PROXIMITY INDUCED SITE-SPECIFIC ANTIBODY CONJUGATION

DETAILED ACTIONS 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, 4-5, 30, 34, 48-49, 94-101 are under consideration. Rejections/Objections Withdrawn All 35 USC 103 rejections articulated in the previous Office Action have been withdrawn in view of claim amendments. New Rejections Necessitated by Amendment Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1, 4-5, 30, 48-49, 94-95 and 97-101 and is/are rejected under 35 U.S.C. 103 as being unpatentable over Hobbes (Hobbes, et al., US 2013/0184442 A1; Published 07/18/2013, of record) in view of Xuan (Xuan, et al., Agnew. Chem. Int. Ed. 2017 56:5096, of record)) and Strambio de Castilla (Strambio de Castilla, et al., J Proteome Research (2005) 4(6):2250). Hobbes teaches that BPA is a synthetic, photo-reactive amino acid that can be incorporated into a peptide during synthesis and forms covalent bonds with other amino acids under UV light (Hobbes, ¶ 0005). Regarding claim 1, Hobbes teaches a method of specific covalent labeling to immunoglobins by using a synthetic Z domain (which has affinity for the antibody’s Fc fragment) comprising BPA, with the method comprising a) providing the IgG binding protein with the photoreactive motif, b) forming a mixture of the IgG binding protein and antibodies and c) UV illuminating the mixture for site-specific labeling of said antibodies (this also satisfies claims 48 and 49, as no treatments using any additional agents (Hobbes, ¶ 0006-0007). Regarding claim 100, Hobbes teaches that affinity compound of Hobbes is situated between CH2 and CH3 of the antibody involved 11 residues from helix 1 and helix 2 of the B domain of Protein A (Hobbes, ¶ 0004). Regarding claims 4 and 5, Hobbes discloses that labeled affinity peptide were produced by Fmoc-based solid phased synthesis (Hobbes, ¶ 0040-0045). Hobbes also teaches methods of labeling antibodies to fluorescent compounds and radioisotopes using the antibody-binding platform of Hobbes. (Hobbes, ¶ 0012). Regarding claims 94-95 and 97-100, Hobbes teaches antibody labeling platforms that attach an agent that is a radionuclide residue, wherein the antibody being labeled is human IgG1. Regarding claim 100, Hobbes teaches that the covalent bond between the affinity compound and the antibody to be labeled is located within the antibody CH2-CH3 hinge region (Hobbes ¶ 0004) Hobbes does not teach the antibody labeling platform of Hobbes wherein antibody-reactive crosslinker is FPheK that is inserted at position 6 of an FcIII cyclic peptide. Xuan teaches on the use of noncanonical amino acids (ncAAs) PheK and FPheK, which comprise aryl carbamate side chains, to form crosslinks with adjacent Lys, Cys and Tyr residues (Xuan, Abstract). Xuan teaches that aryl carbamates are moderate electrophiles that have been used as cleavable linkers in ADCs that undergo proximity-assisted nucleophilic attack to release drugs (Xuan, p 5096, ¶ 2). Xuan teaches that the distance between the Lys8 of an anti-thioredoxin affimer (a peptide mimetic that is structurally similar to an antibody’s Fc domain) (Xuen, p 5097, ¶ 2) is only 7.1 angstroms when the Z-protein/affimer complex is formed (Xuan, p 5097, ¶ 2-3; Fig 3A.; Fig 3 A-B) PNG media_image1.png 184 197 media_image1.png Greyscale Fig 4A of Xuan reference. Xuan also teaches that mutation position amino acid was Glu 98 to non-nucleophilic Asn resulted in a crosslinker that was not able to form stable, covalent crosslinks with Lys8 upon formation of the ProteinZ/ Affimer complex. Both of the nucleophilic side chains of Cys and Tyr were also able form stable crosslinks and that His and Ser were also able to form crosslinks but had low efficiency due to competitive hydrolysis because Xuan teaches p 5097, ¶ 4 – p 5098, ¶ 2); Xuan teaches that prior work within the Xuan group showed that FPheK (para-isothiocyanate phenylalanine; a previously characterize proximity-inducible moiety at position 25 of a Z protein was able to form a stable thiourea linkage with Lys8 of a Afb-Trx fusion protein (an antibody mimetic that also binds to protein A, leading Xuan to hypothesize that FPheK integrated at position 25, leading Xuan to hypothesize that a Z protein with PFeK integrated at position 25 would form a covalent bond to Lys8 (Xuan, p 5098, ¶ 2) and that this was confirmed by generating a Z protein with FPheK at position 25 of a Z protein, incubating it with Afb-Trx and then analyzing it via ESI-QTOF mass spectrometry with Afb-Trx Lys8Asn as a negative control (Xuan, p 5098, ¶ 3). Strambio de Castilla teaches the peptide FcIII mimics the portion