DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicants’ submission filed on March 20 2026 has been entered.
Receipt of Arguments/Remarks filed on March 20 2026 is acknowledged. Claims 3, 6, 8, 10-11, 19, 21-22, 25 and 30-32 were/stand cancelled. Claims 1-2, 4-5, 7, 9, 12-18, 20, 23-24 and 26-29 are pending.
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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on January 14 2026 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-2, 4-5, 7, 9, 12-18, 20, 23-24 and 26-28 are rejected under 35 U.S.C. 103 as being unpatentable over O’Connor et al. (WO2020163454) in view of Costariol et al. (Biotechnol. J. 2020, cited on PTO Form 1449) and Villiger et al. (USPGPUB No. 20190085284) and Shevitz (USPGPUB No. 20130270165) as evidenced by Lim et al. (USPGPUB No. 20160024460).
Applicant Claims
The instant application claims a method of producing a T-cell culture in a fully closed system, comprising: a) obtaining an T-cell; b) introducing the T-cell into a stirred-tank bioreactor comprising an T-cell complete medium; c) activating the T-cell with an activation reagent to produce an activated T-cell in the stirred-tank bioreactor; d) expanding the activated T-cell to produce an expanded T-cell culture in the stirred-tank bioreactor; e) exchanging a defined amount of fresh medium for spent medium via an alternating tangential flow filtration (ATF) connected to the bioreactor; f) depleting the expanded T-cell culture of (d) to produce a depleted T-cell culture in the stirred-tank bioreactor; g) harvesting the depleted T-cell culture of (f) to produce a harvested T-cell culture in the fully closed system; and h) concentrating the harvested T-cell culture of (g) in the fully closed system, wherein the method results in less than 1% loss of the T-cell culture.
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
O’Connor et al. is directed to a cell concentration methods and devices for use in automated bioreactors. The cassettes and methods are utilized and carried out in a fully enclosed automated cell engineering system (paragraph 0028). A user can provide an automated cell engineering system prefilled with a cell culture and reagents (e.g., an activation reagent, a vector, cell culture media, nutrients, selection reagent, and the like) and parameters for the cell production (e.g., starting number of cells, type of media, type of activation reagent, type of vector, number of cells or doses to be produced, and the like). The automated cell engineering system is able to carry out the various automated methods, including methods of producing genetically modified immune cell cultures, including CAR T cells, without further input from the user (paragraph 0029). Fig. 1 shows various processes can be carried out in an enclosed, automated system. The processes include activating, transducing, expanding, concentration, washing and collecting/harvesting steps (paragraph 0026). In order to receive the greatest cell recovery without significant loss in viability, process parameters are optimized (paragraph 00168).
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.02)
While O’Connor et al. teaches an enclosed system for use in automated bioreactors, O’Connor et al. does not expressly teach a stirred-tank bioreactor. However, this deficiency is cured by Costariol et al.
Costariol et al. teach the manufacture of human CAR-T cells in an automated stirred-tank bioreactor. When selecting a suitable expansion platform for cell production, it is important to consider multiple factors to mitigate clinical and commercial risk. Stirred-tank bioreactors (STRs) have significant potential advantages. The provide a robust cell expansion platform, they are widely used in the biological industry, they have well characterized and proven high-thruput small-scale models, they have well-established supply chain infrastructure and have an existing and well-established pathway to enable full process integration (page 1-2, last paragraph and left column). The study demonstrated the expansion of CAR-T cells in a STR (conclusions).
While O’Connor et al. teaches a tangential flow filtration for T-Cells, O’Connor et al. does not teach alternating tangential flow filtration or pluripotent stem cells. However, this deficiency is cured by Villiger et al.
Villiger et al. is directed to the production of extracellular vesicles in single-cell suspension using chemically-defined cell culture media. Taught are culturing cells in a bioreactor such as a stirred-tank bioreactor. A stirred-tank bioreactor is connected to a cell retention device such as hollow fibrous membrane run in alternating tangential flow filtration (ATF), tangential flow filtration (TFF) or an acoustic cell separator (paragraph 00077). Parent cells which can be utilized include erythrocytes, platelets, neutrophils, stem cells including cells derived from pluripotent stem cells (paragraph 0088).
Shevitz is directed to fluid filtration systems. Shevitz discusses alternating tangential flow filtration systems and discusses the desire for a complete culture system, e.g. a system that inspirates or combines the culture vessel and the perfusion device into a single apparatus. (paragraph 0007). Taught is an enclosed fluid filtration system and filtrate reservoir shown in Figs. 2 and 3 which can be encapsulated in a protective bag for additional protection (i.e. fully enclosed). It is taught that by specific compartmentalization for the alternating tangential flow filtrate process, one can produce systems that may greatly facilitate certain biological and chemical reactions or be used for purification or isolation of certain constituent from biological or other fluids (paragraph 0009).
