Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
Application Status
Claims 1-5, 12-17, and 19-26 are pending and examined on the merits herein.
Grounds of Rejection Withdrawn
All previous objections to the specification are withdrawn in view of amendment.
All previous objections and rejections of claims 6-11 and 18 have been rendered moot by claim cancellation.
Previous rejection of claims 13 and 19 under 35 U.S.C. 112(b) are withdrawn in view of claim amendments.
Previous rejection of claim 19 under 35 U.S.C. 112(a) are withdrawn in view of claim amendments.
Previous rejection of claims 1-4, 12, 14-17 and 19 under 35 U.S.C. 102 are withdrawn in view of claim amendments.
Previous rejection of claims 5 and 13 under 35 U.S.C. 103 are withdrawn in view of claim amendments.
Claim Objections
Claims 12, 19 and 26 are objected to because of the following informalities:
Claim 12 is listed as canceled and as previously presented; for the purpose of compact prosecution the canceled claims will be read as 6-11 and 18;
Claim 19, line 4 recites “subject in heed thereof” should read “subject in need thereof”;
Claim 26, line 1 recites “further comprising one or linker” should read “further comprising one or more linker(s)”;
Appropriate correction is required.
Claim Rejections - 35 USC § 103
New Rejection Necessitated by Amendment
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 12, 14-17, and 19-24 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Pieczykolan (WO 2013/080147 A2; IDS entered 02/15/2023) and Olombrada (Biol. Chem., 2017, 398(1): 135-142; IDS entered 02/15/2023) as evidenced by Uniprot database A0A014PJJ6 (IDS entered 02/15/2023).
Regarding claim 1, Pieczykolan teaches a fusion protein comprising domain a) which is a functional fragment of the TRAIL protein and domain b) which is an effector peptide inhibiting protein synthesis (claim 1), in which the effector peptide has ribonuclease activity and is selected from the protein toxins hirsutellin… (claims 11-12). Hirsutellin is a homologue of anisoplin.
Regarding claim 2, Pieczykolan teaches to achieve high specificity toxins can be fused to antibodies (page 3, lines 26-31).
Regarding claims 3 and 21-23, Pieczykolan teaches which additionally comprises a flexible steric linker between domains (a), (b) (claim 25), steric linker may be a combination of glycine and serine residues, such as for example Gly Gly Gly Gly Ser/GGGGS or any fragment thereof acting as steric linker (page 25, lines 18-20).
Regarding claims 4, 14, and 23, Pieczykolan teaches which between domain (a) and domain (b) containing protease cleavage site (claim 20). Pieczykolan further teaches that the invention also provides the use of the fusion protein of the invention as defined above for treating cancer diseases in mammals (page 36, lines 19-20) and comprising the sequence of a cleavage site between domains a) and b) recognized by proteases present in the cell environment, especially in the tumor cell environment, e.g. such as metalloprotease, urokinase or furin (page 21, lines 33-34-page 22, lines 1-2). Therefore the protease cleavage site would be specific to an enzyme expressed by a mammalian cell and localized to the cell surface, which are not expressed in plants.
Regarding claims 12, 15, and 24, Pieczykolan teaches heterologous expression systems based on various well-known host cells may be used including plant cell lines (page 32, lines 8-12). Expression in a plant cell line would naturally include plant specific glycosylation.
Regarding claim 16, Pieczykolan teaches a pharmaceutical composition comprising as an active ingredient the fusion protein as defined in any one of claims 1 to 30, in combination with a pharmaceutically acceptable carrier (claim 37).
Regarding claim 17, Pieczykolan teaches concomitant therapeutic interventions (page 39, line 9).
Regarding claim 19, Pieczykolan teaches the fusion protein as defined in any one of claims 1 to 30 for use in the treatment of neoplastic diseases in mammals, including humans (claim 39) and a method of treating cancer diseases in mammal, including human, which comprises administration to a subject in a need thereof an anti-neoplastic- effective amount of the fusion protein as defined in claims 1 to 30, or the pharmaceutical composition as defined in claims 37 or 38 (claim 40).
