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, 15 and 16 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 has been entered.
Objection and Rejection Withdrawn
The objection to claims 1, 3-4, 6-7 and 9 is withdrawn in view of the claim amendment.
The rejection of claim 8 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph is withdrawn in view of claim amendment.
The rejection of claims 1, 3-7, 15 and 16 under 35 U.S.C. 103 as being unpatentable over Gao et al (WO2013006544, published January 10, 2013; PTO 892) in view of de Kruif et al (US20190352401, published November 21, 2019; PTO 892), and Loew et al (US20170368169, published December 28, 2017; PTO 892) is withdrawn in view of the amendment to claim 1. In particular, the references above do not teach the multispecific antibody comprising one polypeptide a chain and two polypeptide b chains.
The rejection of claim 2 under 35 U.S.C. 103 as being unpatentable over Gao et al (WO2013006544, published January 10, 2013; PTO 892) in view of de Kruif et al (US20190352401, published November 21, 2019; PTO 892), and Loew et al (US20170368169, published December 28, 2017; PTO 892) as applied to claims 1, 3-7, 15 and 16 mentioned above and further in view of Lazar (WO2016164480, published Oct 13, 2016; PTO 892) and Holliger et al (Protein Eng 9(3): 299-305, 1996; PTO 892) is withdrawn in light of the amendment to claim 1. The addition of Lazar and Hollinger do not cure the deficiency of Gao, de Kruif and Loew.
The rejection of claim 8 under 35 U.S.C. 103 as being unpatentable over Gao et al (WO2013006544, published January 10, 2013; PTO 892) in view of de Kruif et al (US20190352401, published November 21, 2019; PTO 892), and Loew et al (US20170368169, published December 28, 2017; PTO 892) as applied to claims 1, 3-7, 15 and 16 mentioned above and further in view of Sabzevari (WO2016115274, published July 21, 2016; PTO 892) and/or Berett et al (WO2018045110, published March 8, 2018; PTO 892) is withdrawn in light of the amendment to claim 1. The addition of Sabzevari and/or Berett do not cure the deficiency of Gao, de Kruif and Loew.
The rejection of claim 9 under 35 U.S.C. 102 (a)(1) as being anticipated by Brinkmann et al (of record, US20130266568, published Oct 10, 2013; PTO 892) is withdrawn in view of the claim amendment.
Claim rejections under - 35 U.S.C. 112
The following is a quotation 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 35 U.S.C. 112 (pre-AIA ), first paragraph:
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, 15 and 16 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 Written Description Guidelines for examination of patent applications indicates, “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 characteristics and/or other 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 applicant was in possession of the claimed genus.” (see MPEP 2163).
Claim 1 encompasses any multispecific antibody comprising a Fab region that comprises one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a variable region Val, a constant region Cal, a peptide linker LL, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the Val region of the polypeptide a chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a chain is associated with the Cb region of the second peptide b chain.
Claim 2 encompasses the multispecific antibody according to claim 1, wherein a length of the peptide linker LL is 70 to 280 A.
Claim 3 encompasses the multispecific antibody according to claim 1, wherein the peptide linker LL comprises any protease recognition sequence.
Claim 4 encompasses the multispecific antibody according to claim 3, wherein the peptide linker LL comprises any protease recognition sequence Lrl on the constant region Cal side and a protease recognition sequence Lr2 on the variable region Va2 side.
Claim 5 encompasses the multispecific antibody according to claim 1, wherein the multispecific antibody is IgD, IgE, IgG, or F(ab')2.
Claim 6 encompasses the multispecific antibody according to claim 1, wherein the polypeptide a chain comprises a polypeptide in which a heavy-chain variable region VHal, a heavy-chain constant region CHal, a peptide linker LL, a heavy-chain variable region Vla2, and a heavy-chain constant region CHa2 are linked in the stated order.
Claim 7 encompasses the multispecific antibody according to claim 1, wherein the polypeptide a chain comprises a polypeptide in which a heavy-chain variable region VHal, a light-chain constant region CLal, a peptide linker LL, a heavy-chain variable region Vla2, and a light-chain constant region CLa2 are linked in the stated order.
Claim 8 encompasses the multispecific antibody according to claim 1, further comprising a single-chain antibody linked to the N-terminus of further binds to the variable region Val and/or further comprising a single-chain antibody linked to the C-terminus of the constant region Ca2.
Claim 9 encompasses any multispecific antibody comprising a Fab region comprising one polypeptide a' chain below, one polypeptide a" chain below, and two first and second polypeptide b chains below:
the polypeptide a' chain comprising a polypeptide in which any variable region Val, any constant region Cal, and any cleavage fragment Lrl' of any protease recognition sequence Lrl are linked in the stated order;
the polypeptide a" chain comprising a polypeptide in which a cleavage fragment Lr2' of a protease recognition sequence Lr2, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb binding to the constant region Cal or the constant region Ca2 wherein the polypeptide a' chain, the polypeptide a" chain and the first and second polypeptide b chains constitute a Fab region and are assembled so that:
the Val region of the polypeptide a' chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a' chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a" chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a" chain is associated with the Cb region of the second peptide b chain.
Claim 15 encompasses any diagnostic agent comprising the multispecific antibody according to claim 1.
Claim 16 encompasses a pharmaceutical composition comprising the multispecific antibody according to claim 1.
The genera encompassed by the claims are of large size and substantial variability.
Comparing the claim scope with the scope of the description, the specification as filed discloses:
Example 1: Design and Production of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-1)
[0194] (1) Design of Anti-HER2×HER3 Bispecific Antibody (HER2×HER3 TribsMab CLC)
[0195] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed.
