DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicant’s election without traverse and amendment filed May 11, 2026 is acknowledged. Group I, species (a) NK cell as the cell type, (b) SEQ ID NO: 18 as the fibrin-derived peptide, (c) Fc fragment with mutations G236A, S239D, and I332E, and (d) the Fc fragment is bound to a spacer further coupled to an azide, and the peptide is bound to a spacer further coupled to an alkyne including a cyclooctyne and in particular DBCO is acknowledged. Claims 1-12 have been amended and are under examination.
Specification
The use of the term for example, Thermofisher (page 35) (which is a trade name or a mark used in commerce, has been noted in this application. The term should be accompanied by the generic terminology; furthermore the term 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. Please, review the specification for other trademarks and make the appropriate corrections.
Claim Rejections - 35 USC § 112
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 1-5 and 8-12 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 applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
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, disclosure of drawings, or by disclosure of relevant identifying characteristics, for example, 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 Applicants were in possession of the claimed genus.
The MPEP states that the purpose of the written description requirement is to ensure that the inventor had possession, as of the filing date of the application, of the specific subject matter later claimed. The MPEP lists factors that can be used to determine if sufficient evidence of possession has been furnished in the disclosure of the application. These include “level of skill and knowledge in the art, partial structure, physical and/or chemical properties, functional characteristics alone or coupled with a known or disclosed correlation between structure and function, and the method of making the claimed invention.”
The claims are drawn to an immune cell comprising at least one Fc receptor on its surface, wherein a hybrid molecule is grafted onto the Fc receptor, said hybrid molecule comprising at least one antibody Fc fragment covalently bound to a fibrin-derived peptide having at least one citrullyl residue, a spacer being optionally present between said Fc fragment and said citrullinated peptide.
The claims encompass a genus of immune cells comprising any FC receptor, any hybrid molecule comprising any FC fragment and any fibrin- derived peptide having at least one citrullyl residue grafted on the surface of the immune cell. The encompassed immune cells which have no correlation between their structure and function. Therefore, the specification provides insufficient written description to support the genus encompassed by the claim. Vas-Cath Inc. v. Mahurkar, 19 USPQ2d 1111, makes clear that "applicant must convey with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention. The invention is, for purposes of the 'written description' inquiry, whatever is now claimed." (See page 1117.) The specification does not "clearly allow persons of ordinary skill in the art to recognize that [he or she] invented what is claimed." (See Vas-Cath at page 1116.)
The skilled artisan cannot envision the detailed chemical structure of the encompassed polypeptides, regardless of the complexity or simplicity of the method of isolation. Adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method for isolating it. See Fiers v. Revel, 25 USPQ2d 1601, 1606 (CAFC 1993) and Amgen Inc. V. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016. In Fiddes v. Baird, 30 USPQ2d 1481, 1483, claims directed to mammalian FGF's were found unpatentable due to lack of written description for the broad class. The specification provided only the bovine sequence.
University of California v. Eli Lilly and Co., 43 USPQ2d 1398, 1404. 1405 held that: ...To fulfill the written description requirement, a patent specification must describe an invention and does so in sufficient detail that one skilled in the art can clearly conclude that "the inventor invented the claimed invention." Lockwood v. American Airlines Inc. , 107 F.3d 1565, 1572, 41 USPQ2d 1961, 1966 (1997); In re Gosteli , 872 F.2d 1008, 1012, 10 USPQ2d 1614, 1618 (Fed. Cir. 1989) (" [T]he description must clearly allow persons of ordinary skill in the art to recognize that [the inventor] invented what is claimed."). Thus, an applicant complies with the written description requirement "by describing the invention, with all its claimed limitations, not that which makes it obvious," and by using "such descriptive means as words, structures, figures, diagrams, formulas, etc., that set forth the claimed invention." Lockwood, 107 F.3d at 1572, 41 USPQ2datl966.