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of O’Connor et al., Costariol et al., Shevitz and Villiger et al. and utilize a stirred-tank bioreactor. One skilled in the art would have been motivated to utilize a stirred-tank bioreactor for the numerous advantages taught by Costariol et al. One skilled in the art would have a reasonable expectation of success as O’Connor et al. teaches the use of bioreactors with CAR-T cells which is the same type of cells used in Costariol et al.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of O’Connor et al., Costariol et al., Shevitz and Villiger et al. and utilize alternating tangential flow filtration. It would have been obvious to one skilled in the art to utilize either ATF or TFF as both are taught as being suitable to be used with stirred-tank bioreactors as taught by Villiger et al. Since Shevitz recognizes that alternating tangential flow filtration systems can be compartmentalized and utilized in enclosed systems for cell culture related applications, there is a reasonable expectation of success in utilizing the alternating tangential flow filtration system with the enclosed system of O’Connor et al.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of O’Connor et al., Costariol et al., Shevitz and Villiger et al. and utilize any desirable parent cell. Since the method is designed to culture cells it would have been obvious to one skilled in the art to utilize any known cell types such as pluripotent stem cells as all are taught as suitable by Villiger et al.
Regarding claim 1, O’Connor et al. teaches prefilled with a cell culture and reagents (e.g., an activation reagent, a vector, cell culture media, nutrients, selection reagent, and the like) reading on obtaining an immune cell (CAR T-Cell) and introducing the immune cell into a stirred-tank bioreactor comprising the immune cell complete medium, activating the immune cell with an activation reagent. Fig. 1 shows processes of expanding, concentrating and harvesting. The systems are monitored. Taught is providing fresh media and/or nutrients to the cell culture (paragraph 0089) reading on the instantly claimed exchanging. Exemplified are the use of tangential flow filtration which can be used to separate, clarify, recover and collect cells from a post-harvest suspension fluid reading on depleting.
Regarding claim 2, O’Connor et al. teaches that a culture media with nutrients (paragraph 0029). Costariol et al. teaches Dulbecco’s Modified Eagle Medium (DMEM) (experimental section). As evidenced by Lim et al., DMEM includes amino acids, inorganic salts, trace elements, glucose, buffers, serum, vitamins (paragraph 0040).
Regarding claim 4, O’Connor et al. in Fig 8A-8B shows reduction of peripheral blood mononuclear cells (PBMC). As taught by Costariol et al., T-cells (immune cells) were isolated form fresh peripheral blood mononuclear cells (experimental section).
Regarding claim 7 and 18, O’Connor et al. teaches a magnetic separation process can be utilized to further eliminate and separate undesired cells and debris from a cell population. In such embodiments, a magnetic bead or other structure, to which a biomolecule (e.g., antibody, antibody fragment, etc.) has been bound, can interact with a target cell. Various magnetic separation methods, including the use of filters, columns, flow tubes or channels with magnetic fields, etc., can then be used to separate the target cell population from undesired cells, debris, etc., that may be in a cellular sample. For example, a target cell population can flow through a tube or other structure and be exposed to a magnetic field, whereby the target cell population is retained or held-up by the magnetic field, allowing undesired cells and debris to pass through the tube. The magnetic field can then be turned off, allowing the target cell population to pass onto a further retention chamber or other area(s) of the cassette for further automated processing.
Regarding claim 9, O’Connor et al. teaches that the cell concentration during the process varies from 0.3*106 cells/ml to approximately 10*106 cells/ml (paragraph 0068). Costariol et al., teaches that viability and live cell concentration was accessed daily (section 2.1). Since O’Connor et al. teaches that process conditions can be optimized, one skilled in the art would manipulate the process conditions in order to achieve the desired level of viability and cell concentration.
