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 .
Claims 1-9, 11 and 15 are pending and being acted upon in this Office Action.
Priority
Receipt is acknowledged of papers submitted under 35 U.S.C. 119(a)-(d), which papers have been placed of record in the file.
Specification
The amendment to the specification filed January 8, 2026 has been entered.
Objection and Rejection Withdrawn
The objection to claims 1-2 is withdrawn in view of the claim amendment.
The rejection of claims 1-9, 11 and 15 on the ground of nonstatutory obviousness-type double patenting as being unpatentable over claims 1-13 of U.S. Patent No. 12,227,594 is withdrawn in view of the terminal disclaimer filed on January 8, 2026.
Claim rejections under - 35 U.S.C. 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 1-9, 11 and 15 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.
The MPEP § 2163 lists factors that can be used to determine if sufficient evidence of possession has been furnished in the disclosure of the Application. These include: the 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. Disclosure of any combination of such identifying characteristics that distinguish the claimed invention from other materials and would lead one of skill in the art to the conclusion that the applicant was in possession of the claimed species is sufficient. See Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406.
For claims drawn to a genus, 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, See Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406, M.P.E.P. § 2163, II, A, 3, (a), (ii).
Claim 1 encompasses any multispecific antibody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) the first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused either directly or via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused either directly or via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is a heavy chain Fab fragment (VH1-CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa, and
the first part of the first binding domain and the second part of the first binding domain are associated with each other and are together the first antigen binding site,
b) the second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and the second part of the third binding domain, wherein
the first part of the second binding domain is fused either directly or via a third peptidic linker to the N-terminus of the second part of the third binding domain,
the second part of the second binding domain is fused either directly or via a fourth peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is a heavy chain Fab fragment (VH2-CH1) or a light chain Fab fragment (VL2-CL1), whereby the second part of the second binding domain is a light chain Fab fragment if the first part of the second binding domain is a heavy chain Fab fragment, or vice versa,
the first part of the second binding domain and the second part of the second binding domain are associated with each other and are together the second antigen binding site,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is either a variable heavy chain-CH3 domain fusion polypeptide (VH3-CH3) or a variable light chain-CH3 domain fusion polypeptide (VL3-CH3),
the second part of the third binding domain is a variable heavy chain-CH3 domain fusion polypeptide if the first part of the second binding domain is a variable light chain-CH3 domain fusion polypeptide, or vice versa,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site,
wherein the two constant heavy chain domains 3 (CH3) are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii),wherein the multispecific antibody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region.
Claim 2 encompasses the multispecific antibody according to claim 1, wherein the first and/or the second and/or the third antigen binding site is independently of each other disulfide stabilized by introduction of cysteine residues at the following positions to form a disulfide bond between the VH and VL domains (numbering according to Kabat): - VH at position 44, and VL at position 100, - VH at position 105, and VL at position 43, or - VH at position 101, and VL at position 100.
Claim 3 encompasses the multispecific antibody according to claim 1, wherein the first, second, third and fourth peptidic linker are peptides of at least 5 amino acids.
Claim 4 encompasses the multispecific antibody according to claim 1, wherein the first and third peptidic linker have the amino acid sequence of SEQ ID NO: 38; and the second and fourth peptidic linker have the amino acid sequence of SEQ ID NO: 16.
Claim 5 encompasses the multispecific antibody according to claim 1, wherein the C-terminus of the VH3 domain is directly connected to the N-terminus of one of the CH3 domains, and the C-terminus of the VL3 domain is directly connected to the N-terminus of the other one of the CH3 domains.
Claim 6 encompasses the multispecific antibody according to claim 1, wherein the antibody is trivalent.
Claim 7 encompasses the multispecific antibody according to claim 1, wherein the antibody is bispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby two of the first, the second and the third antigen are the same antigen and the other is a different antigen); or trispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby the first, the second and the third antigen are different antigens).
Claim 8 encompasses the multispecific antibody according to claim 1, wherein the first part of the first binding domain and the second part of the first binding domain are associated covalently by a disulfide bond with each other, and/or wherein the first part of the second binding domain and the second part of the second binding domain are associated covalently by a disulfide bond with each other.
Claim 9 encompasses the multispecific antibody according to claim l, wherein the third binding site specifically binds to human CD3.
Claim 11 encompasses the multispecific antibody of claim 1, wherein said multispecific antibody is produced by a method comprising the steps of transforming a host cell with expression vectors comprising nucleic acids encoding the multispecific antibody, culturing said host cell under condition that allow synthesis of said multispecific antibody and recovering said multispecific antibody from said host cell culture.
Claim 15 encompasses a composition comprising the multispecific antibody according to claim 1, optionally in combination with at least one pharmaceutically acceptable carrier.
The specification discloses just two TriFab-Contorsbodies that bind to LeY and biotin or LeY and CD3.
The specification exemplifies:
[0493] FIG. 11 m/z spectra of TriFab-Contorsbody LeY/biotin.
[0494] FIG. 12 FACS analysis of LeY/biotin-TriFab-Contorsbody.
[0495] FIG. 13 Scheme of bispecific anti-LeY/CD3 TriFab Contorsbody.
[0496] FIG. 14 Coomassie-stained SDS PAGE gel of anti-LeY/CD3 TriFab Contorsbody
Example 9
TriFab Contorsbody Efficiently Mediates T Cell-Induced Tumor Cell Killing
[0536] To assess the suitability of the TriFab Contorsbody format in T-cell-induced tumor cell killing, as third binding entity an anti-CD3 binding entity was used (FIG. 13). The VH and VL sequences are exemplary sequences of the CD3-binder as described in US 2015/0166661 A1. Any anti-CD3 Fv can be substituted herein. This has simply been chosen as an example. This anti-LeY/CD3 TriFab Contorsbody comprises the polypeptides of SEQ ID NO: 36 and SEQ ID NO: 37.
[0537] Expression and purification (performed as outlined in the Examples above) of the anti-LeY/CD3 TriFab Contorsbody was achieved in a yield of 8 mg/L expression volume. In Coomassie-stained SDS PAGE analysis clear bands are present at expected weight (FIG. 14).
