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 .
Claims 86-88, 90, 91, 93, 94, 96 and 97 are pending in this application and were examined on their merits.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 86-88, 90, 91, 93, 94, 96 and 97 are rejected under 35 U.S.C. § 103 as
being unpatentable over Rao et al. (WO 2016/130940 A1) in view of Lipinski (WO
2015/086598 A2), both of record, and Vela (WO 2020/168230 A1), cited in the IDS.
Rao et al. teaches a method for producing Enterovirus A comprising culturing
adherent Vero cells in a bioreactor in culture medium, inoculating the cells with
Enterovirus A under conditions in which the Enterovirus A infects the cells,
culturing/incubating the cells under conditions in which the infected cell produces the virus and harvesting the produced virus (Pg. 99, Claims 1 and 3), and reading on
Claims 86, 87 and 88.
The Rao reference further teaches that the conditions in which Enterovirus A
infects cells are known in the art and depend on the type of cell, the type of Enterovirus,
the culture medium, cell density, viral density (e.g., MOI), cell growth rate and number of
cell passages (Pgs. 13-14, Paragraph [0060]).
The Rao reference further teaches that cell density at the time of infection may impact viral production and an optimal cell density at viral inoculation may result in increased specific productivity, volumetric productivity, and/or stability, as well as reduced media consumption and/or contaminants in the harvest (Pg. 14, Paragraph [0061] and Pg. 95, Paragraph [0342]).
The Rao reference further teaches that maintaining suitable oxygen levels in a cell culture medium may promote cell growth and/or virus productivity by providing oxygen for cellular respiration, embodiments wherein the density of oxygen in the culture medium is maintained above 50% and that methods for maintaining and/or measuring the density of oxygen (DO) in a culture medium are known in the art (Pg. 17, Paragraph [0072]).
With regard to Claims 86 and 90, the Rao reference teaches methods wherein the Vero cells are grown at a constant initial DO level, pH and temperature, wherein the DO is controlled and measured (monitored over time, thus actively) within the culture medium in a bioreactor and DO is maintained by automated injection of air/oxygen (e.g. by a process controller) (Pg. 75, Paragraph [0267] and Pg. 76, Paragraph [0268] and Pgs. 77-78, Paragraph [0275] and Fig. 30b).
The Examiner notes Rao et al. utilizes an iCELLis)™ NANO bioreactor (Pg. 75, Paragraph [0266]-[0267]) which is also disclosed in the instant disclosure, see the Specification as published at Pg. 5, Paragraph [0062]).
Rao et al. does not teach a method wherein the host cells are grown within the bioreactor under an average air flow rate of about 80-100 ml/min and an average oxygen flow rate of about 0-30 ml/min, and at a constant initial dissolved oxygen level of 80-100% in the culture medium,
reducing the airflow rate over time and increasing the oxygen flow rate over time based on measured air parameters and infecting the host cells with virus when the reducing airflow rate and the increasing oxygen flow rate are within 30 mL/min of each other, as required by Claim 86;
wherein infecting the host cells in Claim 86, step d) comprises infecting the host cells when the air flow rate and the oxygen flow rate into the bioreactor are equal, as required by Claim 91;
wherein the infecting the host cells in Claim 86, step d) occurs at a multiplicity of infection (MOI) of 0.1 to 0.05. as required by Claim 93;
a method further comprising a step of incubating the host cells at a second dissolved oxygen (dO2) level, pH, and temperature different from the initial dO₂ level, pH, and temperature during the growing the host cells of b), as required by Claim 94;
or wherein the first-initial (O₂ level is 100%, and wherein the second dO₂ level is between 50 % to 20 %, as required by Claim 97.
Lipinski teaches a method of culturing Vero cells to produce a virus, wherein the virus may be influenza virus or Japanese encephalitis virus (Pg. 7, Lines 9-26) and wherein an iCELLis™ bioreactor is utilized to culture Vero cells at a DO of 50% and an airflow rate of 30 mL/min (Pg. 15, Lines 16-24).
Vela teaches a method of producing virus in a bioreactor comprising the following steps:
a) providing host cells in the bioreactor;
b) growing host cells in a constant initial (100% O₂ level, pH, and temperature, Pg. 2, Paragraph [0004]);
c) decreasing the dO2 to 20-90% of initial oxygen level; d) infecting the host cells with at least one virus or virus particle 2-24 hours after step c);
e) incubating said host cells infected with said virus or virus particle to propagate said virus; and
f) harvesting the virus (Pg. 16, Claim 1); wherein the host cells are adherent cells (Pg. 16, Claim 2); wherein the infection of the host cells with the virus is at multiplicity of infection (MOI) of about 0.1 to 0.05 (Pg. 17, Claim 9);
wherein the virus is selected from a group consisting of VSV, adenovirus, Influenza virus, Ross River virus, Hepatitis A virus, Vaccinia virus and recombinant Vaccinia virus, Herpes Simplex virus, Japanese Encephalitis virus, Herpes Simplex virus, West Nile virus, Yellow Fever virus, and chimeras thereof, as well as Rhinovirus and Reovirus (Pg. 17 Claim 12);
and wherein the host cells are Vero cells (Pg. 17 Claim 16).
It would have been obvious to those of ordinary skill in the art to modify the method of Rao of producing virus from infected Vero cells wherein the cell culture is maintained at a constant initial dO2 of 100% which is actively monitored and adjusted automatically by a controller to use an average air flow rate and average oxygen flow rate as claimed to maintain said initial dO2, further to reduce the air flow rate and increase the oxygen flow rate to maintain the constant initial dO2 level based on the monitored air parameters and then infecting the cells when the reducing of the air flow rate and increasing of the oxygen flow rate are within 30mL/min of each other because the dissolved oxygen percentage in the culture and the air flow and oxygen flow rates (including the average thereof) vis-a-vis the time of infection in a method of producing virus from host cells in a bioreactor are result effective variables subject to routine optimization and experimentation.
