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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 01/26/2026 has been entered.
DETAILED ACTION
Claims 1-43, 57, and 61-63 are canceled. Claims 44-56, 58-60 and 64-66 are pending and under consideration.
Priority
The instant claims are entitled to an effective filing date of 04/24/2019.
Claim Rejections - 35 USC § 112(d)
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.
Claims 64 and 65 are 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.
Claims 64 and 65 fail to further limit claim 44 from which they depend. Claim 44 requires a folding buffer that does not comprise any oxidizing agent (last line of claim 44). Claim 64 requires the folding buffer to not comprise the oxidizing agent cystine. Claim 65 requires the folding buffer to not comprise the oxidized form of glutathione, which is glutathione disulfide (GSSG) (i.e. an oxidizing agent). See [0080] of the instant specification. As such, claims 64 and 65 broaden the scope of the folding buffer because the claims encompass folding buffers with oxidizing agents, as long as those oxidizing agents are not cystine and GSSG respectively.
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 Interpretation
Claim 44 requires two active method steps. First, a) a granulocyte colony-stimulating factor (i.e. G-CSF) contained in inclusion bodies (i.e. IBs) is solubilized with a solubilization buffer comprising a denaturing agent. The denaturization agent may be sarkosyl, which is also referred to as N-lauroyl sarcosine (see instant claims 50-51). Second, b) folding of the solubilized G-CSF is initiated by diluting the solubilized G-CSF with a folding buffer comprising only the reduced form of a thiol redox pair to obtain a folding mixture comprising folded G-CSF, wherein the folding buffer does not any oxidizing agent. Part b) of claim 44 requires diluting the solubilized G-CSF “via sequential stepwise dilution process”. However, the “sequential stepwise dilution process” is not defined in the claim. Therefore, any dilution is considered to be a ‘sequential stepwise dilution process’. Moreover, part b) requires the folding buffer to “comprise only” the “reduced form of a thiol redox pair”, and “the folding buffer does not comprise any oxidizing agent”. As such, the folding buffer may be defined as the reduced form of a thiol redox pair. However, claim 44 overall is open-ended due to the term “comprising” in line 2. Therefore, the method of claim 44 does not exclude the use oxidizing agents. Rather, claim 44 requires the folding buffer to be the reduced form of a thiol redox pair. For example, the folding buffer may be cysteine, which is the reduced form of the cysteine/cystine thiol redox pair.
In claim 49, the ionic denaturing detergents include N-lauroyl sarcosine (sarkosyl), which is specifically an anionic denaturing detergent. See paragraphs [0051] and [0054] of the instant specification.
Claim 52-55 recite the term “about”, which means plus or minus 10% of the provided value, or rounded to the nearest significant figure. See paragraph [0030].
Claim 54 requires a solubilization buffer with about 40mM tris(hydoxymethyl)aminomethane, about 2% sarkosyl and has a pH of about 8.4, which encompasses pH ranges between 7.56-9.24 due to the term “about”.
Claim 55 requires the volume ratio of a suspension buffer to the solubilization buffer to be adjusted such that the final pH ranges from about 7.5 to about 7.8, which encompasses a pH range of 6.75 to 8.58 due to the term “about”.
Claim 56 recites WFI, which is water for injection. See [0012] of the instant specification. There is no structural distinction between WFI and water.
Claim 58 requires the reduce form of a thiol redox pair to be selected from a group that includes cysteine.
Claim 60 requires the method to be devoid of a strong denaturing agent, a strong reducing agent, a redox reaction, or a heavy metal. For example, claim 60 encompasses methods that use sarkosyl as a denaturing agent because sarkosyl is not categorized as a strong denaturing agent. For examples of strong denaturing agents, see paragraph [0052] of the instant specification.
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 44-56, 58-60, and 64-66 are rejected under 35 U.S.C. 103 as being unpatentable over Fellföldi (US 2015/0057439) in view of Rao (Biotechnology and applied biochemistry, 2008, 50(2), 77-87; as cited in the IDS mailed 08/11/2025).