[0538] LeY positive MCF7 cells were seeded out in 96 well plates and incubated overnight, followed by exposure to different concentrations of i) an anti-LeY TriFab as positive control, ii) an anti-LeY/X TriFab with X being not present on MCF7 cells as negative control, and iii) the anti-LeY/CD3 TriFab Contorsbody (see FIG. 15). To assess T cell-mediated killing, PBMCs from whole blood of healthy donors (isolated via Ficoll® Paque Plus purification according to manufacturer's instructions (GE Healthcare) were added in a 5:1 ratio. Cultures were thereafter maintained at 37° C. and 5% CO.sub.2 for 48 hours, followed by assessment of the degree of tumor cell lysis (applying LDH release assays according to manufacturer's instructions (Cytotoxicity Detection Kit (LDH), Roche). It was confirmed that the TriFab Contorsbody induces dose-dependent killing even at low picomolar range. Compared to the positive control anti-LeY/CD3 TriFab (˜120 μM) the TriFab Contorsbody showed significantly lower IC.sub.50 value (˜2.4 μM) (FIG. 16). The first peptide linker comprising DKTHGGGS (SEQ ID NO: 38), and the second linker comprises SEQ ID NO: 16.
Note the multispecific antibody has the following structure:
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However, the specification does not describe the structure, e.g., amino acid sequences of VH1 and VL1 of the first binding domain, the VH2 and VL2 of the second binding domain, and VH3 and VL3 of the third binding domain encompassed by the claimed multispecific antibody. There is no limitation on the structure or function of the antibody, or the antigens to which it binds. The specification does not describe a representative number of species falling with the scope of the genus or structural features common to the members of the genus so the one of skill in the art can visualize or recognize the member of the genus of the actual claimed multispecific antibody.
Even assuming the first, second and third binding domains are Fabs that bind to LeY and CD3 or LeY and Biotin, the description of two species of bispecific antibodies are not representative of the entire genus because the genus is highly variable, comprises different combination of heavy and light chains variable domain comprising six different CDRs that bind to different antigens. One of skill in the art would reasonably conclude that the disclosure does not provide a representative number of species of multispecific antibodies to demonstrate possession of the genus at the time of filing.
It is known in the art that antibodies have a large repertoire of distinct structures and that a huge variety of antibodies can be made to bind to a single epitope.
For example, Lloyd et al. taught that hundreds of functional antibody fragments can be isolated from an antibody library that bind to the same antigen wherein these antibodies have distinct heavy and light chain sequences (Lloyd et al. of record, Protein Engineering, Design & Selection 22:159-168, 2009, PTO 1449; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, Nov 14, 2003; PTO 1449), found that over 1000 antibodies, all different in amino acid sequence, were generated to a single protein; 568 different amino acid sequences identified for the V(H) CDR3 domains of these antibodies (Abstract).
Poosarla et al. (of record, Biotechn. Bioeng., 114(6): 1331-1342, 2017; PTO 892) teach substantial diversity in designed mAbs (sharing less than 75% sequence similarity to all existing natural antibody sequences) that bind to the same 12-mer peptide, binding to different epitopes on the same peptide. Said reference further teaches “most B-cell epitopes... in nature consist of residues from different regions of the sequence and are discontinuous...de novo antibody designs against discontinuous epitopes present additional challenges...". (See entire reference.)
Given that hundreds of unique antibody structures may bind a single antigen, the structure of an antibody cannot be predicted from the structure of the antigen (as held in Amgen), and a single species, or small group of species, cannot define a structure-function relationship so as to be representative of all the antibodies that bind to that antigen (as held in Abbvie).
Given the lack of guidance as to the amino acid sequences of the claimed multispecific antibody, the corresponding nucleic acids encoding such (claim 11), the specification does not teach how to make and use the invention commensurate in scope with the claims.
While the specification discloses screening library to identify binding sites (para. [0346] to [0347]), “Possession may not be shown by merely describing how to obtain possession of members of the claimed genus or how to identify their common structural features.” See University of Rochester, 358 F.3d at 927, 69 USPQ2d at 1895.
A “patentee of a biotechnological invention cannot necessarily claim a genus after only describing a limited number of species because there may be unpredictability in the results obtained from species other than those specifically enumerated.”), see Noelle v. Lederman, 69 USPQ2d 1508 1514 (CAFC 2004), (citing Enzo Biochem II, 323 F. 3d at 965; Regents, 119 F.3d at 1568), MPEP 2163.IIAii
Section 112 states that “[t]he specification shall contain a written description of the invention . . . in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains . . . to make and use the same . . . .” This requirement ensures “that the inventor actually invented the invention claimed.” Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc). To show invention, a patentee must convey in its disclosure that it “had possession of the claimed subject matter as of the filing date.” Id. at 1350. Demonstrating possession “requires a precise definition” of the invention. Id. To provide this “precise definition” for a claim to a genus, a patentee must disclose “a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can ‘visualize or recognize’ the members of the genus.” Id.
When there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. A description of what a material does, rather than of what it is, usually does not suffice. Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406.
In Abbvie v. Centocor (Fed. Cir. 2014), the Court held that a disclosure of many different antibodies (in that case neutralizing antibodies to IL-12 with a particular binding affinity) was not enough to support the genus of all IL-12 neutralizing antibodies because the disclosed antibodies were very closely related to each other in structure and were not representative of the full diversity of the genus. The Court further noted that functionally defined genus claims can be inherently vulnerable to invalidity challenge for lack of written description support especially in technology fields that are highly unpredictable where it is difficult to establish a correlation between structure and function for the whole genus or to predict what would be covered by the functionally claimed genus.
In Amgen v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017), the court explained in Amgen that when an antibody is claimed, 35 U.S.C § 112(a) requires adequate written description of the antibody itself. Citing its decision in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., the court also stressed that the "newly characterized" test could not stand because it contradicted the quid pro quo of the patent system whereby one must describe an invention in order to obtain a patent. Amgen, 872 F.3d at 1378-79, quoting Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1345 (Fed. Cir. 2010).
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).
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.
One cannot describe what one has not conceived. See Fiddles v. Baird, 30 USPQ2d 1481, 1483. In Fiddles v. Baird, 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.
