DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.
Remarks
The amendments and remarks filed on 01/20/2026 have been entered and considered. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The rejections and/or objections presented herein are the only rejections and/or objections currently outstanding. Any previously presented objections or rejections that are not presented in this Office Action are withdrawn.
Claims 30-31, 33, 36-37, 39-42, 55-58, 88-98, and 111-121 are pending.
Claims 30 and 88 are amended.
Claims 1-29, 32, 34-35, 38, 43-54, 59-87, and 99-110 are canceled.
Claim 121 is new.
Claims 30-31, 33, 36-37, 39-42, 55-58, 88-98, and 111-121 have been examined on the merits.
Priority
This application, U.S. Application No. 17/842528, is a continuation of U.S. Application No. 16/355,387, filed on 03/15/2019, now issued as U.S. Patent No. 11391725, which claims benefit of provisional applications No. 62/645,755 filed on 03/20/2018 and No. 62/644,339 filed on 03/16/2018.
Objections - Withdrawn
Objection to the claim 88 is withdrawn due to the amendment to the claim filed on 01/20/2026.
Rejections - Withdrawn
The rejection of Claims 30, 31, 33, 36, 37, 39-42, and 55-58 under 35 U.S.C. 103 over Hwang et al. in view of Laluce et al. is withdrawn in favor of the rejection listed below.
Claim Objections
Claims 30 and 121 are objected to because of the recitation of “LDH”. Abbreviations should be spelled out at least once in the claims. Appropriate correction is required.
Claims 111 and 112 are objected to because of the recitation of “a volume of gas per volume of liquid per minute (VVM) (min-1)”. It is noted that the unit “min-1” is not a part the abbreviation VVM. The recitation should be changed to “a volume of gas per volume of liquid per minute (VVM)” and the unit “min-1” should be placed after the specific VVM values recited in the claims, to be consistent with the claim language of the claims 115 and 116. Appropriate correction is required.
Claim Rejections - 35 USC § 112(d), or 112, Fourth Paragraph
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 95 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends
Claim 95 recites the limitation “the production bioreactor has a volume of about 5L to about 20,000 L”. Since this limitation is already present in the base claim 88, upon which the claim 95 depend, the claim 95 fails to further limit the method of the claim 88.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 112, First Paragraph
The following is a quotation 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 35 U.S.C. 112 (pre-AIA ), first paragraph:
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 30, 36-37, and 39-42 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
The claims are directed to a method for improving cell viability in a bioreactor, comprising steps: (a) determining cell viability under test conditions, which are defined by a set of parameters and are selected based on full factorial screening and/or inscribed center composite design; (b) based on the cell viability under the plurality of test conditions, selecting a condition that is optimal for cell viability in the bioreactor; and (c) culturing a cell in the bioreactor under the selected condition resulting in: a specific cell death rate of less than 40% per day ,a cell specific LDH production of less than 150 nU/cell/day, and an apparent growth rate of greater than 1% per day during the culturing of the cell in the production bioreactor.
It is noted that the claim 30 merely recites that the test conditions are defined by a set of parameters, but does not define any specific test conditions or any specific parameters to be used for defining the test conditions in the step (a) and (b) of the base claim 30. Accordingly, the steps (a) and (b) in the claimed method are conducted under any test conditions defined by any set of parameters for selecting a condition optimal for cell viability in the bioreactor by using the statistic method of full factorial screening and/or inscribed center composite design. As such, the scope of the claim encompasses a huge number of possible parameters and defined test conditions thereof, such as pH, temperatures, inhibitors of cell growth, types and concentrations of various nutrients, types and densities of cells, types and concentrations of protective agents in culture media, a length of time for culturing cells, agitation speeds, sheer stress, perfusion rates, gas components and contents in headspace (e.g. O2 and CO2), and osmotic pressure/potential. Furthermore, neither the base claim 30 nor its dependent claims define any specific selected condition optimal for cell viability in the step (b) and (c). As such, the condition used for culturing the cell in the step (c) is open to any condition which could result in the outcome of achieving the specific cell death rate of less than 40% per day ,a cell specific LDH production of less than 150 nU/cell/day, and an apparent growth rate of greater than 1% per day during the culturing of the cell.
The specification of the instant application discloses only the parameters of RPM of rotary agitation, concentrations of a sensitizer (antifoam agent), and concentrations of a protectant (poloxamer-188), and determination of cell viability under test conditions based on these three parameters. The specification does not provide information or guidance about determining cell viability under test conditions based on all other possible parameters; selecting test conditions based on all other possible parameters by statistic method of full factorial screening and/or inscribed center composite design; and selecting all possible conditions optimal for cell viability, to be used for culturing cells, which result in the claimed specific cell death rate of less than 40% per day , cell specific LDH production of less than 150 nU/cell/day, and apparent growth rate of greater than 1% per day. Furthermore, the prior art does not provide any information or guidance regarding how to perform the claimed method by using any parameters for defining any test conditions, and using statistic method of full factorial screening and/or inscribed center composite design for selecting the test conditions, and by selecting all possible conditions optimal for cell viability for culturing cells, which result in the claimed specific cell death rate, cell specific LDH production, and apparent growth rate.