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In this test example, the bispecific antibody was designed to target HER2 and HER3 expressed on the surface of tumor cells. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of MCLA-128 (Cancer Cell 33, 922-936 (2018)) known as the anti-HER2×Her3 bispecific antibody, that is, sequences of the heavy-chain variable region 3958VH (specific to HER2) and the heavy-chain variable region 3178VH (specific to HER3) of MCLA-128, and the light-chain variable region 128VL of MCLA-128 were adopted. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, peptide linkers with different lengths each having GGGGS as a basic sequence and including or not including the HRV3C protease recognition sequence (LEVLFQGP) were designed.
[0196] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the bispecific antibody designed in the present test example is shown in the following Tables 1 and 2, and the schematic diagram of the bispecific antibody designed in the present test example is shown in FIG. 18. Approximate calculation of specific lengths (A) and specific sequences of the peptide linkers with different lengths are as shown in Table 1. Each peptide linker is represented by L(x), “x” in parentheses indicates the total number of amino acid residues constituting the peptide linker in the case of those containing a protease recognition sequence (for example, a peptide linker which includes a protease recognition sequence and in which the total number of amino acid residues constituting the peptide linker is 68, is indicated as “L(68)”), and “delP” is added in the case of those not containing a protease recognition sequence.
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Test Example 2: Activity Evaluation of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-I)
[0224] (1) Binding Activity Evaluation-1
[0225] For the multispecific antibodies 12 of Examples 1 to 5 prepared in Test Example 1, binding activity evaluation by flow cytometry to HER2 and HER3-positive human mammary adenocarcinoma cells MCF-7 was performed as follows.
Test Example 3: Examination of Production Conditions of Multispecific Antibody
[0239] A multispecific antibody was prepared in the same manner as in Example 1, except that the introduction ratio of the recombinant vector va and the recombinant vector vb prepared in Test Example 1 was changed, and the generation amount of the tetramer 12BQ was confirmed in the same manner as in (5-2) of Test Example 1 on a gel filtration chromatogram. The introduction ratio (weight basis) of the recombinant vector va and the recombinant vector vb adopted in the present test example is shown in the following table. The introduction ratio (weight basis) of the recombinant vector va and the recombinant vector vb shown in the following table is substantially the same as the introduction ratio on a molar basis. In the following table, the introduction ratio in Example 1 prepared in Test Example 1 is also described.
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Test Example 4: Design and Production of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-2)
[0241] (1) Design of HER2×HER3 Bispecific Antibody
[0242] A bispecific antibody corresponding to the multispecific antibody 13 of FIG. 7 was designed. Specifically, the multispecific antibody 13 (Example 9) was designed in the same manner as in Example 1 in Test Example 1, except that the heavy-chain constant region CHa1 and the light-chain constant region CHb of the multispecific antibody 12 prepared in Example 1 of Test Example 1 were interchanged, and the heavy-chain constant region CHa2 and the light-chain constant region CHb were interchanged. The correspondence relationship between the domains of the multispecific antibody 13 (Example 9) of FIG. 7 and the bispecific antibody designed in the present test example is shown in the following Tables 5 and 6, and the schematic diagram of the bispecific antibody (Example 9) designed in the present test example is shown in FIG. 31.
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Test Example 5: Design and Production of Multispecific Antibodies (Anti-CD20×CD3 Bispecific Antibody and Anti-BCMA×CD3 Bispecific Antibody)
[0249] (1) Design of Bispecific Antibody
[0250] (1-1) Design of Anti-CD20×CD3 Bispecific Antibody (CD20×CD3 TribsMab CLC)
[0251] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed. The bispecific antibody was designed to target CD20 and CD3. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of REGN1979 (Eric J. Smith, Kara Olson, Lauric J. Haber, Bindu Varghese, Paurene Duramad. Sci Rep, 5, 17943 (2016)) known as the anti-CD20×CD3 bispecific antibody, that is, sequences of the heavy-chain variable region 1979VH-CD20 (specific to CD20) and the heavy-chain variable region 1979VH-CD3 (specific to CD3) of REGN1979, and the light-chain variable region 1979VL of REGN1979 were adopted. The light chain class of REGN1979 is λ. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, a peptide linker having GGGGS as a basic sequence was designed.
[0252] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the designed anti-CD20×CD3 bispecific antibody is shown in the following Tables 7 and 8, and the schematic diagram of the designed anti-CD20×CD3 bispecific antibody is shown in FIG. 35A.
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The correspondence relationship between the domains of the multispecific antibody 12 of Fig. 5 and the designed anti-CD20xCD3 bispecific antibody is shown in Tables 7 and 8.
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[0253] (1-2) Design of Anti-BCMA×CD3 Bispecific Antibody (BCMA×CD3 TribsMab CLC)
[0254] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed. The bispecific antibody was designed to target BCMA and CD3. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of pSCHLI372 (Japanese Patent Laid-open Publication No. 2018-502062) known as the anti-BCMA×CD3 bispecific antibody, that is, sequences of the heavy-chain variable region 372VH-BCMA (specific to BCMA) and the heavy-chain variable region 372VH-CD3 (specific to CD3) of pSCHLI372, and the light-chain variable region 372VL of pSCHLI372 were adopted. The light chain class of pSCHLI372 is K. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, a peptide linker having GGGGS as a basic sequence was designed.
[0255] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the designed anti-BCMA×CD3 bispecific antibody is shown in the following Tables 9 and 10, and the schematic diagram of the designed anti-BCMA×CD3 bispecific antibody is shown in FIG. 35B.
The correspondence relationship between the domains of the multispecific antibody 12 of Fig. 5 and the designed anti-BCMAxCD3 bispecific antibody is shown in Tables 9 and 10.
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Test Example 6: Activity Evaluation of Multispecific Antibodies (Anti-CD20×CD3 Bispecific Antibody and Anti-BCMA×CD3 Bispecific Antibody)
[0271] (1) Binding Activity Evaluation of Anti-CD20×CD3 Bispecific Antibody
[0272] For the anti-CD20×CD3 bispecific antibodies of Examples 10 and 11 prepared in Test Example 5 (purified by cation exchange chromatography), the binding activity to Raji cells (CD20-positive cells) and T-LAK cells (CD3-positive cells) was evaluated as follows.
