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 .
DETAILED OFFICE ACTION
This Office Action is in response to the papers filed on 28 August 2025.
CLAIMS UNDER EXAMINATION
Claims 12 and 21-31 have been examined on their merits.
PRIORITY
The Applicant claims priority to Provisional Application 62/906983, filed on 27 September 2019.
WITHDRAWN REJECTIONS
The previous rejections have been withdrawn due to amended claim 12 and new claims 23-31.
NEW REJECTIONS
New rejection have been necessitated by claim amendment.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 12 and 21-31 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 12 has been amended to recite “an optimal osmolality level”. The term “optimal” is a relative term which renders the claim indefinite. The term “optimal” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Appropriate correction sir quired. All dependent claims are included in this rejection.
Claim 23 recites the osmolality is increased using i) “a constant concentrated feed perfusion rate…” or ii) “…an increased concentrated feed perfusion rate”. The base claim recites an “alkaline concentrated feed”, an “acidic concentrated feed” and a “near neutral concentrated feed”. It is unclear which concentrated feed claim 23 is referring to. The metes and bounds of the claim are unclear. Appropriate correction is required.
Regarding claim 24: There is a lack of antecedent basis for “the optimum osmolality level” in the base claim. It is unclear if claim 24 is referring to the “optimal osmolality level”. Appropriate correction is required.
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 12 and 21-31 are rejected under 35 U.S.C. 103 as being unpatentable over Disorbo et al. (Media Concentrate Technology. US5681748) in view of Gorfien et al (Serum-Free Mammalian Cell Culture Medium and Uses Thereof. US2009/0280533) and Han et al. (Enhanced Interferon-β Production by CHO Cells Through Elevated Osmolality and Reduced Culture Temperature. Biotechnol. Prog., 2009 Vol. 25, No. 5 pages 1440-1447).
Disorbo teaches a method of subgrouping media formulations into stable, compatible components that can then be solubilized at high concentrations (10× to 100×). Concentrated solutions of the ingredient containing subgroups can be used to prepare media formulations. Concentrated culture media formulations (2-10×) or 1× cell culture media can be prepared by mixing a sufficient amount of the concentrated subgroup solutions with a sufficient amount of a diluent (water, buffer, etc.) See Abstract.
Disorbo teaches a method of preparing a cell culture media comprising (see column 2, lines 50-67):
(a) dividing the compatible ingredients of a cell culture media into one or more subgroups, such subgroups comprising:
(i) an acid soluble subgroup,
(ii) a weak acid-base soluble subgroup,
(iii) a glutamine-containing subgroup,
(iv) an alcohol soluble subgroup,
(v) an alkali-soluble subgroup, and
(vi) a supplement-containing subgroup;
(b) dissolving each of the subgroups of compatible ingredients in a carrier to give concentrated solutions of the subgroup in the respective carrier; and
(c) admixing a sufficient amount of each of the subgroups obtained in step (b) with a sufficient amount of a diluent to produce the cell culture media.
Disorbo teaches subgrouping of compatible components, production of liquid concentrates of such subgroups, and mixing sufficient amounts of these concentrated subgroups with a sufficient amount of a diluent to produce a desired media formulation (column 5, lines 60-67).
The art teaches an acidic soluble subgroup comprising components soluble in acid (pH of about 0 to 1.0) (see column 7, lines 57-63). Said components are dissolved in an acidic solution with a pH of about 0 to 1.0. Preferably, the resulting solution is concentrated (10x to 100x) (see column 8, lines 40-46). Therefore the art teaches an acidic concentrated feed.
The art teaches an alkali-soluble subgroup (column 12, line 1). For media components that require an alkaline environment for solubilization (pH 9.0), an alkali soluble subgroup is employed. Therefore the art teaches an alkaline concentrated feed.
Disorbo teaches a weak acid-weak base soluble subgroup (see column 10, lines 9-25).
The pH of the weak acid-base subgroup may range from about 4.0-9.0. The specification discloses “a near neutral concentrated feed refers to a pH of 7.5±1.0. Thus the near neutral concentrated feed has a pH of about 6.5 to about 8.5” ([0097]). The specification does not define the term “about”. Therefore “about 6.5 to about 8.5” includes values below 6.5 and above 8.5. Therefore the weak-acid-weak-base subgroup taught by Disorbo reads on the claimed near neutral feed.
