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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 13 April 2026 has been entered.
DETAILED OFFICE ACTION
This Office Action is in response to the papers filed on 13 April 2026.
CLAIMS UNDER EXAMINATION
Claims 12 and 21-23, 26 and 28-31 have been examined on their merits.
PRIORITY
The Applicant claims priority to Provisional Application 62/906983, filed on 27 September 2019.
WITHDRAWN REJECTIONS
The rejection of claims 12 and 21-31 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, has been withdrawn due to claim amendment.
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 29-31 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.
Regarding claims 29-31: The base claim recites “a target cell density”. There is a lack of antecedent basis for “the target viable cell density”. The metes and bonds of the claims are unclear. Appropriate correction is required.
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 26 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.
Regarding claim 26: Step c) of claim 12 recites “increasing the osmolality…to about 380 mOsm or higher”. Claim 26 is not further limiting because it recites the medium in step c is “increased to about 380 mOsm or higher”.
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 § 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, 21-23, 26 and 28-31 are rejected under 35 U.S.C. 103 as being unpatentable over Hiller et al. (Cell-Controlled Perfusion In Continuous Culture. WO2016/196261) in view of Satakarni et al. (Enhanced protein expression. US20130210075), Disorbo et al. (previously cited; Media Concentrate Technology. US5681748) and Gorfien et al. (previously cited; Serum-Free Mammalian Cell Culture Medium and Uses Thereof. US2009/0280533)
Hiller teaches a method of protein production in continuous perfusion mammalian cell culture (Abstract). The art teaches perfusion culture of CHO cells in a bioreactor (see Example 4; page 27, first paragraph). The art teaches cells are cultured for 6 days in a perfusion medium with osmolality of 345 mOsm (280 to less than 350 mOsm). After 6 days, the culture is perfused with a highly concentrated perfusion nutrient solution having osmolality of approximately 1300 mOsm/kg and a saline diluent (osmolality of 250 mOsm/kg) in varying ratios as indicated in figure 9F (see Example 4; page 27, first paragraph).
The art teaches a Glutamine Synthetase CHO cell line expressing a recombinant immunoglobulin G (heterologous CHO cells; see Example 6).
The rates of perfusion achieved by adding the saline diluent and concentrated perfusion nutrient solution were manipulated to maintain the osmotic strength near the desired 250-350 mOsm window (see last paragraph of page 27 bridging first page of 28).
The art teaches removing permeate (spend medium) and adding fresh medium (page 3, second paragraph; Figure 1; page 15, first paragraph). The permeate may be cell-free (i.d.). Therefore the cells can be retained.
The deficiencies of Hiller are:
Hiller does not teach culturing at an osmolality between 280 mOsm to less than 350 mOsm once a target cell density has been reached, and increasing the osmolality to 380 mOsm or higher once the target cell density has been reached.
Hiller does not teach a serum-free culture.
Hiller does not teach compartmentalized feed medium.
Satakarni et al. teach a method to enhance protein production using mammalian cells (Abstract). The art teaches an alternative way of increasing protein production is by addition of nutrients and/or salts after attaining a required cell density ([0021]). The art teaches the disclosure “provides strategies to enhance heterologous protein production from cells” ([0022]).The art teaches culturing in an osmolality of 320 mOsm/kg, followed by culturing the cells at a higher osmolality range of about 380-420 mOsm/kg by gradual addition of nutrients ([0032]). The art teaches CHO cells ([0042]).
Satakarni teaches any marked change in osmolality depresses cell growth and reduces cell densities ([0017]). At [0020] the art teaches “in this application….the cells are…subjected to increased osmolar conditions which enhance protein production and cells are maintained viable and productive without significant cell proliferation, leading to an increased time integral of viable cells and product yield”.
Disorbo teaches a method of subgrouping media formulations components that can be solubilized to prepare media formulations (Abstract). Concentrated subgroup solutions are mixed with a diluent (Abstract). The art teaches an acid soluble subgroup, an alkali-soluble subgroup and a weak acid-base soluble subgroup (see column 2, lines 50-67). The pH of the “weak acid-base soluble subgroup” is 8.28 (hence, near neutral; Table 2 of Example II). The art teaches mixing a sufficient amount of each of the subgroups with a sufficient amount of a diluent (i.d.). The art teaches perfusion culture (Example 3).DiSorbo teaches adjusting the pH of the individual subgroup concentrates such that, upon combination thereof, the resulting prepared medium is within the desired pH range (col. 13, lines 27-31). Therefore it is configured for adjustment to neutral pH. Figure 4 discloses separation of the subgroups into different drums (containers). Therefore the art is interpreted to teach the groups are compartmentalized.