Regarding claim 44, Fellföldi teaches dissolving inclusion bodies (IB) in solubilization buffer containing 1% w/v N-lauroylsarcosin, also referred to as sarkosyl (denaturing agent). See paragraph [0269]. For oxidative refolding, the solubilized IB suspension is diluted 2-fold with water to 0.5% sarkosyl. CuSO4 is added. G-CSF is oxidized and partially refolded. See paragraph [0270]. Fellföldi discloses that in a typical refolding process the concentration of the solubilizing agent is first decreased below denaturing concentrations often by stepwise dilution. The presence of an oxidant such as CuSO4 or a redox system such as glutathion [misspelling of glutathione] red/ox, GSH/GSSG, promotes the disulfide formation during the refolding incubation. See paragraph [0106]. Fellföldi cites and incorporates Rao 2008 (discussed below). See paragraph [0027], [0036] and [0087].
Fellföldi does not teach a folding buffer comprising only the reduced form of a thiol redox pair, wherein the folding buffer does not comprise any oxidizing agent.
Rao teaches investigating the effect of reducing and oxidizing agents on protein refolding by performing experiments in the presence and absence of dithiothreitol, GSH (i.e. glutathione) and GSS (i.e. glutathione disulfide), CuSO4, and cysteine at different concentrations. Incomplete refolding is observed in the absence of cysteine. Rao suggests that the cysteine concentration has a significant impact on rhG-CSF refolding. See the paragraph spanning the left and right column on page 82. Rao suggests previous studies investigated the refolding of rhG-CSF using Cu2+ and it has been reported that ~80% refolding can be achieved. However, Rao suggests that such method is not feasible for large-scale operations, owing to the free cysteine residue present in the backbone of the protein, which tends to form inter- and intra-molecular disulfide bonds and leads to low recovery by aggregate formation at physiological pH. See the first paragraph in the right column on page 83. Rao teaches observing complete refolding of rhG-CSF in the presence of cysteine. See the last full paragraph on page 82.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to replace the CuSO4 with the cysteine of Rao. One would be motivated to use the cysteine of Rao because Rao suggests that incubation with cysteine significantly impacts refolding, whereas CuSO4, only results in partial refolding. There would be a reasonable expectation of success because Rao demonstrates refolding rhG-CSF with cysteine.
Regarding claims 45, Fellföldi teaches three G-CSF production lots with final purities of 97.5%, 96.9% and 97%. See table II. The biological activities of the 3 G-CSF production lots are 107%, 99% and 107%. See table IV. Thus, Fellföldi teaches a method for preparing biologically active (i.e. correctly folded) G-CSF with purities of 97.5%, 96.9% and 97%, which is greater than 80% as instantly claimed.
Rao teaches a protein purity that is more than 99%, and rhG-CSF biological activity of 1x108 i.u./mg. See the first paragraph on page 86, figure 4B-4D.
Regarding claim 46, Fellföldi teaches three G-CSF production lots with final purities of 97.5%, 96.9% and 97%. See table II. The biological activities of the 3 G-CSF production lots are 107%, 99% and 107%. See table IV. Thus, Fellföldi teaches a method for preparing biologically active (i.e. correctly folded) G-CSF with purities of 97.5%, 96.9% and 97%, which is greater than 85% as instantly claimed.
Rao teaches a protein purity that is more than 99%, and rhG-CSF biological activity of 1x108 i.u./mg. See the first paragraph on page 86, figure 4B-4D.
Regarding claim 47, Fellföldi teaches a final polishing step by cation exchange chromatography (CEX) in which a G-CSF pool consisting of correctly folded protein is applied onto a CEX column and pure G-CSF is collected (i.e. recovered). See paragraph [0276]. Moreover, Fellföldi teaches eluting correctly folded G-CSF from an AEX (anion exchange) column. See paragraph [0275], claim 14 part (e) and claim 20 of Fellföldi.
Regarding claim 48, Fellföldi teaches separating inclusion bodies from cell debris by sedimentation. The sedimented inclusion bodies are discharged in washing buffer (i.e. a suspension buffer). The concentrated IB suspension is diluted. The final sediment of IBs is frozen. See paragraph [0268]. Frozen inclusion bodies are thawed and dissolved in solubilization buffer containing N-lauroylsarcosin (sarkosyl). See paragraph [0269].
Regarding claim 49-51, Fellföldi teaches a solubilization buffer containing sarkosyl (i.e. an ionic detergent, specifically an anionic detergent). See paragraph [0269] and the discussion regarding instant claim 44 above.
Regarding claim 52, Fellföldi teaches a solubilization buffer with 1% (w/v) sarkosyl, which is within the instantly claimed about 0.2% to about 5.0% by weight range. See paragraph [0269] of Fellföldi.