[0285] Results are shown in FIG. 41B. As clearly shown from FIG. 41B, it was found that BCMA×CD3 TribsMab CLC of Examples 12 and 13 crosslinked the fluorescently labeled BCMA-ECD-Fc and the CD3-positive T-LAK cell.
Test Example 7: Bispecific Antibody with Linker Cleaved
[0286] The linker of HER2×HER3 TribsMab CLC of Example 1 was cleaved with an HRV3 protease to prepare Her2×HER3 TribsMab CLC (Example 14) in a linker-cleaved state.
[0287] To 1 mg of HER2×HER3 TribsMab CLC (after protein A purification) of Example 1, 5 μL of Turbo3C (HRV3C) protease (Funakoshi Co., Ltd.) was added, and the mixture was left to stand still at 4° C. overnight. Next, in order to remove the protease, purification was performed by column chromatography using Glutathione Sepharose 4B (GE Healthcare). After equilibration with PBS, each antibody solution was added and the flow-through was recovered. The remaining protease was eluted using an elution buffer (50 mM Tris-HCl, 10 mM reduced glutathione, pH 8.0) after the column was washed with PBS. The purified sample was analyzed by SDS-PAGE.
[0288] Results of SDS-PAGE are shown in FIG. 42. As clearly shown from FIG. 42, it could be confirmed that the linker of HER2×HER3 TribsMab CLC of Example 1 was cleaved, and the bispecific antibody of Example 14 was obtained.
[0289] The binding activity evaluation of the linker-cleaved HER2×HER3 TribsMab CLC of Example 14 obtained as described above by flow cytometry to HER2 and HER3-positive human mammary adenocarcinoma cells MCF-7 was performed.
[0290] Using MCF-7 cells cultured in a 10% FBS/DMEM medium, the linker-cleaved HER2×HER3 TribsMab CLC (500 nM) of Example 14 as a primary antibody was reacted with MCF-7 cells for 30 minutes, and then washed twice with 0.1% NaN.sub.3/PBS. Subsequently, 1 μL of an anti-human IgG (Fc-specific)-FITC antibody (Sigma Aldrich) as a secondary antibody and 499 μL of 0.1% NaN.sub.3/PBS were added and reacted for 30 minutes, and then washed twice with 0.1% NaN.sub.3/PBS. Thereafter, the cells were subjected to flow cytometric analysis using BD Accuri™ C6 (BD Biosciences).
[0291] Results are shown in FIG. 43. As clearly shown from FIG. 43, the linker-cleaved HER2×HER3 TribsMab CLC of Example 14 also maintained binding activity.
However, the specification does not describe the structure-identifying information, e.g., amino acid sequences of variable region Va1, variable region Va2, variable region Vb (claims 1, 9) or heavy-chain variable region VHa1, a heavy-chain variable region VHa2 (claim 6) or any single-chain antibody further binds to any variable region Va1 and/or the constant region Ca2, or Vb (claim 8) about the claimed multispecific antibodies. The specification fails to disclose a correlation between structure, e.g., amino acid sequences and function, e.g., binding specificity of all multispecific antibodies. There is no limitation on the structure or function of the multispecific antibody, or the epitope to which it binds. The specification does not describe a representative number of species falling within 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 antibodies themselves. Thus, three species of bispecific antibodies that bind to CD20 and CD3, BCMA and CD3, HER2 and HER3 fail to convey evidence of possession of the entire genus of multispecific antibody at the time of filing.
At the time the invention was made, it was 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 (of record, Lloyd et al. Protein Engineering, Design & Selection 22:159-168, 2009; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, 2003; PTO 892), 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). 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 binding specificity of the multispecific antibody, and the lack of in vivo working examples, it is unpredictable which undisclosed multispecific antibody is effective as a pharmaceutical composition (claim 16) for treating disease such as cancer or diagnostic agent (claim 15).
Regarding peptide linker LL, the specification discloses just protease cleavable flexible peptide linker consisting of the amino acid sequence of SEQ ID NO: 2, 4, 5 and 6 that linked CHa1-CHa1 and VHa2-Cha2 wherein the peptide linker has a particular length in terms of Angstrom, see Table 1.
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It should be noted that all flexible cleavable linker comprises the same protease recognition sequence LEVLFQGP (SEQ ID NO: 8), see Table 1 above.
However, one species of human rhinovirus 3C (HRV3C) protease recognition sequence LEVLFQGP (SEQ ID NO: 8) is not representative of the genus of protease recognition sequences (claims 3-4, 9) and any peptide linker LL having a length between 70 and 280 Angstrom (claim 2) to demonstrate possession of the genus at the time of filing.
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. Thus, the specification fails to describe these DNA sequences.
For genus claims, an adequate written description of a claimed genus requires more than a generic statement of an invention's boundaries. A patent must set forth either a representative number of species falling within the scope of the genus or structural features common to the members of the genus. Kubin, Exparte, 83 USPQ2d 1410 (Bd. Pat. App. & Int. 2007); Ariad Pharms., Inc. v. Eli Lilly& Co., 598 F.3d 1336, 1350 (Fed. Cir. 2010).
