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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 05 March 2026 has been entered.
DETAILED OFFICE ACTION
This Office Action is in response to the papers filed on 05 March 2026.
CLAIMS UNDER EXAMINATION
Claims 1, 7-9, 12 and 16-17 have been examined on their merits.
PRIORITY
EP19174976.1, filed on 16 May 2019, is acknowledged.
WITHDRAWN REJECTIONS
The previous rejections have been withdrawn due to claim amendment.
REJECTIONS
The arguments made in the response filed on 05 March 2026 are acknowledged. New grounds of rejection have been necessitated by claim amendment.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 7-8, 12 and 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Johnson et al. (previously cited; Taurine supplemented cell culture medium and methods of use. US20240018467 with benefit of PCT/US 2016045403 filed 03 August 2016) in view of Sheikholeslami et al. (previously cited; Elucidating the Effects of Postinduction Glutamine Feeding on the Growth and Productivity of CHO cells. American Institute of Chemical Engineers. 2014. Vol. 30 (3): pages 535-546) and Fonta et al. (Serum-Free Culture Medium for the Production of Recombinant Gonadotropins. US200900124006A1).
Johnson et al. teach a cell culture medium for the production of a recombinant protein of interest (Abstract). The recombinant protein of interest can be aflibercept ([0107]; see claim 27 of Johnson) produced in CHO cells ([0108] see claim 27). The culture medium comprises taurine and additional amino acids ([0010] [0011]). The art teaches a growth phase followed by a production phase ([0054]).The art teaches point-of-use additions during the course of cell growth or protein production ([0093]).The art teaches adding glutamine as a point-of-use amino acid at a final concentration of about 1 mM to 13 mM ([0097]).
It is noted the art teaches glutamine and methionine can be added ([0027] [0069]). Table 1 teaches 0.2-2 g/L methionine (200-2000 mg/L methionine).
The art teaches daily feeding ([0079] [0088]).
Johnson teaches a method of producing a recombinant protein, including aflibercept in CHO cells. The art teaches a growth phase and a production phase. The art teaches culturing in a composition comprising taurine and 1 mM-13 mM glutamine as a point-of-use ingredient. The art teaches point-of-use addition during the growth phase. The art teaches methionine (200-2000 mg/L) can be added to the culture medium. The art teaches daily feeding.
Johnson does not feed cells with glutamine and methionine as claimed.
Sheikholeslami et al. examine the effects of glutamine feeding on the metabolism and recombinant protein productivity of induced CHO cells (page 536, left column, third paragraph). Cells are inoculated and cultured in basal medium (page 536, right column, second paragraph). This is interpreted to be a growth phase. Cells are induced at 48 hours (day 2) to trigger recombinant antibody expression (same cited section). This is interpreted to be a production phase. Following induction of protein expression, the culture are operated in semicontinuous mode, whereby a fixed culture volume was replaced by fresh medium on a daily basis so as to maintain pseudo-constant cell and nutrient concentrations (same cited section). Medium is supplemented with 1 mM glutamine (same cited section; “low glutamine”). On day 9 the cultures reached and maintained pseudo-steady state conditions, semi-continuous operation was continued, but the cultures were fed with specific labeled containing media. The feeding was continued for 5 consecutive days, so as to maximize the wash out of unlabeled nutrients and metabolites (see page 540, right column, first paragraph). Figure 2A discloses cells are cultured in low glutamine for 14 days. Therefore the art teaches daily feeding with 1mM glutamine for 12 days (hence, including days 3 to 12 of culture).
The art also teaches the following:
Excess glutamine can inhibit growth or protein production due to the formation and accumulation of toxic by-products (see page 536, left column, first paragraph).
The effect of glutamine production on antibody produce was determined: the highest protein productivity is observed in the culture with 1mM glutamine (low glutamine) (page 540, left column, first paragraph). High glutamine cultures exhibit reduce cell productivity (page 41, right column, second paragraph). The art teaches lactate production is reduced in low glutamine (page 540, left column, second paragraph). Lactate is a toxic-byproduct of excess glutamine (see page 536, left column, first paragraph). Further improvement can be anticipated by reducing the temperature during the production phase to further prolong the culture time (page 544, left column, Conclusion section).
Fonta teaches is directed to a method of making a recombinant proteins ([0001]) manufactured in CHO cells ([0056]). The art teaches culturing with L-methionine as an antioxidant to reduce oxidized forms of a recombinant protein ([0010]). Fonta teaches 250 mg/L and 500 mg/L can be added during a production phase (Table III).
Fonta also teaches the following:
The art teaches growth phase during which process parameters are set in order to support cell growth ([0062] [0064]). Once the desired cell density has been reached, the cell culture is switched into a production phase, in which the process parameter are set to support cel productivity ([0063] [0064]). Antioxidant can be added to the medium before cell inoculation or shortly after inoculation ([0065]). Fonta teaches methionine can be added during the production phase (Table III).
It would have been obvious to combine the teachings of the prior art by feeding cells with 1 mM glutamine on days 3-5 and 6-12 of a cell culture. Johnson teaches glutamine as a point-of-use amino acid during cell culture and Sheikholeslami teaches feeding 1 mM glutamine daily during days 3-12 of a cell culture. The skilled artisan would do so since Sheikholeslami teaches this concentration and schedule can be used to produce recombinant proteins while reducing accumulation of toxic byproducts harmful to cells. One would have had a reasonable expectation of success since Johnson teaches glutamine can be used as a point-of-addition ingredient, and can be added daily. One would have expected similar result since Johnson and Sheikholeslami both teach methods of producing recombinant proteins in CHO cells.