Therefore, only (1) a TriFab contorsbody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) a first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused indirectly via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused indirectly via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is VH1-CH1 and the second part of the first binding domain is VL1-CL1 or the first part of the first binding domain is VL1-CL1 and the second part of the first binding domain is VH1-CH1 and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide,
b) a second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and a first part of a third binding domain, wherein
the first part of the second binding domain is fused indirectly via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the second binding domain is fused indirectly via a second peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is VH2-CH1 and the second part of the first binding domain is VL2-CL1 or the first part of the second binding domain is VL2-CL1 and the second part of the first binding domain is VH2-CH1 and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is a VH3-CH3 and the second part of the third binding domain is VL3-CH3 or the first part of the third binding domain is a VL3-CH3 and the second part of the third binding domain is a VH3-CH3,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site, and
wherein the two CH3 domains are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii), and
wherein the TriFab contorsbody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region,
(2) the TriFab contorsbody wherein the VH and VL domains of the first, second and/or third antigen binding sites is disulfide stabilized by introducing cysteine residues at the following positions numbering according to Kabat: VH at position 44, VL at position 100, VH at position 105, and VL at position 43, or VH at position 101 and VL at position 100,
(3) the TriFab contorsbody wherein the first and third peptide linker have the amino acid sequence of SEQ ID NO: 38 and the second and fourth peptide linker have the amino acid sequence of SEQ ID NO: 16,
(4) the TriFab contorsbody wherein the C-terminus of the VH3 domain is directly connected to the N-terminus of one of the CH3 domains, and the C-terminus of the VL3 domain is directly connected to the N-terminus of the other one of the CH3 domains.
(5) the TriFab contorsbody according to claim 1, wherein the contorsbody is trivalent.
(6) the TriFab contorsbody according to claim 1, wherein the contorsbody is bispecific or trispecific.
(6) the TriFab contorsbody according to claim 1, wherein the third binding site specifically binds to human CD3.
(7) the TriFab contorsbody according to claim 1, wherein the first and second binding site specifically bind to LeY, and
(8) a composition comprising the TriFab contorsbody according to claim 1, in combination with at least one pharmaceutically acceptable carrier,
(9) the TriFab contorsbody according to claim 1, wherein the first circular fusion polypeptide comprises the amino acid sequence of SEQ ID NO: 34, and the second circular fusion polypeptide comprises the amino acid sequence of SEQ ID NO: 35, but not the full breadth of the claims meets the written description provision of 35 U.S.C. § 112, first paragraph.
Applicant is reminded that Vas-Cath makes clear that the written description provision of 35 U.S.C. § 112 is severable from its enablement provision (see page 1115).
Applicants’ arguments filed January 8, 2026 have been fully considered but are not found persuasive.
Applicant observes that the presently pending claims are directed to new bispecific antibody constructs called "Trispecific Contorsbodies" or "Contorsbodies." The Trispecific Contorsbodies are characterized in that they comprise two fusion polypeptides (two "heavy" chains), do not comprise any canonical light chains, and do not comprise any CH2 domains. In the disclosed Trispecific Contorsbodies, all three antigen binding domains are fused in a way that ensures the correct assembly of the three antigen binding domains. And all three antigen binding domains are positioned in a way that every antigen binding domain can bind to their respective targets.
For example, a pair of fusion polypeptides has a structure that can be represented schematically, as shown in Fig. 9 of the application as filed:
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where, proceeding from the amino terminus to the carboxy terminus of the left member of the pair of fusion polypeptides, a first circular fusion polypeptide comprises a first part of a first binding domain (VHa-CH1), a second part of a first binding domain (VLa-Ck (C kappa)), and a first part of a third binding domain (VLb-CH3kn ("knob")). The second circular fusion polypeptide comprises a first part of a second binding domain (VHa-CK1), a second part of a second binding domain (VLa-Ck), and the second part of the third binding domain (VLb-CH3ho ("hole")).
Note that the Trifab Contorsbodies do not need to maintain this specific organization. For example, in the first polypeptide, the VLa-CK domain can be linked to the N-terminus of the VLb-CH3kn domain, and the VHa-CH1 domain can be linked to the C-terminus of the VLb-CH3kn domain. The VLa:VHa pair in the first circular fusion polypeptide and the second circular fusion polypeptide may bind to different epitopes or different antigens. The first circular fusion polypeptide may comprise a CH3ho domain and the second circular fusion polypeptide may comprise a CH3kn domain. See, e.g., Figs. 6 and 7 of the application as filed.
Importantly, the function of the Trifab Contorsbodies, as it relates to proper assembly of the binding domains into the Trifab Contorsbody structure, is not limited by any particular amino acid sequence of the CDRs therein; instead, after proper assembly, the three antigen binding domains sufficiently bind their targets.
Applicant respectfully traverses because the inventors possessed the claimed subject matter because the specification describes the claimed subject matter in sufficient detail that one skilled in the art can reasonably conclude that the inventor possessed the claimed subject matter, which is evidenced here by at least the disclosures of the Examples and the Figures.
The Office Action makes the error of misinterpreting which aspect of the claims to apply the law of written description to. The Office Action cites written description cases involving monoclonal antibodies directed to a specific target, which case held that a specification that described only one or a small number of antibodies to a particular antigen did not provide sufficient written description to claim all antibodies to that antigen. It is important to note, however, that the claims are not directed to "antibodies that bind to antigen X". Instead, the claims are directed to circular bispecific antibodies having a particular domain structure, with domains that interact with each other in a particular way. The particular CDR sequences within the variable domains in the Trifab Contorsbodies do not contribute to assembly of the polypeptide chains of the trifab Contorsbodies into the circular shape shown in, e.g., Figures 6, 7 and 9, which is the defining characteristic of the molecules being claimed. The proper written description inquiry, therefore, is applied to the interaction between the domains, not the antigen- binding portions.
Applicant's specification has described in sufficient detail to demonstrate possession of the full scope of the claimed subject matter by the inventors. Various embodiments of the Trifab Contorsbodies are described at pages 22-28 and 34-44, in Examples 7-9, and in Figures 8 and 9. Examples of the basic organization of the circular Trifab Contorsbodies are depicted in, e.g, Figs. 8 and 9, and comprise CL (C kappa) and CH1 domains; VH and VL domains; and CH3 and CH3 domains, all of which have the following characteristics: (1) VH, VL and CH3 sequences (other than CDR) are well-known; (2) VH, VL and CH3 sequences (other than CDR) are highly conserved; (3) knob-and-hole modifications in CH3 domains are well-known; (4) these domains interact with each other predictably; and (5) persons of skill in the art are very knowledgeable about these domains and how they interact. Specific linkers useful in constructing the Trifab Contorsbodies are provided in the specification at page 21.
Example 9 describes a Trifab Contorsbody that binds LeY and CD3. See Figure 13.
Examples 7-9 demonstrates expression and purification of the molecule, and that the molecule bound to LeY-expressing MCF7 cells. Example 9 demonstrates that the TriFab Contorsbody promoted T cell killing of LeY-expressing MCF7 cells in a dose-dependent manner, even at low picomolar range. The LeY/CD3 Trifab Contorsbody showed a lower IC50 value than a simple TriFab LeY/CD3 positive control molecule.