The state of the art regarding chimeric molecules and treatment. Luddy et al (“Extending the functional lifespan of natural killer (NK) cells: towards durable cytotoxicity in NK- cell based immunotherapy”, BMJ Oncology 2025; 4) teach contemporary natural killer (NK) cell- based cancer therapies include adoptive transfer of autologous and allogenic NK cells, chimeric antigen receptor- engineered NK (CAR- NK) cell therapy and the use of bispecific or trispecific NK cell engagers. These emerging technologies capitalize on the innate cytotoxicity of NK cells and their ability to recognize malignant cells in an antigen/major histocompatibility complex independent manner, offering reduced risk of graft- versus-host disease and cytokine release syndrome seen in T cell- based therapies. However, clinical efficiency remains limited by poor NK cell persistence in vivo and impaired functionality within the tumor microenvironment. Overcoming these barriers is a critical challenge in the field (page 1). Luddy further teaches that their study directly addresses the challenges of NK cell functionality and persistence, another key issue is inefficient NK cell homing to tumor sites. Current studies using CAR- NK therapy are trying to resolve this problem, including modulation of chemokine receptor expression. It is of great importance to analyze when these sNK cells would be of the greatest benefit. With the limited persistence being a common issue, it would be reasonable to expect that the sNK cells would be a great second strike or adjuvant therapy following first- line therapies to capitalize on tumor sensitivity or to target minimum residual disease (page 2). Li et al (Mechanisms of failure of chimeric antigen receptor, www.co-hematology.com, 2019) teach that the chimeric antigen receptor T (CART)-cell therapy was most recognized by its antitumor ability in relapse/refractory (R/R) hematological cancers to achieve a high complete remission rate. It thus led us into a new era of immunotherapy. Although CART19 cell therapy has achieved striking curative effect in B-cell hematological cancers in recent years, it still shows a high relapse rate. Li et al teach that the four generations of CART cells with different structures of co-stimulatory domain, identical T-cell amplification degree in vitro and CART19 cells infusion dose, heterogeneity of the diseases, as well as the different chemotherapy and lymphodepletion regimen, have been considered as the confounding factors of the research results of CART cell immunotherapy. At present, there are a series of clinical studies on the relapsed B-cell hematological cancers at home and abroad. Patients who relapse after CART cell treatment have been divided into two categories, CD19+ relapse and CD19− relapse, providing clues for the further exploration of the complicated relapse mechanism after CART cell treatment (see the Introduction section).
Carlson et al (Emerging Therapeutics in Rheumatoid Arthritis, Volume 28, article 2 (2026) teach despite the wide variety of current molecular targets, many patients are difficult to treat and fail to respond. Carlson et al’s review aims to highlight recent advances in precision medicine and novel therapeutic targets in RA, which may lead to better disease control or possibly cures in the future (see the Abstract). Carlson et al teach that while rheumatoid arthritis is one of the most common diseases seen in a rheumatology office, there continues to be significant unmet needs. Within the last several years, a plethora of research has identified disease phenotypes and evaluated multiple novel therapeutic targets with mixed results (see the Abstract).
Applicant is reminded that generally, in an unpredictable art, adequate written description of a genus which embraces widely variant species cannot be achieved by disclosing only one species within the genus (Enzo Biochem, Inc. v. Gen- Probe Inc., 323 F.3d 956 (Fed. Cir. 2002); Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004); Regents of the University of California v. Eli Lilly Co., 119 F.3d 1559 (Fed. Cir. 1997)). A patentee must disclose “a representative number of species within the scope of the genus of structural features common to the members of the genus so that one of skill in the art can visualize or recognize the member of the genus” (see Amgen Inc. v. Sanofi, 124 USPQ2d 1354 (Fed. Cir. 2017) at page 1358). An adequate written description must contain enough information about the actual makeup of the claimed products — “a precise definition, such as structure, formula, chemical name, physical properties of other properties, of species falling with the genus sufficient to distinguish the gene from other materials”, which may be present in “functional terminology when the art has established a correlation between structure and function” (Amgen page 1361).