In order for the written description provision of 35 USC 112, first paragraph to be satisfied, Applicant must convey with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention. The invention is, for purposes of the 'written description' inquiry, whatever is now claimed. For example, MPEP 2163 states in part,
An adequate written description of a chemical invention also requires a precise definition, such as by structure, formula, chemical name, or physical properties, and not merely a wish or plan for obtaining the chemical invention claimed. See, e.g., Univ. of Rochester v. G.D. Searle & Co., 358 F.3d 916, 927, 69 USPQ2d 1886, 1894-95 (Fed. Cir. 2004) (The patent at issue claimed a method of selectively inhibiting PGHS-2 activity by administering a non-steroidal compound that selectively inhibits activity of the PGHS-2 gene product, however the patent did not disclose any compounds that can be used in the claimed methods. While there was a description of assays for screening compounds to identify those that inhibit the expression or activity of the PGHS-2 gene product, there was no disclosure of which peptides, polynucleotides, and small organic molecules selectively inhibit PGHS-2. The court held that “without such disclosure, the claimed methods cannot be said to have been described.”).
Without additional information, the person of ordinary skill in the art has to do undue experimentation to find and select specific conditions based on all possible parameters, optimal for cell viability in a production bioreactor, encompassed by the entire scope of the claimed method. Adequate written description requires more than a mere statement that it is part of the invention.
Therefore, the full breadth of the steps (a), (b), and (c) encompassed by the claims do not meet the written description provision of 35 USC 112, first paragraph.
Claim Interpretation
The base claim 30 recites the limitation “production bioreactor”. Specific structures of the production bioreactor are not defined in the specification. It is noted that the specification (page 13) discloses the bioreactor is a “large-scale bioreactor”. However, the specific size range of the “large-scale bioreactor” is not defined in the specification. It is noted that the term “large-scale” is a relative term (in relative to small scale), and in the absence of a benchmark the size range of the large-scale bioreactor is not clear. For the purpose of examination, the term is interpreted as any vessel that has a volume for culturing or fermenting cells to amplify cells or produce desirable products from the cells.
Claim Rejections - 35 USC § 103
Claims 88-98 and 111-121 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (Biotechnol. Progress, 3394: 1146-1159, published online 5/17/2017, cited in IDS) in view of Zhang et al. (J. Biotechnol., 1992, 25: 289-306, cited in IDS) and Velugula-Yellela et al. (Biotech. Progress, 34(1): 262-270, published online 11/16/2017, cited in IDS), as evidenced by Shaaltiel et al. (US 2010/0112700, 2010, of record). This rejection is maintained for Claims 88-98 and 111-120, and applied to the new claim 121.
Xu et al. teach optimization of variables/parameters for scale-up of bioreactor systems for production of monoclonal antibodies via mammalian cell culture (abstract); and Xu et al. teach a process for culturing a cell in a liquid culture medium in a production bioreactor, wherein the culturing is conducted under the conditions with controlled P/V and vvm (title, page 1147/right col/para 2 – page 1148/left col/para 1, page 1150/left col/para 2, table 1), wherein the P/V is in the range of 20 to 40 W/m3 (page 1149, right col, para 4, last 2 lines) (Note: this P/V range reads on the claimed P/V range of about 1.0 to about 110 W/m3, as required by the a) of the claim 88); wherein the vvm for the process ranges from 0.001 to about 0.16 vvm with specific data points falling into the claimed range of 0.01 to 0.1 vvm in claim 111 (Figs. 1, 1A, and 1B, Tables 2-3); and wherein an antifoam EX-Cell is also added to the culture medium for controlling foam in the bioreactor, with increased bioreactor scale (page 1147/bottom of right column, page 1154/left col/para 1/last 2 lines). It is noted that the antifoam EX-Cell taught by Xu et al. reads on the “sensitizer” and “antifoam” recited in the claims 88, 89, 117, and/or 118, and it also reads on the “simethicone” recited in the claim 91 since EX-Cell is a synonym of simethicone, as evidenced by the disclosure of the specification (page 19, lines 4-5), thus, meeting the limitation of the claim 91. Xu et al. further teach that the bioreactor has a volume of 500 L, 200 L, or 2000 L (page 1147, right col, paras 2-3 and table 1), which reads on the claimed range “about 5 L to about 20000 L” in the claim 88.
Xu et al. further teach the use of Pluronic F68 as a shear protectant in the cell culture (page 1154, bottom of left column of last full para). It is noted that Pluronic F68 is a synonym of the “poloxamer-188” recited in the claim 93, as evidenced by the disclosure of the specification (see page 118, last 2 lines). Thus, the Pluronic F68 taught by Xu et al. meets the limitations of the protectant recited in the claims 92-94.
Xu et al. do not teach that the concentration of the Pluronic protectant (poloxamer-188) is from about 1g/L to about 15 g/L (recited in the c of the claim 88), from about 2 g/L to about 10 g/L (recited in the claim 119), or about 5 g/L (recited in the claim 120).