Additionally, the specification discloses and describes a monospecific dicircular fusion polypeptide (a Contorsbody; a structural basis for the claimed TriFab Contorsbodies) that binds to HER2. The specification at page 29 discloses the HER2-binding sequences (SEQ ID NO: 23)1 of this molecule, and how to purify it. The specification here also shows by two different methods that this dicircular fusion polypeptide bound to HER2. Further, the specification at page 30 explains that this anti-Her2 Contorsbody outperformed Trastuzumab (a bivalent anti-Her2 antibody) in a proliferation assay; in part because the Contorsbody was more compact than Trastuzumab, "recruited receptors on the cell surface and promoted an activation signal", while Trastuzumab kept receptors apart from each other, antagonizing proliferation. The anti-HER2 Contorsbody also bound to the FcRn receptor with higher affinity than Trastuzumab. SEQ ID NO: 23 comprises the entire heavy and light chain amino acid sequences of Trastuzumab.
Thus, the specification describes an example TriFab Contorsbody that binds to a target cell, and promotes killing of the target cell by T cells. Persons of skill in the art are able to, and routinely do, select different CDRs, or variable domains, based on what antigen or antigens they are interested in targeting. A person of skill in the art would expect that this new antibody format
- the TriFab Contorsbody - would work as well with a set of CDRs, or a variable domain, directed to another antigen because the domains comprised within the first circular fusion polypeptide and the second circular fusion polypeptide interact with each other in known, predictable ways, and the CDRs or variable domains, selected by such a person of skill in the art, would work as expected (that is, they would enable the TriFab Contorsbody to bind to the selected antigen.
It is important to bear in mind that it is the novel and nonobvious three-dimensional structure of the claimed TriFab Contorsbodies that is the inventive aspect of the present claims, and not the particular targets to which the Trifab Contorsbodies may be directed. If the Office were to require recitation of CDR sequences for such an invention, a person of ordinary skill in the art could never successfully claim a new antibody format per se, which would violate 35 U.S.C. § 101, which states that "Whoever invents ...any new and useful ... composition of matter, or any new and useful improvement thereof, may obtain a patent therefor". Requiring the present claims to specify CDR sequences would vitiate this mandate for patenting of the overall TriFab Contorsbody structure.
For at least the above reasons, Applicant submits that the present specification provides written description support for the pending claims in satisfaction of 35 U.S.C. § 112(a). Applicant requests withdrawal of this rejection of the claims.
In response, nowhere in any of the rejected claims recite a TriFab Contorsbody having the structure shown in Figure 9 comprising a first circular fusion polypeptide comprises a first part of a first binding domain (VHa-CH1), a second part of a first binding domain (VLa-Ck (C kappa)), and a first part of a third binding domain (VLb-CH3kn ("knob")). The second circular fusion polypeptide comprises a first part of a second binding domain (VHa-CK1), a second part of a second binding domain (VLa-Ck), and the second part of the third binding domain (VLb-CH3ho ("hole")) and proper assembly of the binding domains into the Trifab Contorsbody structure based on the pairing of the binding domains in the first and second circular fusion polypeptides.
Claim 1 encompasses any multispecific antibody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) the first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused either directly or via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused either directly or via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is a heavy chain Fab fragment (VH1-CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa, and
the first part of the first binding domain and the second part of the first binding domain are associated with each other and are together the first antigen binding site,
b) the second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and the second part of the third binding domain, wherein
the first part of the second binding domain is fused either directly or via a third peptidic linker to the N-terminus of the second part of the third binding domain,
the second part of the second binding domain is fused either directly or via a fourth peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is a heavy chain Fab fragment (VH2-CH1) or a light chain Fab fragment (VL2-CL1), whereby the second part of the second binding domain is a light chain Fab fragment if the first part of the second binding domain is a heavy chain Fab fragment, or vice versa,
the first part of the second binding domain and the second part of the second binding domain are associated with each other and are together the second antigen binding site,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is either a variable heavy chain-CH3 domain fusion polypeptide (VH3-CH3) or a variable light chain-CH3 domain fusion polypeptide (VL3-CH3),
the second part of the third binding domain is a variable heavy chain-CH3 domain fusion polypeptide if the first part of the second binding domain is a variable light chain-CH3 domain fusion polypeptide, or vice versa,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site,
wherein the two constant heavy chain domains 3 (CH3) are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii),wherein the multispecific antibody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region.
Claim 1 as written has no resemble to the claimed structure shown in Figure 9. For example, even assuming the first part of the first binding domain is VHa-CH1, the clause “the first part of the first binding domain is fused directly to the N-terminus of a first part of a third binding domain, the second part of the first binding domain is fused directly to the C-terminus of the first part of the third binding domain”.
Figure 9 requires that the first fusion protein comprising VHa-CH1 fused indirectly via a linker DKTHGGGS to a third VLb-CH3 having a knob and the C-terminus of the VLb-CH3 is fused to a VLa-CL via a linker GGGGSGGGGS, see Fig. 9 left, or the first fusion protein comprising VHa-CH1 fused indirectly via a linker DKTHGGGS to a third VHb-CH3 having a hole and the C-terminus of the VHb-CH3 hole is fused indirectly via a linker GGGGSGGGGS to a VLa-CL, see Fig. 9 right.
Further, the third clause “the first part of the first binding domain is a heavy chain Fab fragment (VH1- CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa” is confusing at best because the second part of the first binding domain is not clearly defined. “A light chain Fab fragment” could be “VL” or “CL”.
A proper clause should have been “the first part of the first binding domain is VH1-CH1 and the second part of the first binding domain is VL1-CL1 or the first part of the first binding domain is VL1-CL1 and the second part of the first binding domain is VH1-CH1” and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide.
The same issues applies to b) the second circular fusion polypeptide and c) the first part of the third binding domain and the second part of the third binding domain.
In response to the argument that particular CDR sequences within the variable domains in the Trifab Contorsbodies do not contribute to assembly of the polypeptide chains of the trifab Contorsbodies into the circular shape shown in, e.g., Figures 6, 7 and 9, it is noted that sequences within the variable domains VH and VL comprising the six CDRs in the Trifab Contorsbodies contribute to the binding specificity of the claimed multispecific antibody or bispecific antibody as argued. Further, it is the proper pairing between VLa and VHa to form a binding site that binds to an antigen or epitope of an antigen. Neither the art nor the specification random pairing between VLa and VHb from different antibodies and still maintains binding to the particular antigen.
