Prosecution Insights
Last updated: September 17, 2026
Application No. 18/017,236

CD8 BINDING POLYPEPTIDE AND USE THEREOF

Non-Final OA §112§DP
Filed
Sep 15, 2023
Priority
Jul 21, 2020 — CN 202010703962.9 +1 more
Examiner
WEN, SHARON X
Art Unit
1641
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Suzhou Smartnuclide Biopharmaceutical Co., Ltd.
OA Round
1 (Non-Final)
57%
Grant Probability
Moderate
1-2
OA Rounds
9m
Est. Remaining
89%
With Interview

Examiner Intelligence

Grants 57% of resolved cases
57%
Career Allowance Rate
359 granted / 632 resolved
-3.2% vs TC avg
Strong +33% interview lift
Without
With
+32.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
33 currently pending
Career history
664
Total Applications
across all art units

Statute-Specific Performance

§101
2.9%
-37.1% vs TC avg
§103
20.8%
-19.2% vs TC avg
§102
19.7%
-20.3% vs TC avg
§112
32.6%
-7.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 632 resolved cases

Office Action

§112 §DP
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Applicant’s amendment, filed 09/15/2023, has been entered. Amendment to the specification, filed 09/15/2023, has been entered. Claims 1-13, 16-18, 20, 23, 32, 34 are pending. Election/Restrictions Applicant’s election without traverse of Group I and species of CDR sequences of SEQ ID NOs: 26, 27 and 28 in the reply filed on 06/24/2026 is acknowledged. Claims 6-9, 16, 20, 23, 32, 34 have been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Inventions, there being no allowable generic or linking claim. Claims 1-5, 10-13, 17-18 are currently under examination as they read on a CD8 binding polypeptide comprising at least one immunoglobulin single variable domain binding to CD8α. 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 1, 3, 4, 5, 10-13, 17-18 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 and dependent claims thereof are indefinite for requiring CDR sequences (CDR1, CDR2, and CDR3) without specifying the particular sequences associated with each CDR or the method by which they are meant to be determined (e.g. Chothia, Kabat, IGMT, etc.). The recited SEQ ID NO in the claim corresponds only to a variable domain, and it is unclear which subsequences thereof are intended to correspond to which CDR. As such, it is unclear what is intended to be encompassed by the claimed CDR sequences or how one is to determine the metes and bounds for CDR1, CDR2, and CDR3. 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, 3, 4, 5, 10-13, 17-18 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. The present claims are directed to CD8α binding polypeptides comprising a variable domain comprising CDR1, CDR2, CDR3 from any one of the reference sequences recited. Therefore, the breadth of the claimed polypeptide encompasses a large genus of extremely diverse polypeptide variable domains that comprise miss matched CDR sequences from any one of the variable domains. Moreover, given the recitation of “an amino acid sequence”, the variable domains read on any sequences in the reference sequence. The present claims do NOT satisfy the written description requirement for the claimed genus for the following reasons: The written description requirement for a claimed genus/subgenus may be satisfied through description of 1) a representative number of species OR 2) disclosure of relevant identifying characteristics, i.e., functional characteristics coupled with a known or disclosed correlation between function and structure. Representative Species Regarding representative number of species, the instant specification disclosed a number of species of the genus (claim 2). However, the disclosed species are not sufficient to represent the entire genus as claimed. A “representative number of species" means that those species that are adequately described are representative of the entire genus. AbbVie Deutschland GMBH v. Janssen Biotech, 111 USPQ2d 1780, 1790 (Fed. Cir. 2014). Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. The “structural features common to the members of the genus” needed for one of skill in the art to 'visualize or recognize' the members of the genus takes into account the state of the art at the time of the invention. For example, the Federal Circuit has found that possession of a mouse antibody heavy and light chain variable regions provides a structural “stepping stone” to the corresponding chimeric antibody, but not to human antibodies. Centocor Ortho Biotech Inc. v. Abbott Labs., 97 USPQ2d 1870, 1875 (Fed. Cir. 2011). The size of the claimed antibody genus comprises substantial variations as one of skill in the art is well aware of the high level of polymorphism and complex nature of immunoglobulins. Schroeder et al. taught that through somatic variation, combinatorial rearrangement of individual gene segments and combinatorial association between different L and H chains, the repertoire of antibody diversity can have greater than 1016 different immunoglobulins (J Allergy Clin Immunol 2010, 125:S41-S52). Moreover, it is well-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 over 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 (Protein Engineering, Design & Selection 2009, 22:159-168; see, e.g., Discussion). Therefore, the disclosed species are not representative of the claimed genus encompassing the substantial variation due to the high level of polymorphism of antibodies as exemplified by the above references. Structure-function correlation Written description can also be satisfied with disclosure of relevant identifying characteristics, i.e., functional characteristics coupled with a known or disclosed correlation between function and structure. While the term “antibody” does impart some structure, the structure that is common to antibodies is generally unrelated to antigen-binding function because antibody CDRs are necessary for binding and they are highly diverse in structure, and their sequence does not correlate to binding in a predictable fashion. The subgenus as recited in claim 30 encompasses more than 220,000 possible variants with substitutions in the CDRs. The Applicant does not have possession of all these variants as not all of them will have the binding function as required by the claims. It is well established in the art that the formation of an intact antigen-binding site in an antibody usually requires the association of the complete heavy and light chain variable regions of a given antibody, each of which consists of three CDRs (or hypervariable regions), which provide the majority of the contact residues for the binding of the antibody to its target epitope. The amino acid sequences and conformations of each of the heavy and light chain CDRs are critical in