Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/10/2026 has been entered.
Withdrawn Rejections
Rejections of claims 1-11 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paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter are hereby withdrawn in view of amendments to the claims.
Rejections of claims 1-11 under 35 U.S.C. 103 as being unpatentable over Elias et al. (US 2019/0062457 A1, in IDS filed 08/07/2023), in view of Chupp et al. (US 2019/060675 A1, in PTO-892 filed 04/21/2026), in view of Lu et al. (in IDS filed 08/07/2023), General Hospital Corporation (WO 2019/157533 A1, in IDS filed 08/07/2023, hereinafter “GHC”), and Wang et al. (WO 2018/0327501 A1, in IDS filed 08/07/2023) are hereby withdrawn in view of Applicant’s arguments, which point to the novelty of the sequence for the CTLA4 scFv in SEQ ID NO: 23.
Modified Rejections Necessitated by Amendment
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-11 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claims 1-11 are directed to an antibody that binds chitinase 3-like-1 (CHI3L1) and cytotoxic T-lymphocyte associated protein 4 (CTLA4) that claims the sequences in a combinatorial fashion. As such, the claims are directed to an antibody defined entirely by function (binding). See MPEP §2163(I)(A) which states:
"The claimed invention as a whole may not be adequately described where an invention is described solely in terms of a method of its making coupled with its function and there is no described or art recognized correlation or relationship between the structure of the invention and its function. A biomolecule sequence described only by a functional characteristic, without any known or disclosed correlation between that function and the structure of the sequence, normally is not a sufficient identifying characteristic for written description purposes, even when accompanied by a method of obtaining the claimed sequence.”
In this case, antibodies generally share certain characteristics such as Fc regions or hinge regions. However, these structures are not correlated with the binding function of the antibody. The hyper variable regions (HVRs), i.e., complementarity determining regions (CDRs) of an antibody, are well established in the art as the portion of the binding region which imparts the specificity of an antibody. However, there is no way to a priori look at an antigen sequence (CHI3L1 and CTLA4) and envisage the combination of twelve CDRs or pairs of heavy and light variable region sequences that will bind that antigen. First, even highly related CDRs may not bind the same target. See for example Kussie (in PTO-892 filed 10/21/2025) who demonstrates that a single amino acid change in the heavy chain of an antibody which binds p-axophenylarsonate (Ars) completely abrogates the ability of the antibody to bind Ars but adds the functionality of binding the structurally related p-azophenylsulfonate (e.g., abstract). Second, even when provided with several related antibodies that bind the desired target, this does not represent the astronomical and potentially unknowable breadth of all possible amino acid sequences which will result in the desired binding properties. This is exemplified by the Court decision in Abbvie (Abbvie v Janssen 759 F.3d 1285 (Fed. Cir. 2014)), where Abbvie developed over 200 antibodies that shared 99.5% identity in the variable regions (p.7) and which bound the target, but in no way allowed one to envisage the unique structure of Centocor’s antibodies which bound the same target but shared only 50% sequence similarity (see table on page 11).
Thus, the art recognizes that the CDRs define the binding properties of an antibody and that even single amino acid changes to this region can completely abrogate the binding specificity of an antibody. As a further example, see Chen et al., 1995 (in PTO-892 filed 10/21/2025) which demonstrates single amino acid changes in the VH CDR2 sequence can increase binding, decrease binding, destroy binding, or have no effect on binding when compared to the wild-type antibody.
See also Koenig 2017 (in PTO-892 filed 10/21/2025) which provides a large mutation analysis study where every amino acid in both variable regions are substituted with every other amino acid. Looking at figure 1 of Koenig, the bottom half of each section (labeled VEGF) relates to the ability of the mutant to bind the original target, with blue meaning a reduced affinity and black meaning a complete loss of binding ability. In VH-CDR2, for example, mutating any given residue to cysteine, which is encompassed by the instant claims, resulted in reduced binding at 12 residues and a complete loss of binding at 5 residues. That is, at 100% of the positions, mutation to cysteine reduced or ablated the antibody’s ability to bind the target. Looking at a specific position, in 100% of the mutations of residue 55, binding was reduced (15/19) or eliminated (4/19). While residues 56-65 appear more tolerant of change, residues 50-55 are generally intolerant of change.
It is appreciated that Koenig is studying one specific antibody and there is no evidence that the instant antibodies would react in the same way. However, this is part of the problem. It is entirely unclear from the specification which residues of Applicant’s CDRs are tolerant or intolerant to change, and whether those tolerant positions are only tolerant to conservative mutations. The fact that some residues might tolerate mutation does not convey to the skilled artisan that Applicant knew which of the claimed residues were tolerant of such, i.e., does not convey that Applicant was in possession of those sequences which are mutated yet preserve the claimed function. In other words, the specification fails to convey possession of an invention commensurate in scope with what is now claimed and therefore fails to meet the written description requirement. Looking at Koenig figure 2A, ~200 mutations in the CDR region of the VH chain completely abrogates any binding. While 2B appears to indicate that the CDRs of VL are more tolerant of change than the heavy chain CDRs, still over half of the mutations reduce binding compared to the parent.
