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
The amendment to the claims filed after non-final office action on January 15, 2026 is acknowledged. Claims 1, 3, 4, were amended, claims 2, 9-16 were canceled, claims 17-18 were newly added and claims 1, 3-8, 17-18 are pending in the instant application.
The was restriction deemed proper and made FINAL in the previous office action. Claims 4-8 are withdrawn as being drawn to a non-elected species/invention. Claims 1, 3, 17-18 are examined on the merits of this office action.
Withdrawn Rejections/Objections
The rejection of claims 1-3 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or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention is withdrawn in view of amendment of claims filed January 15, 2026.
The rejection of Claim(s) 1-3 under 35 U.S.C. 102(a)(1) as being anticipated by Pier (INFECTION AND IMMUNITY, Jan. 2008, p. 437–442) as evidenced by Ichtchenko (US20110206616 A1, cited in Applicant’s IDS) is withdrawn in view of amendment of claims filed January 15, 2026 to require only one substitution in the light chain.
The rejection of claim(s) 1 and 3 under 35 U.S.C. 102(a)(1) as being anticipated by Ichtchenko (US20110206616 A1, cited in Applicant’s IDS) is withdrawn in view of amendment of claims filed January 15, 2026 to require only one substitution in the light chain.
The rejection of claim(s) 1-3 under 35 U.S.C. 103 as being unpatentable over Ichtchenko (US20110206616 A1, cited in Applicant’s IDS) and Pier (INFECTION AND IMMUNITY, Jan. 2008, p. 437–442) is withdrawn in view of amendment of claims filed January 15, 2026.
The rejection of claims 1-3 on the ground of nonstatutory double patenting as being unpatentable over claims 1, 17-18, 23 of U.S. Patent No. 8980284 B2 in view of Pier (INFECTION AND IMMUNITY, Jan. 2008, p. 437–442) is withdrawn in view of amendment of claims filed January 15, 2026. In particular, claim 1 now exclude including an n-terminal cargo attachment peptide sequence to enable attachment of a cargo which is an essential feature of US Patent No. ‘284.
Sequence Compliance
This application fails to comply with the requirements of 37 C.F.R 1.821-1.825 for the reasons set forth on the attached Notice to Comply With Requirements For Patent Applications Containing Nucleotide Sequence And/or Amino Acid Sequence Disclosures. Applicant must comply with the requirements of the sequence rules (37 CFR 1.821-1.825) before the application can be examined under 35 U.S.C 131 and 132. Each sequence disclosed must appear separately in the “Sequence Listing.” Each sequence set forth in the “Sequence Listing” must be assigned a separate sequence identifier. Applicant failed to include sequence identifiers in either Figure 1 or in the description of Figure 1.
Drawings
The drawings are objected to because according to 37 CFR 1.821(b) the sequence information so conveyed must still be included in a "Sequence Listing” and the sequence identifier (“SEQ ID NO:X”) must be used, either in the drawing or in the “Brief Description” of the Drawings. Figure 1 comprises sequences without sequence identifiers. There are no sequence identifiers listed in Figure 1 or the description of Figure 1. 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.
Maintained/Revised Rejections
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, 3, 17-18 remain rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of U.S. Patent No. 11897921 in view of Pier (INFECTION AND IMMUNITY, Jan. 2008, p. 437–442).
Although the claims at issue are not identical, they are not patentably distinct from each other because:
The instant application claims a recombinant Clostridium botulinum neurotoxin comprising: a light chain of a Clostridium botulinum neurotoxin, wherein the light chain comprises only one mutation corresponding to Y366>F of BoNT A, a heavy chain of a Clostridium botulinum neurotoxin BoNT A, wherein the light and heavy chains are linked by a disulfide bond; wherein the recombinant Clostridium botulinum neurotoxin has a 2-20 fold reduced toxicity compared to wild type Clostridium botulinum neurotoxin and wherein the neurotoxin has SNAP25 activity, is non immunogenic and wherein the derivative does not have a cargo attachment peptide sequence at the N-terminus (see claim 1). The instant application further claims “wherein X is PHE” (see claim 2) and wherein the recombinant Clostridium botulinum neurotoxin has a 8 fold reduced toxicity compared to wild type Clostridium botulinum neurotoxin (Claim 3). The instant application claims SEQ ID NO:23 (which is the native light chain sequence of rBoNT A with the substitution Y366F and SEQ ID NO:24 is the native heavy chain.