In response to the argument that the claims are not directed to "antibodies that bind to antigen X”, it is noted that claim 7 encompasses the multispecific antibody according to claim 1, wherein the antibody is bispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby two of the first, the second and the third antigen are the same antigen and the other is a different antigen); or trispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby the first, the second and the third antigen are different antigens).
When a patent claims a genus using functional language to define a desired result, "the specification must demonstrate that the applicant has made a generic invention that achieves the claimed result and do[es] so by showing that the applicant has invented species sufficient to support a claim to the functionally-derived genus" (Id. at 1349). The Federal Circuit has held that “a sufficient description of a genus … requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can "visualize or recognize" the members of the genus" (Id. at 1350, quoting Regents of the University of California v. Eli Lilly & Co., 119 F.3d 1559, 1568-69 (Fed. Cir. 1997)).
Satisfactory disclosure of a “representative number” depends on whether one of skill in the art would recognize that the applicant was in possession of the necessary common attributes or features possessed by the members of the genus in view of the species disclosed. For inventions 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. See, e.g., Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406. Instead, the disclosure must adequately reflect the structural diversity of the claimed genus, either through the disclosure of sufficient species that are “representative of the full variety or scope of the genus,” or by the establishment of “a reasonable structure-function correlation.” Such correlations may be established “by the inventor as described in the specification,” or they may be “known in the art at the time of the filing date.” See AbbVie, 759 F.3d at 1300-01, 111 USPQ2d 1780, 1790-91 (Fed. Cir. 2014) (Claims to all human antibodies that bind IL-12 with a particular koff rate constant were not adequately disclosed by specification describing only a single type of human antibody having a particular type of heavy and light chain, because such disclosure was not representative of other types of the claimed antibodies. For example, the specification failed to disclose other antibodies encompassed by the claimed genus that bound to different epitopes on IL-12, had different types of heavy and light chains, and shared only a 50% sequence similarity in their variable regions with the disclosed antibodies.).
In this case, exemplary trifab Contorsbodies that bind to LeY/CD3 or HER2/CD3 are not representative of the genus of multispecific antibody according to claim 1, wherein the antibody is bispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby two of the first, the second and the third antigen are the same antigen and the other is a different antigen); or trispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby the first, the second and the third antigen are different antigens).
It is known in the art that antibodies have a large repertoire of distinct structures and that a huge variety of antibodies can be made to bind to a single epitope.
For example, Lloyd et al. taught that hundreds of functional antibody fragments can be isolated from an antibody library that bind to the same antigen wherein these antibodies have distinct heavy and light chain sequences (Lloyd et al. of record, Protein Engineering, Design & Selection 22:159-168, 2009, PTO 1449; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, Nov 14, 2003; PTO 1449), found that over 1000 antibodies, all different in amino acid sequence, were generated to a single protein; 568 different amino acid sequences identified for the V(H) CDR3 domains of these antibodies (Abstract).
Poosarla et al. (of record, Biotechn. Bioeng., 114(6): 1331-1342, 2017; PTO 892) teach substantial diversity in designed mAbs (sharing less than 75% sequence similarity to all existing natural antibody sequences) that bind to the same 12-mer peptide, binding to different epitopes on the same peptide. Said reference further teaches “most B-cell epitopes... in nature consist of residues from different regions of the sequence and are discontinuous...de novo antibody designs against discontinuous epitopes present additional challenges...". (See entire reference.)
Given that hundreds of unique antibody structures may bind a single antigen, the structure of an antibody cannot be predicted from the structure of the antigen (as held in Amgen), and a single species, or small group of species, cannot define a structure-function relationship so as to be representative of all the antibodies that bind to that antigen (as held in Abbvie).
Given the structure, e.g., amino acid sequence of the multispecific antibody of claim 1 is not adequately describe, the nucleic acids encoding such (claim 11) for transforming a host cell with expression vectors comprising said nucleic acids for producing said multispecific antibody is not adequately described.
While the specification discloses screening library to identify binding sites (para. [0346] to [0347]), “Possession may not be shown by merely describing how to obtain possession of members of the claimed genus or how to identify their common structural features.” See University of Rochester, 358 F.3d at 927, 69 USPQ2d at 1895.
For all of these reasons, the skilled artisan would not reasonably conclude that the inventor(s), at the time the application was filed, had possession of the full scope of the claimed invention.
As such, the rejection is maintained.
Claims 1-9, 11 and 15 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for (1) a TriFab contorsbody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) a first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused indirectly via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused indirectly via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is VH1-CH1 and the second part of the first binding domain is VL1-CL1 or the first part of the first binding domain is VL1-CL1 and the second part of the first binding domain is VH1-CH1 and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide,
b) a second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and a first part of a third binding domain, wherein
the first part of the second binding domain is fused indirectly via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the second binding domain is fused indirectly via a second peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is VH2-CH1 and the second part of the first binding domain is VL2-CL1 or the first part of the second binding domain is VL2-CL1 and the second part of the first binding domain is VH2-CH1 and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is a VH3-CH3 and the second part of the third binding domain is VL3-CH3 or the first part of the third binding domain is a VL3-CH3 and the second part of the third binding domain is a VH3-CH3,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site, and
wherein the two CH3 domains are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii), and
wherein the multispecific contorsbody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region,
(2) the TriFab contorsbody wherein the VH and VL domains of the first, second and/or third antigen binding sites is disulfide stabilized by introducing cysteine residues at the following positions numbering according to Kabat: VH at position 44, VL at position 100, VH at position 105, and VL at position 43, or VH at position 101 and VL at position 100,
(3) the TriFab contorsbody wherein the first and third peptide linker have the amino acid sequence of SEQ ID NO: 38 and the second and fourth peptide linker have the amino acid sequence of SEQ ID NO: 16,
(4) the TriFab contorsbody wherein the C-terminus of the VH3 domain is directly connected to the N-terminus of one of the CH3 domains, and the C-terminus of the VL3 domain is directly connected to the N-terminus of the other one of the CH3 domains.
(5) the TriFab contorsbody according to claim 1, wherein the contorsbody is trivalent.
(6) the TriFab contorsbody according to claim 1, wherein the contorsbody is bispecific or trispecific.
(6) the TriFab contorsbody according to claim 1, wherein the third binding site specifically binds to human CD3.