The specification does not provide an explicit definition for the term “compartmentalized”. Disorbo separates ingredients into separate categories. Disorbo teaches the subgroups of compatible ingredients of the invention are ideally suited for preparation of a kit. Such a kit may comprise a carrier means being compartmentalized to receive in close confinement one or more container means such as vials, test tubes, bottles, drums, and the like. Each of said container means comprises one of the individual subgroups of compatible ingredients as defined above. Such subgroups may be hydrated or dehydrated but are typically a concentrated liquid solution. See column 12, lines 50-67. Figure 4 discloses separation of the subgroups into different drums (containers). Therefore the art is interpreted to teach the groups are compartmentalized.
In Example 3, Disorbo teaches reconstitution of RPMI-1640 Medium Concentrated Subgroups Using a Continuous Feed Mixing Chamber. The art teaches RPMI is commonly used to grow mammalian cells in culture (see Example II).
A reconstitution experiment was carried out using RPMI-1640 media concentrate subgroups in the 15 L Biospin bioreactor. Three media subgroups at 50× per subgroup and two 25× NaHCO3 subgroup were continually pumped (fed) into the bioreactor at a rate of 250 ml/hour. Deionized distilled water (diluent) was pumped into the reactor at a rate of 12.5 L per hour. The perfused concentrates were continually admixed in the mixing chamber. Therefore the art teaches the concentrated feeds and the diluent are added separately to the mixing chamber (reaction vessel). Because the art teaches mixing the three concentrated components, they would automatically be adjusted to neutral pH upon mixing as recited in the claim. It is noted the art teaches RPMI-1640 has a pH of 7.0 (neutral). See column 14, lines 33-34).
While the art teaches medium can be supplemented with additional components, including antibiotics, protein concentrates, undefined broths and serum in a Supplement-Containing Group (see section H), it is not required.
The deficiencies of Disorbo are:
The art teaches the media is can be used to grow mammalian cells, but does not explicitly culture mammalian cells.
The art does not teach mammalian cells that produce a heterologous protein in a serum-free culture medium using perfusion culture.
Disorbo does not teach increasing osmolality above an optimal osmolality level after a rage viable cell density is reached as recited in claim 12.
Gorfien teaches a serum-free medium for culturing mammalian cells in suspension ([0001]). The media is used for perfusion culture ([0150]). The culture media is used for the production of recombinant proteins from mammalian cells (see [0171]). Mammalian cells (e.g., CHO cells) are engineered to express a polypeptide of interest (e.g., a recombinant protein; a heterologous protein) [0172] [0182]). Improved levels of recombinant protein production when cells are grown in serum-free medium relative to cells grown in serum ([0008]). Gorfien teaches “In some embodiments, ingredients for a feed supplement may be divided into multiple feed supplement media, e.g., based upon compatible subgroups. For examples of compatible subgroups and related considerations, see U.S. Pat. No. 5,681,748” ([0271]). Examiner notes this is the Disorbo reference cited above.
The following is also taught by Gorfien:
For suspension culture, cells are suspended in the disclosed culture media and introduced into a culture vessel ([0164]). Cells in perfusion culture (e.g., in bioreactors or fermenters) will receive fresh media on a continuously recirculating basis ([0167]). Because the cells continuously receive fresh media, the spent media is interpreted to be removed.
Gorfien measures the osmolality of the medium ([0193]). Gorfien measures the viable cell density of 293 cells and HeLaS3 cervical epithelial cells (human/mammalian cells) cultured in the disclosed method ([0205]).
Han investigates the effect of hyperosmolality in protein production in recombinant CHO cells (Abstract). Cells are cultured at 310 mOsm/kg to obtain a high cell concentration (Abstract). When the cells are in mid-exponential phase of growth (hence, a targeted viable cell density), cells are subjected to hyperosmolalities (Abstract; page 1442, left column, first paragraph). Han teaches despite suppressed cell growth, shifting to a hyperosmolality 470 mOsm/kg to achieve high protein concentration (Abstract).
It would have been obvious to combine the teachings of the prior art by excluding serum from the media taught by Disorbo. Disorbo teaches a media for culturing mammalian and Gorfien teaches serum-free conditions for culturing mammalian cells. Gorfien teaches improved levels of recombinant protein expression are obtained from cells grown in serum-free medium relative to cells grown in serum. Therefore one would prepare a serum free media when culturing cells. One would have had a reasonable expectation of success since Gorfien teaches serum free media can be used to culture cells. One would have expected similar results since Disorbo and Gorfien are directed to cell culture media.