Therefore, only (1) a multispecific antibody comprising one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a light chain variable region Val, a light chain CL constant region Cal, a flexible cleavable peptide linker LL, a light chain variable region Va2, and a light chain constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively, each comprising a polypeptide in which a heavy chain variable region Vb is linked to a heavy chain CH1 constant region Cb, a CH2 domain and a CH3 domain,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the light chain Val region of the polypeptide a chain is associated with the heavy chain Vb region of the first polypeptide b chain,
the light chain CL Cal region of the polypeptide a chain is associated with the heavy chain CH1 Cb region of the first polypeptide b chain,
the light chain Va2 region of the polypeptide a chain is associated with the heavy chain Vb region of the second polypeptide b chain, and
the light chain CL Ca2 region of the polypeptide a chain is associated with the heavy chain CH1 Cb region of the second peptide b chain, wherein the peptide linker LL is 70 to 280 Å long and comprises a protease recognition sequence of SEQ ID NO: 8, (2) The multispecific antibody wherein the peptide linker LL comprises a protein recognition sequence on the constant region Ca1 side and a protease recognition sequence Lr2 on the variable region Va2 side, (3) The multispecific antibody above wherein the flexible cleavable peptide linker LL comprises the amino acid sequence selected from the group consisting of SEQ ID NO: 2, 4, 5, and 6 and wherein the multispecific antibody binds to CD20 and CD3 or BCMA and CD3 or HER2 and HER3, (4) the multispecific antibody further comprises a single chain antibody linked to N-terminus of the first VH domain and/or C-terminus of the CL domain, (5) a composition comprising said multispecific antibody and a pharmaceutically acceptable carrier, a diagnostic agent comprising said multispecific antibody, 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 July 15, 2026 have been fully considered but are not found persuasive.
Applicants’ position is that it appears that the Patent Office did not understand that the structure of the claimed multispecific antibody is as depicted in Figure 1 and Figure 2 of the specification, which shows how the polypeptide a chain and the two polypeptide b chains assemble to form a multispecific antibody. The presently claimed multispecific antibody is not characterized by the discovery of a new antibody having a particular function. Rather, it relates to a novel antibody design in which the chain linkage design in a multispecific antibody has been devised so as to theoretically eliminate by-products exhibiting immune activity without relying on hetero-association technology.
For clarity, claims 1 and 9 are amended to describe the structural relationship between the polypeptide a chain and the two polypeptide b chains when assembled. As discussed in paragraphs [0011]-[0012], an object of the present invention is to provide a novel antibody format that does not use a hetero-association technology and that is theoretically free of by-products exhibiting immune activity.
The present inventors have found that, when a bispecific antibody is designed such that a constant region in one arm and a variable region in the other arm are linked by a peptide linker so that variable regions of both arms are present in the same polypeptide chain, there are only two kinds of polypeptide chains constituting the bispecific antibody, and a by-product exhibiting immune activity is not theoretically generated.
In response, amended claim 1 recites a multispecific antibody comprising a Fab region that comprises one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a variable region Val, a constant region Cal, a peptide linker LL, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the Val region of the polypeptide a chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a chain is associated with the Cb region of the second peptide b chain.
The specification discloses
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Applicant appears to equate polypeptide chain a comprising a Va1 as light chain variable region, Ca1 as light chain constant domain, LL as the linker, Va2 as the second light chain variable region and Ca2 as the second light chain constant region. The first and second polypeptide b chain as the two heavy chain each comprising a Vb as the heavy chain variable region, Cb as the heavy chain CH1 domain as shown in Fig 1.
However, MPEP 2173.05(s) states that where possible, claims are to be complete inthemselves.
Further, M.P.E.P. § 2106 (II) states:
USPTO personnel are to give claims their broadest reasonable interpretation in light of the supporting disclosure. In re Morris, 127 F.3d 1048, 1054-55, 44 USPQ2d 1023, 1027-28 (Fed. Cir. 1997). Limitations appearing in the specification but not recited in the claim should not be read into the claim. E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (claims must be interpreted “in view of the specification” without importing limitations from the specification into the claims unnecessarily). In re Prater, 415 F.2d 1393, 1404-05, 162 USPQ 541, 550- 551 (CCPA 1969). See also In re Zletz, 893 F.2d 319, 321-22, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (“During patent examination the pending claims must be interpreted as broadly as their terms reasonably allow.... The reason is simply that during patent prosecution when claims can be amended, ambiguities should be recognized, scope and breadth of language explored, and clarification imposed.... An essential purpose of patent examination is to fashion claims that are precise, clear, correct, and unambiguous. Only in this way can uncertainties of claim scope be removed, as much as possible, during the administrative process.”) (Emboldened added for emphasis).
M.P.E.P. § 2106 (II) continues:
While it is appropriate to use the specification to determine what applicant intends a term to mean, a positive limitation from the specification cannot be read into a claim that does not itself impose that limitation. A broad interpretation of a claim by USPTO personnel will reduce the possibility that the claim, when issued, will be interpreted more broadly than is justified or intended. An applicant can always amend a claim during prosecution to better reflect the intended scope of the claim.
In this case, the Va1, Vb, Ca1, Cb, Va2 and Ca2 in claim 1 are not defined in the claim. Furthermore, the IgG antibody comprises two Fab region, not one Fab region as recited in claim 1. Further, the IgG heavy chain (aka first and second polypeptide b chain) each comprises a CH2 and a CH3 domain, see Figure 1. However, the two polypeptide b chain in claim 1 do not comprise a CH2 and a CH3 domains. It is not clear how the claimed multispecific antibody recited in claim 1 ends up with IgD, IgE or IgG (claim 5). Other than light chain variable region paired with heavy chain variable region, light chain CL domain paired with heavy chain CH1 domain, the specification does not adequately describe the structure, e.g., amino acid sequence of all light chain variable domain that associated with all heavy chain variable domain that correlated with binding specificity as a pharmaceutical composition (claim 16) or a diagnostic agent (claim 15). The specification fails to adequately describe the genus of Va1 that associated with Vb, Ca1 that associated with Cb, Va2 that associated with Vb and Ca2 that associated with Cb.
At the time the invention was made, it was 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 (of record, Lloyd et al. Protein Engineering, Design & Selection 22:159-168, 2009; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, 2003; PTO 892), 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). 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 binding specificity of the multispecific antibody, and the lack of in vivo working examples, it is unpredictable which undisclosed multispecific antibody is effective as a pharmaceutical composition (claim 16) for treating disease such as cancer or diagnostic agent (claim 15).