Regarding claim 53, Fellföldi teaches a solubilization buffer comprising 40 mM Tris-HCl, pH 8 and 1% (w/v) sarkosyl. See paragraph [0269]. Thus, Fellföldi teaches a Tris [i.e. tris(hydroxymethyl)aminomethane] molar concentration within the instantly claimed about 20 mM to about 60 mM, a sarkosyl percentage within the instantly claimed about 0.2% to about 5.0%, and a pH within the instantly claimed about 7.5 to about 9.0.
Regarding claim 54, Fellföldi teaches a solubilization buffer comprising 40 mM Tris-HCl [i.e. Tris is tris(hydroxymethyl)aminomethane], pH 8 and 1% (w/v) sarkosyl. See paragraph [0269]. Fellföldi suggests that the sarkosyl concentration during solubilization is 0.2-2.0% w/v. See paragraph [0101]. Therefore, Fellföldi suggests a solubilization buffer that comprises 40 mM Tris-HCl, 2% (w/v) sarkosyl and a pH of 8, which is encompassed with the “about 8.4” pH range.
Regarding claim 55, Fellföldi teaches discharging sedimented inclusion bodies into a washing buffer (i.e. a suspension buffer) at pH 7.2 and diluting the concentrated inclusion body suspension with the same buffer. See paragraph [0268]. Fellföldi teaches performing the solubilization of G-CSF at a pH value greater than 7. See claim 6 of Fellföldi. Fellföldi teaches a solubilization buffer with 1% sarkosyl a pH of 8. See paragraph [0269]. Fellföldi teaches diluting the solubilized IB suspension 2-fold with water to 0.5% sarkosyl. See paragraph [0270]. Moreover, Fellföldi suggests optimizing parameters such as pH, buffer, etc. to improve yield. See paragraph [0102].
Fellföldi and Rao do not teach adjusting the volume ratio of a suspension buffer to a solubilization buffer such that the final pH is about 7.5 to about 7.8. However, Fellföldi suggests performing solubilization at a pH value greater than 7 and demonstrates a solubilization buffer at a pH of 8, which is within the instantly claimed about 7.5 to about 7.8 range.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to optimize the 0.5% sarkosyl percentage in the solubilized IB suspension and in the process adjust the volume ratio of the IB suspension to the solubilization buffer and the pH. Doing so is mere optimization through routine experimentation. One would be motivated to optimize the buffer concentrations and, consequently, the pH because Fellföldi suggests optimizing the pH and buffer to improve yield. There would be a reasonable expectation of success because Fellföldi demonstrates using a solubilization buffer with a pH of 8 and Fellföldi demonstrates diluting the IB suspension with sarkosyl (e.g. a denaturing agent in the solubilization buffer). MPEP 2144.05(II) indicates that differences in concentration generally amount to “routine optimization” and will not support patentability unless there is evidence indicating the claimed feature is critical. “Where 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).
Regarding claim 56, Fellföldi teaches dissolving inclusion bodies in solubilization buffer with 1% sarkosyl. See paragraph [0269]. For refolding, Fellföldi teaches diluting the solubilized IB suspension 2-fold with water (i.e. WFI) to 0.5% sarkosyl. See paragraph [0270]. Fellföldi discloses that for a typical refolding process the concentration of the solubilizing agent is at first decreased below denaturing concentrations often by step-wise dilution. See paragraph [0106].
Regarding claim 58, Rao teaches investigating the effect of cysteine at different concentrations. Incomplete refolding is observed in the absence of cysteine. Rao suggests that the cysteine concentration has a significant impact on rhG-CSF refolding. See the paragraph spanning the left and right column on page 82.
Regarding claim 59, Fellföldi teaches a final polishing step by cation exchange chromatography (CEX) in which a G-CSF pool consisting of correctly folded protein is applied onto a CEX column and pure G-CSF is collected (e.g. recovered). See paragraph [0276]. Moreover, Fellföldi teaches eluting correctly folded G-CSF from an AEX (anion exchange) column. See paragraph [0275], claim 14 part (e) and claim 20 of Fellföldi.
Regarding claim 60, Fellföldi teaches dissolving IBs in solubilization buffer containing Tris-HCl, and 1% w/v N-lauroylsarcosin, also referred to as sarkosyl (i.e. not a strong denaturing agent). See paragraph [0269].