MPEP § 2163.02 states, “[a]n objective standard for determining compliance with the written description requirement is, 'does the description clearly allow person of ordinary skill in the art to recognize that he or she invented what is claimed’”. The courts have decided: the purpose of the "written description" requirement is broader than to merely explain how to "make and use"; the Applicant must convey with reasonable clarity to those skilled in the art, that as of the filing date sought, he or she was in possession of the invention. The invention is for purposes of the “written description” inquiry, whatever is now claimed. See Vas-Cath, Inc v. Mahurkar, 935 F.2d 1555, 1563-64, 19 USPQ2d 1111, 1117 (Federal Circuit, 1991).
Furthermore, the written description provision of 35 USC §112 is severable from its enablement provision; and adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method for isolating it. Fiers v. Revel, 25 USPQ2d 1601, 1606 (CAFC 1993). And Amgen Inc. v. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016. Moreover, an adequate written description of the claimed invention must include sufficient description of at least a representative number of species by actual reduction to practice, reduction to drawings, or by disclosure of relevant, identifying characteristics sufficient to show that Applicant was in possession of the claimed genus. However, factual evidence of an actual reduction to practice has not been disclosed by Applicant in the specification; nor has Applicant shown the invention was “ready for patenting” by disclosure of drawings or structural chemical formulas that show that the invention was complete; nor has the Applicant described distinguishing identifying characteristics sufficient to show that Applicant were in possession of the claimed invention at the time the application was filed.
Therefore for all these reasons, the specification lacks adequate written description, and one of skill in the art cannot reasonably conclude that Applicant had possession of the claimed invention at the time the instant application was filed.
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, 4, 6 and 12 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.
Claims 1 and 12 recite “fibrin-derived”. The metes and bounds of the phrase cannot be ascertained. Clarification/correction is required.
Claim 4 recite “derived from”. The metes and bounds of the phrase cannot be ascertained. Clarification/correction is required.
Claim 6 recite “defined by”. The metes and bounds of the phrase cannot be ascertained. Clarification/correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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.
Claim(s) 1-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over in view of Campbell (US Patent No. 7,618,817 B2 issued November 2009) in view of Sebbag et al (Epitopes of human fibrin recognized by the rheumatoid arthritis-specific autoantibodies to citrullinated proteins, European Journal of Immunology, 2006, 36, 2250-2263) and Tomas et al (“Optimization and Stability of Cell−Polymer Hybrids Obtained by “Clicking” Synthetic Polymers to Metabolically Labeled Cell Surface Glycans”, Biomacromolecules 2019, 20, 2726-2736), Zhang et al (Site-Selective Cysteine-Cyclooctyne Conjugation, Angew Chem Int Ed Engl. 2018 May 28; 57(22): 6459–6463) and further in view of Richards et al (Optimization of antibody binding to FcyRIIa enhances macrophage phagocytosis of tumor cells, Molecular Cancer Therapeutics 2008, 7(8) August, 2517-2527).
Claim 1 is drawn to an immune cell comprising at least one Fc receptor on its surface, wherein a hybrid molecule is grafted onto the Fc receptor, said hybrid molecule comprising at least one antibody Fc fragment covalently bound to a fibrin-derived peptide having at least one citrullyl residue, a spacer being optionally present between said Fc fragment and said citrullinated peptide. Claim 2 is drawn to immune cell according to claim 1, said cell being selected from an NK or macrophage. Claim 3 is drawn to the immune cell according to claim 1, in which the Fc receptor is an Fc gamma receptor, including FcyRIIl.
Claim 4 is drawn to the immune cell according to claim 1, in which said peptide of the hybrid molecule is derived from all or part of the sequence of the a or Q chain of a vertebrate fibrin by substitution of at least one arginyl residue by a citrullyl residue, said vertebrate fibrin being a mammalian, including a human, fibrin.
Claim 5 is drawn to an immune cell according to claim 1 wherein said spacer of the hybrid molecule is a polymer containing one or more repeating units containing the ether group, said spacer being polyethylene glycol of formula PEGn, wherein n represents an integer between 1 and 100.
