The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-12 are pending and under consideration.
Priority: This application is a 371 of PCT/IN2022/050078, filed January 30, 2022, which claims benefit to foreign application IN 202141004385, filed February 1, 2021. A copy of the foreign priority document has been received in the instant application on August 1, 2023, and is in the English language.
Failure to Comply with Sequence Rules
Where the description of a patent application discusses a sequence of 4 or more amino
acids or a sequence of 10 or more nucleic acids, reference must be made to the sequence by use
of the sequence identifier preceded by “SEQ ID NO:” in the text of the description even if the
sequence is also embedded in the text of the description of the patent application (see 37 CFR
1.821, especially paragraphs (a)-(d)). The sequence identifier may be used in either the drawing
or the Brief Description of Drawings (see MPEP 2422).
Objection to the Drawings:
The drawings are objected to because: Fig. 1 depicts an amino acid sequence without a sequence identifier (i.e. “SEQ ID NO: X” or the like). Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
The sequences must be in computer readable form (CRF) for search. See also MPEP
2422 for sequence compliance requirements. Appropriate correction is required.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Borys et al. (2010 Biotechnology and Bioengineering 105(6): 1048-1057, published online December 28, 2009). Borys et al. teach CHO cells express glycoproteins containing both the N-acetylneuraminic acid (Neu5Ac) and minor amounts of the N-glycolylneuraminic acid (Neu5Gc) forms of sialic acid (at least p. 1048). Borys et al. teach that as Neu5Gc is not expressed in humans and can be recognized as a foreign epitope, there is the potential for immunogenicity issues for glycoprotein therapeutics (at least p. 1048). Borys et al. teach that high Neu5Gc levels on a chimeric CT4-IgG fusion protein are associated with more rapid clearance profiles in vivo (at least p. 1049). Borys et al. teach that during product development of a glycosylated fusion protein expressed by CHO cells, culture conditions were identified that affected the Neu5Gc content of the recombinant glycoprotein (at least p. 1048-1049). Borys et al. teach a shift in culture temperature to a lower value after the exponential growth phase is used to extend the culture period; it is found that Neu5Gc levels are 59% lower when the temperature shift occurs later near the stationary phase of the culture; and studies on the effects of pCO2 show that the Neu5Gc levels are 46% lower at high pCO2 conditions (140 mm Hg) compared to moderate pCO2 levels (20-80 mm Hg) (at least p. 1048-1049).
Borys et al. teach CHO cells expressing recombinant fusion glycoprotein B1 cultured in a protein-free growth and feed media formulation in bioreactors, where the bioreactors are operated at 37º C and then shifted to a lower temperature as viable cell density (VCD) reaches a predetermined value, the pH and dissolved oxygen are maintained at 7.0 ± 0.10 and 50% air saturation (at least p. 1049), where the growth and feed media formulation necessarily comprises a sugar. Borys et al. teach that to limit the effect of high pCO2 inhibiting cell growth, the bioreactors are shifted to high pCO2 later in the culture period on days 3 and 6 (at least p. 1051-1052). Borys et al. teach Neu5Gc at harvest averaged 0.13 for moderate pCO2 levels of 20-80 mm Hg, while the conditions shifted to high pCO2 on days 3 and 6 averaged 0.07 (at least p. 1052-1053); the net result for total sialic acid was a decrease from 0.91 at moderate pCO2 to 0.82 at high pCO2 (at least p. 1052-1053). Therefore, Borys et al. can be deemed to anticipate at least instant claims 1, 3, 9.
Regarding instant claim 2, since Borys et al. teach a cell culture method for producing a fusion protein comprising the same steps, features, and conditions recited in instant claim 1, it would follow that the fusion protein produced in the method of Borys et al. noted above has a reduced sialylated N-glycan content as recited, of about 21% to 38%.
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.
Claims 1-4, 5-7, 9, 10, 12 are rejected under 35 U.S.C. 103 as being unpatentable over Borys et al. (2010 Biotechnology and Bioengineering 105(6): 1048-1057, published online December 28, 2009). The teachings of Borys et al. over at least instant claims 1-3, 9 are noted above.
Regarding instant claim 5, as noted above, Borys et al. disclose culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation in bioreactors, where the bioreactors are operated at 37º C and then shifted to a lower temperature (at least p. 1049). Borys et al. disclose known shifts in temperature include to 33º C (at least p. 1055). Borys et al. disclose that the amount of Neu5Gc is affected by low temperature and can be modulated by the timing of the temperature shift; this is an important finding as shifts to lower incubation temperature are commonly used in industry to increase culture duration and titer (at least p. 1055). Borys et al. disclose one may still retain the positive effects of incorporation of a temperature shift to increase culture duration and titer, yet modulate potential negative effects of increased Neu5Gc due to low temperatures by selection of shift timing closer to the stationary phase (at least p. 1055). It is known that “[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). MPEP 2144.05. In this instance, the prior art discloses that a low temperature shift from 37º C during cell culture of mammalian cells producing a fusion protein, closer to the stationary phase, decreases Neu5Gc content, where known low temperatures include 33º C. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to arrive at the recited temperature shift from about 37º C to 34º C on day 6 of the cell culture by routine optimization. The motivation to do so is given by the prior art, which discloses similar cell culture conditions in a mammalian cell culture method for producing the same fusion protein products. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including temperature shifts from 37º C to a lower temperature, were known.