U.S. Patent No. 11897921 claims a propeptide fusion protein comprising a light chain of clostridium botulinum neurotoxin with a Y366A mutation along with E224A, a heavy chain of the neurotoxin with a disulfide linkage.
U.S. Patent No. 11897921 is silent to specifically teaching rBoNT A with only Y366F.
However, Pier teaches recombinant BoNT/A holotoxoid mutants comprising Y366F (reported as Y365F due to numbering offset) exhibit reduced toxicity (see abstract, pages 437-438). Pier further demonstrates that immunization with BoNT/A^R363A/Y366F protects mice against lethal BoNT/A challenge.
It would have been obvious before the effective filing date of the claimed invention to substitution phenylalanine at residue Y366 in the recombinant BoNT/A disclosed in U.S. Patent No. 11897921, motivated by Pier’s explicit teaching that Y366F effectively attenuates toxicity while retaining structural integrity. The skill artisan would have had a reasonable expectation of success that such substitution would yield a recombinant neurotoxin with reduced toxicity suitable for therapeutic or experimental applications.
Furthermore, because U.S. Patent No. 11897921 teaches Y366 as a modifiable residue, and Pier specifically teaches phenylalanine substitution at Y366 as a known alternative for creating atoxic derivatives, one of ordinary skill in the art would have been motivated to try/evaluate Y366F in the recombinant BoNT/A construct of Ichtchenko as one of the finite number of predictable substitutions at a known active site residue (See MPEP 2143, I(E)).
Regarding the limitation of “wherein the rBoNT A neurotoxin has SNAP-25 substrate cleaving activity and is non immunogenic..” the combination of U.S. Patent No. 11897921 in view of Pier teach the same neurotoxin of the instant claims with the substitution Y366F. The skilled artisan would recognized that the toxin of U.S. Patent No. 11897921 in view of Pier (BoNT/A with a single Y366 mutation) inherently produces a substantial reduction in toxicity, which encompasses a ten fold reduction relative to wild type and would inherently retain the SNAP activity and be non immunogenic. A property necessarily present is inherent even if not explicitly described (MPEP 2112). Furthermore, U.S. Patent No. 11897921 does not require a cargo attachment peptide sequence at the N-terminus.
Regarding claim 17, U.S. Patent No. 11897921 claims a rBoNT A neurotoxin comprising instant SEQ ID NO:23 with a substitution at position Y366 and E224 (see SEQ ID NO:12). However, the combination of U.S. Patent No. 11897921 and Pier render obvious the rBoNT A neurotoxin with only a substitution at Y366 with phenylalanine resulting in a sequence with 100% sequence identity to instant SEQ ID NO:23.
Regarding claim 18, U.S. Patent No. 11897921 claims a rBoNT A neurotoxin comprising instant SEQ ID NO:24(see SEQ ID No:12).
Response to Applicant’s Arguments
Applicant’s state “For at least these reasons including all of the reasons provided above, the rejection of claims 1-3 for obviousness type double patenting over claim 1 of the '921 Patent should be withdrawn.”
Applicants arguments have been fully considered but not found persuasive. Applicant’s arguments presented with respect to the rejection under 35 U.S.C. 103 and incorporated by reference (see below response) against the obviousness type double patenting rejection have been considered but are unpersuasive for substantially the same reasons discussed above.
New Rejections
Claim Rejections - 35 USC § 112, first paragraph
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 3, 17-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
MPEP § 2163 states that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus.
Scope of the claims
Claim 1 is directed to a recombinant Clostridium botulinum serotype A neurotoxin comprising a light chain having a single amino acid substitution in the catalytic domain corresponding to Y366, and further recites that the “neurotoxin derivative” does not possess a cargo attachment peptide sequence and exhibits functional properties including reduced toxicity, SNAP-25 substrate cleaving activity, and non-immunogenicity. The inclusion of the term “neurotoxin derivative” broadens the scope of the claim beyond a neurotoxin containing only a single amino acid substitution at position Y366. The term “derivative”, as used in the claim encompasses structurally modified forms of the neurotoxin beyond the expressly recited substitution, including but not limited to variants having additional modifications, truncations, engineered domains, or other alterations to the native BoNT/A structure, so long as the recited functional properties are met. Thus, the claim is directed to a broad genus of structurally modified BoNT/A derivatives, rather than a narrowly defined single substitution variant.
