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 ACTION
Claims 12-13 and 20 are cancelled.
Claims 1-11, 14-19, and 21-22 are pending and under examination.
Specification
The use of the terms sepharose, superdex, sephacryl, superose, Sephadex, and Sepharose, which are trade names or a marks used in commerce, has been noted in this application. These terms should be accompanied by the generic terminology; furthermore the terms should be capitalized wherever it appears or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
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 1-11, 14-19, and 21-22 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 1 recites in steps (a) and (c) loading a column to capture the toxin and to pass impurities. It is unclear whether the steps of capturing the toxin and passing impurities are part of the claimed method step, i.e. whether the steps (a) and (c) each only requires loading (i.e. feeding) the column. In one interpretation, steps (a) and (c) only require loading the column and binding the toxin to the column and do not require passing impurities. In a second interpretation, the steps require passing impurities (such as by washing the column).
Claim 1 is further indefinite for “a Clostridium botulinum toxin complex protein” because it is unclear whether the claim is directed to purifying a protein component of the complex or a complex comprising proteins.
Claim 2 recite “The method of claim 1, comprising the step of culturing a Clostridium botulinum strain prior to the step (a).” Claim 1 step (a) recites loading on a primary hydrophobic interaction column, a solution including the Clostridium botulinum toxin complex protein isolated from a culture. Claim 2 has multiple reasonable interpretations, rendering the claim indefinite. In one interpretation, the claim requires culturing a Clostridium botulinum strain, isolating the clostridium toxin complex protein from the culture, and then loading the toxin on a primary hydrophobic interaction column. In a second interpretation, the claim requires culturing a Clostridium botulinum strain but does not require that the Clostridium botulinum toxin complex protein is isolated from the same culture.
Claim 4 recites adding an acid to pH 3.0 to pH 4.0. It is unclear whether this is a pH range or alternative pH.
Claim 7 recites the limitation "the column buffer solution" in line 1. There is insufficient antecedent basis for this limitation in the claim.
Claim 8 recites “a concentration gradient is used in the step (b) or (d).” However, claim 8 does not specify how the concentration gradient pertains to the step of isolating the toxin to obtain an eluent including the toxin. Since “use” is not active method step, it is unclear how the concentration gradient limits step (b) or (d).
Claim 10 recites adding ammonium sulfate to the eluent at a final saturation of 30% to 50%. Claim 15 recites adding ammonium sulfate to the eluent at a final saturation of 70% to 90%. Both claims 10 and 15 are indefinite because both claims have multiple reasonable interpretations. In one interpretation, the final saturation is the percentage of ammonium sulfate in a solution added to the eluent. In a second interpretation, the eluent already has ammonium sulfate in it (“the eluent at a final saturation”). In a third interpretation, the ammonium sulfate is added to a final saturation (i.e. the percentage is the final amount of ammonium sulfate in the eluent after the adding ammonium sulfate).
Claim 16 recites the limitation "the hydrophobic interaction column" in line 1. There is insufficient antecedent basis for this limitation in the claim. Claim 16 depends from claim 1, which recites two different hydrophobic interaction columns in steps (a) and (c).
Claim 16 contains the trademark/trade name sepharose. Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph. See Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case, the trademark/trade name is used to identify/describe a cross-linked gel matrix derived from seaweed and, accordingly, the identification/description is indefinite.
Claim 18 contains the trademarks/trade names superdex, sephacryl, superose, Sephadex, and Sepharose. Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph. See Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case, the trademark/trade name is used to identify/describe specific chemical compositions of column materials (e.g. superdex is used to describe a dextran-agarose composite) and, accordingly, the identification/description is indefinite.
Claim 19 recites the size exclusion chromatography of the step (e) is performed under condition of pH 5 to pH 7. However, size exclusion chromatography necessarily includes steps of loading the column and eluting. It is unclear to which operation the condition of pH 5 to pH 7 applies.
Claims 2-11, 14-19, and 21-22 are rejected for depending from a rejected base claim and not rectifying the source of indefiniteness.
Claim Rejections - 35 USC § 103
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 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 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-7, 11, 14, 16-17, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Luo (US 7,452,697 B2).