Regarding peptide linker LL, the claimed peptide linker LL encompasses any rigid linker as well as any flexible linker of any length without a protease recognition sequence (claim 1) or comprises any protease recognition sequence (claims 3, 4, 9). The specification discloses just flexible cleavable linker comprising the amino acid sequence of SEQ ID NO: 2, 4, 5 and 6, each linker comprises just one protease recognition sequence LEVLFQGP (SEQ ID NO: 8). However, the specification does not describe the structure of all linker comprises any and all protease recognition sequence (claim 3) such as Lr1, Lr2 (claim 4), Lr1’, Lr1, Lr2’ and Lr2 (claim 9). The specification does not describe the structure, e.g., amino acids sequence of a sufficient number of species of the genus of linker comprising any and all possible protease recognition sequence. When there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. The specification fails to adequately describe the genus of linker comprising any potential protease recognition sequence or structure common to members of the genus to reasonably convey to the skilled artisan that Applicant had possession of the claimed invention at the time the application was filed.
For these reasons, the skilled artisan could not immediately envision, recognize or distinguish which multispecific antibody would effectively as a pharmaceutical composition to treat a patient with cancer or other disease or diagnostic without guidance as to the binding specificity of such multispecific antibody; and as such, the specification would not reasonably convey to the skilled artisan that Applicant had possession of the claimed invention at the time the application was filed.
For these reasons, the rejection is maintained.
Claims 1-9, 15 and 16 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 multispecific antibody comprising one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a light chain variable region Val, a light chain CL constant region Cal, a flexible cleavable peptide linker LL, a light chain variable region Va2, and a light chain constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively, each comprising a polypeptide in which a heavy chain variable region Vb is linked to a heavy chain CH1 constant region Cb, a CH2 domain and a CH3 domain,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the light chain Val region of the polypeptide a chain is associated with the heavy chain Vb region of the first polypeptide b chain,
the light chain CL Cal region of the polypeptide a chain is associated with the heavy chain CH1 Cb region of the first polypeptide b chain,
the light chain Va2 region of the polypeptide a chain is associated with the heavy chain Vb region of the second polypeptide b chain, and
the light chain CL Ca2 region of the polypeptide a chain is associated with the heavy chain CH1 Cb region of the second peptide b chain, wherein the peptide linker LL is 70 to 280 Å long and comprises a protease recognition sequence of SEQ ID NO: 8, (2) The multispecific antibody wherein the peptide linker LL comprises a protein recognition sequence on the constant region Ca1 side and a protease recognition sequence Lr2 on the variable region Va2 side, (3) The multispecific antibody above wherein the flexible cleavable peptide linker LL comprises the amino acid sequence selected from the group consisting of SEQ ID NO: 2, 4, 5, and 6 and wherein the multispecific antibody binds to CD20 and CD3 or BCMA and CD3 or HER2 and HER3, (4) the multispecific antibody further comprises a single chain antibody linked to N-terminus of the first VH domain and/or C-terminus of the CL domain, (5) a composition comprising said multispecific antibody and a pharmaceutically acceptable carrier, a diagnostic agent comprising said multispecific antibody, does not reasonably provide enablement for any and all multispecific antibody as a pharmaceutical composition. 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 and 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 a Fab region that comprises one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a variable region Val, a constant region Cal, a peptide linker LL, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the Val region of the polypeptide a chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a chain is associated with the Cb region of the second peptide b chain.
Claim 2 encompasses the multispecific antibody according to claim 1, wherein a length of the peptide linker LL is 70 to 280 A.
Claim 3 encompasses the multispecific antibody according to claim 1, wherein the peptide linker LL comprises any protease recognition sequence.
Claim 4 encompasses the multispecific antibody according to claim 3, wherein the peptide linker LL comprises any protease recognition sequence Lrl on the constant region Cal side and a protease recognition sequence Lr2 on the variable region Va2 side.
Claim 5 encompasses the multispecific antibody according to claim 1, wherein the multispecific antibody is IgD, IgE, IgG, or F(ab')2.
Claim 6 encompasses the multispecific antibody according to claim 1, wherein the polypeptide a chain comprises a polypeptide in which a heavy-chain variable region VHal, a heavy-chain constant region CHal, a peptide linker LL, a heavy-chain variable region Vla2, and a heavy-chain constant region CHa2 are linked in the stated order.
Claim 7 encompasses the multispecific antibody according to claim 1, wherein the polypeptide a chain comprises a polypeptide in which a heavy-chain variable region VHal, a light-chain constant region CLal, a peptide linker LL, a heavy-chain variable region Vla2, and a light-chain constant region CLa2 are linked in the stated order.
Claim 8 encompasses the multispecific antibody according to claim 1, further comprising a single-chain antibody linked to the N-terminus of further binds to the variable region Val and/or further comprising a single-chain antibody linked to the C-terminus of the constant region Ca2.
Claim 9 encompasses any multispecific antibody comprising a Fab region comprising one polypeptide a' chain below, one polypeptide a" chain below, and two first and second polypeptide b chains below:
the polypeptide a' chain comprising a polypeptide in which any variable region Val, any constant region Cal, and any cleavage fragment Lrl' of any protease recognition sequence Lrl are linked in the stated order;
the polypeptide a" chain comprising a polypeptide in which a cleavage fragment Lr2' of a protease recognition sequence Lr2, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb binding to the constant region Cal or the constant region Ca2 wherein the polypeptide a' chain, the polypeptide a" chain and the first and second polypeptide b chains constitute a Fab region and are assembled so that:
the Val region of the polypeptide a' chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a' chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a" chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a" chain is associated with the Cb region of the second peptide b chain.
Claim 15 encompasses any diagnostic agent comprising the multispecific antibody according to claim 1.