Regarding instant claim 4, Borys et al. disclose culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation in bioreactors, where the bioreactors are operated at 37º C and then shifted to a lower temperature (at least p. 1049). Borys et al. disclose that the bioreactors are shifted to high pCO2 later in the culture period on days 3 and 6 (at least p. 1051-1052) and that Neu5Gc at harvest averaged 0.13 for moderate pCO2 levels of 20-80 mm Hg, while the conditions shifted to high pCO2 on days 3 and 6 averaged 0.07, i.e. 140 mm Hg (at least p. 1052-1053); the net result for total sialic acid was a decrease from 0.91 at moderate pCO2 to 0.82 at high pCO2 (at least p. 1052-1053). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to arrive at the recited pCO2 conditions of about 20 to about 50 mm Hg during the growth phase and increase to 100 to 135 mm Hg during the production phase by routine optimization. The motivation to do so is given by the prior art, which discloses similar cell culture conditions in a mammalian cell culture method for producing the same fusion protein products. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including shifts in pCO2 levels from low to high, were known.
Regarding instant claim 7, Borys et al. disclose that high Neu5Gc levels on a chimeric CT4-IgG fusion protein have been noted (at least p. 1049). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate CT4-IgG (i.e. CTLA4-IgG) fusion protein for the fusion glycoprotein B1 in the method for culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation of Borys et al. noted above. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including temperature shifts from 37º C to a lower temperature and shifts in pCO2 from low 20-80 mm Hg to high 140 mm Hg, were known.
Regarding instant claims 6, 12, as noted above, Borys et al. disclose culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation in bioreactors at pH 7.0, where the bioreactors are operated at 37º C and then shifted to a lower temperature, where a low temperature shift from 37º C during cell culture of mammalian cells producing a fusion protein, closer to the stationary phase, decreases Neu5Gc content, where known low temperatures include 33º C, and shifting the pCO2 levels from a low 20-80 mm Hg to high pCO2 levels, including 140 mm Hg, also reduced sialic acid content (at least p. 1048-1055). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to arrive at the recited pCO2 conditions of about 20 to about 50 mm Hg during the growth phase and increase to 100 to 135 mm Hg during the production phase and arrive at the recited temperature shift from about 37º C to 34º C on day 6 of the cell culture by routine optimization in the method for culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation of Borys et al. noted above. The motivation to do so is given by the prior art, which discloses similar cell culture conditions in a mammalian cell culture method for producing the same fusion protein products. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including temperature shifts from 37º C to a lower temperature and shifts in pCO2 from low 20-80 mm Hg to high 140 mm Hg, were known.
Additionally, regarding instant claim 6, since Borys et al. disclose a cell culture method for producing a fusion protein comprising the same steps, features, and conditions recited in instant claim 6, it would follow that the fusion protein produced in the method of Borys et al. noted above for instant claim 6 has a reduced sialylated N-glycan content as recited, including of about 50.82% total sialylated glycans.
Regarding instant claim 10, Borys et al. disclose that high Neu5Gc levels on a chimeric CT4-IgG fusion protein have been noted (at least p. 1049). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate CT4-IgG (i.e. CTLA4-IgG) fusion protein for the fusion glycoprotein B1 in the method for culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation of Borys et al. noted above, the method comprising the recited pCO2 conditions of about 20 to about 50 mm Hg during the growth phase and increase to 100 to 135 mm Hg during the production phase and arrive at the recited temperature shift from about 37º C to 34º C on day 6 of the cell culture by routine optimization. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including temperature shifts from 37º C to a lower temperature and shifts in pCO2 from low 20-80 mm Hg to high 140 mm Hg, were known.
Claims 1-4, 5-7, 8, 9, 10, 11, 12 are rejected under 35 U.S.C. 103 as being unpatentable over Borys et al. (2010 Biotechnology and Bioengineering 105(6): 1048-1057, published online December 28, 2009) in view of Dubois et al. (2009 Br J Clin Pharmacol 68:4, pages 480-481). The teachings of Borys et al. over at least instant claims 1-7, 9-10, 12 are noted above.
Regarding instant claims 8, 11, as noted above, Borys et al. disclose that high Neu5Gc levels on a chimeric CT4-IgG (i.e. CTLA4-IgG) fusion protein have been noted (at least p. 1049). Dubois et al. disclose that abatacept is CTLA4-IgG fusion protein (p. 480). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the abatacept of Dubois et al. for the fusion glycoprotein B1 in the method for culturing CHO cells expressing a recombinant fusion glycoprotein in a growth and feed media formulation of Borys et al. noted above, the method comprising the recited pCO2 conditions of about 20 to about 50 mm Hg during the growth phase and increase to 100 to 135 mm Hg during the production phase and arrive at the recited temperature shift from about 37º C to 34º C on day 6 of the cell culture by routine optimization. One of ordinary skill would have a reasonable expectation of success because cell culture conditions for reducing sialic content in fusion proteins produced in mammalian cells, including temperature shifts from 37º C to a lower temperature and shifts in pCO2 from low 20-80 mm Hg to high 140 mm Hg, were known.
No claim is allowed.
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/Marsha Tsay/Primary Examiner, Art Unit 1656