It would have been obvious to culture mammalian cells expressing a heterologous protein in the perfusion culture taught by Disorbo. One would have been motivated to do so since Disorbo teaches a compartmentalized media that can be used to culture mammalian cells in a perfusion reactor and Gorfien teaches mammalian cells that express a heterologous protein can be cultured in a perfusion culture comprising compartmentalized media. One would have had a reasonable expectation of success since Disorbo teaches mammalian cells expressing a heterologous protein can be cultured using perfusion with a media such as the one taught in Disorbo. One would have expected similar results since both references teach concentrated media that can be used to culture mammalian cells.
It would have been obvious to increase the osmolality of a serum free culture medium after a target viable cell density of mammalian cells is reached. One would have been motivated to do so to suppress excessive cell growth while increasing protein production in the cell culture, as taught by Han. One would had a reasonable expectation of success since Han teaches despite suppressed cell growth, shifting to a hyperosmolality 470 mOsm/kg to achieve high protein concentration despite suppressed cell growth. One would have expected similar results since Disorbo, Gorfien and Han are directed to medias for improved mammalian cell culture. Therefore claim 12 is rendered obvious.
Disorbo teaches the solutions comprising the subgrouped ingredients are more concentrated than the concentration of the same ingredients in a 1x formulation. The grouped ingredients are preferably 25 fold more concentrated (25x formulation) and most preferable 50 fold more concentrated (50x formulation) (column 6, lines 18-25). 25x subgrouped formulations read on the ranges recited in claim 21. Therefore claim 21 is included in this rejection.
Disorbo teaches an alkali-soluble subgroup comprising media components that require an alkaline environment for solubilization (pH 9.0) (supra). Disorbo teaches an acidic soluble subgroup comprising components soluble in acid (pH of about 0 to 1.0) (supra).
Disorbo teaches the pH of the weak acid-base subgroup may range from about 4.0-9.0 (supra). In Table 2, the art teaches a weak acid-base soluble subgroup with a pH of 8.28. This reads on the near neutral concentrated feed recited in claim 22.
Claim 22 is included in this rejection.
In Example III, Disorbo performs a reconstitution experiment using RPMI-1640 media concentrate subgroups in a 15L Biospin bioreactor. Three media subgroups at 50× per subgroup (hence, a fixed ratio relative to each other) were continually pumped into the bioreactor at a rate of 250 ml/hour (hence, a constant concentrated feed perfusion rate). Deionized distilled water (a diluent) was pumped into the reactor at a rate of 12.5L per hour (hence, a decreased overall perfusion rate). The perfused concentrates were continually admixed in the mixing chamber (see Example III). Because the art teaches, a constant concentrated feed perfusion rate for the media subgroups, and a decreased diluent perfusion rate, it would result in a decreased overall perfusion rate as recited in claim 23. Therefore claim 23 is included in this rejection.
Han teaches cells are first cultured at 310 mOsm/kg. This is interpreted to read on claim 24.
Han teaches 470 mOsm/kg (supra). This reads on claims 25-26.
Gorfein teaches CHO cells (supra). Therefore claim 27 is rejected. The CHO cells taught in Gorfien are interpreted to be derivatives of the CHO cells recited in claim 28. Therefore claim 28 is included in this rejection.
The specification does not define the term “about”. In Figure 1A, Han discloses the vial cell concentration (cells/ml) at day 2 (see arrow). Han teaches this is the time point at which osmolality is increased (see text below Figure 1). While Han does not explicitly teach the target densities recited in claims 29-31, it would have been obvious to optimize the target viable cell density at which hyperosmolality is increased. Han teaches cell growth is depressed at hyperosmolalility, while protein production is increased. The skilled artisan would optimize the concentration at which hyperosmolality is increased based on the desired amount of cell growth. See MPEP 2144.05 [R-5]:
Therefore claim 29-31 are rendered obvious.
Therefore Applicant’s Invention is rendered obvious as claimed.
RESPONSE TO APPLICANT’S ARGUMENTS
The arguments made in the response filed on 28 August 2025 are acknowledged. The Applicant argues the prior art does not teach increasing osmolality as now recited in claim 12. New grounds of rejection have been set forth above to address the amended claims.
CONCLUSION
No Claims Are Allowed
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
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) 273-8300.
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/NATALIE M MOSS/ Examiner, Art Unit 1653
/SHARMILA G LANDAU/Supervisory Patent Examiner, Art Unit 1653