(7) the TriFab contorsbody according to claim 1, wherein the first and second binding site specifically bind to LeY, and
(8) a composition comprising the TriFab contorsbody according to claim 1, in combination with at least one pharmaceutically acceptable carrier,
(9) the TriFab contorsbody according to claim 1, wherein the first circular fusion polypeptide comprises the amino acid sequence of SEQ ID NO: 34, and the second circular fusion polypeptide comprises the amino acid sequence of SEQ ID NO: 35, does not reasonably provide enablement for the claimed multispecific antibody as set forth in claims 1-9, 11 and composition thereof as set forth in claim 15. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make/use the invention commensurate in scope with these claims.
Enablement is considered in view of the Wands factors (MPEP 2164.01(a)). These factors include, but are not limited to: (A) The breadth of the claims; (B) The nature of the invention; (C) The state of the prior art; (D) The level of one of ordinary skill; (E) The level of predictability in the art; (F) The amount of direction provided by the inventor; (G) The existence of working examples; and (H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure. . In re Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988).
Claim 1 encompasses any multispecific antibody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) the first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused either directly or via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused either directly or via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is a heavy chain Fab fragment (VH1-CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa, and
the first part of the first binding domain and the second part of the first binding domain are associated with each other and are together the first antigen binding site,
b) the second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and the second part of the third binding domain, wherein
the first part of the second binding domain is fused either directly or via a third peptidic linker to the N-terminus of the second part of the third binding domain,
the second part of the second binding domain is fused either directly or via a fourth peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is a heavy chain Fab fragment (VH2-CH1) or a light chain Fab fragment (VL2-CL1), whereby the second part of the second binding domain is a light chain Fab fragment if the first part of the second binding domain is a heavy chain Fab fragment, or vice versa,
the first part of the second binding domain and the second part of the second binding domain are associated with each other and are together the second antigen binding site,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is either a variable heavy chain-CH3 domain fusion polypeptide (VH3-CH3) or a variable light chain-CH3 domain fusion polypeptide (VL3-CH3),
the second part of the third binding domain is a variable heavy chain-CH3 domain fusion polypeptide if the first part of the second binding domain is a variable light chain-CH3 domain fusion polypeptide, or vice versa,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site,
wherein the two constant heavy chain domains 3 (CH3) are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii),wherein the multispecific antibody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region.
Claim 2 encompasses the multispecific antibody according to claim 1, wherein the first and/or the second and/or the third antigen binding site is independently of each other disulfide stabilized by introduction of cysteine residues at the following positions to form a disulfide bond between the VH and VL domains (numbering according to Kabat): - VH at position 44, and VL at position 100, - VH at position 105, and VL at position 43, or - VH at position 101, and VL at position 100.
Claim 3 encompasses the multispecific antibody according to claim 1, wherein the first, second, third and fourth peptidic linker are peptides of at least 5 amino acids.
Claim 4 encompasses the multispecific antibody according to claim 1, wherein the first and third peptidic linker have the amino acid sequence of SEQ ID NO: 38; and the second and fourth peptidic linker have the amino acid sequence of SEQ ID NO: 16.
Claim 5 encompasses the multispecific antibody according to claim 1, wherein the C-terminus of the VH3 domain is directly connected to the N-terminus of one of the CH3 domains, and the C-terminus of the VL3 domain is directly connected to the N-terminus of the other one of the CH3 domains.
Claim 6 encompasses the multispecific antibody according to claim 1, wherein the antibody is trivalent.
Claim 7 encompasses the multispecific antibody according to claim 1, wherein the antibody is bispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby two of the first, the second and the third antigen are the same antigen and the other is a different antigen); or trispecific (the first binding site binds to a first antigen, the second binding site binds to a second antigen and the third binding site binds to a third antigen, whereby the first, the second and the third antigen are different antigens).
Claim 8 encompasses the multispecific antibody according to claim 1, wherein the first part of the first binding domain and the second part of the first binding domain are associated covalently by a disulfide bond with each other, and/or wherein the first part of the second binding domain and the second part of the second binding domain are associated covalently by a disulfide bond with each other.
Claim 9 encompasses the multispecific antibody according to claim l, wherein the third binding site specifically binds to human CD3.
Claim 11 encompasses the multispecific antibody of claim 1, wherein said multispecific antibody is produced by a method comprising the steps of transforming a host cell with expression vectors comprising nucleic acids encoding the multispecific antibody, culturing said host cell under condition that allow synthesis of said multispecific antibody and recovering said multispecific antibody from said host cell culture.
Claim 15 encompasses a composition comprising the multispecific antibody according to claim 1, optionally in combination with at least one pharmaceutically acceptable carrier.
The specification discloses just two TriFab-Contorsbodies that bind to LeY and biotin or LeY and CD3.
The specification exemplifies:
[0493] FIG. 11 m/z spectra of TriFab-Contorsbody LeY/biotin.
[0494] FIG. 12 FACS analysis of LeY/biotin-TriFab-Contorsbody.
[0495] FIG. 13 Scheme of bispecific anti-LeY/CD3 TriFab Contorsbody.
[0496] FIG. 14 Coomassie-stained SDS PAGE gel of anti-LeY/CD3 TriFab Contorsbody
Example 9
TriFab Contorsbody Efficiently Mediates T Cell-Induced Tumor Cell Killing
[0536] To assess the suitability of the TriFab Contorsbody format in T-cell-induced tumor cell killing, as third binding entity an anti-CD3 binding entity was used (FIG. 13). The VH and VL sequences are exemplary sequences of the CD3-binder as described in US 2015/0166661 A1. Any anti-CD3 Fv can be substituted herein. This has simply been chosen as an example. This anti-LeY/CD3 TriFab Contorsbody comprises the polypeptides of SEQ ID NO: 36 and SEQ ID NO: 37.
[0537] Expression and purification (performed as outlined in the Examples above) of the anti-LeY/CD3 TriFab Contorsbody was achieved in a yield of 8 mg/L expression volume. In Coomassie-stained SDS PAGE analysis clear bands are present at expected weight (FIG. 14).