Claim 6 is drawn to an immune cell according to claim 1 wherein said hybrid molecule peptide comprises at least one citrullyl residue, and is selected from the group consisting of: a) a peptide defined by the sequence XIPAPPPISGGGYX2AX3 (SEQ ID NO: 1) wherein X1, X2, and X3 each represent a citrullyl residue or an arginyl residue, and at least one of the X1 or X2 or X3 residues is a citrullyl residue; b) a peptide defined by the sequence GPX1VVEX2HQSACKDS (SEQ ID NO: 2) wherein X1 and X2 each represent a citrullyl residue or an arginyl residue, and at least one of the XI or X2 residues is a citrullyl residue; c) a peptide defined by the sequence SGIGTLDGFX1HX2HPD (SEQ ID NO: 3) wherein X1 and X2 each represents a citrullyl residue or an arginyl residue, and at least one of the X1 or X2 residues is a citrullyl residue; d) a peptide defined by the sequence VDIDIKIX1SCX2GSCS (SEQ ID NO: 4) wherein X1 and X2 each represent a citrullyl residue or an arginyl residue, and at least one of the X1 or X2 residues is a citrullyl residue; e) a peptide defined by the sequence XIGHAKSX2PVX3GIHTS (SEQ ID NO: 12) wherein X1, X2 and X3 each represent a citrullyl residue or an arginyl residue, and at least one of the X1 or X2 or X3 residues is a citrullyl residue; and f) a peptide comprising at least 5 consecutive amino acids, including at least one citrullyl residue, from one of the peptides a) to e) above. Claim 7 is drawn to the immune cell according to any one of claims 1-5, wherein said peptide of the hybrid molecule is selected from the group consisting of: SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22 and SEQ ID NO: 23.
Claim 8 is drawn the immune cell according to claim 1,in which said Fc fragment of the hybrid molecule is a human Fc fragment, including IgG.
Claim 9 is drawn to the immune cell according to claim 1, wherein said Fc fragment of the hybrid molecule is wild-type or mutated, said mutated Fc fragment comprising at least the following mutations: - L234A and L235A, or - L234A, L235A and P329G, or - G236A, S239D and I332E, or - G236A, S239D, A330L and I332E, or-S239D, H268F, S324T and I332E, the numbering being Indicated in the sequence of a human IgG1 according to the EU index.
Claim 10 is drawn to an immune cell according to claim 1,wherein in said hybrid molecule: - the Fc fragment is coupled to an azide and said peptide is coupled to an alkyne, including DBCO (dibenzocvclooctvne) or - the Fc fragment is coupled to an alkyne, including DBCO, and said peptide is coupled to an azide, or - the Fc fragment is coupled to an azide and said peptide is bound to a spacer, itself coupled to an alkyne, including DBCO, or - the Fc fragment is coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is bound to a spacer, itself coupled to an azide, or - the Fc fragment is bound to a spacer, itself coupled to an azide, and said peptide is coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, or - the Fc fragment is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is coupled to an azide, or - the Fc fragment is bound to a spacer, itself coupled to an azide, and said peptide is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, or - the Fc fragment is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is bound to a spacer, itself coupled to an azide, the covalent bond between said Fc fragment and said peptide, optionally in the presence of one or more spacers, being created between the azide and the alkyne.
Claim 11 (currently amended): A medicinal product comprising the immune cell according to claim 1.
Claim 12 (currently amended) A set of elements comprising: (a) a cell of the innate or adaptive immune system that expresses at least one Fc receptor on its surface, including an NK cell or a macrophage, and (b) a hybrid molecule comprising at least one antibody Fc fragment covalently bound to a fibrin-derived peptide having at least one citrullyl residue, a spacer being optionally present between said Fc fragment and said citrullinated peptide.
