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
Election/Restrictions
Applicant's election with traverse of Group I, claims 1-18 and species: type 1 domain according to SEQ ID NO: 1, extracellular domain of CD28, SEQ ID NO: 16 as the sequence for the extracellular spacer, CD19 as the tumor antigen, SEQ ID NO: 24 as the CD28 intracellular domain, and SEQ ID NO: 32 as the sequence for the CAR in the reply filed on 04/08/2026 is acknowledged. The traversal is on the ground(s) that there is no search burden for the various groups. This is not found persuasive because the unity of invention was broken over a reference, which teaches the shared technical feature. Additionally, Group III is drawn to a method instead of a product as in Group I, which belong to different statutory categories of inventions.
The requirement is still deemed proper and is therefore made FINAL.
Claims 19-28 are withdrawn from consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected inventions and species, there being no allowable generic or linking claims. Election was made in the reply filed 04/08/2026.
Claims 1-18 are now under consideration in the instant Office Action.
Claim Objections
Claims 2, 5-7, 11, and 17-18 are objected to because of the following informalities: references to sequence identities numbers are recited as “SEQ ID NO” when the correct recitation is “SEQ ID NO:”. Appropriate correction is required.
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 6-7 and 11-12 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Instant claims 6-7 and 11 recite sequences with the terminology “…according to SEQ ID NO: [X]…” It is unclear what is meant by this terminology as it broadens the scope of the claim since it does not explicitly define all embodiments of the sequence or what is comprised within it. Applicant is encouraged to amend the claim language to read as “…comprising SEQ ID NO:…” or “…comprising the amino acid sequence of SEQ ID NO:…” at every iteration to obviate this rejection.
Instant claim 12 recites the term “optionally”. The phrase “optionally” is interpreted as "for example" which renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. For the purposes of examination, the instant claims will be interpreted without the optional limitations as they are not required or claimed as necessary to the invention.
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 1-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for 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 1-18 are directed to any chimeric antigen which comprises an extracellular spacer which comprises at least one Ig-like C1 domain of signal-regulatory protein alpha (SIRP-alpha). As such, the claim is 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 (CD19) and envisage the combination of six CDRs that will bind that antigen. First, even highly related CDRs may not bind the same target. See for example Kussie (instant PTO-892) 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 (instant PTO-892) 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 (instant PTO-892), 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 or the structure of a chimeric antigen receptor 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 a variety of sequences for the SIRP-alpha Ig-like C1 type domains, the CD28 extracellular domains, hinge regions, transmembrane domain, heavy and light chain variable regions, linkers, and spacers for the chimeric antigen receptors starting on page 36. However, as discussed above, without any way to determine how broad the genus of such antibodies and chimeric antigen receptors are, there is no way to determine if these embodiments represent the full breadth of what is claimed. Additionally, the instant claims describe these components as “fragments” or “variants” thereof, which is undefined and extremely broad given that the structure(s) have not yet been identified in the claims. The disclosure of these specific antibodies and sequences would not convey to the artisan that Applicant was in possession of the full genus of all antibodies and chimeric antigen receptors which possess the required functions nor does it allow the skilled artisan to envisage the specific structure of such antibodies. In the instant claims, Applicant does not recite a complete embodiment of the chimeric antigen receptor in its entirety.
As recited in the instant claims, the chimeric antigen receptor molecule is described fully functionally and by generic structures, such as acknowledging the presence of a transmembrane domain, without acknowledging the identity of many of these protein structures. Applicant points to the extracellular spacers as being the inventive concept, but does not point to specific sequence(s) in the broader context which elucidate this effect.
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.
It is appreciated that certain claims do include at least an antigen target for the chimeric antigen receptor, e.g., claim 16, which recites that the antigen targets can be CD19 or HER-2. However, this recitation is defined to include no particular structure so long as the function is retained. The claims only require that the chimeric antigen receptor against CD19 or HER-2 only binds to an epitope without providing a structure for its antigen binding regions on the chimeric antigen receptor.