Regarding claim 64, Fellföldi teaches an oxidative refolding process in which a solubilized IB suspension is diluted 2-fold with water to 0.5% sarkosyl. CuSO4 (i.e. an oxidizing agent that is not cystine) is added. See paragraph [0270] and claims 1 and 5 of Fellföldi.
Rao teaches observing the complete refolding of rhG-CSF in the presence of cysteine. See the last paragraph on page 82. Rao meets the instant limitation because Rao does not teach or suggest that cystine is present in the experiments in which cysteine is used.
Regarding claim 65, Fellföldi teaches an oxidative refolding process in which a solubilized IB suspension is diluted 2-fold with water to 0.5% sarkosyl. CuSO4 (i.e. an oxidizing agent that is not the oxidized form of glutathione, GSSG) is added. See paragraph [0270] and claims 1 and 5 of Fellföldi.
Rao teaches investigating the effect of reducing and oxidizing agents on protein refolding by performing experiments in the presence and absence of dithiothreitol, GSH and GSS, CuSO4, and cysteine at different concentrations. See the paragraph spanning the left and right column on page 82. Thus, Rao suggests that GSSG is not present in experiments in which cysteine is used.
Regarding claim 66, Fellföldi teaches a refolding strategy for producing biologically active G-CSF. See, e.g., figure 1. Fellföldi discloses that fully active, pure human G-CSF possesses a specific biological activity of 1.0x108 IU/mg. See [0286]. Fellföldi teaches an oxidative refolding process in which a solubilized IB suspension is diluted 2-fold with water to 0.5% sarkosyl. CuSO4 (i.e. an oxidizing agent that is not cystine) is added. See paragraph [0270] and claims 1 and 5 of Fellföldi.
Fellföldi does not teach a folding mixture that comprises folded G-CSF of at least 1x105 IU/mg, because the instantly claimed “folding mixture” includes the folding buffer comprising only the reduced form of a thiol redox pair, which is not taught by Fellföldi as discussed above with respect to instant claim 1.
Rao teaches refolding rhG-CSF in the presence of cysteine at different concentrations. See the paragraph spanning the left and right column on page 82. Rao teaches testing the biological activity of the rhG-CSF and finding that the activity is 1x108 i.u./mg. See the first paragraph on page 86. Thus, Rao teaches refolded G-CSF with a 1x108 i.u./mg biological activity.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to replace the CuSO4 of Fellföldi with the cysteine of Rao, as discussed above, and in the process arrive at a refolded and biologically active G-CSF that has an activity of 1x108 i.u./mg, which is at least 1x105 IU/mg as instantly claimed. One would be motivated to do so because Rao suggests refolding with Cu2+ may not be feasible for large-scale operations (see the first paragraph in the right column on page 83 of Rao). There would be a reasonable expectation of success because Fellföldi and Rao demonstrate refolding and obtaining G-CSF with an activity of 1.0x108 IU/mg.
Response to Arguments
Applicant's arguments filed 01/26/2026 have been fully considered, but they are unpersuasive.
§ 103 rejection
Applicant argues that claim 44 was amended to recite “wherein the folding buffer does not comprise any oxidized thiol agent and the method is for preparing biologically active G-CSF, and wherein the folding mixture in (b) comprises folded G-CSF with a purity of greater than 80%”. See the fourth paragraph on page 6 of the remarks.
This argument is not persuasive because amended claim 44, filed 01/26/2026, does not recite ‘wherein the folding buffer does not comprise any oxidized thiol agent and the method is for preparing biologically active G-CSF, and wherein the folding mixture in (b) comprises folded G-CSF with a purity of greater than 80%’, as argued. Rather, claim 44 was only amended to replace “the folding buffer does not comprise any oxidized thiol agent” with “the folding buffer does not comprise any oxidizing agent” (last line). This amendment does not significantly alter the claim scope of the folding buffer that is required to comprise “only the reduced form a thiol redox pair”. See lines 6-7 of claim 44 filed 08/11/2025 and filed 01/26/2026.