Campbell teaches a natural killer cell, NK-92, modified to express an Fc receptor on the surface of the cell. Such as CD16 (FcyRIII-A), or other Fcγ or Fc receptors. Campbell teaches modified NK-92 cell can be further modified to concurrently express an associated accessory signaling protein, such as FcꞓRI-γ. TCR-ζ, or to concurrently express interleukin-2 (IL-2) or other cytokines. Additional methods are disclosed for various assays, assessments, and therapeutic treatments with the modified NK-92 cells (see Abstract). Campbell teaches the invention is directed to NK-92 cells modified to express a Fc receptor on a surface of the cell; the Fc receptor can be an activating Fcγ receptor, CD16 (FcyRIII A), or any member of an Fc receptor class, such as FCYRI (CD64), FCyRII (CD32), FCyRIII, FcRn, FcC. and Fcꞓ. The Fc receptors can be of any binding affinity for their ligands, or fragments of their ligands, including low- and high-binding affinity forms (column 3). Campbell teaches the antibody can be monoclonal (purified or in hybridoma supernates), polyclonal, chimeric (such as one having at least two dissimilar antigen binding domains (wherein one binding domain can be adapted to bind the Fc receptor), or any other form of antibody (column 4). Campbell teaches that another aspect of development in this area is directed toward the creation of chimeric antibodies that incorporate two or more antigen-binding Fall domains having differing specificities. A chimeric “bi-specific antibody’ can, by way of example, incorporate one F binding domain that specifically binds to a cell surface marker that is uniquely or characteristically expressed on the target tumor or infected cells and a second F domain that specifically engages activating receptors such as CD16 on NK or other effector cells (column 32). Campbell teaches the antibodies of the invention can be administered in pharmaceutical compositions (column 30). Additionally, Campbell teaches cells (e.g., modified and unmodified NK-92 cells), polypeptides, and Abs, and derivatives, fragments, analogs and homologs thereof, can be incorporated into pharmaceutical compositions. Such compositions typically comprise the cell, polypeptide, and/or antibody and a pharmaceutically acceptable carrier. A “pharmaceutically acceptable carrier' includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration (Gennaro, 2000). Preferred examples of such carriers or diluents include, but are not limited to water, saline, Ringer's Solutions, dextrose solution, and 5% human serum albumin. Liposomes and non-aqueous vehicles such as fixed oils may also be used. Supplementary active compounds can also be incorporated into the compositions (column 35).
Campbell does not teach the claim limitation “said hybrid molecule comprising at least one antibody Fc fragment covalently bound to a fibrin-derived peptide having at least one citrullyl residue, a spacer being optionally present between said Fc fragment and said citrullinated peptide”.
Sebbag et al teach epitopes recognized by the rheumatoid arthritis (RA)-specific autoantibodies to citrullinated proteins (ACPA) on filaggrin and on the α- and β-chains of fibrin, their synovial target, requires conversion of their arginyl residues into citrullyl residues, but is also affected by their amino-acyl environment. Using competition with five citrullinated filaggrin-derived peptides bearing major ACPA epitopes, we confirmed the close cross-reactivity between filaggrin and citrullinated fibrin (see the Abstract). Sebbag et al teach identifying the sequential epitopes recognized on fibrin by ACPA, 71 citrullinated 15-mer peptides derived from all the sites of the α- and β-chains of fibrin harboring arginyl residues were tested by ELISA using ACPA-positive RA sera exhibiting different reactivity profiles to the five filaggrin peptides and of these identified peptide Sebbag et al disclose the α621–635cit621,627,630 peptide (SEQ ID NO:18)(Discussion section). Sebbag et al teach one autoimmune response today considered as most probably playing an important role in the disease pathophysiology is the generation of disease-specific IgG autoantibodies to deiminated (“citrullinated”) proteins detectable in the serum of patients (anti-citrullinated protein autoantibodies, ACPA).