Regarding claim 12, O’Connor et al. teaches chambers with the activation agent is maintained at a temperature for growing cells (e.g. at about 37 °C) (paragraph 0056; 0088). Costariol et al. also teaches activation at 37 °C (section 5). While both O’Connor et al. and Costariol et al. are silent to the exact time, one skilled in the art would recognize that depending on the activation agent utilized or level of activation required, one skilled in the art would incubate the cells at 37 °C for the necessary amount of time to achieve the desired activation level
Regarding claim 13, Villiger et al. teaches agitation conditions for culturing to ensure proper aeration at sufficiently high cell densities can vary and depend upon cell type, type of culture vessel, volume of culture, etc. Agitation can be achieved by stirring or shaking. In certain embodiments, the speed of shaking ranges from 350 rpm and 10 rpm, or ranges from 300 rpm and 50 rpm, or ranges from 275 and 150 rpm, or ranges from 250 and 200 rpm. In certain embodiments, the speed of shaking is 250 rpm. In certain embodiments, the speed of agitation will vary according to cell culture volume, shaking diameter and/or if the culture vessel is tilted or cultured at 90 degree angle (paragraph 0058). O’Connor et al. teaches that in order to receive the greatest cell recovery without significant loss in viability, process parameters are optimized. Therefore, one skilled in the art would manipulate the process parameters in order to determine the optimal stirring speed.
Regarding claim 14, Costariol et al. teaches a pH between 7.3-7.4. O’Connor et al. describes the use of a pH sensor (see figures). Therefore, one skilled in the art would use a medium which achieves the desired pH for activation.
Regarding claim 15, O’Connor et al. teaches PBMC were stimulated with Dynabeads and then expanded in complete T-cell media. A pre-wash protocol has been used (paragraph 00156). O’Connor et al. teaches the cassettes include one or more of a pH sensor 524, a glucose sensor (not shown), an oxygen sensor 526, a carbon dioxide sensor (not shown), a lactic acid sensor/monitor (not shown), and/or an optical density sensor (not shown). See FIG. 5 for exemplary positions within the flowpath (0054). Uses these systems to monitor is suggested (paragraph 0089).
Regarding claims 16-17, O’Connor et al. teaches the automated cell engineering system automatically adjusts the schedule of cell feeding (i.e. , providing fresh media and/or nutrients to the cell culture) based on the cell growth rate and/or cell count, or other monitored factors, such as pH, oxygen, glucose, etc. The automated cell engineering system may be configured to store media (and other reagents, such as wash solutions, etc.) in a low-temperature chamber (e.g., 4°C or -20°C), and to warm the media in a room temperature chamber or a high-temperature chamber (e.g., 25°C or 37°C, respectively) before introducing the warmed media to the cell culture (paragraph 0089). Therefore, O’Connor et al. teaches that the system adjusts depending on the results of the monitored factors. One skilled in the art would determine the devel of viable cell density required.
Regarding claim 20, O’Connor et al. teaches a cellular sample output can be utilized to harvest the cells (paragraph 0042). Tangential flow filtration can be used for harvesting (example 1). Taught is the use of a pump system (paragraph 0034) and the flow controller is an additional pumping system (claim 50). Villiger et al. suggests the use of ATF.
Regarding claim 23, Costariol et al. teaches harvest at 7 days. O’Connor et al. teaches that the system recirculates through until such time as collection is desired (paragraph 0049). Therefore, one skilled in the art would determine when harvesting/collecting is desired and harvest the cells at that time.
Regarding claim 24, 26-28, O’Connor et al. teaches centrifuged (examples) and generally teaches filtration (examples). Costariol et al. also teaches centrifuged (section 5). O’Connor et al. teaches that in order to receive the greatest cell recovery without significant loss in viability, process parameters are optimized. While concentration, the pump was set to 60 ml/min and the permeate control pump was set to either 0, 5, 10, or 15 ml/min. Villiger et al. teaches the use of hollow fiber filters (TFF or ATF) or an acoustic cell separator (paragraph 0037). Therefore, since O’Connor et al. expressly teaches that the process parameters are optimized in order to achieve the greatest cell recovery without significant loss in viability, absent a demonstration of the criticality, one skilled in the art would manipulate the flow rate and processing conditions in order to achieve the desired result. O’Connor et al. teaches passage into storage (paragraph 0034; 0042) and the closed system allows the processes to be formed aseptically (paragraph 0142) resulting in a sterile and enclosed container.
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over O’Connor et al. in view of Costariol et al. , Shevitz and Villiger et al. as evidenced by Lim et al. as applied to claims 1-2, 4-5, 7, 9, 12-18, 20, 23-24 and 26-28 and in further view of Castella et al. (Frontiers in Immunology, 2020, cited on PTO Form 1449).
Applicant Claims
The instant application claims the activating and the expanding of the T-cell in the stirred-tank bioreactor results in a T-cell culture producing greater than five cytokines, and with greater than 75% central memory T-cells, less than 10% effector memory T-cells, and greater than 10% naïve/stem memory T-cells.
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
The teachings of O’Connor et al., Costariol et al. and Villiger et al. are set forth above.
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.02)
O’Connor et al. does not expressly teach the limitations of instant claim 29. However, this deficiency is cured by Castella et al.