Zhang et al. investigate protectant effects of Pluronic F68 (i.e. poloxamer-188) on cells in culture media in stirred and sparged bioreactors for monoclonal antibody production (title, abstract). Zhang et al. teach that Pluronic F-68 is a surfactant that is used as a protectant against hydrodynamic cell damage, and the surfactant is known to cause foaming (page 290, last paragraph).; and Zhang et al. continue to teach that the purpose of their study is to tackle the problems associated with the foaming caused by Pluronic F68 (pages 291, first full paragraph). Zhang et al. also teach a process of culturing mammalian cells (derived from a mouse) in a culture medium to produce monoclonal antibodies (i.e. anti-alpha fetal protein IgG) in bioreactors (page 291, second full paragraph), wherein the culture medium is supplemented with 0.2% (w/v) Pluronic F68 (equivalent to 2 g/1000 ml or 2 g/L, 1 L of water is considered to have a weight of 1000 g), in which as much as 10% of the culture medium was lost due to foam, but no cellular debris was found, indicating the supplemented Pluronic F68 prevented cell losses in the foam (page 297, last paragraph). Zhang et al. further teach that when the 0.2% Pluronic F68 was supplemented to the culture medium along with an antifoam agent, antifoam C, at 10 ppm, 50 ppm, 100 ppm and 200 ppm, the improvement in decreased foam with increased cell density and/or increased monoclonal antibody (Mab) production is observed, and antifoam C at levels greater than 50 ppm completely eliminated foam in the medium (page 292/para 2, Figs. 8(a) –(d), the para in page 299). It is noted that the concentration of 2 g/L taught by Zhang et al. reads on the claimed protectant ranges of “about 1g/L to about 15 g/L” and “about 2 g/L to about 10 g/l” recited in the claims 88 and 119, respectively. It is noted that the antifoam C taught by Zhang et al. is an emulsion of polydimethylsiloxane (PDMS) recited in the claim 90, as evidenced by Shaaltiel et al., who teach using antifoam C emulsion of polydimethylsiloxane (PDMS) to control foaming (paras [0186]/lines 1-3, and [0262]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ Pluronic F68 at a concentration in the range of about 1g/L to about 15 g/L or “about 2 g/L to about 10 g/L”, specifically 2 g/L, in the production bioreactor of Xu et al. for producing monoclonal antibodies, as taught by Zhang et al. The ordinary artisan would have been motivated to do so because both Xu et al. and Zhang et al. teach Pluronic F68 to protect cells that produce proteins, specifically monoclonal antibodies (MAbs), and Zhang et al. teach an effective concentration of Pluronic F68 (falling into the claimed ranges) to accomplish this objective. The ordinary artisan would have had a reasonable expectation that Pluronic F68 at a concentration in the claimed ranges (specifically 2 g/L) would be effective to protect the cells in a culture medium in the method of Xu et al., because Zhang et al. demonstrate that 2 g/L is effective for the protection. Furthermore, both the method of Xu et al. and the method of Zhang et al. are directed to producing MAbs from cultured cells in the presence of Pluronic F68. The teachings of Zhang et al. about the concentration of Pluronic F68 are readily appliable to practice the method of Xu et al.
Regarding the limitation “about 5 g/L” recited in the claim 120, it is noted that this recited concentration is reasonably suggested by the 2g/L taught by Zhang et al., because the use of the modifier “about” in the instant claim indicates that a precise amount 5g/L is not required for operability. In the reasonable and broadest interpretation, the scope of the “about 5g/L” encompasses a concentration of 2 g/L. Furthermore, one of ordinary skill in the art would recognize that the concentration of the protectant is an optimizable variable dependent on the degree of protection needed by the cells during the bioreactor process, thus to practice or test the parameter values widely to find those that are functional or optimal which then would be inclusive or cover that values as instantly claimed. Absent any teaching of criticality by the Applicant concerning the concentration of the protectant, it would be prima facie obvious that one of ordinary skill in the art would recognize these limitations are an optimizable variable which can be met as a matter of routine optimization (MPEP § 2144.05 (II)(B).
Regarding the limitations about the sensitizer’s concentration ranges: up to about 5,000 ppm, from about 50 to about 120 ppm, and about 100 ppm respectively recited in the claims 88 and 117-118, Xu et al. are silent about a specific concentration of the sensitizer (Ex-Cell antifoam agent) in the cell culture for producing the antibodies. However, Zhang et al. teach that an amount of 0.2% Pluronic F68 was added to the culture medium with anti-foam C agent (the sensitizer) at 10 ppm, 50 ppm, 100 ppm and 200 ppm (Note: these read on the claimed range in claim 88, and the 50 ppm and/or 100 ppm read on the claimed ranges in claims 117-118), which decreased foam in cell culture medium and increased cell density and/or increased MAb production when the medium was in the presence of the protectant Pluronic F68 and anti-foam C agent, as indicated above.
Velugula-Yellela et al. investigated the impact of antifoams and media on the production of monoclonal antibodies (MAbs) in a bioreactor, by testing different antifoams including: Dynamis, ProCHO5, PowerCHO2, EX-Cell Advanced, and OptiCHO media, and 204, C, EX-Cell, SE-15, and Y-30; and Velugula-Yellela et al. teach that antifoam C, Ex-cell and SE-15 are capable of providing adequate control of foaming, while antifoams 204 and Y-30 noticeably stunted cellular growth (abstract).
Velugula-Yellela et al. also conducted comparisons among the different anti-foams at a concentration of 30 ppm (page 264, right column under the heading of “Antifoam preparations”). It is noted that the concentration of 30 ppm reads on the claimed range of sensitizer in the claim 88.
Examiner notes that the Ex-Cell and anti-foam C sensitizers taught by Xu, Zhang, and Velugula-Yellela, respectively, read on the sensitizers of polydimethylsiloxane and simethicone recited in the claims 90 and 91, as indicated above.