Pieczykolan does not teach the toxin having a sequence according SEQ ID 48 or 49, an active fragment thereof or a homologue with 80% sequence identity therewith.
Regarding claims 1 and 20, Olombrada teaches that a well-known family of toxic proteins secreted by fungi are ribotoxins, specific ribonucleases (RNases) against the large rRNA in the ribosome with lethal consequences for the target cell and that recent studies focused on their antitumor properties conjugated as immunotoxins (page 136, col 1, para 2). Olombrada further teaches that anisoplin is structurally similar to hirsutellin A with 70% sequence identity to the mature protein and conserved cysteine and active site residues (page 136, col 1, para 3). Olombrada further teaches that anisoplin shows the ribonucleolytic activity typical of ribotoxins and cytotoxicity against insect cells (abstract). Olombrada expressed anisoplin as a fusion protein with thioredoxin for characterization (page 136, col 2, para 2) finding that anisoplin has a signal sequence of 19 amino acid residues similar to hirsutellin as well as similar activity (Fig 1A).
As evidenced by the UniProt ID A0A014PJJ6, which is the sequence of anispolin ARSEF23 tested by Olombrada and named Hirsutellin A ribotoxin like protein, the UniProt sequence has 100% sequence identity to the SEQ ID NO: 48 and 98.6% sequence identity to SEQ ID NO: 49 with the first 19 amino acid residue signal sequence removed as taught by Olombrada, as seen in the alignments below.
PNG
media_image1.png
339
731
media_image1.png
Greyscale
SEQ ID NO: 48 to A0A014PJJ6
PNG
media_image2.png
252
598
media_image2.png
Greyscale
SEQ ID NO:49 to A0A014PJJ6
PNG
media_image3.png
242
600
media_image3.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to substitute anisoplin for hirsutellin as taught by Olombrada into the binder-toxin fusion protein as taught by Pieczykolan. The ordinary artisan would have been motivated to do so because this is a simple substitution of the same element in the fusion protein. Olombrada teaches that anisoplin is structurally similar to hirsutellin A and shows the ribonucleolytic activity typical of ribotoxins and cytotoxicity and that these ribotoxins are useful for their antitumor properties conjugated as immunotoxins. Therefore the ordinary artisan has a reasonable expectation of success to use anisoplin in the binder-toxin fusion protein.
Claims 5 and 25-26 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Pieczykolan (WO 2013/080147 A2; IDS entered 02/15/2023) and Olombrada (Biol. Chem., 2017, 398(1): 135-142; IDS entered 02/15/2023) as evidenced by Uniprot database A0A014PJJ6 (IDS entered 02/15/2023) as applied to claims 1-4, 12, 14-17, and 19-24 above, and further in view of Gelsen (WO 2017/053290 A1; IDS entered 02/15/2023) and Pfeifer (Leukemia 29, 1578–1586 (2015); PTO-892).
The teachings of Pieczykolan and Olombrada as evidenced by UniProt regarding claims 1-4, 12, 14-17, and 19-24 are detailed above.
Pieczykolan and Olombrada as evidenced by UniProt do not teach wherein the binder toxin fusion protein binds to CD20 or CD79b; or the structure of the binder fusion toxin protein.
Regarding claim 5, Gelsen teaches a fusion protein comprising fusion proteins comprising modified ribotoxin (ex. sarcin) molecules and targeting molecules (para 0010), wherein the targeting molecule is an antibody or antigen-binding fragment thereof (claim 6). Gelsen further teaches the targeting molecule may be directed to a particular tumor surface antigen including CD20 (para 00206) or CD79b (para 00182).
Regarding claims 25-26, Gelsen teaches wherein the modified ribotoxin is fused or linked to the antibody or antigen-binding fragment thereof via a linker (claim 7). Gelsen further teaches scFv-linker-sarcin fusion (figure 1A), wherein the targeting molecule comprises at least one functional FcRn binding site (para 00366) and wherein the fusion protein comprises a modified ribotoxin dimer (para 00171) wherein the ribotoxin fusion protein comprises a cleavable linker linking the modified sarcin molecule to the targeting molecule (para 00384), wherein the cleavable linker can be cleaved in the cytosol (para 00385). This results in a scFv-Fc-cleavable linker-ribotoxin dimer.