Therefore, to meet the written description requirement of 35 U.S.C. § 112, first paragraph, the specification must disclose a representative number of species that meet both the structural and functional limitations of the genus or the specification and/or the prior art must identify the structural elements that correlate to the claimed function in a manner that demonstrates to one of ordinary skill in the art that Applicant was in possession of the claimed genus at the time the application was filed.
Actual Reduction to Practice
MPEP § 2163 states that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice. A “representative number of species” means that the species which are adequately described are representative of the entire genus. Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. The specification discloses a limited number of specific embodiments including a double mutant (E224A, Y366A) neurotoxin (Example 1), a single substitution mutant Y366F (Example 3; Cyto-014), representing the only disclosed embodiment corresponding to a single substitution at position Y366 and additional variants involving substitutions at positions other than Y366 (e.g. E224Q). These embodiments are specific, structurally defined constructs and do not represent a broad class of “derivatives”. Rather, they reflect a small number of engineered variants with particular, intentionally selected modifications. Therefore, the instant specification has failed to meet the written description requirement by actual reduction to practice of a representative number of species alone.
Sufficient relevant identifying characteristic
MPEP § 2163 states that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination thereof.
The specification does not provide sufficient identifying characteristics to support the full scope of “neurotoxin derivatives” encompassed by the claim. In particular, the term derivative is not clearly defined in terms of structural boundaries. The specification does not describe what types or extent of modifications (beyond the disclosed substitutions) are included or excluded within the claimed derivatives. There is no description of common structural features that would allow one of ordinary skill in the art to recognize the full class of claimed derivatives. Instead, the disclosure is limited to a small number of specific constructs, without generalization to a broader derivative class.
Physical and/or chemical properties:
The specification does not described any physical or chemical properties common to the full scope of the claimed “neurotoxin derivatives”. The disclosed embodiments exhibit differing structural modifications and functional outcomes, indicating that variations in structure significantly impact the properties of the peptide. The specification does not establish that all derivatives falling within the scope of the claim would share any consistent physical or chemical characteristics.
Functional characteristics when coupled with a known or disclosed correlation between function and structure:
The claims rely on functional characteristics, including reduced toxicity, retention of SNAP-25 cleavage activity, and non-immunogenicity. However, the specification does not provide correlation between the broad class of “neurotoxin derivatives” and these functional properties. The limited examples demonstrate that certain constructs may retain activity while reducing toxicity and some constructs may still elicit an immune response, while others show reduced immunogenicity.
There is no teaching that would allow one of ordinary skill in the art to predict which derivative structures, beyond the specifically disclosed embodiments, would achieve the claimed functional results. The specification instead suggests that modifications are selected based on specific structural considerations, indicating that functionality is not broadly predictable across derivatives.
Method of Making
While the specification provides methods for producing specific recombinant neurotoxin constructs, it does not describe how to make and identify the full scope of claimed “neurotoxin derivatives”. Thus, given the breadth of the claims, lack of structure in general, the lack of guidance in the specification regarding a structure/function correlation, it is not possible for one of ordinary skill in the art to determine what protein encompassed within the claimed genus would have the desired functional property.
Conclusion
The specification does not reasonably convey to one of ordinary skill in the art that the inventors were in possession of the full scope of the claimed invention. In particular, the use of the term “neurotoxin derivative” expands the claim to encompass a broad and undefined class of structurally modified neurotoxins, while the specification discloses only a limited number of specific embodiments. The disclosure fails to provide representative species, common structural features, or a s correlation between structure and function sufficient to support this breadth.
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, 3, 17-18 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 was amended to claim “…and wherein the neurotoxin derivative does not possess…”. There is insufficient antecedent basis for this limitation in the claim. Earlier portions of claim 1 recite “a recombinant clostridium botulinum serotype A (rBoNT A) neurotoxin” comprising a light chain and a heavy chain. The claim does not previously introduce or define a distinct element identified as a “neurotoxin derivative”. It is therefore unclear whether “neurotoxin derivative” refers to the neurotoxin as a whole, only the light chain, only the heavy chain or some other modified form of the neurotoxin not otherwise recited. Because the scope and identify of the recited “neurotoxin derivative” cannot be determined with reasonable certainty, claim 1 is indefinite. Claims 3, 17-18 are also rejected due to their dependence on claim 1 and not clarifying this point of confusion.
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 (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 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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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.
Claim(s)1, 3, 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Ichtchenko (US20160159866 A1), Pier (INFECTION AND IMMUNITY, Jan. 2008, p. 437–442, cited previously) and Chaddock (US20160279208).