It would have been obvious to one of ordinary skill in the art to employ EX-cell or antifoam C as an antifoam agent/sensitizer at a concentration up to about 5,000 ppm, or in a range from about 50 to about 120 ppm, or at about 100 ppm in the cell culture in the method of Xu et al. for controlling foam of cell culture in the bioreactor, as taught by Velugula-Yellela et al. and Zhang et al. One of ordinary skill in the art would have been motivated to do so, because antifoam C is an art-recognized equivalent of EX-Cell for the same purpose of preventing foam in the process of producing monoclonal antibodies, as taught by Velugula-Yellela. One of ordinary skill in the art would have recognized that either EX-cell or antifoam C is readily applicable to the method of Xu for controlling foam in cell cultures and producing monoclonal antibodies. Furthermore, EX-cell and anti-foam C are anti-foam agents commonly used in the art and it is well known in the art that these antifoam agents at the concentrations in the claimed ranges are effective at preventing foam in cell cultures for producing the antibodies, as supported by Velugula-Yellela et al. and Zhang et al. One of ordinary skill in the art would have had a reasonable expectation of success at applying the antifoam agent EX-Cell or antifoam C at a concentration in the claimed ranges for preventing foam in the cell culture in method of Xu et al., because it has been demonstrated that EX-Cell and antifoam C at the claimed concentrations including 30 ppm, 50 ppm, and 100 ppm are successful at preventing foam formation in cell cultures and for promoting production of monoclonal antibodies, as supported by Velugula-Yellela et al. and Zhang et al.
Examiner notes that Zhang et al. teach that higher concentrations of anti-foam agent tested in their study are more effective at preventing foam in cell cultures, which indicates that a concentration of anti-foam agent is an optimizable variable for improving antifoam effect in the method suggested by the cited prior art. Thus, it would have been obvious to further modify the concentrations taught by the cited prior art (e.g. the concentration of EX-Cell taught by Velugula-Yellela et al.) through routine optimization, when needed, for achieving a desirable antifoam effect in the method suggested by Xu. It is further noted that generally, differences in concentration or temperature will not support the patentability of subject matter unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456,105 USPQ 233, 235 (CCPA 1955). Absent any teaching of criticality by the Applicant concerning the concentration ranges of the antifoam agent/sanitizer, the claimed concentration ranges about the antifoam agent would be prima facie obvious over the cited prior art. MPEP § 2144.05 (II)(B).
Regarding Claim 90, Examiner notes that the antifoam C in the modified method of Xu et al. described above is an emulsion of polydimethylsiloxane (PDMS), as indicated above. Thus, the claim would have been obvious over the cited prior art.
Regarding the claims 95-96 and 98, Xu et al. teach the bioreactor used for culturing cells is a fed batch bioreactor, and the bioreactor has a volume of 500 L, 200 L, or 2000 L (as indicated above), which reads on the claimed ranges in claims 95-96. Thus, the claims 95-96 and 98 would have been obvious over the cited prior art.
Regarding the claim 97, Xu et al. teach cells can be cultured in a 500 L perfusion bioreactor (page 1147, left col, para 2, line 13). Velugula-Yellela et al. also teach that either a fed-batch mode (using a fed-batch bioreactor) or a perfusion mode (using a perfusion bioreactor) is suitable for culturing cells (the sentence spanning both columns of page 268). As such, in view of teachings of the cited prior art, it would have been obvious to one of ordinary skill in the art to replace the fed-batch bioreactor with a perfusion bioreactor in the method of Xu et al. for culturing cells and producing monoclonal antibodies, thus arriving at the claimed method.
Regarding the limitations of vvm from about 0.2 to about 0.8 min-1 (in the claims 112 and 115) and vvm of about 0.06 min-1 (in the claim 116), Xu et al. teach a range that encompasses these claimed vvm ranges/values, as indicated above. In addition, Xu et al. teach multiple specific data points of vvm, which either read on or are very close to the claimed vvm values (see Figs 1 and 4A, and the rows of vvm in Tables 2 and 3). In view of Xu et al., one of ordinary skill in the art would recognize that the vvm is an optimizable variable dependent on the degree of gas flow rate needed by the cell during the bioreactor process, thus to practice or test the parameter values widely to find those that are functional or optimal which then would be inclusive or cover that values as instantly claimed. Absent any teaching of criticality by the Applicant concerning the claimed ranges, it would be prima facie obvious that one of ordinary skill in the art would recognize these limitations are an optimizable variable which can be met as a matter of routine optimization (MPEP § 2144.05 (II)(B).
Regarding Claims 113 and 114, the P/V range taught by Xu et al. does not exactly match the claimed range of 3.0 to 8.0 W/m3 or about 6.0 W/m3. However, it is considered that the P/V range of Xu et al. can be readily modified by routine optimization for increasing antibody production. One of ordinary skill in the art would have recognized that the P/V is an optimizable variable dependent on the desired cell growth rate/density and antibody production yield during the bioreactor process, given Xu et al. teach power input per volume (P/V) is an important criterion for achieving adequate oxygen supply and cell growth in a bioreactor scale-up process (abstract, lines 1-4). Overall, in the absence of any evidence of criticality by the Applicant concerning the claimed P/V ranges, it would be prima facie obvious that one of ordinary skill in the art would recognize these limitations are an optimizable variable which can be met as a matter of routine optimization (MPEP § 2144.05 (II)(B).