Claim 16 encompasses a pharmaceutical composition comprising the multispecific antibody according to claim 1.
Example 1: Design and Production of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-1)
[0194] (1) Design of Anti-HER2×HER3 Bispecific Antibody (HER2×HER3 TribsMab CLC)
[0195] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed.
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In this test example, the bispecific antibody was designed to target HER2 and HER3 expressed on the surface of tumor cells. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of MCLA-128 (Cancer Cell 33, 922-936 (2018)) known as the anti-HER2×Her3 bispecific antibody, that is, sequences of the heavy-chain variable region 3958VH (specific to HER2) and the heavy-chain variable region 3178VH (specific to HER3) of MCLA-128, and the light-chain variable region 128VL of MCLA-128 were adopted. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, peptide linkers with different lengths each having GGGGS as a basic sequence and including or not including the HRV3C protease recognition sequence (LEVLFQGP) were designed.
[0196] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the bispecific antibody designed in the present test example is shown in the following Tables 1 and 2, and the schematic diagram of the bispecific antibody designed in the present test example is shown in FIG. 18. Approximate calculation of specific lengths (A) and specific sequences of the peptide linkers with different lengths are as shown in Table 1. Each peptide linker is represented by L(x), “x” in parentheses indicates the total number of amino acid residues constituting the peptide linker in the case of those containing a protease recognition sequence (for example, a peptide linker which includes a protease recognition sequence and in which the total number of amino acid residues constituting the peptide linker is 68, is indicated as “L(68)”), and “delP” is added in the case of those not containing a protease recognition sequence.
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Test Example 2: Activity Evaluation of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-I)
[0224] (1) Binding Activity Evaluation-1
[0225] For the multispecific antibodies 12 of Examples 1 to 5 prepared in Test Example 1, binding activity evaluation by flow cytometry to HER2 and HER3-positive human mammary adenocarcinoma cells MCF-7 was performed as follows.
Test Example 3: Examination of Production Conditions of Multispecific Antibody
[0239] A multispecific antibody was prepared in the same manner as in Example 1, except that the introduction ratio of the recombinant vector va and the recombinant vector vb prepared in Test Example 1 was changed, and the generation amount of the tetramer 12BQ was confirmed in the same manner as in (5-2) of Test Example 1 on a gel filtration chromatogram. The introduction ratio (weight basis) of the recombinant vector va and the recombinant vector vb adopted in the present test example is shown in the following table. The introduction ratio (weight basis) of the recombinant vector va and the recombinant vector vb shown in the following table is substantially the same as the introduction ratio on a molar basis. In the following table, the introduction ratio in Example 1 prepared in Test Example 1 is also described.
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Test Example 4: Design and Production of Multispecific Antibody (Anti-HER2×HER3 Bispecific Antibody-2)
[0241] (1) Design of HER2×HER3 Bispecific Antibody
[0242] A bispecific antibody corresponding to the multispecific antibody 13 of FIG. 7 was designed. Specifically, the multispecific antibody 13 (Example 9) was designed in the same manner as in Example 1 in Test Example 1, except that the heavy-chain constant region CHa1 and the light-chain constant region CHb of the multispecific antibody 12 prepared in Example 1 of Test Example 1 were interchanged, and the heavy-chain constant region CHa2 and the light-chain constant region CHb were interchanged. The correspondence relationship between the domains of the multispecific antibody 13 (Example 9) of FIG. 7 and the bispecific antibody designed in the present test example is shown in the following Tables 5 and 6, and the schematic diagram of the bispecific antibody (Example 9) designed in the present test example is shown in FIG. 31.
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Test Example 5: Design and Production of Multispecific Antibodies (Anti-CD20×CD3 Bispecific Antibody and Anti-BCMA×CD3 Bispecific Antibody)
[0249] (1) Design of Bispecific Antibody
[0250] (1-1) Design of Anti-CD20×CD3 Bispecific Antibody (CD20×CD3 TribsMab CLC)
[0251] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed. The bispecific antibody was designed to target CD20 and CD3. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of REGN1979 (Eric J. Smith, Kara Olson, Lauric J. Haber, Bindu Varghese, Paurene Duramad. Sci Rep, 5, 17943 (2016)) known as the anti-CD20×CD3 bispecific antibody, that is, sequences of the heavy-chain variable region 1979VH-CD20 (specific to CD20) and the heavy-chain variable region 1979VH-CD3 (specific to CD3) of REGN1979, and the light-chain variable region 1979VL of REGN1979 were adopted. The light chain class of REGN1979 is λ. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, a peptide linker having GGGGS as a basic sequence was designed.
[0252] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the designed anti-CD20×CD3 bispecific antibody is shown in the following Tables 7 and 8, and the schematic diagram of the designed anti-CD20×CD3 bispecific antibody is shown in FIG. 35A.
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The correspondence relationship between the domains of the multispecific antibody 12 of Fig. 5 and the designed anti-CD20xCD3 bispecific antibody is shown in Tables 7 and 8.
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[0253] (1-2) Design of Anti-BCMA×CD3 Bispecific Antibody (BCMA×CD3 TribsMab CLC)
[0254] A bispecific antibody corresponding to the multispecific antibody 12 of FIG. 5 was designed. The bispecific antibody was designed to target BCMA and CD3. As for the variable regions (portions surrounded by dashed lines in FIG. 5), the same sequences as those of the variable regions of pSCHLI372 (Japanese Patent Laid-open Publication No. 2018-502062) known as the anti-BCMA×CD3 bispecific antibody, that is, sequences of the heavy-chain variable region 372VH-BCMA (specific to BCMA) and the heavy-chain variable region 372VH-CD3 (specific to CD3) of pSCHLI372, and the light-chain variable region 372VL of pSCHLI372 were adopted. The light chain class of pSCHLI372 is K. As for the constant region, a sequence derived from the human IgG1 class was adopted. As a sequence corresponding to the peptide linker LL of FIG. 5, a peptide linker having GGGGS as a basic sequence was designed.