Ichtchenko discloses isolated recombinant Clostridium botulinum neurotoxins comprising a heavy chain, a light chain and wherein they are linked via disulfide bond (abstract, see claim 1). More specifically, Ichtchenko teaches a light chain of a Clostridium Botulinum neurotoxin BoNT/A comprising a mutation corresponding to Y366X of BoNT/A (see claim 7, reciting Y366A mutation). This directly corresponds to the claimed substitution of Y366 but with an alanine. Ichtchenko describes “Propeptide fusions described herein have amino acid substitutions in the light chain region that render a mature neurotoxin of the propeptide (i.e., the fusion protein of the present invention discussed supra) atoxic. In one embodiment, the amino acid substitutions include E224>A and Y366>A (of BoNT/A LC), which render the fusion protein atoxic. Corresponding mutations may be made in other BoNT serotypes to likewise render them atoxic” (see paragraph 0160). Ichtchenko teaches “In one embodiment, the nucleic acid molecule encodes one or more of the following mutations in the light chain region of the Clostridial neurotoxin (BoNT/A): E224>A, Y366>A, K438>H, K440>Q, K444>Q, K871>N, Q162>Y, L256>Y, R257>E, L322>E, Q163>E, E263>L, and L323>I” (see paragraph 0183).
Ichtchenko is silent to specifically teaching Y366F and only Y366F but does teach derivatives with one substitution at position Y366 but clearly recognizes Y366 is a modifiable residue in BoNT/A constructs.
However, Pier teaches recombinant BoNT/A holotoxoid mutants comprising Y366F (reported as Y365F due to numbering offset) exhibit reduced toxicity (see abstract, pages 437-438). Pier further demonstrates that immunization with BoNT/A^R363A/Y366F protects mice against lethal BoNT/A challenge.
Chaddock teaches engineered BoNT/A mutant constructs expressly including an E224Q/Y366F mutant (see paragraph 0066, pDB1XTF:”Neurtoxin BoNT/A E224Q Y366F mutant”). Thus, the prior art independently recognized phenylalanine substitution at residue Y366 as a known and workable modification site in BoNT/A. This evidences that skill artisans had already selected Y366F as a suitable substation in engineered BoNT/A proteins.
It would have been obvious before the effective filing date of the claimed invention to substitute phenylalanine at residue Y366 in the recombinant BoNT/A disclosed in Ichtchenko, motivated by Pier’s explicit teaching that Y366F effectively attenuates toxicity while retaining structural integrity. The skill artisan would have had a reasonable expectation of success that such substitution would yield a recombinant neurotoxin with reduced toxicity suitable for therapeutic or experimental applications.
Furthermore, because Ichtchenko teaches Y366 as a modifiable residue, and Pier and Chaddock specifically teaches phenylalanine substitution at Y366 as a known alternative for creating atoxic derivatives, one of ordinary skill in the art would have been motivated to try/evaluate Y366F in the recombinant BoNT/A construct of Ichtchenko as one of the finite number of predictable substitutions at a known active site residue (See MPEP 2143, I(E)).
Regarding the limitation of “wherein the rBoNT A neurotoxin has SNAP-25 substrate cleaving activity and is non immunogenic..” the combination of Ichtchenko in view of Pier and Chaddock teach the same neurotoxin of the instant claims with the substitution Y366F. The skilled artisan would recognized that a Y366 mutation inherently produces a substantial reduction in toxicity (8 fold reduced toxicity), which encompasses a ten fold reduction relative to wild type and would inherently retain some level of SNAP activity. A property necessarily present is inherent even if not explicitly described (MPEP 2112). Furthermore, Ichtchenko teaches that the BoNT A toxin comprising a Y366 substitution does have SNAP25 activity (see Figure 14, for example). Additionally, Ichtchenko does not require a cargo attachment peptide sequence at the N-terminus.
Regarding claim 17, Ichtchenko teaches a rBoNT A neurotoxin comprising instant SEQ ID NO:23 with a substitution at position Y366 and E224 (see SEQ ID NO:12). However, the combination of Ichtchenko, Pier and Chaddock render obvious the rBoNT A neurotoxin with only a substitution at Y366 with phenylalanine resulting in a sequence with 100% sequence identity to instant SEQ ID NO:23.
