DETAILED ACTION
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 .
Claim Status
Applicant’s reply filed on 10/28/2025 is acknowledged. Claim 12 is amended.
Claims 1-5, 7-12, 15-20, 23-30 are pending. Claims 1-5, 7-11, 16-20, 24-27, and 29 remain withdrawn from consideration as being drawn to nonelected inventions.
Claims 12, 15, 23, 28, and 30 are under examination.
Rejections Withdrawn
The rejection of claims 12, 15, 23, 28, and 30 under 35 U.S.C. 103 as being unpatentable over Choi (MAbs. 2014;6(6):1402-14, IDS 10/17/2024) in view of Foss (J Immunol. 2016 Apr 15;196(8):3452-3459) and Monnet (US2018/0030111A1, published 02/01/2018, effectively filed 05/07/2025) is withdrawn.
Rejections Maintained
Claim Rejections - 35 USC § 112(a)
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 12, 15, 23, 28, and 30 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 claims contain 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.
MPEP § 2163 states that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus. A “representative number of species” means that the species which are adequately described are representative of the entire genus. See, e.g., 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 to provide a "representative number” of species. 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.
The teachings of the specification and the claimed invention
The claims are directed to an antigen-binding molecule comprising an altered TRIM21-binding domain, wherein the TRIM21-binding domain is an IgG1 Fc region and comprises an amino acid substitution selected from I253F, M428R, H433A and H435A.
Regarding claim 12, the antigen-binding molecule has the following characteristics: an altered IgG Fc region and a cytosolic antigen binding domain.
Regarding claim 15, the claim discloses that the antigen-binding molecule of claim 12 also has a cytosol-penetrating ability. Therefore, the antigen-binding molecule of claim 15 has two required functions: (1) the ability to bind a cytosolic antigen and (2) the ability to penetrate the cytosol. The claim does not disclose what structure imparts either of these functions and how one can identify what molecules meet this limitation. The examples distilled to practice in the specification comprise known cytosol-penetrating antibodies 3D8VH-G4T1E356K.Avi/hT4VL-KT0 (Pg. 78) and RT11 (Pg. 81).
The state of the relevant art
Pertaining specifically to antibodies that enter the cytoplasm of living cells, that art teaches that therapeutic use of full-length IgG antibodies is limited by the fact that most antibodies do not readily cross cell membranes (Choi et al. MAbs. 2014;6(6):1402-14, IDS 10/17/2024, Abstract, Lines 1-2), however a small subset of both naturally occurring and engineered antibodies do possess properties that allow them to traffic to the cytosol.
Rhodes (Trends Immunol. 2017 Dec;38(12):916-926) teaches naturally occurring cell-penetrating autoantibodies. The disclosed antibody’s ability to localize to the cytoplasm is conferred by the antigen-binding region of the 3E10 antibody, as the Fab and scFv fragments penetrate into the cytosol independent of the Fc region (Pg. 919, Lines 9-14). Purified 3E10 has been investigated as a cytosolic delivery vehicle for covalently attached moieties; bivalent or bispecific antibody derivatives, which take advantage of the cell-penetrating properties of 3E10 have been tested in cell culture (Pg. 919, Lines 19-24).
Choi (MAbs. 2014;6(6):1402-14) teaches a general strategy for the generation of full-length IgG antibodies which internalize into living cells and localize into the cytosol, identified in the disclosure as cytotransmabs (Abstract, Lines 1-3). Choi demonstrates that cytotransmabs can directly target cytosolic proteins (Abstract, Lines 11-13). The disclosed cytotransmab KT4 binds the cytosolic protein lysyl-tRNA synthetase (KRS) via its VH domain while the cytosol-penetrating ability is conferred by the hT4 VL domain (Page 1408, Left column, Full paragraph 1, Lines 1-10).
Similarly, Shin (Nat Commun. 2017 May 10;8:15090) teaches the generation of the human IgG1-format RT11 iMab, disclosed in the instant specification examples (Specification, Pg 81). RT11 internalizes into the cytosol of living cells and selectively binds to the activated GTP-bound form of various oncogenic Ras mutants (Abstract, Lines 3-7). RT11 was generated by substituting out the antigen-binding VH domain of the Choi’s cytotransmab and retaining the cytosol-penetrating VL domain (Pg. 2, Right column, Lines 5-11).
Another methodology for delivering therapeutic antibodies to cytosolic targets is through fusing cell penetrating peptides to antibodies. Gaston (Sci Rep. 2019 Dec 10;9(1):18688) discloses various cell penetrating peptides (Pg. 3, Table 1) and teaches fusion of cell penetrating peptides at various regions of the antibody framework (Fig. 1). The researchers screened the different embodiments, identifying specific antibody-fusions with the cytosol penetrating ability (Fig. 2A).