However, as above, arbitrarily altering any amino acid in the CDR of an antibody is unpredictable and the specification does not convey possession of any CDRs other than those of the disclosed antibodies. Further, it is well-known in the art that specificity of an antibody stems from the interaction of six CDRs. Moreover, CDRs are not generally recognized as interchangeable, such that using one CDR from one antibody would not be reasonably expected to confer the same binding properties or even the same binding target when combined with two to five CDRs from other antibodies. For example, WO 2008068048 (instant PTO-892) discloses an antibody with a heavy chain comprising three CDRs (SEQ ID NO: 2) that binds secreted aspartyl protease from Candida sp. US 20170355756 (instant PTO-892) describes the same three CDRs in the heavy chain (C10-VH3) combined with a different light chain that binds human TDP-43. There is no evidence in the instant specification that a single CDR placed in the context of two to five other CDRS, regardless of what those other CDRs are, would result in the required function, nor that a single chain is correlated to the required function when combined with any other chain. As such, the specification fails to set forth a structure-function correlation sufficient to claim all possible antibodies defined by function and one-three CDRs or alterations thereof.
As such, the disclosure of a combination of randomly assorted sequences of components of a chimeric antigen receptor does not convey possession of other chimeric antibodies with the same binding properties; possession of precisely defined sequences of six CDRs is required as well as other essential structural elements.
With respect to product claims 1-18, 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 chimeric antigen receptor, or at the least disclosure of a new chimeric antigen receptor that could not have been envisaged from the prior art indicates that the prior art was not in possession of all CD19 antibodies comprised within chimeric antigen receptors. 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. A chimeric antigen receptor that is described only by functional characteristic, such as by its antigen binding region that binds CD19 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 CD19 antibodies comprised within chimeric antigen receptors 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 (instant PTO-892) 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 CD19 or a chimeric antigen receptor comprising an extracellular spacer which comprises at least one Ig-like C1 domain of signal-regulatory protein alpha (SIRP-alpha). 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 CDRs, 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 1-18 do not meet the written description requirement.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 8-9, and 12-16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hudecek et al. (in IDS filed 06/15/2023).
Hudecek et al. analyzes the "influence of length and composition of IgG-derived extracellular spacer domains on the function of CARs. CD19-CARs with a long spacer from IgG4 hinge-CH2-CH3 are functional in vitro but lack antitumor activity in vivo due to interaction between the Fc domain within the spacer and the Fc receptor-bearing myeloid cells, leading to activation-induced T-cell death. We demonstrate that in vivo persistence and antitumor effects of CAR-T cells with a long spacer can be restored by modifying distinct regions in the CH2 domain that are essential for Fc receptor binding", see Abstract. Hudecek et al. also teaches that “each spacer was linked to a CD28 transmembrane domain and a signaling module composed of CD3ζ with a membrane-proximal 4-1BB costimulatory domain”, see p. 126.
Hudecek et al. also teaches "CAR's comprising CH2-deleted spacers that abrogated adverse effects related to FcR binding", see p. 126. Hudecek et al. teaches “that the length of the nonsignaling spacer exerts a major effect on T-cell effector functions after target engagement, and that the composition of spacers that contain Fc domains must be altered or mutated to prevent in vivo interactions with cells expressing Fc gamma receptors (FcγR) that result in off-target activation of CAR-modified T cells and impair antitumor efficacy”, see p. 126.
This meets the limitations of instant claim 1 wherein the chimeric antigen receptor comprises an extracellular spacer derived from Ig-like C1 domains, instant claim 8 wherein the extracellular spacer is located between a transmembrane domain and an antigen binding domain (see instant application’s figure 1a), instant claim 9 wherein antigen binding domain comprises a scFv, instant claim 12 wherein the chimeric antigen receptor comprises an extracellular domain, an antigen binding domain, a transmembrane domain, an intracellular signaling domain, instant claim 13 wherein the antigen binding domain comprises an antibody or its fragment, instant claim 14 wherein the antigen binding domain is a scFv, instant claim 15 wherein the antigen binding domain targets a tumor antigen, and instant claim 16 wherein the tumor antigen is CD19.
Therefore, claims 1, 8-9, and 12-16 are rejected as anticipated by Hudecek et al.
Conclusion
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/SELAM BERHANE/Examiner, Art Unit 1675
/AURORA M FONTAINHAS/Primary Examiner, Art Unit 1675
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