It would have been obvious to feed cells with 250 to 500 mg/L methionine. Johnson produces a recombinant protein and Fonta teaches methionine can be used to prevent oxidation of a recombinant protein. The skilled artisan would feed methionine during the production phase to reduce protein oxidation. Fonta teaches 250-500 mg/L methionine can be added when the production phase begins (Production day 0) through day 19 of of production phase. Therefore feeding on days 8-12 of a culture is rendered obvious. One would have had a reasonable expectation of success since Johnson teaches methionine can be used for recombinant cell production. One would have expected similar results since Johnson and Fonta are both directed to methods of producing recombination protein in CHO cells. Johnson, Sheikholeslami and Fonta teach a growth phase and a production phase. Claim 1 is interpreted to require culture for at least 12 days. One would adjust the day on which glutamine and methionine are added based on the time and duration of each of the growth and production phase, respectively. Therefore claim 1 is included in this rejection.
Johnson teaches a temperature shift between the growth and production phase ([0110]). A growth phase may occur at a higher temperature than a production phase. For example, a growth phase may occur at a first temperature of about 35° C to 38° C, and a production phase may occur at a second temperature of about 29° C to 37° C, optionally from about 30° C to 36° C or from about 30° C to 34° C ([0110]). Therefore claims 7-8 are included in this rejection.
Johnson teaches CHO cells ([0023]). Therefore claim 12 is included in this rejection.
Because the method steps recited in claim 1 are rendered obvious, it follows the percentage of oxidized methionine residues would be reduced by at least 20% and at least 50%. Therefore claims 16-17 are rejected.
Therefore Applicant’s Invention is rendered obvious as claimed.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Johnson et al. in view of Sheikholeslam and Fonta as applied to claim 7 above, and further in view of Xu et al. (previously cited; Systematic development of temperature shift strategies for Chinese hamster ovary cells based on short duration cultures and kinetic modeling. MAbs. 2018 Oct 2;11(1):191–204).
Claim 7 is rejected on the grounds set forth above. The teachings of the prior art are reiterated. Johnson teaches a method of culturing CHO cells to produce an antibody. The art teaches a temperature shift (supra). The art teaches downshifting from a first temperature of about 35° C to 38° C, to a second of about 29° C to 37° C, optionally from about 30° C to 36° C or from about 30° C to 34° C (supra). The art does not explicitly teach shifting in two steps.
Xu teaches temperature shift (TS) to a hypothermic condition has been widely used during protein production processes that use Chinese hamster ovary (CHO) cells (Abstract). Xu studied the effect of temperature on cell culture performance for protein production by industrial CHO cell lines. (Abstract).The art teaches daily feeding of glutamine (see page 201, right column, last paragraph). In Table 2, Xu teaches different temperature shift strategies can be used. Table 2 discloses temperature can be reduced from an initial culture temperature (36.5 °C) to 34°C, followed by a shift to 32°C (see TS strategy 29). The art teaches this condition produces a high titer value (see text of Table 2).
It would have been obvious to combine the teachings of the prior art by shifting from 37°C to 34°C, and from 34°C to 32°C. One would have been motivated to do so since Johnson teaches a method of culturing CHO cells comprising a temperature shift from 35°C-38° C to 30° C-34° C and Xu teaches a temperature shift from 36.5 to 32°C can be performed using two shifts. Motivation to do so is provided by Xu, who teaches this strategy produces high product yield. One would have had a reasonable expectation of success since Johnson and Xu are both directed to methods of using CHO cells for protein production. Therefore claim 9 is rendered obvious.
Therefore Applicant’s Invention is rendered obvious as claimed.
APPLICANTS ARGUMENTS
The arguments made in the response filed on 05 March 2026 are acknowledged. The arguments directed to Lam are moot because the reference is not cited as prior art.
Argument 1: The Applicant argues Johnson does not teach the feed schedule recited in claim 1.
Response to Argument 1: New grounds of rejection have been made to address amended claim 1.
Argument 2: The Applicant argues unexpected the results. The percentage of oxidized methionine residues decreased from 19.0% to 8.1% when glutamine and methionine were fed (Example 2, Table 4).
Response to Argument 2: Feeding cells with the claimed concentrations of glutamine and methionine on the claimed days of a cell culture is rendered obvious. Therefore one would expected the percentage of oxidized methionine to be reduced as claimed.
The arguments directed to unexpected results are not persuasive. Table 4 discloses the “control run” has 19.0% Met 192 oxidation. “SF run 6” has 8.1% Met 192 oxidation. The conditions disclosed in Table 4/SF run 6 are not commensurate with the conditions recited in claim 1.
Conclusion
No claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATALIE MOSS whose telephone number is (571) 270-7439. The examiner can normally be reached on Monday-Friday, 8am-5pm EST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sharmila Landau can be reached on (571) 272-0614. The fax phone number for the organization where this application or proceeding is assigned is (571) 270-8439.
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/NATALIE M MOSS/ Examiner, Art Unit 1653
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