maintaining the antigen binding specificity and affinity which is characteristic of the parent immunoglobulin. It is expected that all of the heavy and light chain CDRs in their proper order and in the context of framework sequences which maintain their required conformation, are required in order to produce a protein having antigen-binding function and that proper association of heavy and light chain variable regions is required in order to form functional antigen binding sites. Even minor changes in the amino acid sequences of the heavy and light variable regions, particularly in the CDRs, may dramatically affect antigen-binding function as evidenced by Rudikoff et al. (Proc Natl Acad Sci USA 1982 Vol 79 page 1979). Rudikoff et al. teach that the alteration of a single amino acid in the CDR of a phosphocholine-binding myeloma protein resulted in the loss of antigen-binding function. MacCallum et al. (J. Mol. Biol. 1996 262, 732-745), analyzed many different antibodies for interactions with antigen and state that although CDR3 of the heavy and light chain dominate, a number of residues outside the standard CDR definitions make antigen contacts (see page 733, right col) and non-contacting residues within the CDRs coincide with residues as important in defining canonical backbone conformations (see page 735, left col.). Pascalis et al. (The Journal of Immunology (2002) 169, 3076-3084) demonstrate that grafting of the CDRs into a human framework was performed by grafting CDR residues and maintaining framework residues that were deemed essential for preserving the structural integrity of the antigen binding site (see page 3079, right col.). Although abbreviated CDR residues were used in the constructs, some residues in all 6 CDRs were used for the constructs (see page 3080, left col.). The fact that not just one CDR is essential for antigen binding or maintaining the conformation of the antigen binding site, is underscored by Casset et al. (BBRC 2003, 307:198-205), which constructed a peptide mimetic of an anti-CD4 monoclonal antibody binding site by rational design and the peptide was designed with 27 residues formed by residues from 5 CDRs (see entire document). Casset et al. also states that although CDR H3 is at the center of most if not all antigen interactions, clearly other CDRs play an important role in the recognition process (page 199, left col.) and this is demonstrated in this work by using all CDRs except L2 and additionally using a framework residue located just before the H3 (see page 202, left col.). Vajdos et al. (J. Mol. Biol. (2002) 320, 415-428), additionally state that antigen binding is primarily mediated by the CDRs more highly conserved framework segments which connect the CDRs are mainly involved in supporting the CDR loop conformations and in some cases framework residues also contact antigen (page 416, left col.). Chen et al. (J. Mol. Bio. (1999) 293, 865-881) describe high affinity variant antibodies binding to VEGF wherein the results show that the antigen binding site is almost entirely composed of residues from heavy chain CDRs, CDR-H1, H2, H3 (page 866). Wu et al. (J. Mol. Biol. (1999) 294, 151-162) state that it is difficult to predict which framework residues serve a critical role in maintaining affinity and specificity due in part to the large conformational change in antibodies that accompany antigen binding (page 152 left col.) but certain residues have been identified as important for maintaining conformation. Padlan et al. (PNAS 1989, 86:5938-5942) described the crystal structure of an antibody-lysozyme complex where all 6 CDRs contribute at least one residue to binding and one residue in the framework is also in contact with antigen. In addition, Lamminmaki et al. (JBC 2001, 276:36687-36694) describe the crystal structure of an anti-estradiol antibody in complex with estradiol where, although CDR3 of VH plays a prominent roll, all CDRs in the light chain make direct contact with antigen (even CDR2 of VL, which is rarely directly involved in hapten binding). Recently, studies have shown that changes in CDRs even alter Fc binding to the Fc receptor and pharmacokinetics (Piche-Nicholas et al. MABS 2018, 10:81-94). Given the highly diverse nature of antibodies, particularly in the CDRs, by claiming a genus of antibodies defined by the antigen specificity without any defined structure/sequences is analogous to searching for a key “on a ring with a million keys on it” Centocor, 636 F.3d at 1352. Therefore, the claims do not satisfy the written description requirement as the structure-function correlation of the claimed subgenus not sufficiently described. Given the well-known high level of polymorphism of immunoglobulins / antibodies, the skilled artisan would not have been in possession of the vast repertoire of antibodies and the unlimited number of antibodies encompassed by the claimed invention; one of skill in the art would conclude that applicant was not in possession of the structural attributes of a representative number of species possessed by the members of the genus of CD8 binding polypeptides broadly encompassed by the claimed invention. One of skill in the art would conclude that the specification fails to disclose a representative number of species to describe the claimed genus. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-5, 10-13, 17-18 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 7, 9, 11, 13, 15-18, 30, 34 of copending Application No. 18573006 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because the copending claims are directed to the a CD8 binding polypeptide comprising CDRs of the same sequences (see below sequence alignment). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. PNG media_image1.png 756 830 media_image1.png Greyscale Allowable Subject Matter Claim 2 to the extent of elected species is objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHARON X WEN whose telephone number is (571)270-3064. The examiner can normally be reached Mon-Fri 8-5. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, 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. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SHARON X WEN/Primary Examiner, Art Unit 1641
Read full office action

Prosecution Timeline

Sep 15, 2023
Application Filed
Sep 01, 2026
Non-Final Rejection mailed — §112, §DP (current)

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Prosecution Projections

1-2
Expected OA Rounds
57%
Grant Probability
89%
With Interview (+32.6%)
3y 9m (~9m remaining)
Median Time to Grant
Low
PTA Risk
Based on 632 resolved cases by this examiner. Grant probability derived from career allowance rate.

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