Campbell and Sebbag et al do not teach the claim limitations of claim 10, “wherein in said hybrid molecule: - the Fc fragment is coupled to an azide and said peptide is coupled to an alkyne, including DBCO (dibenzocvclooctvne) or - the Fc fragment is coupled to an alkyne, including DBCO, and said peptide is coupled to an azide, or - the Fc fragment is coupled to an azide and said peptide is bound to a spacer, itself coupled to an alkyne, including DBCO, or - the Fc fragment is coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is bound to a spacer, itself coupled to an azide, or - the Fc fragment is bound to a spacer, itself coupled to an azide, and said peptide is coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, or - the Fc fragment is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is coupled to an azide, or - the Fc fragment is bound to a spacer, itself coupled to an azide, and said peptide is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, or - the Fc fragment is bound to a spacer, itself coupled to an alkyne, such as a cyclooctyne, and in particular including DBCO, and said peptide is bound to a spacer, itself coupled to an azide, the covalent bond between said Fc fragment and said peptide, optionally in the presence of one or more spacers, being created between the azide and the alkyne”.
Tomas et al teach that re-engineering of mammalian cell surfaces with polymers enables the introduction of functionality including imaging agents, drug cargoes or antibodies for cell-based therapies, without resorting to genetic techniques. Glycan metabolic labeling has been reported as a tool for engineering cell surface glycans with synthetic polymers through the installation of biorthogonal handles, such as azides. Quantitative assessment of this approach and the robustness of the engineered coatings has yet to be explored. Here, we graft poly(hydroxyethyl acrylamide)onto azido-labeled cell surface glycans using strain remote dazide−alkyne “click” cyclo addition and, using a combination of flow cytometry and confocal microscopy, evaluate the various parameters controlling the outcome of this grafting to” process.
Tomas et al teach that additional noncovalent approaches include electrostatic deposition of polycations onto the negatively charged membrane. These approaches dramatically and rapidly reduce cell viability (<1 h), severely damaging the cell membrane even when contact is minimized with the incorporation of polyethylene glycol (PEG) chains. Tomas et al teach that cell membrane proteins remain one of the most exploited sites for antibody conjugation in immunotherapy, especially tyrosine and selenocysteine residues. However, biocompatibility of protein conjugation approaches varies due to mammalian cell sensitivity to cell surface modification. Hawker et al. demonstrated that covalent conjugation of chain transfer agent (CTA) initiators for “grafting-from” approaches to membrane proteins resulted in extensive mechanical stress leading to cell death. Limitations of grafting-from approaches arise due to denaturing of proteins and side-reactions during the polymerization with protein side-chain functional groups. Furthermore, most protein conjugation approaches only last 24–48 h and will nonspecifically bind to any cell type. Existing site-specific amino acid modifications mainly rely on the use of cytotoxic heavy metal catalysts. A successful polymer conjugation approach should be simple, robust, biorthogonal and biocompatible (page 2727). In all cases, homogeneous cell coatings were formed with >95% of the treated cells being covalently modified, superior to nonspecific“ grafting to” approaches. Controllable grafting densities could be achieved through modulation of polymer chain length and/or concentration, with longer polymer shaving lower densities. Cell surface bound polymers were retained or at least 72h, persisting through several mitotic divisions during this period. Furthermore, we postulate that glycan/membrane recycling is slowed by the steric bulk of the polymers, demonstrating robustness and stability even during normal biological processes. This cytocompatible, versatile and simple approach shows potential for re-engineering of cell surfaces with new functionality for future use in cell tracking or cell-based therapies.
