Prosecution Insights
Last updated: April 19, 2026
Application No. 18/448,842

COMPOSITIONS AND METHODS RELATED TO IMMUNOGLOBULIN PROTEASES AND FUSIONS THEREOF

Non-Final OA §102§103§112
Filed
Aug 11, 2023
Examiner
ALFANO, ALAN
Art Unit
1641
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Cartesian Therapeutics Inc.
OA Round
1 (Non-Final)
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant

Examiner Intelligence

Grants only 0% of cases
0%
Career Allow Rate
0 granted / 0 resolved
-60.0% vs TC avg
Minimal +0% lift
Without
With
+0.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
4 currently pending
Career history
4
Total Applications
across all art units

Statute-Specific Performance

§101
14.3%
-25.7% vs TC avg
§103
38.1%
-1.9% vs TC avg
§102
14.3%
-25.7% vs TC avg
§112
33.3%
-6.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 0 resolved cases

Office Action

§102 §103 §112
Notice of Pre-AIA or AIA Status 1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Information Disclosure Statement 2. The information disclosure statement(s) (IDS) submitted on 1/11/2024 and 2/11/2026 are acknowledged and the references cited therein have been considered. Priority 3. The present application claims the benefit of US Provisional Patent Application No. 63/463,942, filed 05/04/2023, US Provisional Patent Application No. 63/443,130, filed 02/03/2023, US Provisional Patent Application No. 63/437,523, filed 01/06/2023, US Provisional Patent Application No. 63/413,005, filed 10/04/2022, US Provisional Patent Application No. 63/406,829, filed 09/15/2022, and US Provisional Patent Application No. 63/397,383, filed 08/11/2022 . Applicant' s claim for the benefit of prior-filed applications is acknowledged. Status of Claims 4. Applicant’s amendments received 02/11/2026 are acknowledged. Claims 16-30 and 34-41 have been canceled. Claims 1 and 2 have been amended. Claim 42 is new. Claims 1-15, 31-33, and 42 are pending in the instant application. 5. Applicant’s election without traverse of Group I , claims 1-15 (now claims 1-15 and 42) directed to compositions comprising an Ig protease protein. filed on 02/11/2026, is acknowledged. 6. Claims 31-33 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to nonelected inventions. Claim Rejections - 35 USC § 112 Written Description 7. 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. 8. Claims 1-15 and 42 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. Claim 1 encompasses a broad genus Ig protease domains that increase circulating half-life relative and (ii) a broad genus of Fc domains resistant to proteolysis by the Ig protease, or a human serum albumin protein. Dependent claim3-5 encompasses a broad genus of Ig protease fusion protein that binds to a region of a target immunoglobulin and cleaves the target immunoglobulin in a hinge region of the target immunoglobulin IgG or IgA. Dependent claim 6-8 Encompasses a genus of Ig protease domains from an Ig protease from a bacterial strain such as Streptococcal bacterial strain, Streptococcus pyrogenes, Streptococcus equii, Mycoplasma bacterial strain, Streptococcus krosus. Dependent claims 12-15 encompasses IdeS protease, IdeZ protease, IdeMC protease and IdeSORK. However, there does not appear to be an adequate written description in the specification as-filed of the essential structural features that provide the recited functions of increasing circulating half-life, binding to a region of a target immunoglobulin and cleaving the target immunoglobulin. The Guidelines for the Examination of Patent Applications Under the 35 U.S.C. 112(a) or U.S.C 112, ¶ 1 "Written Description" Requirement make clear 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, 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 genus. The specification discloses the synthesis and activity of an engineered Ides-mouse Fc fusion protein (Examples 1 and 2, page 69). The specification also discloses a Xork-Fc fusion homodimer, which can be expressed in CHO cells and E. coli, shows low cross reactivity to preexisting antibodies in human serum, and enables efficient AAV transduction in an in vivo model of passive transfer of neutralizing human serum (Examples 6 and 7, page 72). The specification fails to disclose any fusion compositions with IdeZ protease domain, or IdeMC protease domain. Also, despite specific structures being disclosed in the specification (e.g., SEQ ID NOs), none are specified in the claims. While the specification describes Ig proteinase domains, the specification does not describe any correlation between the sequence and the structure of Ig protease domain that binds and cleaves a target immunoglobulin. There is no information regarding what structural features would likely be associated with such the binding and cleaving a target immunoglobulin. Thus, the specification does not disclose a correlation between an Ig protease domain and binds and cleaves a target immunoglobulin and the structure of a putative Ig protease domain. The level of skill and knowledge in the art is that there are no known Ig protease domains that bind and cleave a target immunoglobulin and no known correlation between any