Regarding claim 1, Luo teaches a process for purifying a BoNT A complex (Clostridium botulinum toxin complex protein): Luo teaches obtaining a fermentation medium (“culture”) which comprises a biologically active botulinum toxin, precipitating the botulinum toxin, extracting the botulinum toxin, contacting a first chromatography column with the extracted botulinum toxin (“loading on a primary hydrophobic interaction column a solution including the Clostridium botulinum toxin complex protein”), eluting the botulinum toxin from the first chromatography column (“isolating the toxin to obtain an eluent including the toxin”), contacting a second chromatography column with the botulinum toxin-containing eluent from the first chromatography column, and eluting the toxin (Luo claim 1). The first column and the second column are either a hydrophobic interaction chromatography column or an ion exchange column but the first column and the second column are different (Luo claim 1). Luo Fig. 9 on sheet 10 teaches two separate processes to purify BoNT A complex. The first process (Examples 12-15 process) comprises butyl sepharose™ chromatography and the second process (Example 16 process) comprises phenyl sepharose™ chromatography (Luo Fig. 9). Both butyl Sepharose™ and phenyl Sepharose™ chromatography are specific types of hydrophobic interaction chromatography (column 18 lines 33-35; column 52 lines 15-25). Luo teaches that the phenyl Sepharose™ column in particular offers high resolution separation, high physical and chemical stability, and very high reproducibility (column 52, lines 20-24). Luo teaches that the butyl Sepharose™ column has high binding capacity, allows fast flow rates with low back pressure, and is suitable for a capturing step that requires fast removal of impurities (column 37, lines 4-9). Luo teaches that the butyl Sepharose™ column is useful in reducing process volume (lines 5-6 of column 57). Additionally, Luo teaches that the butyl column removes a lot of impurities (lines 60 on column 50).
Luo teaches loading the butyl Sepharose™ column with the toxin (line 11 on column 39) and eluting the toxin bound to the column (line 49 on column 39). Luo teaches loading the phenyl Sepharose™ column with the toxin (lines 22-23 on column 55) and eluting the toxin from the column (line 26 on column 55).
Luo also teaches analyzing the product purity by SEC-HPLC (line 55 on page 45).
Luo does not exemplify a botulinum toxin purification process in which the first column chromatography step is hydrophobic interaction chromatography, the second chromatography step is also hydrophobic interaction chromatography, and the product is analyzed by SEC-HPLC (size exclusion high performance liquid chromatography).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add a butyl Sepharose™ hydrophobic interaction chromatography step (includes loading the column and subsequently eluting the toxin from the column) before the step of phenyl Sepharose™ HP chromatography in the process of Example 16 of Fig. 9 in order to further reduce the process volume and purify the toxin prior to the subsequent chromatography steps. The person of ordinary skill in the art would have had a reasonable expectation of success in adding butyl Sepharose™ hydrophobic interaction chromatography to the process of Example 16 of Fig. 9.
It would have been further obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to analyze the eluent of the phenyl column (“secondary hydrophobic interaction column”) by SEC-HPLC (size exclusion chromatography-high performance liquid chromatography), as suggested by Luo. The person of ordinary skill in the art would have had a reasonable expectation of success in analyzing the phenyl column eluent by SEC-HPLC.
Regarding claim 2, Luo teaches fermenting Clostridium botulinum bacterium so that the bacterium releases botulinum toxin into the medium (column 15, lines 1-6). Fig. 9 on sheet 10 illustrates the culture supernatant is the input to the process, so the step of culturing occurs before the first chromatography step.
Regarding claims 3-4, Luo teaches harvesting the toxin from clarified culture by acid precipitation to pH 3.5 (lines 22-24 of column 30). pH 3.5 is within the claimed range of pH 3.0 to pH 4.0. The acid precipitation occurs before the chromatography steps (Fig. 9 on sheet 10, Example 16 process).
Regarding claim 5, Luo teaches filtering (sheet 10, Fig. 9, see UF/DF) but Luo does not teach filtering the acid-precipitated solution.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add a step of filtering the acid-precipitated solution to the process of Example 16 of Fig. 9 in order to improve the purity of the toxin before the subsequent chromatography steps. The person of ordinary skill in the art would have had a reasonable expectation of success in filtering the acid-precipitated solution.