[0255] The correspondence relationship between the domains of the multispecific antibody 12 of FIG. 5 and the designed anti-BCMA×CD3 bispecific antibody is shown in the following Tables 9 and 10, and the schematic diagram of the designed anti-BCMA×CD3 bispecific antibody is shown in FIG. 35B.
The correspondence relationship between the domains of the multispecific antibody 12 of Fig. 5 and the designed anti-BCMAxCD3 bispecific antibody is shown in Tables 9 and 10.
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Test Example 6: Activity Evaluation of Multispecific Antibodies (Anti-CD20×CD3 Bispecific Antibody and Anti-BCMA×CD3 Bispecific Antibody)
[0271] (1) Binding Activity Evaluation of Anti-CD20×CD3 Bispecific Antibody
[0272] For the anti-CD20×CD3 bispecific antibodies of Examples 10 and 11 prepared in Test Example 5 (purified by cation exchange chromatography), the binding activity to Raji cells (CD20-positive cells) and T-LAK cells (CD3-positive cells) was evaluated as follows.
[0285] Results are shown in FIG. 41B. As clearly shown from FIG. 41B, it was found that BCMA×CD3 TribsMab CLC of Examples 12 and 13 crosslinked the fluorescently labeled BCMA-ECD-Fc and the CD3-positive T-LAK cell.
Test Example 7: Bispecific Antibody with Linker Cleaved
[0286] The linker of HER2×HER3 TribsMab CLC of Example 1 was cleaved with an HRV3 protease to prepare Her2×HER3 TribsMab CLC (Example 14) in a linker-cleaved state.
[0287] To 1 mg of HER2×HER3 TribsMab CLC (after protein A purification) of Example 1, 5 μL of Turbo3C (HRV3C) protease (Funakoshi Co., Ltd.) was added, and the mixture was left to stand still at 4° C. overnight. Next, in order to remove the protease, purification was performed by column chromatography using Glutathione Sepharose 4B (GE Healthcare). After equilibration with PBS, each antibody solution was added and the flow-through was recovered. The remaining protease was eluted using an elution buffer (50 mM Tris-HCl, 10 mM reduced glutathione, pH 8.0) after the column was washed with PBS. The purified sample was analyzed by SDS-PAGE.
[0288] Results of SDS-PAGE are shown in FIG. 42. As clearly shown from FIG. 42, it could be confirmed that the linker of HER2×HER3 TribsMab CLC of Example 1 was cleaved, and the bispecific antibody of Example 14 was obtained.
[0289] The binding activity evaluation of the linker-cleaved HER2×HER3 TribsMab CLC of Example 14 obtained as described above by flow cytometry to HER2 and HER3-positive human mammary adenocarcinoma cells MCF-7 was performed.
[0290] Using MCF-7 cells cultured in a 10% FBS/DMEM medium, the linker-cleaved HER2×HER3 TribsMab CLC (500 nM) of Example 14 as a primary antibody was reacted with MCF-7 cells for 30 minutes, and then washed twice with 0.1% NaN.sub.3/PBS. Subsequently, 1 μL of an anti-human IgG (Fc-specific)-FITC antibody (Sigma Aldrich) as a secondary antibody and 499 μL of 0.1% NaN.sub.3/PBS were added and reacted for 30 minutes, and then washed twice with 0.1% NaN.sub.3/PBS. Thereafter, the cells were subjected to flow cytometric analysis using BD Accuri™ C6 (BD Biosciences).
[0291] Results are shown in FIG. 43. As clearly shown from FIG. 43, the linker-cleaved HER2×HER3 TribsMab CLC of Example 14 also maintained binding activity.
However, the specification does not teach the structure-identifying information, e.g., amino acid sequences of variable region Va1, variable region Va2, variable region Vb (claims 1, 9) or heavy-chain variable region VHa1, a heavy-chain variable region VHa2 (claim 6) or any single-chain antibody further binds to any variable region Va1 and/or the constant region Ca2, or Vb (claim 8) that correlated with binding about the claimed multispecific antibodies as a pharmaceutical composition. The specification fails to disclose a correlation between structure, e.g., amino acid sequence of the Va1 and Va2, Vb and function, e.g., binding specificity of all multispecific antibodies. One of skill in the art cannot predict which undisclosed multispecific antibody is effective as a pharmaceutical composition (claim 16) for treating or diagnostic (claim 15) which disease.
At the time the invention was made, it was 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 (of record, Lloyd et al. Protein Engineering, Design & Selection 2009, 22:159-168; see, e.g., Discussion).
Similarly, Edwards et al., (of record, J Mol Biol. 2003 Nov 14;334(1): 103-118), 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). 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, 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.
Given the lack of guidance as to the binding specificity of the multispecific antibody, and the lack of in vivo working examples, it is unpredictable which undisclosed multispecific antibody is effective as a pharmaceutical composition (claim 16) for treating disease such as cancer or diagnostic agent (claim 15).
Regarding peptide linker LL, the specification discloses just flexible protease cleavable peptide linker consisting of the amino acid sequence of SEQ ID NO: 2, 4, 5 and 6 that linked VHa1-CHa1 and VHa2-CHa2 wherein the peptide linker has a particular length in terms of Angstrom, see Table 1. It should be noted that all flexible cleavable linker comprises the same protease recognition sequence LEVLFQGP (SEQ ID NO: 8), see Table 1.
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However, one species of human rhinovirus 3C (HRV3C) protease recognition sequence LEVLFQGP is not representative of the genus of protease recognition sequences (claims 3-4, 9) and any peptide linker LL having a length between 70 and 280 Angstrom (claim 2).
Thus, the scope of the claims is extremely broad compared to the guidance and exemplification provided in the specification. 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). As such, one skilled in the art cannot practice the invention with a reasonable expectation of success without undue experimentation.