[0538] LeY positive MCF7 cells were seeded out in 96 well plates and incubated overnight, followed by exposure to different concentrations of i) an anti-LeY TriFab as positive control, ii) an anti-LeY/X TriFab with X being not present on MCF7 cells as negative control, and iii) the anti-LeY/CD3 TriFab Contorsbody (see FIG. 15). To assess T cell-mediated killing, PBMCs from whole blood of healthy donors (isolated via Ficoll® Paque Plus purification according to manufacturer's instructions (GE Healthcare) were added in a 5:1 ratio. Cultures were thereafter maintained at 37° C. and 5% CO.sub.2 for 48 hours, followed by assessment of the degree of tumor cell lysis (applying LDH release assays according to manufacturer's instructions (Cytotoxicity Detection Kit (LDH), Roche). It was confirmed that the TriFab Contorsbody induces dose-dependent killing even at low picomolar range. Compared to the positive control anti-LeY/CD3 TriFab (˜120 μM) the TriFab Contorsbody showed significantly lower IC.sub.50 value (˜2.4 μM) (FIG. 16). The first peptide linker comprising DKTHGGGS (SEQ ID NO: 38), and the second linker comprises SEQ ID NO: 16.
Note the multispecific antibody has the following structure:
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However, enablement is not commensurate in scope with how to make and how to use the claimed multispecific antibody without guidance as to the structure that correlated with binding specificity of the antibody. Notably, the specification does not teach the structure, e.g., amino acid sequences of VH1 and VL1 of the first binding domain, the VH2 and VL2 of the second binding domain, and VH3 and VL3 of the third binding domain encompassed by the claimed multispecific antibody, the corresponding nucleic acid sequence to enable one of skilled in the art to make and use without undue experimentation.
Even assuming the first, second and third binding domains are Fabs that bind to LeY and CD3 or LeY and Biotin, two species of bispecific antibodies are not representative of the entire genus because the genus is highly variable, comprises different combination of heavy and light chains variable domain comprising six different CDRs that bind to different antigens. The specification does not teach the structure common to members of the genus of first, second and third binding domains that bind to LeY and CD3 or LeY and Biotin.
It is known in the art that antibodies have a large repertoire of distinct structures and that a huge variety of antibodies can be made to bind to a single epitope.
For example, Lloyd et al. taught that hundreds of functional antibody fragments can be isolated from an antibody library that bind to the same antigen wherein these antibodies have distinct heavy and light chain sequences (Lloyd et al. Protein Engineering, Design & Selection 22:159-168, 2009, PTO 1449; see, e.g., Discussion).
Similarly, Edwards et al. (J Mol Biol. 334(1): 103-118, Nov 14, 2003; PTO 1449), found that over 1000 antibodies, all different in amino acid sequence, were generated to a single protein; 568 different amino acid sequences identified for the V(H) CDR3 domains of these antibodies (Abstract).
Poosarla et al. (Biotechn. Bioeng., 114(6): 1331-1342, 2017; PTO 892) teach substantial diversity in designed mAbs (sharing less than 75% sequence similarity to all existing natural antibody sequences) that bind to the same 12-mer peptide, binding to different epitopes on the same peptide. Said reference further teaches “most B-cell epitopes... in nature consist of residues from different regions of the sequence and are discontinuous...de novo antibody designs against discontinuous epitopes present additional challenges...". (See entire reference.)
There are no in vivo working examples. It is unpredictable which multispecific antibody is effective for treating which disease given the lack of guidance as to the binding specificity of the claimed multispecific antibody. As such, it would require undue experimentation of one skilled in the art to practice the claimed invention, commensurate in scope with the claims. See page 1338, footnote 7 of Ex parte Aggarwal, 23 USPQ2d 1334 (PTO Bd. Pat App. & Inter. 1992).
The scope of the claims must bear a reasonable correlation with the scope of enablement. See In re Fisher, 166 USPQ 19 24 (CCPA 1970).
In re wands, 858 F.2d at 737, 8 USPQ2d at 1404 (Fed. Cir. 1988), the decision of the court indicates that the more unpredictable the area is, the more specific enablement is necessary.
Applicants’ arguments filed January 8, 2026 have been fully considered but are not found persuasive.
Applicant respectfully traverses because the specification is enabling for the full scope of the claims. Applicant's arguments set forth above in response to the written description rejection apply, mutatis mutandis, to the present enablement rejection.
A person of ordinary skill in the art will be able to construct and use the claimed Trifab Contorsbodies based on the disclosure of the specification. Given the particular pairs of fusion polypeptides described in the specification, a skilled artisan apprised of the present specification's teachings could readily construct other Trifab Contorsbodies that bind any given first and second antigens using the recombinant methods, affinity assays, and functional assays described in the specification, as previously described above. Thus, the specification enables the full scope of Trifab Contorsbodies that specifically bind to a first and second antigen. For the purpose of the format of the Trifab Contorsbodies, the sequence of the binders is immaterial; the requirement of the binders is that they must access and bind their target antigens (a consideration that would be readily understood by one of skill in the art); thus the claimed subject matter is not limited to particular sequences, as one of skill in the art will readily appreciate.
For at least the above reasons, the present application is enabling for the full scope of the presently claimed Trifab Contorsbodies and pharmaceutical compositions thereof. Applicant respectfully requests withdrawal of the rejection.
In response, MPEP 2164 states that:
The enablement requirement refers to the requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph that the specification describe how to make and how to use the invention. The invention that one skilled in the art must be enabled to make and use is that defined by the claim(s) of the particular application or patent.
Enablement is not just how to make the claimed multispecific antibody.