Applicant argues that Rao does not teach the use of a redox pair without an oxidizing agent. Applicant asserts that the Office is wrong to assume that the cysteine of Rao is used without cystine. Applicant argues that the Office ignored Rao’s statement that “[t]he available literature indicates the use of cysteine-cystine redox system for refolding of some other recombinant proteins, but it has not been reported for rhG-CSF” (last full paragraph on page 82). Therefore, Applicant asserts that Rao is not clear as to whether cysteine is used alone or in a cysteine-cystine redox pair while specifying the cysteine concentration. Nowhere does Rao teach or suggest refolding without an oxidizing thiol agent as presently claimed. See the second paragraph on page 7 of the remarks.
This argument is not persuasive because MPEP 2121(I) discloses that a reference is presumed to be operable until applicant provides facts rebutting the presumption of operability. In the instant case, Rao specifically states “[w]e observed complete refolding of rhG-CSF in the presence of cysteine” (last full paragraph on page 82). Rao is silent regarding the presence of cystine during refolding. Rao states “[t]he effect of reducing and oxidizing agents on protein refolding was investigated by performing the experiments in the presence and absence of DTT (dithiothreitol), GSH and GSSG, CuSO4 and cysteine at different concentrations (25, 50, 75, 100 and 200 mM)”. See the last passage in the left column on page 82. In this statement, Rao lists the redox pair “GSH and GSSG” by including both the reducing agent, GSH, and the oxidizing agent, GSSG. Whereas, the oxidizing agent cystine is not included in the list. Therefore, it would be improper to assume that cystine was present in these experiments because Rao teaches nothing to that effect. The only mention of cystine in Rao is within the quote cited by Applicant above. See the last paragraph on page 82 of Rao. In the quote, Rao references the use of a cysteine-cystine redox system in available literature, but Rao does not teach or suggest using that same redox system. MPEP 2123 states that “[a] reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art”.
Applicant argues that one of skill in the art would have no motivation to combine the references. Applicant asserts that the present claims make it clear that there is no oxidizing agent present in the refolding step. This is indirect contrast to Fellföldi, which stresses the importance of an oxidizing agent. Applicant references paragraph [0106] of Fellföldi, which states “[o]xidation the reducing and cysteines and disulfide formation is necessary for correct folding of G-CSF”. Fellföldi exemplifies CuSO4 as an oxidizing agent, which Examiner alleges one skilled in the art would then substitute for cysteine based on Rao. However, the present claims make it clear that no oxidizing agent is used. As such, one would not turn to Fellföldi as a starting point, which stresses the use of oxidizing agents, to design a method with CuSO4 and then switch this with cysteine. See the last paragraph on page 7 of the remarks.
This argument is not persuasive because it is not commensurate in scope with the instant claims. Claim 44 does not exclude the use of oxidizing agents all together. Rather, claim 44 requires a folding buffer that does not comprise any oxidizing agent. Claim 44 recites the open-ended terms “comprising” (line 2) and “comprise” (last line), so the method as a whole does not exclude additional unrecited elements. As discussed above, Rao is relied upon for teaching the instantly claimed folding buffer, not Fellföldi. As pointed out by Applicant, Fellföldi exemplifies the use of CuSO4 as an oxidizing agent (see [0270]), and Rao teaches investigating the effect of CuSO4 and cysteine on protein refolding (see the last passage of the left column on page 82). Thus, Rao suggests that CuSO4 is interchangeable with cysteine for refolding. As such, Applicants argument that one would not be motivated to switch from CuSO4 to cysteine is unpersuasive.
Applicant references page 9 of the office action mailed 09/24/2025, which states that “Fellföldi suggests that CuSO4 promotes disulfide formation during refolding incubation; and Rao demonstrates refolding rhG-CSF with cysteine and suggests that cysteine promotes complete refolding because it blocks the free cysteine residue that tends to cause inter- and intra- molecular disulfide bonds leading to low recovery by aggregate formation”. Applicant argues that CuSO4 and cysteine perform opposite actions, where CuSO4 promotes disulfide formation while the cysteine blocks free cysteine residues that form disulfide bonds. See the first paragraph on page 8 of the remarks. Applicant asserts that Fellföldi teaches that oxidation of reduced cysteines and disulfide formation is necessary for correct refolding of G-CSF. See [0106] and the second paragraph on page 8 of the remarks. Applicant asserts that it seems counterintuitive for the Office to state it would be a simple substitution to use the method of Fellföldi but then switch out the CuSO4 after Fellföldi teaches that oxidation of G-CSF and disulfide formation is necessary for refolding, and Rao teaches that cysteine blocks the residues that form inter-molecular disulfide bonds. See the last full paragraph on page 8 of the remarks.