Thus, making changes to the CDR sequence of an antibody is a highly unpredictable process and the skilled artisan could not a priori make any predictions regarding such mutations with any reasonable expectation of success nor envisage the breadth of structurally unrelated CDR combinations that would still possess the required functions.
The specification discloses antibodies in Table 1 which comprises, as the heavy chain variable region sequences, SEQ ID NOs: 1-12 and as light chain variable region sequences, SEQ ID NOs: 13-20 for the anti-human CHI3L1 specificity and SEQ ID NOs: 23 as the scFv for the CTLA4 specificity. The claims do not recite the combination of exact heavy and light chain variable region sequences that comprise the antibody and instead list 20 sequences that can be put together in any combination. As such, the claims are recited in a combinatorial fashion that gives rise to numerous, undefined permutations of antibody sequences that could potentially be the antibody that Applicant does not have disclosure for. The instant claims also require a particular functionality of detecting and neutralizing an epitope but without a clear structure, Applicant does not have adequate support for all antibodies capable of achieving that function.
However, as discussed above, without any way to determine how broad the genus of such antibodies are, there is no way to determine if these antibodies represent the full breadth of what is claimed. The disclosure of these specific antibodies would not convey to the artisan that Applicant was in possession of the full genus of all antibodies which possess the required functions nor does it allow the skilled artisan to envisage the specific structure of such antibodies.
Further note the decision in Amgen v. Sanofi 2017, where the Court supported previous decisions (Centocor 2011; Abbvie 2014) that defining an antibody solely by what it binds does not satisfy the written description requirement, stating that this would allow patentees to “claim antibodies by describing something that is not the invention, i.e., the antigen”. This decision has precipitated guidance to the Office instructing that the portion of MPEP 2163 regarding the “newly characterized antigen test” (indicating a well-characterized antigen is sufficient to satisfy written description for antibodies which bind that antigen) should no longer be used and that contrary materials should not be relied upon as reflecting the current state of the law.
As such, the disclosure of a list of heavy and light chain variable region sequences that can be paired together in any fashion without guidance from Applicant does not convey possession of all the possible combinations of antibody that may arise, let alone other antibodies with the same binding properties; possession of the precisely defined embodiments of the antibodies are required.
With respect to product claims 1-11, it is recognized that information which is well known in the art need not be described in detail in the specification (MPEP §2163(II)(A)(2)). See, e.g., Hybritech, Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1379-80, 231 USPQ 81, 90 (Fed. Cir. 1986). However, sufficient information must be provided to show that the inventor had possession of the invention as claimed. MPEP §2163(II)(A)(3)(a) also discusses Univ. of Rochester v. G.D. Searle & Co., 358 F.3d 916, 927, 69 USPQ2d 1886, 1894-95 (Fed. Cir. 2004), where a method of using a PGHS-2 inhibitor did not meet the written description as the inhibitor itself was not sufficiently described, clearly indicating that written description of the compound is still required in a method of using that compound. In this case, it is clear from the specification that the invention is in a new antibody, or at the least disclosure of a new antibody that could not have been envisaged from the prior art indicates that the prior art was not in possession of all “anti-human CHI3L1 and CTLA4 antibodies”. Thus, the prior art cannot provide sufficient written description of this genus of compounds and the specification as filed, disclosing one antibody, does not sufficiently describe the genus either as there is an unknown amount of structurally distinct antibodies in this genus (see Amgen and Centocor decisions discussed above).
To satisfy the written description requirement, a patent specification must describe the claimed invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention. See, e.g., Vas-Cath, Inc., v. Mahurkar, 935 F.2d at 1563, 19 U.S.P.Q.2d at 1116. The claimed invention as a whole may not be adequately described where an invention is described solely in terms of a method of its making coupled with its function and there is no described or art-recognized correlation or relationship between the structure of the invention and its function. An antibody described only by functional characteristic, such as antibody that detects and neutralizes CHI3L1 and CTLA4 or one of the claimed epitopes, without any known or disclosed correlation between that function and the structure of the sequence, is not a sufficient identifying characteristic for written description purposes, even when accompanied by a method of obtaining the biomolecule of interest. In re Bell, 991 F.2d 781, 26 U.S.P.Q.2d 1529 (Fed. Cir. 1993). In re Deuel, 51 F.3d 1552, 34 U.S.P.Q.2d 1210 (Fed. Cir. 1995). In the instant case, the specification provides insufficient direction or guidance concerning the relationship between the structure of the possible antibody to demonstrate possession of the breadth of the genus of anti-human CHI3L1 and CTLA4 antibodies encompassed by the instant claims, especially in view of the unpredictability of such an endeavor. The prior art as evidenced by Edwards et al., 2003 (in PTO-892 filed 10/21/2025) teaches there is a substantially huge antibody diversity produced to one single antigen target. Edwards provides evidence that over 1000 antibodies, all different amino acid sequences, were generated towards one single protein antigen target (see abstract). Without a correlation between structure and function, the claims do little more than define the claimed invention by function. That is not sufficient to satisfy the written description requirement. See Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406 (“definition by function … does not suffice to define the genus because it is only an indication of what the gene does, rather than what it is”).