In total, the art teaches the ability to traffic to the cytosol is not an inherent ability of most antibodies and requires experimentation and optimization using known cytosol-penetrating methodologies to generate antibodies that possess both the ability to traffic to the cytosol and the ability to bind cytosolic targets.
Claim analysis
In light of the guidance taught in the specification and the state of the relevant art, the claims have the following written description issues:
Claim 1 and 15 claim an antigen-binding molecule, not specifically an antibody. The claimed antigen-binding molecule has an IgG Fc region, a cytosolic antigen binding domain and the ability to penetrate the cytosol of a cell. Pertaining to the cytosolic antigen binding ability and the cytosol penetrating ability, the claims do not provide a structure that correlates with these claimed functions. The claim is broadly directed to any cytosolic antigen-binding molecule that possesses cytosol penetrating abilities. In contrast, the specification is directed to cytosol penetrating antibodies with KRAS-specific antibody variable regions and defined structures that confer their cytosol-penetrating ability.
In light of the claim language that encompasses any cytosolic antigen-binding molecule with cytosolic penetrating abilities, one of skill in the art would neither expect nor predict the appropriate functioning of the antigen binding molecules with modified TRIM21-binding domains as broadly as is claimed. There is no disclosure of a correlation between structure and function that would allow those of skill in the art to recognize other members of the claimed genus from the disclosure.
Given the lack of shared structural properties that provide the claimed function, the limited number of species described, and the fact that the species that were described cannot be considered representative of the broad genus, Applicant was not in possession of the invention as claimed.
Claims 23, 28, and 30 are also rejected for being dependent on claim 12 or comprising the antigen-binding molecule of claim 12 and for failing to add limitations that satisfy the written description requirement.
Response to Applicant’s Arguments
Applicant's arguments filed 10/28/2025 have been fully considered but they are not persuasive.
The applicant argues that one of ordinary skill in the art would be able to identify antigen-binding molecules which fall within the scope of claim 15. The applicant submits that the specification clearly describes various methods of achieving cell penetration, such as paragraphs [0004], [0160], [0161] and [0350]. (Remarks, Pg. 7).
In response, the claims do not claim an antibody, rather any molecule with an IgG Fc, a cytosolic antigen-binding domain and the ability to penetrate the cytosol. The claims rely on structure and function imparted by antibodies to provide written description support; however the claims are not directed specifically to antibodies. Additionally, even if a selection procedure is disclosed that was, at the time of the invention, sufficient to enable the skilled artisan to identify antibodies with the recited functional properties, the written description provision of 35 U.S.C § 112 is severable from its enablement provision. Therefore, the antibody-specific examples in the specification do not provide sufficient written description for the full scope of the claimed invention.
New Rejections Necessitated by Amendment
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 12, 15, 23, 28, and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Choi (MAbs. 2014;6(6):1402-14, IDS 10/17/2024) in view of Foss (J Immunol. 2016 Apr 15;196(8):3452-3459).
The disclosure of Choi is directed to describing a general strategy for the generation of full-length IgG antibodies which internalize into living cells and localize into the cytosol, identified in the disclosure as cytotransmabs (Abstract, Lines 1-3). Choi demonstrates that cytotransmab can directly target cytosolic proteins (Abstract, Lines 11-13). Choi also discusses the need for innovative technology that enables full-length IgG antibodies to directly target cytosolic proteins for imaging and therapeutic purposes (Page 1409, Left column, Discussion, Lines 1-5).
Regarding the antigen-binding molecule of claim 12, Choi discloses the cytotransmab KT4 which binds the cytosolic protein lysyl-tRNA synthetase (KRS) via its VH domain and demonstrates that the KRS-specific KT4 cytotransmab co-localizes with KRS in the cytosol (Fig. 5C).
Regarding claims 15 and 23, pertaining to the antigen binding molecule of claim 12 which has cytosol penetrating ability (claim 15) and further comprising one or more cytosol-penetrating domains (Claim 23), Choi discloses KT4 cytotransmab expresses the cytosol-penetrating hT4 VL, generated to broadly associate with various human VH gene family members (Page 1405, Right column, Lines 1-3 and Fig. 2).
Regarding claim 28, pertaining to a pharmaceutical composition comprising the antigen-binding molecule of claim 12 and a pharmaceutically acceptable carrier, Choi teaches the antibodies were purified from culture supernatants and dialyzed to achieve a final buffer composition of PBS with pH 7.4. The use of the buffer at physiological pH reasonably meets the limitation of formulating the antibody in a pharmaceutically acceptable carrier.