The oxygen density (DO) is recognized by the Rao reference as important as maintaining suitable oxygen levels in a cell culture medium may promote cell growth and/or virus productivity by providing oxygen for cellular respiration, Lipinski teaches culturing Vero cells in a bioreactor at a particular oxygen density and the same air flow rate as claimed and Vela teaches adjusting (decreasing) dissolved oxygen in a method of infecting Vero cells with virus for viral production. Thus, the prior art recognizes the oxygen density, and therefore the oxygen concentration and flow rate of oxygen into the bioreactor is a critical result-effective variable involved in cell growth and viral productivity. As such, modification of the rate at which air/oxygen is introduced into the bioreactor during growth and inducing viral infection at a particular optimal point when the air flow rate and oxygen flow rate are within 30 mL/min of one another would have been obvious to the ordinary artisan absent any showing of unexpected results. Those of ordinary skill in the art would have been motivated to make this modification in order to optimize the cell growth rate and maximize viral production therein. There would have been a reasonable expectation of success in making this modification because all of the references are drawn to the same field of endeavor, that is, the bioreactor culturing of Vero cells for the production of virus.
It would have been further obvious to those of ordinary skill in the art to modify the method of Rao, Lipinski and Vela of producing virus from infected Vero cells to incubate the host cells at a second dissolved oxygen (dO2) level, pH, and temperature different from the initial dO₂ level, pH, and temperature used during the growing of the host cells because the altering of known culture conditions such as temperature and pH would have been an obvious result-effective adjustment of parameters by routine experimentation. See the MPEP at 2144.05 II., A. While the references listed above do not specifically teach the limitations of altering the temperature and pH (Vela teaching altering the dO2) from the initial culture temperature and pH, one of ordinary skill in the art would recognize culture temperature and pH as optimizable variables dependent on desired culture parameters. This is motivation for someone of ordinary skill in the art 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 difference in culture temperature and pH from initial, 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). Those of ordinary skill in the art would have been motivated to make this modification in order to optimize the cell culture conditions and maximize viral production therein. There would have been a reasonable expectation of success in making this modification because all of the references are drawn to the same field of endeavor, that is, the bioreactor culturing of Vero cells for the production of virus.
With regard to Claim 93, Vela teaches wherein the infection of the host cells with the virus is at multiplicity of infection (MOI) of about 0.1 to 0.05 (Pg. 17, Claim 9).
With regard to Claim 96, Vela teaches wherein the virus is selected from a group consisting of VSV, adenovirus, Influenza virus, Ross River virus, Hepatitis A virus, Vaccinia virus and recombinant Vaccinia virus, Herpes Simplex virus, Japanese Encephalitis virus, Herpes Simplex virus, West Nile virus, Yellow Fever virus, and chimeras thereof, as well as Rhinovirus and Reovirus (Pg. 17 Claim 12).
With regard to Claim 97, Vela teaches growing host cells in a constant initial dO2 level, pH, and temperature and decreasing the dO2 to 20-90% of initial oxygen level (Pg. 16, Claim 1). Thus, the prior art encompasses an embodiment wherein the initial O₂ is 100% and the second dO2 is 20-50%.
Response to Arguments
Applicant's arguments filed 07/29/2026 have been fully considered but they are not persuasive.
The Applicant argues that the amended claims advantageously preclude a required step of counting the host cells. Applicant argues that Rao discloses a method wherein cells are counted (Remarks, Pg. 4, Lines 16-28 and Pg. 5, Lines 1-30).
This is not found to be persuasive for the following reasons, while the Rao reference may disclose specific embodiments wherein host cells are counted, this is not a teaching away or a disclosure that cells must always be counted. The Examiner notes that Rao et al. teaches a method for producing Enterovirus A comprising culturing
adherent Vero cells in a bioreactor in culture medium, inoculating the cells with
Enterovirus A under conditions in which the Enterovirus A infects the cells, culturing/incubating the cells under conditions in which the infected cell produces the virus and harvesting the produced virus (Pg. 99, Claims 1 and 3). Nowhere in the citation is a requirement that the host cells be counted. See the MPEP at 2123, I. and II. In response to Applicant's argument that there are certain advantages in not counting cells, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion/broad disclosure of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
The Applicant argues that Lipinski and Vela do not remedy the alleged deficiency of Rao. Applicant notes that Lipinski teaches cell counting and Vela measure infective particles (Remarks, Pg. 5, Lines 31-34 and Pg. 6, Lines 1-7).
This is not found to be persuasive for the reasoning provided above. Similar to Rao, while the Lipinski and/or Vela references may disclose specific embodiments wherein host cells are counted (though the Examiner notes with regard to Vela that infective particles are not Vero cells as claimed), this is not a teaching away or a disclosure that cells must always be counted.
Conclusion
No claims are allowed.
THIS ACTION IS MADE FINAL. 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to PAUL C MARTIN whose telephone number is (571)272-3348. The Examiner can normally be reached Monday-Friday 12pm-8pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, Applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Sharmila G Landau can be reached at (571) 272-0614. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/PAUL C MARTIN/ Examiner, Art Unit 1653
/SHARMILA G LANDAU/ Supervisory Patent Examiner, Art Unit 1653
Prosecution Insights