Regarding claim 6, Luo teaches an acceptable feed pH to the butyl column is between pH 5 and 6 (column 39 lines 22-24). Luo teaches feed at 4M NaCl increases the binding of botulinum toxin complex to the butyl column (lines 16-18 of column 39). Furthermore, Luo teaches that the conductivity is monitored during the chromatography step (lines 31-32 of column 44) and Luo optimizes the concentration of NaCl to remove the most impurities (lines 17-25 of column 44).
Luo does not teach that the conductivity is 170 mS/cm to 220 mS/cm during the butyl Sepharose™ hydrophobic interaction chromatography step (“primary hydrophobic interaction column”).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize by routine experimentation the amount of conductivity during the butyl Sepharose™ hydrophobic interaction chromatography step in order to maximize the purity of toxin recovered from the butyl column. The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of the conductivity.
Regarding claim 7, Luo teaches that the phenyl column is washed with 50 mM Pi (inorganic phosphate), pH 6.0 (lines 23-24 of column 55), which is a phosphate buffer solution.
Regarding claim 11, Luo teaches that the phenyl column is washed with 2M NaCl, 50 mM Pi, pH 6.0, followed with 1.0 M NaCl, 50 mM Pi, pH 6.0 (lines 23-26 on column 55). pH 6.0 is within the claimed range of 4 to 8.
Luo does not teach that the conductivity of the phenyl column hydrophobic interaction chromatography step (“secondary hydrophobic interaction column”) is performed under conditions of conductivity of 130 mS/crn to 170 mS/crn.
Luo teaches an acceptable feed pH to the butyl column is between pH 5 and 6 (column 39 lines 22-24). Luo teaches feed at 4M NaCl increases the binding of botulinum toxin complex to the butyl column (lines 16-18 of column 39). Furthermore, Luo teaches that the conductivity is monitored during chromatography (31-32 of column 44) and Luo optimizes the concentration of NaCl to remove the most impurities in the butyl column chromatography step (lines 17-25 of column 44).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize by routine experimentation the conductivity of the phenyl column hydrophobic interaction chromatography loading step. The person of ordinary skill in the art would have been motivated by the teachings of Luo regarding the buffer composition in the butyl column chromatography step (also a form of hydrophobic interaction chromatography). The person of ordinary skill in the art would have had a reasonable expectation of success in optimizing the conductivity of the phenyl column hydrophobic interaction chromatography loading step.
Regarding claim 14, Luo teaches ammonium sulfate precipitation as the final step in the process of Examples 12-15 and 16 processes (Fig. 9 on sheet 10).
Luo does not explicitly teach that the step of acid precipitation comprising adding ammonium sulfate to the secondary hydrophobic interaction chromatography eluent occurs before the SEC-HPLC step.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to isolate the botulinum toxin complex by ammonium sulfate precipitation before characterizing the complex by SEC-HPLC. The person of ordinary skill in the art would have been motivated to remove any remaining impurities residual in the eluent before quantifying the purity of the toxin complex. The person of ordinary skill in the art would have had a reasonable expectation of success in doing so.
Regarding claim 16, Luo teaches both butyl Sepharose™ and phenyl Sepharose™ columns (see Examples 12-15 process and Example 16 process of Fig. 9 on sheet 10).
Regarding claim 17, Luo teaches that the product purified by SEC-HPLC is a botulinum toxin complex with a molecular weight of 900 kDa (Table 1-2 of column 21), which is within the claimed range of 250 kDa-1400 kDa.
Regarding claim 21, Luo also teaches that the purity attained by the Example 16 process comprising a phenyl column hydrophobic interaction chromatography step results in high purity (line 45 of column 57) with the characteristics set forth in Table 1 (lines 54-55 of column 57). Table 1-2 of Luo indicates that the purity of botulinum toxin complex by SEC-HPLC should be greater than 95%. Thus, the person of ordinary skill in the art would have had a reasonable expectation of success in the modified process of Luo comprising both butyl and phenyl hydrophobic interaction columns achieving a purity approaching 98% or more.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Luo (US 7,452,697 B2) in view of JP 5951490 B2.
See discussion of Luo above, which is incorporated into this rejection as well.