Regarding the new claim 121, the cited prior art does not teach a specific cell death rate, a cell specific LDH production, or an apparent growth rate. However, the limitations recited in the claim are directed to the outcome of the claimed method. The cited prior art suggests a method comprising the same steps as the claimed method. In the absence of evidence to the contrary, it is presumed that a method having substantially the same steps is capable of generating substantially the same outcome. Thus, the teachings of the recited prior art render the claim 21 to be obvious.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 30, 31, 33, 36, 37, 39-42, and 55-58 are rejected under 35 U.S.C. 103 as being unpatentable over Hwang et al. (US 20160177361, 2016, cited in IDS) in view of Laluce et al. (Biotechnol. Prod. Process Engineer., 2009, 83: 627-637, cited in IDS) and Popp et al. (US 2017/0058309, 2017, of record).
Hwang et al. teach a method for culturing recombinant mammalian cells for producing recombinant protein in a liquid medium containing poloxamer 188 at 1.8 g/L or more with other variables (abstract, claim 1), wherein the cells are recombinant cells and produce a protein in a perfusion culture containing poloxamer 188 at a concentration of 1.8 g/L, 2.5 g/L, 4.0 g/L, to 7.0 g/L (para [0004]) (Note: these read on the limitations of protectant in claims 31, 55 (c), and 56-58); wherein the medium also includes an anti-foam agent (g/L) that is in a ratio with the poloxamer 188 (g/L) between about 0.5% to 6.0% (para [0006], right col, lines 1-3; claim 8). It is noted that the “0.5%” here is a ratio of 0.005 anti-foam to 1 poloxamer. Thus, if the poloxamer is present at 1.8 g/L, the anti-foam agent is present at an amount of 0.005 x 1.8 g/L, i.e. 0.009 g/L being equivalent to 9 ppm of the anti-foam agent; and the ratio of 6.0% is equivalent to 0.108 g/L or 108 ppm of the antifoam agent. Therefore, Hwang et al. teach the production of a recombinant protein by culturing recombinant cells in a medium containing 1.8 g/L of the poloxamer, where the medium contains 9 to 108 ppm of anti-foam agent (Note: this reads on the limitations about sensitizer in claims 31, 33, and 55 (b)). Hwang further teach that a set of experiments were performed in a test culture vessel to test the effect of increasing concentrations of the poloxamer on improving cell viability, cell growth and recombinant antibody production for selecting optimal condition for the production, wherein one perfusion culture was run with CD-CHO cells at a concentration 1.8 g/L of poloxamer without adding additional poloxamer, and another experiment (second experiment) was run where the CD-CHO cells were initially cultured with 1.8 g/L of poloxamer and additional poloxamer was further added during the course of the culturing (Example 1, paras [0043] and [0132]). Figure 1 shows the results for cell viability with increasing amounts of added poloxamer (black circles) compared to no additional poloxamer added (gray circles):
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As the figure shows, an increasing amount of the poloxamer leads to increased and improved cell viability. It was further found that optimal culture conditions could achieved at a particular ratio of poloxamer to anti-foam (para [0004]). In Example 4 (page 44), Hwang et al. assessed cell viability as a function of the concentrations of added Pluronic (protectant; g/L) and anti-foam at ppm/day with perfusion reactors at various pore sizes, where Table 1 shows that as the sparging rate increases, the optimal ratio of anti-foam C to poloxamer 188 may be between 0 and 5% such as between about 1 to about 3% (paras [0142]-[0143]). Thus, Hwang et al. teach a method of determining optimal conditions for improving cell viability, wherein optimal conditions to improve cell viability and ultimately recombinant protein production were achieved by testing based on parameters including the concentrations and ratios of the poloxamer and antifoam. In the Example 5 ([0144] to [0145]), Hwang et al. further conducted the viability experiments to determine the optimal concentrations and ratios of poloxamer and antifoam by running a fed batch cell culture in baffled shake flasks, which further supports the optimal ratio of the antifoam to the poloxamer is between about 1% and about 3%. It is noted that optimal conditions of Hwang et al. are selected based on results of the cell growth and viability tested under tested conditions based on a set of parameters. Thus, Hwang et al. teach a method of determining and selecting optimal conditions for improving cell viability.
Regarding the step (c) of claim 30, the Examples of Hwang do not specifically teach further culturing recombinant cells (CHO cells) in a production bioreactor under the selected optimal conditions to produce a recombinant protein. However, it would have been obvious to one of ordinary skill in the art to culture recombinant CHO cells in a production bioreactor under the selected optimal conditions in the method of Huang et al. for producing more recombinant proteins, because their method is specifically for production of recombinant proteins by culturing the cells, and Huang et al. teach culturing the cells in a production bioreactor for the production (para 0072). One of ordinary skill in the art would have been motivated to culture the cells under the selected optimal conditions, because Hwang et al. teach these optimal conditions improve cell viability and produce the most proteins and they are selected for being used as the culturing condition. Furthermore, culturing the cells under these conditions in a large production bioreactor would allow more recombinant proteins to be produced. One of ordinary skill in the art has a reasonable expectation of success at applying the selected optimal conditions to culture the cells for improving protein production, because these optimal conditions/parameters had been tested by Hwang et al. and test results show they optimized cell viability and protein production.
Regarding the limitation in the step (a) of the claim 30, Hwang et al. do not teach that the conditions are selected based on full factorial screening and/or inscribed center composite design.