Castella et al. is directed to point-of-care CAR T-cell production using a closed semi-automatic bioreactor. Castella et al. discloses development of semi-automated devices that can reduce the hands-on time and standardize the production of clinical grade CAR T-cells (abstract), wherein the resulting immune cell population comprises a T-cell culture producing greater than five cytokines (Figure S5; Figure S5 Legend : "Cytokine levels measured from supernatants of co-culture experiments of final products with NALM6 cells at different E:T ratios. Cytokine levels were measured by Luminex. Graphs show mean ± SEM": Note: Figure S5 illustrates the expression of IL-10, IL-12, IL-17, IL-1b, IL-2, IL-4, IL-6, IP-10, IL-15, IL-8, and MiP1A), and with greater than 31% central memory T-cells, a specific % of effector memory T-cells, and greater than 10% naive/stem memory T-cells (pg 7, col 2, para 2 - "Average percentage and SD for each
subpopulation in the CAR+ cells of the final product is as follows: TN: 7.71 ± 13.9, TSCM: 5.26 ± 12.0, TCM: 31.01 ± 16.7, TEM: 35.11 ± 17.7, and TE: 4.2 ± 9.5").
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of O’Connor et al., Costariol et al., Shevitz, Villiger et al. and Castella et al. and manipulate the activating and expanding of the immune cells to achieve the desired T-cell populations. Since both O’Connor et al. and Castella et al. are directed to CAR T-cells and Castella et al. show cytokine levels, central memory T-cell level, effector memory T-Cell level and naïve/stem memory T-Cell levels there is a reasonable expectation of success.
Response to Arguments
The examiner notes that Applicants indicated a typo in the previous Office Action. While claim 13 was not included in the statement of rejection, the limitations of the claim were clearly addressed in the body of the rejection. The statement of rejection has been corrected above.
Applicants’ arguments filed March 20 2026 have been fully considered but they are not persuasive.
Applicants argue (pages 2-4) that the present invention method utilizes a fully closed system. O’Conner discloses that the cassette system and methods are designed to be utilized with the COCOONTM automated cell engineering system. Thus, O’Connor does not disclose the use of the TFF cassette system and methods in any automated bioreactor as asserted by the Office. One skilled in the art would not have been motivated to combine O’Connor and Costariol in an attempt to arrive at the presently claimed method because there would not be a reasonable expectation of success. It is argued that Villiger does not overcome the deficiencies of O’Connor and Costariol. Villiger is wholly silent to perfusion culturing methods for T-cells. It is argued Villiger discloses that TFF is suitable to be used with stirred-tank bioreactors. Thus, one skilled in the art would not be motivated to switch from the use of TFF in the cassette system and methods for perfusion culturing T-cells as successfully demonstrated by O’Connor and arrive at the presently claimed invention. It is argued that Lim and Castella do not cure the deficiencies.
Regarding Applicants’ arguments, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). Therefore, in order to render the claims obvious it is not a requirement that O’Connor teaches that other systems can be utilized if the prior art as a whole suggests that other systems can be utilized to produce a cell culture, then the claimed method would be obvious. It appears Applicants are of the position that O’Connor only allows for the use of a COCOONTM, however, nowhere in O’Connor is that taught. Examples and preferred embodiments are not a teachings away from the broader disclosure. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). MPEP 2123. As noted before, Note: MPEP 2143: examples of rationales (B) simple substitution of one known element for another to obtain predictable results.
O’Connor teaches the use of an automated cell engineering system comprising (a) an enclosable housing; (b) a cassette contained within the enclosable house, the cassette comprising i: a cell culture chamber; ii. A pumping system fluidly connected to the cell culture chamber, iii. a tangential flow filter fluidly connected to the pumping system and iv. A cellular sample output fluidly connected to the TFF; and (c) a user interface (claim 36). Thus, O’Connor generally teaches an claims an automated cell engineering system and does not limit the scope to only the device of the examples. It is the examiner’s position that it would have been obvious to replace the TFF system with the ATF system for the advantages taught by Villiger et al. As taught by newly cited Shevitz there is a reasonable expectation of success as Shevitz expressly teaches the use of ATF in enclosed systems. Since as recognized by Shevitz there is a desire for a complete culture system, e.g. a system that inspirates or combines the culture vessel and the perfusion device into a single apparatus, the state of the art would recognize the desire to utilize ATF for its advantage but use it with the enclosed system to provide for a single device.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ABIGAIL VANHORN whose telephone number is (571)270-3502. The examiner can normally be reached M-Th 6 am-4 pm EST.
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/ABIGAIL VANHORN/Primary Examiner, Art Unit 1636