Applicants’ arguments filed July 15, 2026 have been fully considered but are not found persuasive.
Applicants’ position is that the diversity of the protease cleavable linker and the diversity of binding capacity to target antigens is self-evident and would be expected by the person having ordinary skill in the art. A single chain antibody linked to N-terminus of the first VH domain and/or C-terminus of the CL domain is an optional feature that need not be present. Accordingly, the Applicant asserts that the enablement requirement is met by the specification.
In response, amended claim 1 recites a multispecific antibody comprising a Fab region that comprises one polypeptide a chain below and two first and second polypeptide b chains below:
the polypeptide a chain comprising a polypeptide in which a variable region Val, a constant region Cal, a peptide linker LL, a variable region Va2, and a constant region Ca2 are linked in the stated order; and
the first and second polypeptide b chain respectively comprising a polypeptide in which a variable region Vb is linked to a constant region Cb,
wherein the polypeptide a chain and the first and second polypeptide b chains are assembled so that the Val region of the polypeptide a chain is associated with the Vb region of the first polypeptide b chain,
the Cal region of the polypeptide a chain is associated with the Cb region of the first polypeptide b chain,
the Va2 region of the polypeptide a chain is associated with the Vb region of the second polypeptide b chain, and
the Ca2 region of the polypeptide a chain is associated with the Cb region of the second peptide b chain.
The specification discloses
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The Va1, Vb, Ca1, Cb, Va2 and Ca2 in claim 1 are not defined in the claim. Even assuming Va1, Va2 are light chain variable (VL) and Vb is heavy chain variable region (VH), the specification discloses just anti-HER2xHER3, Anti-CD20×CD3, BCMAxCD3 bispecific antibodies.
However, the specification does not teach the structure-identifying information, e.g., amino acid sequences of variable region Va1, variable region Va2, variable region Vb (claims 1, 9) or heavy-chain variable region VHa1, a heavy-chain variable region VHa2 (claim 6) or any single-chain antibody further binds to any variable region Va1 and/or the constant region Ca2, or Vb (claim 8) that correlated with binding about the claimed multispecific antibodies that are effective as a pharmaceutical composition (claim 16) or diagnostic agent (claim 15).
Furthermore, the IgG antibody comprises two Fab region, not one Fab region as recited in claim 1. Further, the IgG heavy chain (aka first and second polypeptide b chain) each comprises a CH2 and a CH3 domain, see Figure 1. However, the two polypeptide b chain in claim 1 do not comprise a CH2 and a CH3 domains. It is not clear how the claimed multispecific antibody recited in claim 1 ends up with IgD, IgE or IgG (claim 5). Other than light chain variable region paired with heavy chain variable region, light chain CL domain paired with heavy chain CH1 domain, the specification does not teach the structure, e.g., amino acid sequence of all Va1, Vb, Ca1, Cb, Va2 and Ca2.
Even assuming the Va1, Vb, and Va2 and Ca2 are light chain variable domain that associated with heavy chain variable domain, the specification does not teach the binding specificity of such multispecific antibody and which one is effective as a pharmaceutical composition (claim 16) or a diagnostic agent (claim 15).
At the time the invention was made, it was 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 (of record, Lloyd et al. Protein Engineering, Design & Selection 22:159-168, 2009; see, e.g., Discussion).
Similarly, Edwards et al. (of record, J Mol Biol. 334(1): 103-118, 2003; PTO 892), 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). 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, 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.
Given the lack of guidance as to the binding specificity of the multispecific antibody, and the lack of in vivo working examples, it is unpredictable which undisclosed multispecific antibody is effective as a pharmaceutical composition (claim 16) for treating disease such as cancer or diagnostic agent (claim 15).
Regarding peptide linker LL, the claimed peptide linker LL encompasses any rigid linker as well as any flexible linker of any length without a protease recognition sequence (claim 1) or comprises any protease recognition sequence (claims 3, 4, 9). The specification discloses just flexible cleavable linker comprising the amino acid sequence of SEQ ID NO: 2, 4, 5 and 6, each linker comprises the same protease recognition sequence LEVLFQGP (SEQ ID NO: 8). However, the specification does not teach the structure of all linker comprises any and all protease recognition sequence (claim 3) such as Lr1, Lr2 (claim 4), Lr1’, Lr1, Lr2’ and Lr2 (claim 9). The specification does not teach the structure, e.g., amino acids sequence of a sufficient number of species of the genus of linker comprising any and all possible protease recognition sequence.
Given diversity of the protease cleavable linker and the diversity of the heavy and light chain variable regions to target antigens, the specification provides insufficient evidence or nexus that would provide sufficient guidance or direction as to how to produce multispecific antibody that would treat or diagnose all possible disease and there is no in vivo working example of such an 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).
Applicant is reminded that reasonable correlation must exist between the scope of the claims and scope of enablement set forth.
For these reasons, the rejection is maintained.
New Ground of Rejection Necessitated by claim amendment filed July 15, 2026
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6 and 7 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 applicant regards as the invention.
Claim 6 recites the limitation "a heavy-chain variable region VHa1, a heavy-chain constant region CHa1…a heavy-chain variable region VHa2, and a heavy-chain constant region CHa2" in claim 1. There is insufficient antecedent basis for this limitation in the claim.
Claim 7 recites the limitation " heavy-chain variable region VHa1, a light-chain constant region CLa1…a heavy-chain variable region VHa2, and a light-chain constant region CLa2” in claim 1. There is insufficient antecedent basis for this limitation in the claim.
Conclusion
Peptide linker (LL) consisting of the amino acid sequence of SEQ ID NO: 2, 4, 5, 6 or 7 is free of prior art.
No claim is allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Misook Yu, can be reached at 571-272-0839. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/PHUONG HUYNH/ Primary Examiner, Art Unit 1641
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