the protein A protein that binds the hinge region of the Fc fragment of an antibody (Strambio de Castilla, p 1, ¶ 3). Strambo de Castilla teaches that the FcIII peptides of Strambio de Castilla were air oxidized overnight to promote cyclization of the FcIII peptides (Strambio de Castilla, p 2, ¶ 1). It would be prima facie obvious to one of ordinary skill in the art to modify the antibody labeling technology of Hobbes to contain the FPheK of Xuan as a conjugating agent instead of the BPA of Hobbes. The net result of this modification would be the antibody labeling system of Hobbes with FPheK incorporated in the Z protein instead of BPA, wherein the FPheK is incorporated at position 25 of the Z protein. One of ordinary skill in the art would be motivated to make this modification in order to link the Z protein to the antibody without requiring the use of UV light to activate the BPA of Hobbes. One of ordinary skill in the art would have a reasonable expectation of success modifying the antibody labeling technology of Hobbes to contain the FPheK of Xuan at position 25 of a Z protein because Xuan demonstrates that Z proteins containing FPheK form covalent bonds with Afb-Trx in the same manner that a previously studied proximity inducible compound and one of ordinary skill in the art would reasonably expect future compounds to behave as previously studied compounds. It would be prima facie obvious to one of ordinary skill in the art to modify the method of Hobbes and Xuan to include the FcIII peptide of Strambio de Castilla as the Fc binding peptide instead of the Z protein fragment of Hobbes and Xuan. One of ordinary skill in the art would be motivated to make such a substitution in order to arrive at an art equivalent Fc hinge binding protein suitable for the conjugation of method of Hobbes and Xuan. One of ordinary skill in the art would have a reasonable expectation of success substituting the FcIII peptide of Strambio de Castilla for the Z protein fragment of Hobbes and Xuan and because both the Z protein of Hobbes and Xuan and the FcIII peptide of Strambio de Castilla possess the shared function of binding the hinge region of the Fc fragment of an antibody. Regarding the conjugation point on the FcIII peptide, it is obvious to pick position 6 of SEQ ID NO: 12 because the chemistry of Xuan comprises lysine-based conjugation and the AA at position 6 of SEQ ID NO: 12 is the only lysine in the FcIII peptide. Response to Arguments Applicant's arguments filed 9/9/2026 have been fully considered but they are not persuasive. Applicant argues that the amendments to the claims which now require the FPheK to be inserted at position 6 of a FcIII peptide of SEQ ID NO: 12 differentiate the instant claimed invention from the prior art. Applicant argues that neither Strambio de Castilla or any other cited art teaches or suggests incorporation of FPheK at position 6 specifically. In response, the sequence of SEQ ID NO: 12 is: DDCAWKLGELVWCT Please note that SEQ ID NO: 12 corresponds to a complete FcIII peptide, as an FcIII peptide is 13 amino acids in length. One of skill in the art, having read and understood both Xuan and Strambio de Castilla, would naturally pick position 6 of SEQ ID NO: 12 because the chemistry of Xuan is lysine-based chemistry and the amino acid residue at position 6 is the only lysine in a FcIII peptide. Claim(s) 1, 4-5, 30, 34, 48-49, 94-95 and 97-101 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hobbes (Hobbes, et al., US 2013/0184442 A1; Published 07/18/2013, of record) and Xuan (Xuan, et al., Agnew. Chem. Int. Ed. 2017 56:5096, of record)) and Strambio de Castilla (Strambio de Castilla, et al., J Proteome Research (2005) 4(6):2250) as applied to claims 1, 4-5, 30, 48-49, 94-95 and 97-101 above and in further view of Sampath (Sampath, et al., J Nucl Med 2007 48:1501, of record). The combined teachings of Hobbes, Xuan and Strambio de Castilla are discussed above. The combined teachings of Hobbes, Xuan and Strambio de Castilla do teach that the antibody being linked to the target agent in the method collectively taught by Hobbes, Xuan and Strambio de Castilla is trastuzumab. Sampath teaches of trastuzumab that has been labeled with 111In and a near infrared dye (IRDye800) is useful for detecting HER2 overexpression in breast cancers (Sampath, Abstract). Sampath teaches that the labeled trastuzumab was made by first adding DTPA groups at available amines on the antibody (Sampath, p 1502, ¶ 4), then allowing amine reactive, commercially available IRDye 800 to react with the antibody (Sampath, p 1502, ¶ 5) and finally complexing 