Regarding claim 18, Ichtchenko teaches a rBoNT A neurotoxin comprising instant SEQ ID NO:24(see SEQ ID Nos:212).
Response to Applicant’s Arguments
*Please note that Applicant’s arguments regarding Ichtchenko (US20110206616) are moot in light of amendment of the claims (to exclude a cargo attachment peptide sequence at the N-terminus) which necessitated a new rejection (see New Rejection above, Ichtchenko US20160159866 A1). However, Applicant’s arguments regarding Pier remain relevant and are addressed below.
Applicant argues “As presently amended, claim 1 recites a light chain of a Clostridium botulinum BoNT A neurotoxin comprising a catalytic domain, wherein the light chain comprises only one amino acid substitution mutation in the catalytic domain corresponding to Y366>F of BoNT A. Pier only discloses properties of a double amino acid substitution mutant R363>A and Y365>F in the light chain catalytic domain of a BoNT A toxoid termed BoNT/ARYM. The properties of the BoNT/ARYM toxoid result from the presence of two mutations. No properties of a single substitution Y366>F (Y365>F) mutant are taught or suggested in Pier. Pier is concerned with the immunogenic properties and non-toxic effects of the BoNT/ARYM double amino acid substitution mutant. The objective of the double amino acid substitutions in Pier is to disable the catalytic activity of the recombinant BoNT derivative and to make a vaccine, necessitating an immunological response by the double mutant. Regarding physiological activity of the double mutant, Pier teaches that the double mutant failed to cleave human SNAP25 at all of the tested concentrations. Regarding the immunological properties of the double mutant, Pier states, "BoNT/ARYM elicited an immune response against the light-chain and heavy-chain components of the toxin." Pier, Abstract, emphasis added. Pier also states, "[h]ere we report the generation of a genetically engineered holotoxoid that elicits a protective immune response similar to chemically inactivated BoNT." Pier, bottom of right column p. 437. The properties of the single Y366>F mutant as presently claimed are not taught or suggested by Pier and could not have been anticipated based on Pier as evidenced by Ichtchenko. The double mutant of Pier and the single mutant of the Present Application are structurally different compositions. Neither mutation of Pier is present without the context of the second mutation affecting the polypeptide as a whole. Furthermore, the single Y366>F mutation achieves a unique combination of functional properties that are very different from the double mutant of Pier. As shown in Example 3 of the Present Application, Cyto-014 (having the single Y366>F mutation) cleaves SNAP-25 as efficiently as wild type BoNT A in vitro when normalized to LDso units. See Present Application, paras. [0016], [0134], and FIG. 4. Furthermore, when mice receiving two injections of Cyto-014 were evaluated by ELISA for anti-BoNT Al antibodies, there was no increase in immunoreactivity compared to mice receiving two injections of wild type BoNT Al, and no BoNT A neutralizing activity was found. See Present Application, paras. [0142]-[0144] and FIGs. 8A-8D, 9A-9B, 11A-11B. Cyto-014 has an IP-LDso of 35 pg in 25 g mice, representing only an 8-fold reduction in toxicity compared to wild type BoNT Al. See Present Application, paras. [0017] and [0136]. As discussed above and in stark contrast to the presently claimed invention, Pier's R362>A/Y365>F double mutant completely abolished proteolytic activity toward SNAP-25 at all tested concentrations. See Pier, p. 439, left column. Pier's double mutant was designed as a vaccine candidate to elicit an immune response rather than to avoid one. Furthermore, Pier's double mutant exhibited complete loss of toxicity with all mice surviving challenge at doses up to 1 pg. See Pier, p. 439, left column. These properties are diametrically opposed to the claimed invention's retention of SNAP-25 substrate cleaving activity, non-immunogenic character, and moderate 2-20 fold toxicity reduction.