Laluce teaches the use of full factorial central composite design combined with surface methodology to optimize variables including temperature, sugar concentration and inoculum size to maximize ethanol production without significant loss in yeast cell viability, wherein the statistical treatment enabled the selection of optimized conditions for the maximal amount of ethanol in an industrial bioreactor (abstract). Laluce (Figure 1) shows the surface curves and contour plot lines showing the variations in ethanol production based on temperature, sucrose concentration and inoculum based on the model. Laluce concludes that the combination of full factorial and center composite design (the fitted equations 2 and 3) were highly significant and adequate to represent the true relationship between the fermentation variables (the para spanning pages 635-636).
Popp et al. teach that statistical experiment planning by DoE (Design of Experiments) approaches is a powerful and well-known technique that has been successfully used for optimization of cell culture media, fermentation processes and cell culture conditions, wherein the DoE approaches comprise full factorial design (screening) and central composite designs, which not only identify critical modulator parameters but also allow quantification of their optimal concentrations or settings (paras 282-283, Fig. 3). Popp et al. further teach a method of culturing mammalian cells for producing recombinant glycoproteins (antibody) with optimized glycosylation by determining optimal conditions based on parameters/variable and controlling/optimizing parameters of cell culture system, wherein parameters such as trace elements are optimized through full factorial screening DoE approach for their effect on cell growth (cell viability) and glycosylation modulation (title; abstract; paras 023, 0184, 0188, 0200, 0279; Example 2: paras 0295-296).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the statistical method of full factorial screening and/or central composite designs to select optimal test conditions for the concentrations and ratios of the poloxamer and anti-foam in the method of Hwang et al. for culturing cells with improved cell viability and optimizing antibody production. The ordinary artisan would have been motivated to do so because the statistical methods of full factorial screening and central composite design are powerful methods well established in the art for optimizing and improving cell culture and cell growth/viability as well as generation of target products from cells (including mammalian cells used for producing recombinant proteins), as supported by Laluce and Popp et al. Furthermore, Laluce teaches that the statistical method is highly significant and adequate to represent variables in fermentation/cultivation in order to optimize the yield of the desired product. The ordinary artisan would have had a reasonable expectation of success at using the statistical method of full factorial screening and/or central composite design to select the optimal testing conditions for the concentrations and ratios of the poloxamer and anti-foam in the method of Hwang for optimizing cell viability and ultimately the yield of recombinant protein/antibody product, because Laluce and Popp et al. demonstrates that this approach is effective and successful in the selection of optimal parameters/conditions to improve cell growth/viability and production of a desirable product.
Regarding the newly added limitation “resulting in: a specific cell death rate of less than 40% per day … a cell specific LDH production of less than 150 nU/cell/day … and an apparent growth rate of greater than 1% per day … ” in the claim 30, Hwang et al. further teach that viable cell density and specific LDH (lactate dehydrogenase) production are determined each day during the culture period, and culturing cells under selected conditions results in a cell specific LDH production of less than 150 nU/cell/day (paras 0144 - 0145, Figs. 14 -15), thus meeting the limitation about cell specific LDH production. In addition, it appears that the culturing of Hwang et al. results in a specific cell death rate of less than 40% per day since viable cell density is consistently increased in every day over the culture period (see Fig. 14). Hwang et al. are silent about the apparent growth rate. However, all the limitations about cell death rate, LDH production, and apparent growth rate are directed to the outcome of the claimed method. The cited prior art suggests a method comprising the same steps as the method of the base claim 30 and its dependent claims. In the absence of evidence to the contrary, it is presumed that a method having substantially the same steps is capable of generating substantially the same outcome. Therefore, the teachings of the recited prior art meet the claimed limitations.
Regarding the limitation “shear stress” recited in the claim 31, the cells of Hwang are cultured in the presence of shear stress, because the perfusion and baffled shaking of cell cultures all generate shear stress to the cells under the tested conditions of the antifoam and poloxamer. Thus, the set of conditions/parameters of Hwang comprise shear stress, meeting the limitation of the claim.
Regarding Claims 39 and 40, Hwang et al. teach the bioreactor has a volume of 24 L to 25,000 L (page 9/para 0072, lines 3-6), which overlaps with the claimed ranges, thus rendering the claims to be obvious. See MPEP 2144.05.
Regarding Claims 36 and 37, Hwang et al. are silent about specific volumes of the test culture vessel used in the Examples. However, a volume of a culture vessel used for culturing cells under test conditions is an obvious design choice, which can be readily modified or adjusted based on a specific scale of a cell culture. Furthermore, Laluce teaches a specific volume, 125 ml, for the test culture vessel (page 628, right col., para 3, lines 14-15), which reads on the claimed ranges. It would have been obvious to use a small volume of a test culture vessel, such as 125 ml, in the claimed range of 5 ml to 5 L or 10 mL to 500 mL for a small scale of culturing process. In the absence of criticality about the claimed ranges, the claims would have been obvious over Hwang et al.
Regarding the claims 41 and 42, Hwang et al. teach using perfusion and fed batch bioreactors, as indicated above (also see para 0072/ lines 3-4 in page 9).
Regarding Claims 56-58, Hwang et al. teach the protectant is a poloxamer, specifically poloxamer 188. Thus, the claims would have been obvious over the teachings of Hwang et al.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Double Patenting
Claims 30-31, 33, 42, and 55-56 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over the claims 1-10 of U.S. Patent No. 11391725. Although the conflicting claims are not identical, they are not patentably distinct from each other for the following reasons. This rejection is maintained.