This argument is not persuasive because arguments of counsel cannot take the place of factually supported objective evidence (MPEP 2145 or 716.01(c)). Applicant argues that CuSO4 and cysteine perform opposite actions. However, the evidence of record indicates otherwise. To clarify, Fellföldi discloses that completely folded intact G-CSF has two disulfide bridges at positions Cys37-Cys43 and Cys65-Cys75, while one cysteine residue is free at position 18. See [0287]. Rao teaches observing completely refolded rhG-CSF in the presence of cysteine. Rao further suggests that oxidative refolding using Cu2+ is not feasible for large-scale operations, owing to the free cysteine residue present in the backbone of the protein, which tends to form inter- and intramolecular disulfide bonds and leads to low recovery by aggregate formation. Rao suggests that the observed complete refolding in the presence of cysteine may be due to effective blocking of the free cysteine residue. See the right column on page 82. Thus, Rao does not teach or suggest that cysteine blocks all disulfide bond formation. Rather, Rao suggests that using cysteine may prevent unwanted disulfide bonding at the free residue; which Rao suggests is an issue when refolding with oxidative Cu2+. Fellföldi also acknowledges that aggregation (i.e. the result of such unwanted bonding) is a major problem during refolding. See [0106]. For clarity, the Office action statement quoted by Applicant above was deleted from the discussion of instant claim 44.
Applicant argues that the methods of Fellföldi and Rao differ. For instance, Rao teaches using urea at a high pH for solubilization, which differs from Fellföldi which exemplifies the use of Tris-HCl at pH of 8 with sarkosyl for solubilization. Fellföldi, in reference to Rao, indicates that Rao uses “unusually high pH values (pH 12-12.8)” for their solubilization. See [0027] of Fellföldi.
This argument is not persuasive because the test for obvious is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). Fellföldi, not Rao, is relied upon for teaching the instantly claimed solubilization buffer. Fellföldi does not teach away from methods that use urea for solubilization, because Fellföldi teaches that solubilization can be divided into two strategies: a classical approach, which includes the use of a strong chaotropic agent such as urea, or a second strategy that uses a strong surfactant such as sarkosyl. See [0065]. Although Fellföldi and Rao use different solubilization buffers, the references overall are not disparate, because Fellföldi and Rao are in the same field of refolding and purifying G-CSF.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 44-56, 58-60, and 64-66 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 38-57 of copending Application No. 17/625,655 to Hopp in view of Fellföldi (US 2015/0057439) and Rao (Biotechnology and applied biochemistry, 2008, 50(2), 77-87)
This is a provisional nonstatutory double patenting rejection.
Copending claim 38 recites a method for purifying granulocyte colony-stimulating factor (GCSF), wherein the method comprising: loading a GCSF-containing sample onto a chromatography vessel comprising an anion exchange chromatography (AEX) material capable of binding the GCSF in the GCF-containing sample, wherein the chromatography vessel is placed in a temperature-controlled enclosure and at least a portion of the temperature-controlled enclosure of the chromatography vessel is set at a temperature of about 7°C to about 13°C; and eluting the GCSF from the AEX material with an elution buffer to obtain a purified GCSF, wherein the elution of the GCSF from the AEX material is carried out at a conductivity ranging between about 7.4 to about 8.2 mS/cm.
Copending claim 41 recites the method of claim 40, where at least one of the temperature-controlled enclosure of the chromatography vessel and the temperature-controlled enclosure of the fluidic channel is set at a temperature of about 10°C.
Copending claim 42 recites the method of Claim 38, wherein the method further comprises, prior to loading of the GCSF-containing sample, equilibrating the AEX material with an equilibration buffer comprising from about 30 mM to about 50 mM Tris, and at pH of about 7.0 to about 8.0.