Disorbo teaches the disclosed method provides for: preparation of media at dramatically reduced cost and storage at room temperature (column 3, lines 25-45).
Gorfien teaches a serum-free medium for culturing mammalian cells in suspension ([0001]). Improved levels of recombinant protein production when cells are grown in serum-free medium ([0008]). The art teaches perfusion culture ([0150]). The art teaches CHO cells engineered to express a polypeptide of interest (e.g., a recombinant protein; a heterologous protein) [0172] [0182]).
It would have been obvious to combine teachings of Hiller and Satakarni by raising osmolarity after reaching the desired cell density. One would have been motivated to do so to enhancing recombinant protein production, as taught by Satakarni. One would have had a reasonable expectation of success since Satakarni teaches CHO cells can be cultured in an osmolality of 320 mOsm followed by a higher range of 380-420 mOsm. One would adjust the pH by adjusting the feed rate since Hiller teaches the rates of perfusion achieved by adding diluent and concentrated perfusion medium are manipulated to achieve a desired osmotic strength. One would have expected similar results since both references culture CHO cells that express heterologous proteins.
It would have been obvious to combine the teachings of the prior art by using the compartmentalized medium taught by Disorbo in Hiller. One would have been motivated to do so since DiSorbo teaches separating medium components into subgroups reduces costs and allows the media to be stored at room temperature. One would have had a reasonable expectation of success since Disorbo teaches the media can be used in perfusion culture. One would have expected similar results since both references are directed to cell culture.
It would have been to combine the teachings of Hiller and Gorfien by using a serum free culture medium to culture CHO cells. One would have been motivated to do so since Gorfien teaches improved levels of recombinant protein production when cells are grown in serum-free conditions. One would have had a reasonable expectation of success since Gorfien teaches CHO cells can be grown in serum free medium. One would have expected similar results since both references teach perfusion culture of heterologous CHO cells.
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.
Regarding claim 23: Hiller teaches perfusing the CHO culture using a highly concentrated perfusion nutrient solution having an osmolality of approximately 1300 mOsm/kg together with a saline diluent having an osmolality of approximately 250 mOsm/kg, wherein the concentrated nutrient solution and saline diluent are supplied in varying ratios (see Example 4, page 27, first paragraph). Hiller teaches manipulating the respective perfusion rates of the concentrated nutrient solution and saline diluent to control the osmotic strength of the culture (supra).
Satakarni teaches increasing the osmolality of the CHO culture after attainment of the required cell density to provide an elevated-osmolality production phase.
DiSorbo teaches the concentrated media subgroups are combined with diluent in amounts selected to provide the desired complete culture-medium composition. 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).
It would have been obvious to maintain the perfusion rate of the concentrated nutrient medium while decreasing the perfusion rate of the lower-osmolality diluent to increase osmolality as taught in Satakarni. Such adjustment would predictably increase the relative contribution of the approximately 1300 mOsm/kg concentrated nutrient medium relative to the approximately 250 mOsm/kg diluent and thereby increase the osmolality of the culture. Because the concentrated-medium perfusion rate remains constant while the diluent perfusion rate is decreased, the combined or overall perfusion rate would necessarily decrease. One would have had a reasonable expectation of success since Hiller teaches the use of highly concentrated perfusion medium permits reduced perfusion rates.
It would have been obvious to maintain the three concentrated subgroup feeds at a fixed volumetric ratio relative to one another based upon their respective fold concentrations when varying the amount of diluent, because maintaining the predetermined relative proportions of the medium components requires the separately concentrated component feeds be supplied in corresponding relative amounts. Maintaining the relative proportions of the concentrated feeds while independently decreasing the diluent would predictably preserve the desired nutrient composition taught by DiSorbo while permitting the concentrated-medium-to-diluent ratio, and therefore culture osmolality, to be adjusted as taught by Hiller and Satakarni.
Therefore claim 23 is included in this rejection.
Satakarni teaches a higher osmolality range of about 380-420 mOsm/kg (supra). Claim 26 is included in this rejection.
Hiller teaches CHO-DG44 cells in Example 5. Claim 28 is included in this rejection.
Hiller teaches a target of 40 x 106 viable cells/ml (page 31, second paragraph). Claim 29 is rejected. Hiller teaches 67-85 x 106 cells/mL on days 5 and 6 (see Example 3, page 26, about line 10). Therefore claim 30 is rejected. 85 x 106 cells/mL is interpreted to be about 90 x 106 cells/mL. Claim 31 is included in this rejection.
Therefore Applicant’s Invention is rendered obvious as claimed.
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