Regarding claim 8, Luo teaches eluting the toxin from the phenyl column with a single buffer composition (column 55, lines 25-26). However, Luo teaches optimizing the elution of botulinum toxin from the butyl column with varying concentrations of NaCl in order to maximize toxin recovery and impurity removal (lines 50-52 of column 39).
Luo does not teach that the toxin is eluted from the phenyl column (“secondary hydrophobic interaction column”) with a concentration gradient.
JP 5951490 B2 teaches loading a phenyl Sepharose™ hydrophobic interaction column with botulinum toxin and eluting from the column with a downward gradient of ammonium sulfate ([0074] and [0076]).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to replace the single buffer of Luo with the ammonium sulfate concentration gradient of JP 5951490 B2 in the elution of the botulinum toxin from the phenyl column (“secondary hydrophobic interaction column”). The person of ordinary skill in the art would have been motivated to maximize recovery of botulinum toxin while minimizing impurities. The person of ordinary skill in the art would have had a reasonable expectation of success given that JP 5951490 B2 teaches the same column and the same protein (botulinum toxin).
Claims 9-10 and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Luo (US 7,452,697 B2) in view of Wingfield (Protein precipitation using ammonium sulfate. Curr Protoc Protein Sci. 2001 May;Appendix 3:Appendix 3F).
See discussion of Luo above, which is incorporated into this rejection as well.
Regarding claims 9-10 and 14-15, Luo teaches ammonium sulfate precipitation as the final step in the process of Examples 12-15 and 16 processes (Fig. 9 on sheet 10). Luo teaches adding 3.5 M ammonium sulfate to filtered toxin solution until the first appearance of opalescence (lines 20-23 of column 47). Luo also teaches adding 3.5 M ammonium sulfate to a final concentration of 1.2 M (column 56, line 8). 1.2 M ammonium sulfate is approximately 30% saturation at 0°C as evidenced by Wingfield (page 3, Basic definitions—Percentage (%) saturation, paragraph 1).
Regarding claim 9, Luo does not teach an acid precipitation step comprising adding ammonium sulfate to the eluent of the primary hydrophobic interaction column.
Wingfield teaches performing ammonium sulfate precipitation prior to applying the resulting concentrated protein to a hydrophobic interaction matrix (page 2, Common Application, Concentration of Proteins).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add an additional step of ammonium sulfate precipitation before the butyl column (“primary hydrophobic interaction column”) in order to further concentrate the botulinum toxin prior to the chromatography step. The person of ordinary skill in the art would have had a reasonable expectation of success in precipitating the toxin complex by adding ammonium sulfate to precipitate the botulinum toxin complex.
Regarding claim 14, Luo does not explicitly teach that the step of acid precipitation comprising adding ammonium sulfate to the secondary hydrophobic interaction chromatography eluent occurs before the SEC-HPLC step or that ammonium sulfate is added at a final saturation of 70% to 90%.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to isolate the botulinum toxin complex by ammonium sulfate precipitation before characterizing the complex by SEC-HPLC. The person of ordinary skill in the art would have been motivated to remove any remaining impurities residual in the eluent before quantifying the purity of the toxin complex.
Regarding claims 10 and 15, Wingfield teaches that ammonium sulfate precipitation is commonly used for both protein concentration and selective purification (bottom 2 paragraphs on page 2). Wingfield teaches that larger molecular weight proteins can be salted out with less than 20% saturation, whereas smaller molecular weight proteins can be salted out with 50-77% saturation (paragraph bridging pages 2-3).
It would have been further obvious to optimize by routine experimentation the amount of ammonium sulfate added to induce precipitation in both steps of ammonium sulfate precipitation (before the phenyl column chromatography step and before the SEC-HPLC step). The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of the amount of ammonium sulfate based upon the teaching of Luo, who suggests adding ammonium sulfate until the “first appearance of opalescence” and also exemplifies a specific value of 1.2 M (corresponding to approximately 30% saturation), as well as the teaching of Wingfield, who suggests that ammonium sulfate precipitation is a technique commonly used for both concentration of proteins and selective protein purification and that the optimal concentration of ammonium sulfate depends on the size of the protein.
Claims 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Luo (US 7,452,697 B2) in view of Gessler et al. (FEMS Immunology and Medical Microbiology 24 (1999) 361^367).
See discussion of Luo above, which is incorporated into this rejection as well.