The PTO acknowledges that Pier describes the double mutant as "nontoxic" but then takes the position that because of this, the limitation of claim 1 that the defined range of the presently claimed recombinant neurotoxin of "2-20 fold reduced toxicity compared to wild type" is allegedly an inherent property of the disclosed Y365>F (Y366>F) substitution. See Office Action, 4. However, the PTO fails to take into account that the double mutant of Pier and the single mutant of the Present Application are structurally and functionally different compositions. The properties of the single Y366>F mutant are not inherent in the double mutant of Pier because both mutations in Pier contribute to all of the properties of the BoNT/ARYM protein. Removing the R362>A substitution structurally and functionally changes the molecule and its properties. And even if one substitution mutation overlaps in the different compositions of Pier and claim 1, as presently amended, the presence of both substitutions materially changes the properties of the protein including conformation, activity, stability, and binding (among other properties) such that any "inherent" property cannot be assumed for the single mutant based on the double mutant. Synergistic effects of the double mutant may cause the protein to have distinctly different properties than each single mutant alone might have. And, as discussed above, the Y366>F mutation of the present application has vastly different properties than the double mutation of Pier. Therefore, the arbitrary determination by the PTO that the Y366>F would inherently have the specific range of a 2-20 fold toxicity reduction is unsupported. Pier teaches away from the invention as presently claimed. Ichtchenko does not test a BoNT neurotoxin with a Y366>F substitution, but, as noted above, the E224>A/Y366>A double mutant of Ichtchenko produces an immunogenic response.
Applicant’s arguments have been fully considered but not found persuasive. The Examiner would like to point out it is the combination of Ichtchenko, Pier and Chaddock that render obvious the instant claims (see new rejection above) and not Pier alone. Ichtchenko was relied upon as the primary reference for teaching recombinant Clostridium botulinum BoNT/A neurotoxins comprising a light chain and a heavy chain linked by a disulfide bond, as well as recombinant BoNT/A constructs in which residue Y366 is identified as a modifiable position. Chaddock teaches engineered BoNT/A mutant constructs expressly including an E224Q/Y366F mutant (see paragraph 0066, pDB1XTF:”Neurtoxin BoNT/A E224Q Y366F mutant”). Thus, the prior art independently recognized phenylalanine substitution at residue Y366 as a known and workable modification site in BoNT/A. This evidences that skill artisans had already selected Y366F as a suitable substation in engineered BoNT/A proteins. Pier was cited for the additional teaching that substitution of residue Y366 with phenylalanine (Y366F) was known in the art and associated with attenuation of toxicity, thereby providing further motivation to employ that specific substitution in the recombinant BoNT/A constructs taught by Ichtchenko. The rejection therefore does not rely on Pier alone as disclosing the entire invention.
Applicant argues that Pier only discloses a double amino acid substitution mutant comprising substitutions comprising substitutions corresponding to R363A and Y366F, and therefore does not teach or suggest that presently claimed recombinant neurotoxin comprising only a single substitution at Y366F. This argument is not persuasive. Pier expressly identifies Y366 as a target substitution with phenylalanine, thereby teaching that residue Y366 was recognized in the art as a suitable site for engineering modification of BoNT/A. A prior art reference need not disclose the identical claimed embodiment to support a conclusion of obviousness. It is sufficient that the reference teaches the desirability of the claimed modification or otherwise provides direction that would have led one of ordinary skill in the art to make the claimed variant. Pier’s disclosure of Y366F therefore remains relevant for the specific substitution recited in the claims, particularly when considered together with Ichtchenko’s and Chaddock’s teachings regarding recombinant BoNT/A constructs and residue modification.
Applicant further argues that Pier’s double mutant abolishes SNAP-25 cleavage activity and therefore would not suggest the presently claimed neurotoxin having SNAP-25 substrate cleaving activity. This argument is unpersuasive. The evidence of record teaches that residue Arg363 of the BoNT/A light chain is critical for binding and hydrolysis of the SNAP-25 substrate (see attached handout, Zuniga et al, 2010). Accordingly, one of ordinary skill in the art would have reasonably understood that any loss of substantial reduction of catalytic activity observed in Pier’s double mutant is attributable primarily to the Arg363 substitution, rather than the Y366F substitution, when employed in the recombinant BoNT/A constructs of Ichtchenko without the Arg363 substitution, would retain useful catalytic activity.
Applicant additionally contends that Pier teaches away because Pier’s construct was designed as a vaccine candidate and elicited an immune response. This argument is not persuasive. Pier does not criticize, discredit or otherwise discourage substitution at residue Y366. At most, Pier reports the properties of a specific double mutant construct designed for a particular purpose. Such disclosure does not constitute teaching away from separately evaluating Y366F in a different recombinant construct lacking the Arg363 substitution. To the contrary, Pier confirms that Y366 was recognized residue for purposeful engineering modification. MPEP 2145 states “the prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004). See also UCB, Inc. v. Actavis Labs, UT, Inc., 65 F.4th 679, 692, 2023 USPQ2d 448 (Fed. Cir. 2023) ("a reference does not teach away if it merely expresses a general preference for an alternative invention but does not criticize, discredit or otherwise discourage investigation into the invention claimed.") (internal quotations omitted) (quoting DePuy Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 1314, 1327 (Fed. Cir. 2009)); and Schwendimann v. Neenah, Inc., 82 F.4th 1371, 1381, 2023 USPQ2d 1173 (Fed. Cir. 2023) ("Although Oez [the prior art] used a white pigment with a cross-linking polymer, it does not discourage a skilled artisan from using the white pigment without a cross-linking polymer or lead the skilled artisan in a direction divergent from the path taken in the Appealed Patents. Thus, Oez's disclosure is substantial evidence that supports the Board's finding that Oez does not teach away from the proposed combination.").”