The claims 1-10 of the ‘725 Patent are directed in part to a method of predicting cell viability in a production bioreactor, the method comprising: (a) selecting a set of parameters; (b) determining cell viability under a plurality of test conditions as defined by the set of parameters in a test culture vessel, wherein the plurality of test conditions are selected based on full factorial screening and/or inscribed center composite design; (c) based on the cell viability in the test culture vessel under the plurality of conditions, predicting cell viability in the production bioreactor; and (d) culturing a cell in the production bioreactor using a condition predicted to result in: a specific cell death rate of less than 40% per day during the culturing of the cell in the production bioreactor; a cell specific LDH production of less than 150 nU/cell during the culturing of the cell in the production bioreactor; or an apparent growth rate of greater than 1% per day during the culturing of the cell in the production bioreactor; wherein the test culture vessel is a baffled shake flask and the plurality of test conditions comprise one or more of: (a) a rotary agitation of about 125 RPM to about 400 RPM; (b) a concentration of the sensitizer of about 0 ppm to about 120 ppm; and (c) a concentration of a protectant that is about 1 g/L to about 10 g/L; wherein the protectant is a poloxamer, a poloxamine, or a non-ionic surfactant; and wherein the sensitizer is an antifoam agent.
Since the claimed method of the ‘725 patent predicts and selects desirable conditions for cell growth and reducing cell death, the predicted and selected conditions would result in improving cell viability in a production bioreactor, thus meeting the requirements of the instant claims.
Therefore, the method of Claims 30-31, 33, 42, and 55-56 of the instant application is deemed obvious over the method of Claims 1-10 of U.S. Patent No. 11391725.
Claims 30-31, 33, 36-37, 39-42, 55-58, 88-98, and 111-121 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over the claims 1-10 of U.S. Patent No. 11391725, as applied to Claims 30-31, 33, 42, and 55-56, further in view of Xu et al. (Biotechnol. Progress, 3394: 1146-1159, published online 5/17/2017, cited in IDS) and Velugula-Yellela et al. (Biotech. Progress, 34(1): 262-270, published online 11/16/2017, cited in IDS), as evidenced by Shaaltiel et al. (US 2010/0112700, 2010, of record). This rejection is maintained for Claims 30-31, 33, 36-37, 39-42, 55-58, 88-98, and 111-120, and applied to the new claim 121.
The subject matter of the claims 1-10 of the ‘725 Patent are described above.
Regarding Claims 88 and 111, the claims of the ‘725 Patent do not teach culturing the cell in the production bioreactor under the conditions with P/V and vvm respectively in the claimed ranges.
The teachings of Xu et al. and Velugula-Yellela et al. are described above.
It would have been obvious to culture the cell under the conditions as defined in the instant claims 88 and 111 in the step (c) of the method of the ‘725 Patent for improving cell growth and cell viability, thus increasing production of desired products, because parameters P/V and vvm in the claimed ranges are important criterion for scale-up bioreactor performance and a combination of consistent P/V and vvm improves cell growth and viability, as supported by Xu et al. (title, abstract, Figs 5-6).
Regarding the claims 39-40, 95-96 and 98, Xu et al. teach a fed batch bioreactor with a volume in the claimed ranges, as indicated above, thus rendering the claims to be obvious.
Regarding the claims 36 and 37, the claims of the ‘725 Patent are silent about a volume of the test culture vessel. However, a volume of a culture vessel used for culturing cells under test conditions is an obvious design choice, which can be readily modified or adjusted based on a specific scale of a cell culture. Given Xu et al. teach bioreactor scale-up with increasing volumes (page 1147, right col, para 2), It would have been obvious to use a culture vessel having a small volume such as in the claimed range for a small scale of culturing process.
Regarding Claims 41 and 97, the claims of the ‘725 Patent are silent about whether the production bioreactor is a perfusion bioreactor. However, it would have been obvious to use a perfusion bioreactor in the step (c) for producing a desired product, because it is a common practice in the art to use a perfusion bioreactor for producing products, as supported by Xu et al. and Velugula-Yellela et al.
Regarding Claims 57-58 and 92-94, the claims of the ‘725 Patent are silent about a specific poloxamer used in the patented method. However, it would have been obvious to use poloxamer-188 as the poloxamer, because it is an effective cell protectant commonly used in the art, as supported by Xu et al.
Regarding the claims 90 and 91, the claims of the ‘725 Patent are silent about a specific antifoam used in the patented method. However, it would have been obvious to use polydimethylsiloxane or simethicone as the antifoam, because they are effective antifoam agents commonly used in the art, as supported by Xu et al. and Velugula-Yellela et al.
Regarding the limitations about VVM ranges in instant claims 112 and 115-116, they would be obvious over Xu et al. for the reasons described above.
Regarding Claims 113 and 114, the P/V range in the method of the ‘725 patent as modified by Xu et al. and Velugula-Yellela et al. does not exactly match the claimed range of 3.0 to 8.0 W/m3 or about 6.0 W/m3. However, it is considered that the P/V range in the method suggested by the ‘725 patent, Xu and Velugula-Yellela can be readily modified by routine optimization improving cell growth/viability, thus increasing production of desired products. One of ordinary skill in the art would have recognized that the P/V is an optimizable variable dependent on the desired cell growth rate/density and antibody production yield during the bioreactor process, given Xu et al. teach power input per volume (P/V) is an important criterion for achieving adequate oxygen supply and cell growth in a bioreactor scale-up process. In the absence of any evidence of criticality by the Applicant concerning the claimed P/V ranges, it would be prima facie obvious that one of ordinary skill in the art would recognize these limitations are an optimizable variable which can be met as a matter of routine optimization (MPEP § 2144.05 (II)(B).