Regarding claim 18, Luo does not teach the specific column used in SEC-HPLC.
Regarding claim 19, Luo does not teach that the pH of the size exclusion chromatography step is pH 5 to pH 7.
Gessler teaches a process for the purification of botulinum toxin comprising both hydrophobic interaction chromatography and size exclusion chromatography using a Superdex™ column (Fig. 1). The pH of the Superdex™ column is 8.0 (page 365, left column, top paragraph).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the pH and column of Gessler to the step of SEC-HPLC in the modified method of Luo. The person of ordinary skill in the art would have had a reasonable expectation of success given that Luo teaches SEC-HPLC, in which an SEC is coupled to an HPLC, and Gessler exemplifies an SEC column (Superdex™) and the conditions for operating it (pH 8.0).
pH 8.0 is above the claimed range of 5 to 7.
It would have been further obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize by routine experimentation the pH of the SEC-HPLC column. The person of ordinary skill in the art would have had a reasonable expectation of success in optimizing the pH of the SEC-HPLC column using Gessler’s pH 8.0 as a starting point.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Luo as evidenced by Chen et al. (Infection and immunity 66.6 (1998): 2420-2425).
See discussion of Luo above, which is incorporated into this rejection as well.
Regarding claim 22, Luo teaches that the botulinum toxin complex comprises a botulinum toxin molecule, one or more non-toxic hemagglutinin proteins and/or non-toxin non-hemagglutinin proteins or NTNH (column 4, lines 3-7). Luo’s 900 kDa botulinum toxin complex (Fig. 9 on sheet 10) necessarily includes hemagglutinin and NTNH as evidenced by Chen (see Abstract and page 2420, Introduction, right column, paragraph 2 on page 1: the 900 kDa complex comprises non-toxic and toxic components and the non-toxic component comprises both agglutinating and non- agglutinating components).
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 1-11, 14, 16-17, and 21 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 and 11-14 of copending Application No. 18/576,556 (hereafter ‘556) in view of Luo (US 7,452,697 B2).
Claim 1 of ‘556 is drawn to a method of purifying a non-complex Clostridium botulinum neurotoxin protein comprising the steps of loading a hydrophobic interaction column, isolating the toxin to obtain an eluent including the toxin, obtaining the non-complex neurotoxin protein from the toxin protein, loading an anion exchange resin column, and isolating the non-complex neurotoxin protein.
Claim 1 of ‘556 is drawn to purifying a non-complex Clostridium botulinum neurotoxin protein rather than a Clostridium botulinum toxin complex protein.
Claim 14 of ‘556 requires that step (c) of claim 1 of ‘556 is dissociating the Clostridium botulinum toxin protein into a non-toxic protein and a pure neurotoxin protein.
Luo teaches that botulinum toxin complex is more stable than the toxin molecule by itself (column 4, lines 8-13). Luo teaches that the Fig. 7 process for the purification of botulinum toxin complex protein can be used to obtain pure 150 kDa botulinum toxin free of non-toxin complex proteins by loading the SP column eluent onto an ion exchange column in pH 8 buffer to dissociate the non-toxin complex proteins from the 150 kDa botulinum toxin molecule, thereby providing in the flow through from the column a botulinum toxin type A neurotoxic component (column 48, lines 21-28). Luo teaches that the process can be used to obtain non toxin components of botulinum toxin such as non- toxin hemagglutinin proteins and/or non-toxin non-hemagglutinin proteins by dissociating the complex into its components (lines 30-34 of column 48).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to eliminate the steps (c)-(e) of the method of claim 1 of ‘556 in order to isolate the entire Clostridium botulinum toxin complex protein rather than only the non-complex Clostridium botulinum toxin protein. The person of ordinary skill in the art would have been motivated by the teaching of Luo that the non-toxin components of the complex confer stability to the toxin and thus would have been beneficial for storing the toxin molecule.
Claim 1 of ‘556 does not recite loading a secondary hydrophobic interaction column with the eluent from the hydrophobic interaction column, isolating the toxin to obtain another eluent including the toxin, or performing size exclusion chromatography using the eluent from the secondary hydrophobic interaction column.