111In with the DTPA groups on the antibody by adding 111InCl3 (Sampath, p 1502, ¶ 6). It would be prima facie obvious to one of ordinary skill in the art to combine the conjugation method collectively taught by Hobbes, Xuan and Cau to make the dual labeled trastuzumab of Sampath. One of ordinary skill in the art would be motivated to make the dual labeled trastuzumab of Sampath using the method of Hobbes, Xuan and Strambio de Castilla in order to make the radiolabeled/fluorescent labeled antibody in order to generate a dual labeled antibody for detecting HER2 overexpression in breast cancers without affecting the antigen binding domain of the trastuzumab. One of ordinary skill in the art would have a reasonable expectation of success using conjugation method collectively taught by Hobbes, Xuan and Strambio de Castilla to make the dual labeled trastuzumab of Sampath because: 1) Sampath teaches that 111In/IRDye800 antibodies are useful for measuring HER2 overexpression in breast cancer and 2) The combined method of Hobbes, Xuan and Strambio de Castilla teaches a method capable of adding both fluorescent and radioisotope labels to antibodies without affecting the antibody’s antigen binding domain. Response to Arguments Applicant's arguments filed 9/9/2026 have been fully considered but they are not persuasive. Applicant did not provide any arguments specific to this rejection other than stating Sampath does not address any of the alleged “deficiencies” of the cited art with respect to incorporation of FPheK at position 6 of a FcIII peptide of SEQ ID NO: 12. These arguments have been addressed above. Claim(s) 1, 4-5, 30, 34, 48-49, 94-101 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hobbes (Hobbes, et al., US 2013/0184442 A1; Published 07/18/2013, of record), Xuan (Xuan, et al., Agnew. Chem. Int. Ed. 2017 56:5096), Strambio de Castilla (Strambio de Castilla, et al., J Proteome Research (2005) 4(6):2250) and Sampath (Sampath, et al., J Nucl Med 2007 48:1501, of record) as applied to claims 1, 4-5, 30, 34, 48-49, 94-95 and 97-101 and in further view of Kim (Kim, et al., Biomol Ther (2015) 23(6):493) The combined teachings of Hobbes, Xuan, Strambio de Castilla and Sampath are discussed above. In addition, Hobbes teaches that labeling moieties are coupled to IgG proteins via linkers (Hobbes, ¶ 0012). The combined teachings of Hobbes, Xuan, Strambio de Castilla and Sampath do not teach that the moiety attached to the antibody is a toxin or chemotherapeutic. Kim teaches on the subject of ADCs (Kim, Abstract). Kim teaches that ADCs were derived to minimize off-target systemic toxicity of chemotherapy by conjugating a mAb to a cytotoxin via a linker, with the mAb acting to minimize off-target systemic toxicity by localizing the cytotoxins around the mAb’s target antigen (typically on a tumor cell). (Kim, p 495, ¶ 4-5). It would be prima facie obvious to one of ordinary skill in the art to combine the trastuzumab of Sampath with the antibody-bound-linker-cytotoxin of Kim and conjugation method collectively taught by Hobbes. The net result of this combination is a trastuzumab ADC, wherein a cytotoxin is conjugated to the trastuzumab via a linker, where conjugation between the linker and antibody takes place using the method collectively taught by Hobbes, Xuan and Kim. One of ordinary skill in the art would be motivated to do this in order to better treat form an ADC capable of targeting HER2+ breast cancer found when the method of Sampath is performed. One of ordinary skill in the art has a reasonable expectation of success conjugating a cytotoxin to a trastuzumab via a linker to form a HER2 targeting ADC because: both Hobbes and Kim teach conjugation to antibodies via linkers and Kim specifically teaching conjugation of cytotoxins to antibodies via linkers, Kim teaches that cytotoxins linked to antibodies are common in the art and the combined method of Hobbes and Xuan provides a highly efficient, site specific means to conjugate numerous moieties to antibodies via linkers. Response to Arguments Applicant's arguments filed 9/9/2026 have been fully considered but they are not persuasive. Applicant did not provide any arguments specific to this rejection other than stating Kim does not address any of the alleged “deficiencies” of the cited art with respect to incorporation of FPheK at position 6 of a FcIII peptide of SEQ ID NO: 12. These arguments have been addressed above. Conclusion Claims 1, 4-5, 30, 34, 48-49, 94-101 are rejected. 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. 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