Without this guidance or direction the skilled artisan would not consider applicant to be in possession of the claimed genus of antibodies because the skilled artisan recognizes that even seemingly minor changes made without guidance or direction as to the relationship between the particular amino acid sequence of the instantly claimed antibody and its ability to bind antigen, can dramatically affect antigen-antibody binding.
Applicant has not described the claimed invention sufficiently to show they had possession of the claimed genus of an antibody that binds CHI3L1 and CTLA4. 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 v. G.D. Searle & Co., 358 F.3d 916, 69 USPQ2d 1886 (Fed. Cir. 2004).
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, reduction to drawings, 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. A “representative number of species” means that the species which are adequately described are representative of the entire genus. Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus.
What constitutes a "representative number" is an inverse function of the skill and knowledge in the art. 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 of the elements 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.
To provide adequate written description and evidence of possession of the claimed genus, the specification must provide sufficient distinguishing identifying characteristics of the genus. The factors to be considered include disclosure of complete or partial structure, physical and/or chemical properties, functional characteristics, structure/function correlation, methods of making the claimed product, or any combination thereof. In the instant case, the only factors present in the claims are a recitation of one generic, broad genus that encompassed a diverse and huge number of possible antibodies that bind the disclosed epitope. The specification does not provide a consistent structure for all of the possible antibodies and fails to provide a representative number of species for the claimed genus. Accordingly, in the absence of sufficient recitation of distinguishing identifying characteristics, the specification does not provide adequate written description of the claimed genus.
Vas-Cath Inc. v. Mahurkar, 19USPQ2d 1111, clearly states 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 they invented what is claimed.” (See Vas-Cath at page 1116).
With the exception of specifically disclosed antibodies with specific pairs of heavy and light chain variable region sequences, the skilled artisan cannot envision the detailed chemical structure of all of the encompassed antibodies, and therefore conception is not achieved until reduction to practice has occurred, regardless of the complexity or simplicity of the method of isolation. Adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method of isolating it. The product itself is required. See Fiers v. Revel, 25 USPQ2d 1601 at 1606 (CAFC 1993) and Amgen Inc. v. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016.
One cannot describe what one has not conceived. See Fiddes v. Baird, 30 USPQ2d 1481 at 1483. In Fiddes, claims directed to mammalian FGF's were found to be unpatentable due to lack of written description for that broad class. 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).
Therefore, claims 1-11 do not meet the written description requirement.
Response to Arguments
Applicant's arguments filed 07/10/2026 have been fully considered but they are not persuasive.
Applicant argues that the independent claim 1 has been amended to obviate the rejections. This is not found persuasive.
As noted above in the modified rejection, the pending claims still retain written description issues regarding the identity of the claimed bispecific antibody. While amendments to the claims have corrected issues like the description of the type of sequence (e.g., accurately naming them as heavy and light chain variable region sequences in line with the disclosure as opposed to referring to them as “CDRs”), these changes alone are not sufficient to obviating the rejection as the claims do not sufficiently describe the structure of the antibody commensurate in scope with the instant specification. The instant claims do provide sequences for the heavy and light chain variable region sequences, but does so in a combinatorial fashion as they do not recite the combination of exact heavy and light chain variable region sequences that comprise the antibody. Instead, they continue to list 20 sequences that can be put together in any combination without having a disclosure that is commensurate in scope with such breadth. As such, the claims are recited in a combinatorial fashion that gives rise to numerous, undefined permutations of antibody sequences that could potentially be the embodied antibody that Applicant does not have disclosure for. The instant claims also require a particular functionality of detecting and neutralizing an epitope but without a clear structure, Applicant does not have adequate support for all antibodies capable of achieving that function. The rejection may be obviated with amendments that pair the sequences to complete an antibody embodiment that is in line with the content of the disclosure.
As such, the rejection has been modified in light of amendments to the claims and still remain on the record.
Conclusion
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/SELAM BERHANE/Examiner, Art Unit 1675
/AURORA M FONTAINHAS/Primary Examiner, Art Unit 1675
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