structural component and the ability to bind and cleave a target immunoglobulin. Thus, the disclosure does not allow one of skill in the art to visualize or recognize the structure of any Ig protease domain required to practice the claimed composition. Accordingly, one of ordinary skill in the art would conclude that the applicant would not have been in possession of the claimed method of using an Ig protease domain that binds and cleaves a target immunoglobulin because an Ig protease possessing the desired activity required to practice the method is not adequately described and was not known in the art. Possession is 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, 358 F.3d at 927, 69 USPQ2d at 1895. Sufficient description to show possession of such a genus may be achieved by means of a recitation of a representative number of Ig protease domains that bind and cleave a target immunoglobulin, defined by amino acid sequence, falling within the scope of the genus or of a recitation of structural features common to members of the genus, which features constitute a substantial portion of the genus. See Eli Lilly, 119F.3d at 1568, 43 USPQ2d at 1406. Without a correlation between structure and function, the claim does 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”). The claims are not supported by a description that satisfies 35 U.S.C. § 112(a) or 35 U.S.C. § 112, first paragraph. "[T]he test for sufficiency [of the written description] is whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date." Ariad Phanns., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en bane). A "sufficient description of a genus ... requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can 'visualize or recognize' the members of the genus." Id. at 1350. "[A]n adequate written description requires a precise definition, such as by structure, formula, chemical name, physical properties, or other properties, of species falling within the genus sufficient to distinguish the genus from other materials." Id. "[F]unctional claim language can meet the written description requirement when the art has established a correlation between structure and function." Id. "But merely drawing a fence around the outer limits of a purported genus is not an adequate substitute for describing a variety of materials constituting the genus and showing that one has invented a genus and not just a species." Id. "A sufficient description of a genus ... requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can "visualize or recognize" the members of the genus." (AbbVie, 759 F.3d at 1297, reiterating Eli Lilly, 119 F.3d at 1568-69) (emphasis added). With respect to representative number of species, see AbbVie Deutschland GmbH & Co. v. Janssen Biotech, Inc. (Fed. Cir. 2014). Also, see MPEP 2163 Il(A)(3)(a))(ii): 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. 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. See Abb Vie Deutschland GmbH & Co., KG v. Janssen Biotech, Inc., 759 F.3d 1285, 1300, 111 USPQ2d 1780, 1790 (Fed. Cir. 2014) (Claims directed to a functionally defined genus of antibodies were not supported by a disclosure that "only describe[d] one type of structurally similar antibodies" that "are not representative of the full variety or scope of the genus."). 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 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. See, e.g., Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406. Instead, the disclosure must adequately reflect the structural diversity of the claimed genus, either through the disclosure of sufficient species that are "representative of the full variety or scope of the genus," or by the establishment of "a reasonable structure-function correlation." Such correlations may be established "by the inventor as described in the specification," or they may be "known in the art at the time of the filing date." See AbbVie, 759 F.3d at 1300-01, 111 USPQ2d 1780, 1790-91 (Fed. Cir. 2014) (Holding that claims to all human antibodies that bind IL-12 with a particular binding affinity rate constant (i.e., koff) were not adequately supported by a specification describing only a single type of human antibody having the claimed features because the disclosed antibody was not representative of other types of antibodies in the claimed genus, as demonstrated by the fact that other disclosed antibodies had different types of heavy and light chains, and shared only a 50% sequence similarity in their variable regions with the disclosed antibodies.). In the instant case, two working examples of an Ig protease-Fc fusion protein were provided (Ides-mouse Fc and Xork-Fc) with the claimed function of IgG and/or IgA protease. These two examples do not sufficiently represent the broad genus of compositions of any length or sequence sought through the instant claims. Furthermore, the instant specification provides little to no guidance on how to generate compositions with the specified desired function. Undue experimentation would be required to produce the invention commensurate with the scope of the claims from the written disclosure alone. Additionally, one with