The copending claims lack the following: isolating and/or purifying G-CSF from inclusion bodies comprising a) solubilizing the G-CSF contained in the IBs with a solubilization buffer comprising a denaturing agent; and b) initiating folding of the solubilized G-CSF by diluting, via a sequential stepwise dilution process, the solubilizate from (a) with a folding buffer comprising only the reduced form of a thiol redox pair to obtain a folding mixture comprising folded G-CSF, wherein the folding buffer does not comprise any oxidizing agent (relevant to instant claim 44); preparing biologically active G-CSF, and wherein the folding mixture in comprises folded G-CSF with a purity of greater than 80%, (relevant to instant claim 45), and greater than 85% (relevant to instant claim 46); recovering folded G-CSF (relevant to instant claim 47); IBs containing G-CSF that are suspended in a suspension buffer prior to solubilization (relevant to instant claim 48); ionic detergent in the solubilizing buffer that is sarkosyl (relevant to instant claims 49-51); wherein the sarkosyl is present in the solubilization buffer in an amount ranging from about 0.2% to about 5.0% by weight (relevant to instant claims 52); a suspension buffer that comprises about 40 mM tris(hydroxymethyl)aminomethane, about 2% sarkosyl and is at a pH of about 8.4 (relevant to instant claims 53 and 54); a volume ratio of the suspension buffer to the solubilization buffer that is adjusted such that the final pH is about 7.5 to about 7.8 (relevant to instant claim 55); gradually reducing the denaturing agent concentration comprising one or more of a list that includes (ii) diluting the solubilizate form (a) with WFI (relevant to instant claims 56); a reduced form of a thiol redox pair selected from a group that includes cysteine (relevant to instant claim 58); a method devoid of a strong denaturing agent, a strong reducing agent, a redox reaction and/or a heavy metal (relevant to instant claim 60); a folding buffer that does not comprise the oxidizing agent cystine or the oxidized form of glutathione (relevant to instant claims 64-65); and folded G-CSF of at least 1x105 IU/mg (relevant to instant claim 66).
However, Fellföldi teaches dissolving inclusion bodies (IB) in solubilization buffer containing 1% w/v N-lauroylsarcosin, also referred to as sarkosyl (e.g. an ionic denaturing agent). See paragraph [0269]. For oxidative refolding, the solubilized IB suspension is diluted 2-fold with water to 0.5% sarkosyl. CuSO4 is added. G-CSF is oxidized and partially refolded. See paragraph [0270]. Rao teaches refolding rhG-CSF in the presence and absence of dithiothreitol, GSH and GSS, CuSO4, and cysteine at different concentrations. See the paragraph spanning the left and right column on page 82 (relevant to instant claims 44, 49-52 and 58). Fellföldi teaches a method for preparing biologically active G-CSF in figure 1 and Fellföldi teaches G-CSF lots with biologically active, correctly folded G-CSF with a purity greater than 80% in table II and IV (relevant to instant claims 45-46). Fellföldi teaches a final correctly folded protein and pure G-CSF. See paragraph [0276] (relevant to instant claim 47). Fellföldi teaches discharging inclusion bodies in a washing buffer to arrive at a concentrated IB suspension. After thawed inclusion bodies (e.g. a suspension) are dissolved it in solubilization buffer. See paragraphs [0268]-[0269] (relevant to instant claim 48). Fellföldi teaches a solubilization buffer comprising 40 mM Tris-HCl, pH 8 and 1% (w/v) sarkosyl. See paragraph [0269] (relevant to instant claims 53-54). Fellföldi teaches diluting the solubilized IB suspension 2-fold with water to 0.5% sarkosyl. See paragraph [0270] (relevant to instant claim 55). Fellföldi teaches diluting a solubilization buffer containing 1% sarkosyl to 0.5% with water. See paragraph [0269]- [0270] (relevant to instant claims 56). Rao teaches testing the biological activity of the rhG-CSF and finding that the activity is 1x108 i.u./mg. See the first paragraph on page 86 (relevant to instant claim 66).
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to apply the anion exchange chromatography (AEX) chromatography technique of the copending claims to the method of Fellföldi, and to further replace the CuSO4 of Fellföldi with the cysteine of Rao in order to purify G-CSF.
Response to Arguments
Applicant requests that the double patenting rejection over co-pending application 17/625,655 be held in abeyance. See the last paragraph on page 9 of the remarks. A request to hold a rejection in abeyance is not a proper response to a rejection. Rather, a request to hold a matter in abeyance may only be made in response to an OBJECTION or REQUIREMENTS AS TO FORM (see 37 CFR 1.111(b) and MPEP §714.02). Thus, the double patenting rejection of record has been maintained as no response to these rejections has been filled by applicant at this time.
Conclusion
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/K.C.B./Examiner, Art Unit 1657