim 5) for T lymphocyte culture (p. 162). T. Smith does not specifically label the process of fed-batch culture; however, cells would require fed-batch process since T. Smith does not initiate perfusion culture until the cells reach 2 x 106 cells/mL (p. 158, section 3.5 and Table 1). T. Smith does not specifically identify ventilation volume; however, Sartorius lists the aeration rate of rocking motion bioreactors is 50-1,000 mL/min (claim 5) (p. 4). MPEP 2144.05(I) states, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. Therefore, the claimed ventilation volume of 0.1-1 L/min overlaps with the standard range for rocking motion bioreactors. T. Smith teaches maintaining the culture at a cell density of 1 x 106 viable cells/mL until minimum volume of 300 mL is reached, 15 x 107 total viable cells (claim 6) (p. 155).
Regarding claims 7 and 15-16, T. Smith teaches culturing conditions will vary from workflow to workflow; however, typical settings include 10 rocks per minute (RPM) and 5% CO2 for T lymphocyte culture (p. 162). T. Smith does not specifically identify ventilation volume; however, Sartorius lists the aeration rate of rocking motion bioreactors is 50–1,000 mL/min (p. 4). MPEP 2144.05(I) states, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. Therefore, the claimed ventilation volume of 0.3-0.8 L/min (claim 7), 0.4-0.6 L/min (claim 15), and 0.5 L/min (claim 16) overlap with the standard range for rocking motion bioreactors.
Regarding claim 8, Smith teaches activation of polyclonal T cells using CTS Dynabeads CD3/CD28, wherein the bead to T cell ratio is 3:1 and the T cells were seeded at 1 x 106 T cell/mL and cultured for 2 weeks (p. 8). Smith does not discuss the ratio of beads to cells in terms of volume; however, the volume of beads would be considered a result-effective variable. A person of ordinary skill in the art would have been motivated to find the volume of beads in order to effectively activate the T cells as a matter of routine optimization and experimentation. Smith is silent to the culturing conditions, such as 37°C and 5% CO2, however, these variables are recognized in the art as standard cell culture conditions, as evidenced by T. Smith (p. 162).
Regarding claims 9 and 17-18, Smith teaches T cells were cultured in CTS OpTmizer T-cell Expansion SFM supplemented titrated amounts of CTS Immune Cell SR, at a range of 0, 2, 5 or 10% (p. 2, Results). Smith teaches T cells supplemented with 5% SR displayed the highest average fold expansion (Fig. 1). Smith teaches polyclonal T cells were activated according to the rapid expansion protocol and cultured in XVIVO15, OpTmizer or CTS AIM-V supplemented with SR (p. 2, Results, 2nd column). Smith teaches the different culture medium formulations supplemented with CTS Immune Cell SR consistently expanded polyclonal and virus-specific T cells (p. 7, Discussion) which suggests XVIVO15, OpTmizer, and AIM-V are equivalent culture mediums. Thus, Smith teaches the method of culturing CAR T-cells by isolating and activating PBMCs with CD3/CD28 magnetic beads, infecting activated T cells with a lentiviral vector in a serum-free culture medium wherein the medium is AIM-V supplemented with 5% Immune Cell SR (claims 17-18) (serum-free media that lacks animal-derived components) and suggest culturing CAR-T cells.
Regarding claim 11, T. Smith in view of Smith renders obvious wherein the composition of the serum-free culture medium is AIM-V with 5% ISR, as discussed in the rejection of claim 1 above.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
Response to Traversal
Applicant’s arguments, see remarks, filed 28 July 2026, with respect to the claim rejections under 35 USC § 103 have been fully considered and are persuasive. Specifically, the rejections of record did not fully address the claims as amended. The rejections of 29 April 2026 have been withdrawn.
The arguments directed to Tao are not persuasive because Tao was utilized as an evidentiary reference to highlight that perfusions rates are dependent on cell viability and density, not to teach the specified perfusion rates.
Applicant argues the previous office action did not set forth a proper routine optimization rationale. This is not persuasive because Tao teaches and suggests the beneficial optimization of media perfusion rate to support exponential growth of cells, which was discussed in the rejection of record. Additionally, T. Smith teaches the perfusion rates as required by claim 1. See the new rejection above.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., the perfusion rates in the claimed method are increased in a preset, stepwise fashion, with different perfusion rates being employed when the cell density reaches specifically defined thresholds) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). While claim 1 recites the limitations when the cell density reaches a specified value, the perfusion rate is a specified value. This does not limit the perfusion rate to a stepwise fashion, only requires the perfusion rate to be at the specified value when the cell density reaches the specified range.
Regarding the arguments directed to the individual references not correcting the deficiencies of the preceding references, this is not persuasive because, as indicated above, the references utilized are shown to not be deficient.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over T. Smith (Methods in Molecular Biology, Chapter 11, published 10 November 2019, of record) and Smith et al. (Clinical & Translational Immunology, 2015, IDS ref., of record) as evidenced by Tao et al. (Biotechnol. Prog., 2011, of record) and Sartorius (Biostat RM Bioreactor product datasheet, 2026, of record) as applied to claims 1-9 and 11-18 above, and further in view of Wenzheng et al. (CN112301060A, published 02 February 2021, of record) and Elegheert et al. (Nat Protoc. 2018, of record).
A machine translation of the specification was used for CN112301060A, as the original was published in Chinese.
This is a new rejection, necessitated by Applicant’s amendments to the claims. A response to Applicant’s traversal follows the rejection below.
Regarding claim 10, T. Smith in view of Smith teach culturing CAR-T cells at 37°C and 5% CO2 for at least 24 hours; however, are silent to the use of polybrene.
However, Wenzheng teaches separating PBMCs from human peripheral blood, activated with CD3 and CD28 antibodies, plating the activated T cells at 1 x 106 cells/well in a 24-well plate, adding virus at MOI=10:1, and 10µg/mL polybrene was added to promote infection (p. 6, section 4, 1st para.). Wenzheng teaches after 24 hours, the cells were collected, centrifuged at 1800 rpm for 60 minutes, the medium discarded, and fresh medium was added (p. 6, section 4, 1st para.). Wenzheng teaches the cells were collected 48 hours after infection with lentivirus and showed a near 100% infection efficiency (p. 6, section 4, 2nd para.).
Elegheert teaches polybrene is a cationic polymer that reduces charge repulsion between viral particles and the cell membrane which will promote virus-host cell fusion, leading to higher transduction efficiencies (p. 19, step 14). Elegheert teaches lentiviral transduction at MOI rates of 0, 1, 4, and 10 at 37°C for 24 hours (p. 26). Elegheert teaches a MOI of approximately 3.2 has a theoretical efficiency of approximately 95% (Box 2).
Therefore, it would have been obvious to one of ordinary skill in the art to utilize polybrene in the method of culturing CAR-T cells of T. Smith in view of Smith with a reasonable expectation of success because Elegheert teaches polybrene is known in the art to enhance transduction efficiency in T cells. One would be motivated to utilize polybrene in the method of culturing CAR-T cells of T. Smith in view of Smith because polybrene is shown to increase infection efficiency, thus, a lower MOI can be utilized while still maintaining a high efficiency of infection.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
Response to Traversal
Regarding the arguments directed to the individual references not correcting the deficiencies of the preceding references, this is not persuasive because, as indicated above, the references utilized are shown to not be deficient.
Conclusion
No claims are allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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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/N.A.H./Examiner, Art Unit 1631
/LAURA SCHUBERG/Primary Examiner, Art Unit 1631