As set forth in the rejection, one of ordinary skill in the art would have been motivated to apply Pier’s expressly taught Y366F substitution to the recombinant BoNT/A constructs of Ichtchenko and evaluate the resulting properties through routine experimentation, with a reasonable expectation of obtaining a functional neurotoxin variant having reduced toxicity. Ichtchenko teaches the recombinant framework and residue modification at Y366, while Pier teaches the specific phenylalanine substitution at the residue. The combination of these teachings along with Chaddock’s teachings renders the presently claimed subject matter obvious.
Applicant’s arguments regarding alleged unexpected properties of Cyto-014 are also unpersuasive. The pending claims are not limited to the specific Cyto-014 construct or to the precise experimental conditions described in the specification, but instead encompass broader recombinant neurotoxin derivatives. Evidence directed to a single disclosed embodiment is therefore not commensurate in scope with the breadth of the pending claims (see MPEP 716.02(d)). Moreover, the asserted results are compared primarily to Pier’s specific double mutant rather than to the closest prior art recombinant BoNT/A constructs taught by Ichtchenko (see MPEP 716.02 (e)).
Applicant’s asserted results do not appear truly unexpected because the prior art already identified residue Y366 as a target for mutation and taught that modifications at this site could attenuate toxicity. Achieving a balance between reduced toxicity and retained activity would have been a matter of routine optimization.
Applicants further argue that in view of all of the above, it would not have been obvious based on the teachings of the properties of materially different double mutants of the prior art alone or in combination, that a recombinant Clostridium botulinum BoNT A neurotoxin (Cyto-014) with a light chain of BoNT A comprising a catalytic domain, where the light chain comprises only one amino acid substitution mutation in the catalytic domain corresponding to Y366>F of BoNT A, and linked by a disulfide bond to a heavy chain of a BoNT A neurotoxin, would have 2-20 fold reduced toxicity compared to wild-type BoNT A, have SNAP-25 cleaving activity, and be non- immunogenic.
Applicant’s argument that the cited prior art, alone or in combination, would not have rendered obvious a recombinant Clostridium botulinum BoNT/A neurotoxin comprising only a Y366F substitution and possessing the recited combination of reduced toxicity, SNAP-25 cleaving activity, and non-immunogenicity is unpersuasive. The rejection is based on the combined teachings of Ichtchenko, Pier and Chaddock which together teach mutation of residue Y366 in recombinant BoNT/A constructs and specifically identify Y366F as a known substitution associated with attenuated toxicity. The prior art therefore provided reason to modify the known recombinant BoNT/A scaffold at a recognized mutational site with a reasonable expectation of success.
It would have been obvious before the effective filing date of the claimed invention to substitute phenylalanine at residue Y366 in the recombinant BoNT/A disclosed in Ichtchenko, motivated by Pier’s explicit teaching that Y366F effectively attenuates toxicity while retaining structural integrity. The skill artisan would have had a reasonable expectation of success that such substitution would yield a recombinant neurotoxin with reduced toxicity suitable for therapeutic or experimental applications.
Furthermore, because Ichtchenko teaches Y366 as a modifiable residue, and Pier and Chaddock specifically teaches phenylalanine substitution at Y366 as a known alternative for creating atoxic derivatives, one of ordinary skill in the art would have been motivated to try/evaluate Y366F in the recombinant BoNT/A construct of Ichtchenko as one of the finite number of predictable substitutions at a known active site residue (See MPEP 2143, I(E)).
Applicant has not provided persuasive evidence that the alleged properties are truly unexpected relative to the closest prior art, nor that such properties are commensurate in scope with the breadth of the claims.
Conclusion
No claims are allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/ERINNE R DABKOWSKI/Examiner, Art Unit 1654
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