Regarding claim 5, Pfeifer teaches that novel therapeutic approach is the use of antibody drug conjugates (ADCs) in which cytotoxic drugs are attached to antibodies that are directed against antigens expressed on tumor cells and that this strategy has already demonstrated high response rates in lymphoma patients (page 1578, col 2, para 2). Pfeifer further teaches that CD79b is physiologically expressed in the vast majority of B cells and therefore represents a promising target for ADC (page 1578, col 2, para 3) which was validated using anti CD79b-MMAE in both in vitro lymphoma cell line testing and phase I clinical testing for relapsed or refractory diffuse large B-cell lymphoma (DLBCL) patients (page 1584, col 2, para 3). Pfeifer further teaches that anti-CD79b had no toxicity alone (page 1585, col 1, para 2) and was rapidly internalized by cells (Fig 2C).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to substitute the antibody binder portion of the binder-toxin fusion protein as taught by Pieczykolan and Olombrada with an antibody targeting CD79b in a scFv-Fc-Toxin dimer as taught by Gelsen and Pfeifer. This results in a CD79b antibody-linker-anispolin construct. The ordinary artisan would have been motivated to do so because Gelsen teaches that CD79b is a known tumor surface antigen in binder fusion protein constructs and this would be a simple substitution of known elements with a reasonable expectation of success. Further, Pfeifer teaches that CD7b antibody internalizes and has been validated in an antibody drug conjugate in vitro and in vivo. Therefore the ordinary artisan has a reasonable expectation of success to generate a CD79b antibody-linker-anisoplin binder fusion toxin protein.
Claim 13 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Pieczykolan (WO 2013/080147 A2; IDS entered 02/15/2023) and Olombrada (Biol. Chem., 2017, 398(1): 135-142; IDS entered 02/15/2023) as evidenced by Uniprot database A0A014PJJ6 (IDS entered 02/15/2023) as applied to claims 1-4, 12, 14-17, and 19-24 above, and further in view of Zoolkefli (Malaysian Journal Of Science (2020): 1-26; cited in OA 11/17/2025).
The teachings of Pieczykolan and Olombrada as evidenced by UniProt regarding claims 1-4, 12, 14-17, and 19-24 are detailed above.
Pieczykolan and Olombrada as evidenced by UniProt do not teach expression of the binder-toxin fusion protein in Nicotania plant cells.
Zoolkefli teaches that different host systems for expression have advantages and disadvantages and that most clinically available therapies are produced from mammalian cells, microbes or yeast but this comes with high cost, inefficient production, and safety concerns. Zoolkefli further teaches that plant host systems for production of therapeutic proteins offers lower production cost and lower risk of contamination compared to mammalian cells, as well as incorporation of post translational modifications that ensure proteins are correctly folded with structural and functional integrity and that numerous functional mammalian proteins have been reported to be produced in plants (page 3, col 1, para 2). Zoolkefli further teaches production of recombinant scFv in Nicotiana tabacum in an economical way without the need for downstream laborious processes (page 20, col 1, para 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to produce the binder-toxin fusion protein as taught by Pieczykolan and Olombrada in Nicotiana as taught by Zoolkefli. The ordinary artisan would have been motivated to do so because as Zoolkefli teaches plant host systems for production of therapeutic proteins offers lower production cost and lower risk of contamination, as well as incorporation of post translational modifications that ensure proteins are correctly folded with structural and functional integrity with demonstrated success and Pieczykolan also teaches expression of the fusion protein in a plant system would be known to the ordinary artisan. The ordinary artisan has a reasonable expectation of success to express the binder-toxin protein in the Nicotania plant to take advantage of lower cost process.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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.
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/AMBER K FAUST/Examiner, Art Unit 1643
/JULIE WU/Supervisory Patent Examiner, Art Unit 1643