Luo teaches a process for purifying BoNT A complex protein (Clostridium botulinum toxin complex protein): Luo teaches obtaining a fermentation medium (“culture”) which comprises a biologically active botulinum toxin, precipitating the botulinum toxin, extracting the botulinum toxin, contacting a first chromatography column with the extracted botulinum toxin (“loading on a primary hydrophobic interaction column a solution including the Clostridium botulinum toxin complex protein”), eluting the botulinum toxin from the first chromatography column (“isolating the toxin to obtain an eluent including the toxin”), contacting a second chromatography column with the botulinum toxin-containing eluent from the first chromatography column, and eluting the toxin (Luo claim 1). The first column and the second column are either a hydrophobic interaction chromatography column or an ion exchange column but the first column and the second column are different (Luo claim 1). Luo Fig. 9 on sheet 10 teaches two separate processes to purify BoNT A complex. The first process (Examples 12-15 process) comprises butyl sepharose™ chromatography and the second process (Example 16 process) comprises phenyl sepharose™ chromatography (Luo Fig. 9). Both butyl Sepharose™ and phenyl Sepharose™ chromatography are specific types of hydrophobic interaction chromatography (column 18 lines 33-35; column 52 lines 15-25). Luo teaches that the phenyl Sepharose™ column in particular offers high resolution separation, high physical and chemical stability, and very high reproducibility (column 52 lines 20-24). Luo teaches that the butyl Sepharose™ column has high binding capacity, allows fast flow rates with low back pressure, and is suitable for a capturing step that requires fast removal of impurities (column 37, lines 4-9). Luo teaches that the butyl Sepharose™ column is useful in reducing process volume (lines 5-6 of column 57). Additionally, Luo teaches that the butyl column removes a lot of impurities (lines 60 on column 50).
Luo teaches loading the butyl Sepharose™ column with the toxin (line 11 on column 39) and eluting the toxin bound to the column (line 49 on column 39). Luo teaches loading the phenyl Sepharose™ column with the toxin (lines 22-23 on column 55) and eluting the toxin from the column (line 26 on column 55).
Luo also teaches analyzing the product purity by SEC-HPLC (line 55 on page 45).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add the phenyl Sepharose™ hydrophobic interaction chromatography step (includes loading the column and subsequently eluting the toxin from the column) of the Example 16 process after the hydrophobic interaction chromatography steps (a) and (b) of the method of claim 1 of ‘556. The person of ordinary skill in the art would have been motivated to further improve the product purity by including the phenyl Sepharose™ column because Luo teaches that the phenyl Sepharose™ column in particular offers high resolution separation. The person of ordinary skill in the art would have had a reasonable expectation of success in the addition of a phenyl Sepharose™ hydrophobic interaction chromatography step to the method of claim 1 of ‘556.
It would have been further obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to analyze the phenyl column eluent (“secondary hydrophobic interaction column” eluent) by SEC-HPLC (size exclusion chromatography-high performance liquid chromatography), as suggested by Luo. The person of ordinary skill in the art would have had a reasonable expectation of success in analyzing the phenyl column eluent by SEC-HPLC.
Instant claim 2 is obvious over claim 3 of ‘556 in view of Luo.
Instant claim 3 is obvious of claim 4 of ‘556 in view of Luo.
Instant claim 4 is obvious over claim 5 of ‘556 in view of Luo.
Instant claim 5 is obvious over claim 6 of ‘556 in view of Luo.
Instant claim 6 is obvious over claim 8 of ‘556 in view of Luo.
Instant claim 7 is obvious over claim 9 of ‘556 in view of Luo.
Instant claim 8 is obvious over claim 11 of ‘556 in view of Luo.
Instant claim 9 is obvious over claim 12 of ‘556 in view of Luo.
Instant claim 10 is obvious over claim 13 of ‘556 in view of Luo.
Regarding instant claim 11, claim 1 of ‘556 does not recite a second hydrophobic interaction chromatography step performed under conditions of pH 4 to pH 8 and a conductivity of 130 mS/cm to 170 mS/cm.
Luo teaches that the phenyl column is washed with 2M NaCl, 50 mM Pi, pH 6.0, followed with 1.0 M NaCl, 50 mM Pi, pH 6.0 (lines 23-26 on column 55). pH 6.0 is within the claimed range of 4 to 8.