Zhang et al teach site-selective protein modification is a powerful approach to precisely manipulate protein structure and function. However, it may be challenging to modify one amino acid sidechain among many others with similar reactivity in a protein. Bioorthogonal reactions with paired functional groups have been developed to solve this selectivity challenge. One such approach (Figure 1a) introduces azides that react with cyclooctyne reagents through strain-promoted azide-alkyne cycloaddition (SPAAC).[ SPAAC has been widely used for selectively labelling cell surface glycans, membrane proteins, and antibodies. Azides are not genetically encoded and therefore need to be introduced into proteins via metabolic glycoengineering[7,8], incorporation of unnatural amino acids[9], or enzyme catalyzed (page 1). Zhang et al teach that In summary, we discovered a cysteine-containing peptide tag (DBCO-tag) that selectively
reacts with aza-dibenzocyclooctyne (DBCO) probe bearing a wide range of cargoes to form a linkage stable to exogenous thiols. This work expanded the idea of promoting otherwise sluggish reactions using short peptide sequences. DBCO-tag enabled site-selective modification of mEGFP and trastuzumab antibody that contain multiple endogenous cysteines, highlighting its potential for selectively labelling other cysteine-containing proteins that are a challenge to modify using traditional alkylation reagents. The reaction rate of DBCO-tag-mediated conjugation is influenced by both the functional group in the DBCO probe and the protein sequence to which the DBCO-tag is fused to. This observation along with the mutagenesis study and salt effect, suggest the local environment at the reaction interface is important for the reactivity of the DBCO-tag. We anticipate this DBCO tag provides a convenient tool for site-selective protein modification as there are many commercially available DBCO-probes (page 5).
The teachings of Campbell, Sebbag et al, Tomas et al and Zhang et al have been described above.
Campbell, Sebbag et al, Tomas et al and Zhang et al do not explicitly teach the claims limitations “wherein said Fc fragment of the hybrid molecule is wild-type or mutated, said mutated Fc fragment comprising at least the following mutations: - L234A and L235A, or - L234A, L235A and P329G, or - G236A, S239D and I332E (elected invention), or - G236A, S239D, A330L and I332E, or-S239D, H268F, S324T and I332E, the numbering being Indicated in the sequence of a human IgG1 according to the EU index”.
However, Richards et al teach that among the most intriguing receptor affinity profiles from this screen were variants with greater affinity for FcγRIIa relative to the inhibitory receptor FcγRIIb. A single mutation, G236A, was identified that fit this target profile. This mutation was combined with I332E and S239D/I332E to generate additional variants I332E/G236A and S239D/I332E/G236A. Variants were constructed in the context of full-length antibodies containing the variable region of a humanized anti-EpCAM antibody expressed in 293T cells, and purified. Richards et al teach that the triple mutant S239D/I332E/G236A dramatically improve the binding by 31-fold. Richards et al teach that the modification of antibodies to optimize FcγR affinities, such as described here and in previous work, has become a promising strategy for improving their therapeutic activity.
It would have been prima facie obvious at the time the invention was made to use the epitopes of human fibrin recognized by the rheumatoid arthritis-specific autoantibodies to citrullinated proteins, particularly the α621–635cit621,627,630 (SEQ ID NO:18) peptide as taught by Sebbag et al in the engineered NK cell of Campbell using the site-selective protein modification of Zhang et al and reengineering techniques of Tomas et al and the high affinity of variants of Richards because Campbell teaches a natural killer cell, NK-92, modified to express an Fc receptor on the surface of the cell to be used for therapeutic treatments, Sebbag et al disclose the α621–635cit621,627,630 peptide and one autoimmune response today considered as most probably playing an important role in the disease pathophysiology is the generation of disease-specific IgG autoantibodies to deiminated (“citrullinated”) proteins detectable in the serum of patients (anti-citrullinated protein autoantibodies, ACPA), Zhang et al teach site-selective protein modification is a powerful approach to precisely manipulate protein structure and function and Richards et al teach high affinity optimized antibodies that bind to FCγRIIa which enhances macrophage phagocytosis (Abstract). One would reasonably conclude that the modified NK cells can be used for therapeutic purposes because Tomas et al that this simple approach shows potential for re-engineering of cell surfaces with new functionality for future use in cell tracking or cell-based therapies.
Applying a known techniques to a known product ready for improvement to yield predictable results is likely to be obvious. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, D.).
Status of Claims
No claims allowed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Vanessa L Ford whose telephone number is (571) 272-0857. The examiner can normally be reached Monday to Friday 9:00 -5:30 EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Yvonne Eyler can be reached at 571.272.1200. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/VANESSA L. FORD/Supervisory Patent Examiner, Art Unit 1674
Prosecution Insights