Therefore, in view of the cited prior art, the method of Claims 30-31, 33, 36-37, 39-42, 55-58, 88-98, and 111-121 of the instant application is deemed obvious over the method of Claims 1-10 of U.S. Patent No. 11391725.
Duplicate Claims, Warning
Warning: Applicant is advised that should the claim 112 be found allowable, the claim 115 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m).
Response to Arguments
Applicant's arguments about the claim objection in the response filed on 01/20/2026 (page 8) have been fully considered but they are moot because the objection has been withdrawn, as indicated above. It is noted that the ground of the claim objection in this office action is different from that in the previous office action.
Applicant's arguments about the claim interpretation in the 01/20/2026 response (page 8) have been fully considered but they are not persuasive. Examiner notes that the internal volumes “over 5 L, 1,000 L, 5,000 L, 10,000 L, 20,000 L, 50,000 L, or 100,000 L” disclosed in the specification are listed as a for-example type of volumes, in view of the fact that the term “e.g.” is placed in the front of these listed volumes. As such, the specification does not define the claimed production bioreactor to have the internal volumes listed in the page 13/lines 1-4 of the specification. Given that Applicant amended only the base claim 88 by limiting the bioreactor’s volume, but not the base claim 30, the Examiner’s claim interpretation (indicated above in this office action) is still applicable to the production reactor recited in the claim 30.
Applicant's arguments about the 103 rejection over Xu et al. in view of Zhang and Velugula-Yellela in the 01/20/2026 response (pages 9-10) have been fully considered but they are not persuasive for the following reasons.
As a first matter, Applicant’s arguments based on volumes of the production bioreactor (disclosed in page 13 of the specification) in the 01/20/2026 response (page 9) are not persuasive for the reasons indicated above.
In response to Applicant’s arguments based on the concentration of EX-Cell taught by Velugula-Yellela in the 01/20/2026 response (pages 9 and 10), it is noted that generally, differences in concentration or temperature will not support the patentability of subject matter unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456,105 USPQ 233, 235 (CCPA 1955). Even assuming that the concentration of 30 ppm used in the micro-bioreactor of Velugula-Yellela is not well suited for cell culture in production bioreactors of Xu et al., it is considered that the concentrations of Velugula-Yellela can be readily modified by routine optimization for achieving a desirable effect at preventing foam in cell culture in the production bioreactors of Xu et al. It is well settled that routine optimization is not patentable, even though it results in significant improvement over the prior art (see MPEP 2144.05).
In response to Applicant’s remaining arguments in pages 9-10 of the 01/20/2026 response, the disclosure of the specification pointed out by Applicant only generally indicates that there is no linear relation in the scale-up process regrading sensitizer parameters such as concentrations of an antifoam agent. However, this disclosure does not change the fact that Applicant failed to provide factual evidence to support that the claimed concentration ranges for protectant and sensitizer as well as the claimed volume range for production bioreactor in the claim 88 are critical for delivering any superior effect in the claimed method of culturing a cell. It is noted that the claim 88 recites an extremely broad volume range “about 5 L to about 20,000 L” for the bioreactor and an extremely broad concentration range “up to about 5,000 ppm” for the sensitizer, which do not provide meaningful limitations over the bioreactor and sensitizer/antifoam agent, in view of that there is no linear relation in the scale-up process regrading concentrations of sensitizer/antifoam agent vs. sizes of bioreactors, as disclosed by the specification of the instant application.
Overall, this is the Examiner’s position that the claims 88-98 and 111-121 lack novelty and the claims would have been obvious over the combined teachings of Xu, Zhang, and Velugula-Yellela for all the reasons indicated above.
18. Applicant's arguments about the 103 rejection over Huang et al. in view of Laluce et al. in the in the 01/20/2026 response (page 11) have been fully considered but they are not persuasive. Examiner notes that the newly added limitations about specific cell death rate, LDH production, and growth rate in the claim 30 are directed to the outcome of the instantly claimed method. These limitations would have been obvious over the cited prior art for the reasons indicated above in the 103 rejection (see page 23 for details).
Overall, the conclusion of the obviousness of the claims 30, 31, 33, 36, 37, 39-42, and 55-58 has been established over the combined teachings of Huang et al., Laluce et al., and Popp et al. for all he reasons indicated above.
19. Applicant’s comments about the double patenting rejections over the claims of U.S. Patent No. 11391725 either alone or in combination with the cited prior art in the 01/20/2026 response (page 12) are acknowledged.
Conclusion
No claim is in condition for allowance.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to Qing Xu, Ph.D., whose telephone number is (571) 272-3076. The examiner can normally be reached on Monday-Friday from 9:30 AM to 5:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Manjunath N. Rao, can be reached at (571) 272-0939. Any inquiry of a general nature or relating to the status of this application or proceeding should be directed to the receptionist whose telephone number is (571) 272-1600.
/Qing Xu/
Patent Examiner
Art Unit 1656
Prosecution Insights