Luo does not teach that the conductivity of the phenyl column hydrophobic interaction chromatography step (“secondary hydrophobic interaction column”) is performed under conditions of conductivity of 130 mS/crn to 170 mS/crn.
Luo teaches an acceptable feed pH to the butyl column is between pH 5 and 6 (column 39 lines 22-24). Luo teaches feed at 4M NaCl increases the binding of botulinum toxin complex to the butyl column (lines 16-18 of column 39). Furthermore, Luo teaches that the conductivity is monitored during chromatography (31-32 of column 44) and Luo optimizes the concentration of NaCl to remove the most impurities in the butyl column chromatography step (lines 17-25 of column 44).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize by routine experimentation the conductivity of the phenyl column (“secondary”) hydrophobic interaction chromatography loading step in the method of claim 1 of ‘556 modified by Luo. The person of ordinary skill in the art would have been motivated by the teachings of Luo regarding the buffer composition in the butyl column chromatography step (also a form of hydrophobic interaction chromatography). The person of ordinary skill in the art would have had a reasonable expectation of success in optimizing the conductivity of the phenyl column hydrophobic interaction chromatography loading step.
Regarding instant claim 14, claim 1 of ‘556 does not recite a step of acid precipitation of the eluent of a secondary hydrophobic interaction column.
Luo teaches ammonium sulfate precipitation as the final step in the process of Examples 12-15 and 16 processes (Fig. 9 on sheet 10). Luo teaches adding 3.5 M ammonium sulfate to filtered toxin solution until the first appearance of opalescence (lines 20-23 of column 47).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to isolate the botulinum toxin complex by ammonium sulfate precipitation before characterizing the complex by SEC-HPLC in the method of claim 1 of ‘556 modified by Luo. The person of ordinary skill in the art would have been motivated to remove any remaining impurities residual in the eluent before quantifying the purity of the toxin complex.
Instant claim 16 is obvious over claim 7 of ‘556 in view of Luo.
Instant claim 17 is obvious over claim 1 of ‘556 in view of Luo because eliminating steps (d)-(e) of the method of claim 1 of ‘556 results in the isolation of the botulinum toxin complex protein (900 kDa) rather than the toxin molecule per the teachings of Luo: Luo teaches that ion exchange chromatography at pH 8 is necessary to dissociate the non-toxin components of the complex from the toxin component (Luo column 48, lines 21-28 and lines 30-34), whereas processes without this step result in the 900 kDa protein (see Fig. 9 on sheet 10 of Luo).
Regarding instant claim 21, the purity of the botulinum toxin complex protein in the method of claim 1 of ‘556 modified by Luo would have been approaching 98% because Luo teaches that the purity attained by the Example 16 process comprising a phenyl column hydrophobic interaction chromatography step results in high purity (line 45 of column 57) with the characteristics set forth in Table 1 (lines 54-55 of column 57). Table 1-2 of Luo indicates that the purity of botulinum toxin complex by SEC-HPLC should be greater than 95%.
This is a provisional nonstatutory double patenting rejection.
Claim 15 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of copending Application No. 18/576,556 (hereafter ‘556) in view of Luo (US 7,452,697 B2) and Wingfield (Protein precipitation using ammonium sulfate. Curr Protoc Protein Sci. 2001 May;Appendix 3:Appendix 3F).
See discussion of claim 1 of ‘556 and Luo above, which is incorporated into this rejection as well.
Regarding claim 15, claim 1 of ‘556 does not recite adding ammonium sulfate to a final saturation of 70% to 90% to a secondary hydrophobic interaction column chromatography eluent.
Luo teaches ammonium sulfate precipitation a s the final step in the process of Examples 12-15 and 16 processes (Fig. 9 on sheet 10). Luo teaches adding 3.5 M ammonium sulfate to filtered toxin solution until the first appearance of opalescence (lines 20-23 of column 47). Luo also teaches adding 3.5 M ammonium sulfate to a final concentration of 1.2 M (column 56, line 8). 1.2 M ammonium sulfate is approximately 30% saturation at 0°C as evidenced by Wingfield (page 3, Basic definitions—Percentage (%) saturation, paragraph 1).