Claim 1 encompasses any multispecific antibody comprising three antigen binding sites and consisting of two circular fusion polypeptides, wherein
a) the first circular fusion polypeptide comprises a first part of a first binding domain, a second part of a first binding domain, and a first part of a third binding domain, wherein
the first part of the first binding domain is fused either directly or via a first peptidic linker to the N-terminus of the first part of the third binding domain,
the second part of the first binding domain is fused either directly or via a second peptidic linker to the C-terminus of the first part of the third binding domain,
the first part of the first binding domain is a heavy chain Fab fragment (VH1-CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa, and
the first part of the first binding domain and the second part of the first binding domain are associated with each other and are together the first antigen binding site,
b) the second circular fusion polypeptide comprises a first part of a second binding domain, a second part of a second binding domain, and the second part of the third binding domain, wherein
the first part of the second binding domain is fused either directly or via a third peptidic linker to the N-terminus of the second part of the third binding domain,
the second part of the second binding domain is fused either directly or via a fourth peptidic linker to the C-terminus of the second part of the third binding domain,
the first part of the second binding domain is a heavy chain Fab fragment (VH2-CH1) or a light chain Fab fragment (VL2-CL1), whereby the second part of the second binding domain is a light chain Fab fragment if the first part of the second binding domain is a heavy chain Fab fragment, or vice versa,
the first part of the second binding domain and the second part of the second binding domain are associated with each other and are together the second antigen binding site,
c) the first part of the third binding domain and the second part of the third binding domain are together the third antigen binding site, wherein
the first part of the third binding domain is either a variable heavy chain-CH3 domain fusion polypeptide (VH3-CH3) or a variable light chain-CH3 domain fusion polypeptide (VL3-CH3),
the second part of the third binding domain is a variable heavy chain-CH3 domain fusion polypeptide if the first part of the second binding domain is a variable light chain-CH3 domain fusion polypeptide, or vice versa,
the first part of the third binding domain and the second part of the third binding domain are associated with each other and form the third antigen binding site,
wherein the two constant heavy chain domains 3 (CH3) are altered to promote heterodimerization by
i) generation of a protuberance in one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a larger side chain volume than the original amino acid residue, and generation of a cavity in the other one of the CH3 domains by substituting at least one original amino acid residue by an amino acid residue having a smaller side chain volume than the original amino acid residue, such that the protuberance generated in one of the CH3 domains is positionable in the cavity generated in the other one of the CH3 domains, or substituting at least one original amino acid residue in one of the CH3 domains by a positively charged amino acid, and substituting at least one original amino acid residue in the other one of the CH3 domains by a negatively charged amino acid, or
ii) introduction of at least one cysteine residue in each CH3 domain such that a disulfide bond is formed between the CH3 domains, or
iii) both modifications of i) and ii),wherein the multispecific antibody is devoid of constant heavy chain domains 2 (CH2) and of a hinge region.
Enablement is not commensurate in scope with how to make and use the claimed multispecific antibody without guidance as to the structure, e.g., VH and VL that forms the first, second and third binding sites that correlated with binding to any first antigen, second antigen and third antigen wherein the first, second and third antigen are different (claims 1, 7) or wherein the binding site binds to human CD3 (claim 9).
As explained in the written description response which incorporated here by reference.
The specification is not enabled the full scope of all trifab Contorsbodies into the circular shape of Figure 9 because Claim 1 has no resemble to the claimed structure shown in Figure 9. For example, even assuming the first part of the first binding domain is VHa-CH1, the clause “the first part of the first binding domain is fused directly to the N-terminus of a first part of a third binding domain, the second part of the first binding domain is fused directly to the C-terminus of the first part of the third binding domain”.
Figure 9 requires that the first fusion protein comprising VHa-CH1 fused indirectly via a linker DKTHGGGS to a third VLb-CH3 having a knob and the C-terminus of the VLb-CH3 is fused to a VLa-CL via a linker GGGGSGGGGS, see Fig. 9 left, or the first fusion protein comprising VHa-CH1 fused indirectly via a linker DKTHGGGS to a third VHb-CH3 having a hole and the C-terminus of the VHb-CH3 hole is fused indirectly via a linker GGGGSGGGGS to a VLa-CL, see Fig. 9 right.
Further, the third clause “the first part of the first binding domain is a heavy chain Fab fragment (VH1- CH1) or a light chain Fab fragment (VL1-CL1), whereby the second part of the first binding domain is a light chain Fab fragment if the first part of the first binding domain is a heavy chain Fab fragment, or vice versa” is confusing at best because the second part of the first binding domain is not clearly defined. “A light chain Fab fragment” could be “VL” or “CL”.
A proper clause should have been “the first part of the first binding domain is VH1-CH1 and the second part of the first binding domain is VL1-CL1 or the first part of the first binding domain is VL1-CL1 and the second part of the first binding domain is VH1-CH1” and wherein the first part of the first binding domain and the second part of the first binding domain form the first binding site and the circular fusion polypeptide.
The same issues applies to b) the second circular fusion polypeptide and c) the first part of the third binding domain and the second part of the third binding domain.
In response to the argument that particular CDR sequences within the variable domains in the Trifab Contorsbodies do not contribute to assembly of the polypeptide chains of the trifab Contorsbodies into the circular shape shown in, e.g., Figures 6, 7 and 9, it is noted that sequences within the variable domains VH and VL comprising the six CDRs in the Trifab Contorsbodies contribute to the binding specificity of the claimed multispecific antibody or bispecific antibody as argued. Further, it is the proper pairing between VLa and VHa to form a binding site that binds to an antigen or epitope of an antigen. Neither the art nor the specification random pairing between VLa and VHb from different antibodies and still maintains binding to the particular antigen.
It is known in the art that antibodies have a large repertoire of distinct structures and that a huge variety of antibodies can be made to bind to a single epitope.
For example, Lloyd et al. taught that hundreds of functional antibody fragments can be isolated from an antibody library that bind to the same antigen wherein these antibodies have distinct heavy and light chain sequences (Lloyd et al. of record, Protein Engineering, Design & Selection 22:159-168, 2009, PTO 1449; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, Nov 14, 2003; PTO 1449), found that over 1000 antibodies, all different in amino acid sequence, were generated to a single protein; 568 different amino acid sequences identified for the V(H) CDR3 domains of these antibodies (Abstract).
Poosarla et al. (of record, Biotechn. Bioeng., 114(6): 1331-1342, 2017; PTO 892) teach substantial diversity in designed mAbs (sharing less than 75% sequence similarity to all existing natural antibody sequences) that bind to the same 12-mer peptide, binding to different epitopes on the same peptide. Said reference further teaches “most B-cell epitopes... in nature consist of residues from different regions of the sequence and are discontinuous...de novo antibody designs against discontinuous epitopes present additional challenges...". (See entire reference.)
There are no in vivo working examples. It is unpredictable which multispecific antibody is effective for treating which disease given the lack of guidance as to the binding specificity of the claimed multispecific antibody. As such, it would require undue experimentation of one skilled in the art to practice the claimed invention, commensurate in scope with the claims. See page 1338, footnote 7 of Ex parte Aggarwal, 23 USPQ2d 1334 (PTO Bd. Pat App. & Inter. 1992).
For these reasons, the rejection is maintained.
Conclusion
SEQ ID NO: 34 and 35 are free of prior art.
No claim is allowed.
THIS ACTION IS MADE FINAL. 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PHUONG HUYNH whose telephone number is (571)272-0846. The examiner can normally be reached on 9:00 a.m. to 6:30 p.m. The examiner can also be reached on alternate alternative Friday from 9:00 a.m. to 5:30 p.m.
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/PHUONG HUYNH/ Primary Examiner, Art Unit 1641