Regarding claim 30, pertaining to an immunoconjugate comprising the antigen-binding molecules of claim 12 conjugated to one or more cytotoxic agents, Choi teaches that cytotransmabs are suitable carriers for the cytosolic delivery of therapeutic agents such as chemical drugs and toxins (Pg. 1410, Right column, full paragraph 1, Lines 19-22).
The disclosure of Choi does not teach the altered TRIM21-binding domain comprises an amino acid substitution selected from the group consisting of I253F, M428R, H433A and H435A.
This deficiency is taught by Foss.
The disclosure of Foss is directed to investigating the functional effects of modifying Fc affinity to TRIM21 (Abstract). The researchers designed a panel of Fc-engineered variants with a range of distinct binding affinities toward TRIM21 (Pg. 3453, Left column, Full paragraph 1, Lines 1-9).
Regarding claim 12, Choi and Foss provide the following teachings:
Choi teaches the cytotransmab antibody is degraded and cleared from the cytosol of living cells by cytosolic proteasomes and that the use of an inhibitor to proteasomal degradation substantially increases persistence in the cytosol up to 18 hours compared to 6 hours without intervention (Pg. 1407, Right column, Full paragraph 2).
Foss teaches the amino acids I253, H433 and H435 are directly engaged in binding at the TRIM21:Fc interface (Pg. 3455, Full paragraph 2, Lines 1-7)
Foss teaches the mutation H433A abolishes Fc binding to TRIM21 (Fig. 3I) and completely abolishes antibody-dependent intracellular neutralization (ADIN) (Pg. 3456, Left column, Lines 14-15).
It would have been obvious to one having ordinary skill in the art to alter the TRIM21-binding domain of the antibody of Choi with a mutation that alters TRIM21:Fc binding, specifically H433A as taught by Foss. The disclosure of Choi is directed to the use of cytosol-penetrating antibodies for therapeutic use. Choi teaches a method of prolonging cytosolic half-life by blocking proteasomal degradation. One would have been motivated to introduce the H433A mutation because Foss teaches it abolishes clearance of the antibody from the cytosol by preventing ADIN. There would be an expectation of success in modifying the antibody of Choi with TRIM21 mutations as taught by Foss who exemplifies the ability to perform site-directed mutations in the Fc regions and provides evidence that H433A prevent ADIN.
Response to Applicant’s Remarks
The applicant argues Choi does not provide a teaching on a need for, or advantage of, increasing cytosolic half-life of the antibody, nor teaching of means to achieve the same. Further pertaining to Choi, the applicant asserts that Choi also does not teach or suggest Fc mutations in the TRIM2 l-binding domain, nor whether there is any effect on cytosolic half-life. The applicant asserts no references show that change in affinity for TRIM21 would affect cytosolic half-life. (Remarks, Pg. 8).
The applicant further argues, “as described in paragraph [0005] of the present specification, TRIM21 is an E3 ubiquitin ligase. Whereas Choi discloses that an inhibitor to proteasomal degradation substantially increased persistence in the cytosol; the inhibitor used in Choi was MG 132. MG 132 is a compound which inhibits the S26 proteasome. Thus, Choi provides no teaching or suggestion that the half-life of antibodies would be increased by modifying the binding activity to TRIM21, as this is not a component of the S26 proteasome.” (Remarks, Pg. 9)
In response, Choi does address the persistence of the antibody in the cytosol, teaching that without modification/intervention, the antibody was significantly reduced at 6 hours and completely undetectable at 18 hours (Pg. 1407, Right column, Full paragraph 1, Lines 15-19). Choi addresses the degradation mechanism of internalized TMab4 by providing MG132, an inhibitor to proteasomal degradation of ubiquitin-conjugated proteins. They determined that treatment with MG132 made the antibody substantially persist in the cytosol after 6 hours and slightly persist up to 18 hours. They determined the clearance of the antibody was degradation by cytosolic proteasomes (Pg. 1407, Right column, Full paragraph 2).
It is known that TRIM21 E3 ubiquitin ligase catalyzes the synthesis of Lys48 (K48)- and ubiquitin chains, resulting in ubiquitin-labeled substrates for degradation by the 26S proteasome (Wang et al. Oncogene. 2023 Dec;42(50):3708-3718). Therefore, Choi’s investigation of prevention of proteasomal degradation is indeed related to TRIM21.
In all, Choi does teach the effect of prevention of proteasomal degradation is an increased persistence of the antibody in the cytosol and Foss teaches specific Fc mutations that abolish proteasomal degradation of antibodies in the cytosol. For these reasons, the 35 U.S.C. 103 rejection will be maintained.
Conclusion
No claims are 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.
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.
/CAROL ANN CHASE/Examiner, Art Unit 1646
/HONG SANG/Primary Examiner, Art Unit 1646