Wingfield teaches that ammonium sulfate precipitation is commonly used for both protein concentration and selective purification (bottom 2 paragraphs on page 2). Wingfield teaches that larger molecular weight proteins can be salted out with less than 20% saturation, whereas smaller molecular weight proteins can be salted out with 50-77% saturation (paragraph bridging pages 2-3).
It would have been obvious to optimize by routine experimentation the amount of ammonium sulfate added to induce precipitation before the SEC-HPLC step. The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of the amount of ammonium sulfate based upon the teaching of Luo, who suggests adding ammonium sulfate until the “first appearance of opalescence” and also exemplifies a specific value of 1.2 M (corresponding to approximately 30% saturation), as well as the teachings of Wingfield, who suggests that ammonium sulfate precipitation is a technique commonly used for both concentration of proteins and selective protein purification and that the optimal amount of ammonium sulfate depends on the size of the protein.
This is a provisional nonstatutory double patenting rejection.
Claims 18-19 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of copending Application No. 18/576,556 (hereafter ‘556) in view of Luo (US 7,452,697 B2) and Gessler et al. (FEMS Immunology and Medical Microbiology 24 (1999) 361^367).
See discussion of claim 1 of ‘556 and Luo above, which is incorporated into this rejection as well.
Regarding claim 18, claim 1 of ‘556 does not recite a step of SEC and Luo does not teach the specific column used in SEC-HPLC.
Regarding claim 19, claim 1 of ‘556 does not recite and Luo does not teach that the pH of the size exclusion chromatography step is 5 to 7.
Gessler teaches a process for the purification of botulinum toxin comprising both hydrophobic interaction chromatography and size exclusion chromatography using a Superdex™ column (Fig. 1). The pH of the Superdex™ column is 8.0 (page 365, left column, top paragraph).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the pH and column of Gessler to the step of SEC-HPLC in the method of claim 1 of ‘5556 modified by Luo. The person of ordinary skill in the art would have had a reasonable expectation of success given that Luo teaches SEC-HPLC, in which an SEC is coupled to an HPLC, and Gessler exemplifies an SEC column (Superdex™) and the conditions for operating it (pH 8.0).
pH 8.0 is above the claimed range of 5 to 7.
It would have been further obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize by routine experimentation the pH of the SEC-HPLC column. The person of ordinary skill in the art would have had a reasonable expectation of success in optimizing the pH of the SEC-HPLC column using Gessler’s pH 8.0 as a starting point.
This is a provisional nonstatutory double patenting rejection.
Claim 22 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of copending Application No. 18/576,556 (hereafter ‘556) in view of Luo (US 7,452,697 B2) evidenced by Chen et al. (Infection and immunity 66.6 (1998): 2420-2425).
See discussion of claim 1 of ‘556 and Luo above, which is incorporated into this rejection as well.
Regarding instant claim 22, eliminating steps (c)-(e) of the method of claim 1 of ‘556 (discussed above in the rejection of instant claim 1) results in the isolation of the botulinum toxin complex protein (900 kDa) rather than the toxin molecule per the teachings of Luo: Luo teaches that ion exchange chromatography at pH 8 is necessary to dissociate the non-toxin components of the complex from the toxin component (Luo column 48, lines 21-28 and lines 30-34), whereas processes without this step result in the 900 kDa protein complex (see Fig. 9 on sheet 10 of Luo). Luo teaches that the botulinum toxin complex comprises a botulinum toxin molecule, one or more non-toxic hemagglutinin proteins and/or non-toxin non-hemagglutinin proteins or NTNH (column 4, lines 3-7). Luo’s 900 kDa botulinum toxin complex (Fig. 9) necessarily includes hemagglutinin and NTNH as evidenced by Chen (see Abstract and page 2420, Introduction, right column, paragraph 2 on page 1: the 900 kDa complex comprises non-toxic and toxic components and the non-toxic component comprises both agglutinating and non- agglutinating components). Therefore, the botulinum toxin complex protein obtained by performing the method of claim 1 of ‘556 modified by Luo is a complex of botulinum toxin (BoNT), nontoxic nonhemagglutinin (NTNH) and hemagglutinin (HA) proteins.
This is a provisional nonstatutory double patenting rejection.
Conclusion
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/CANDICE LEE SWIFT/Examiner, Art Unit 1657