ordinary skill in the art would recognize that there is no clear structure-function relationship between the amino acid sequence of a composition and the function “IgG/IgA protease fusion protein”. Absent any teaching of structure-function relationships, the skilled in the art cannot determine the which polypeptide sequences in the broad genera encompassed by any of claims are critical for the function of “IgG/IgA protease fusion protein”, other than the instant polypeptide sequences that have this function. See AbbVie Deutschland GmbH v. Janssen Biotech, Inc. (Fed. Cir. 2014). Claims 1-15 and 42 do not meet the requirements of 35 U.S.C. 112(a) for written description as they are currently written. Vas-Cath Inc. v. Mahurkar, 19 USPQ2d 1111, makes clear 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 [he or she] invented what is claimed." (See Vas-Cath at page 1116.). Consequently, Applicant was not in possession of the instant claimed invention. See University of California v. Eli Lilly and Co. 43 USPQ2d 1398. It is suggested that in order to remedy this rejection Applicant recites specific structure (SEQ ID NOs) for the Ig protease, and Fc domain that is resistant to proteolysis. Claim Rejections - 35 USC § 102 9. 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 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. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. 10. Claims 1-6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Xie et al. (JASN 33: 918-935 (Feb. 16, 2022), IDS NPL, Submitted 1/11/2024, “Xie”). Xie teaches a composition comprising an Ig protease fusion protein, Fc-AK183 comprising: (i) an Ig protease domain (AK183); and (ii) an Fc domain resistant to proteolysis by the Ig protease, -, wherein the Ig protease fusion protein has an increased circulating half-life relative to the Ig protease that is not fused to the Fc domain resistant to proteolysis by the Ig protease, or the human serum albumin protein (see paragraph 3 and 4, pg 919, and figure 1). Claim 2 is included because the Ig protease fusion protein is the Ig protease domain fused to the Fc domain resistant to proteolysis by the Ig protease. Claim 3 is included because the Ig protease fusion protein binds to a region of a target immunoglobulin, and wherein the Ig protease fusion protein cleaves the target immunoglobulin. Claim 4 is included because the referenced Ig protease domain cleaves the target immunoglobulin in a hinge region of the target immunoglobulin Claim 5 is included because Xie teaches the target immunoglobulin is IgA. Claim 6 is included because the Ig protease domain is from an Ig protease from a bacterial strain. PNG media_image1.png 270 904 media_image1.png Greyscale Claim Rejections - 35 USC § 103 11. 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. 12. Claims 1-8, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (Xie et al. (JASN 33: 918-935 (Feb. 16, 2022)), in view of Johansson et al. (PLoS One, 3(2): e1692 (2008), IDS NPL, Submitted 1/11/2024, “Johansson”). The teachings of Xie have been discussed, supra. The claimed invention differs from the reference by the recitation of a Streptococcal bacterial strain (claim 7), wherein the Streptococcal bacterial strain is Streptococcus pyrogenes (claim 8), wherein the Ig protease domain is of IdeS protease (claim 12). Johansson teaches that IdeS is a proteolytic enzyme produced by Streptococcus pyrogenes which cleaves IgG with a unique degree of specificity, and that before IdeS can cleave IgG in the heavy chain, the enzyme has to bind to the Fc region of the antibody, and the remarkable specificity of IdeS lies in this protein-protein interaction (Results/Discussion paragraph 1). The purpose of Johansson study was investigating the potential of IdeS for the treatment of conditions involving pathogenic IgG antibodies (Introduction paragraph 2). Those of skill in the art would have had reason to use the IdeS of Johansson as a substitute for the Ig protease domain, AK183 taught in Xie et al because, like the Ig protease domain taught in Xie et al., IdeS binds and cleaves immunoglobulins. Substituting a known element for another, to yield the known result, is obvious. See KSR, 550 U.S. at 416, 421 (2007). "[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result." KSR Int'l v. Teleflex Inc., 550 U.S. 398,416 (2007). "Structural similarity, alone, may be sufficient to give rise to an expectation that compounds similar in structure will have similar properties." In re Merck & Co., Inc., 231 USPQ 375,379. From the combined teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. 13. Claims 1-7, 9, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (Xie et al. (JASN 33: 918-935 (Feb. 16, 2022)) in view of Hulting et al. (FEMS Microbiol Lett, 298: 44-50, 2009, IDS NPL #C1, Submitted 2/11/2026, “Hulting”). The teachings of Xie have been discussed, supra. The claimed invention differs from the reference by the recitation of a Streptococcal bacterial strain (claim 7), wherein the Streptococcal bacterial strain is Streptococcus equii (claim 9), wherein the Ig protease domain is of IdeZ protease (claim 13). Hulting teaches that IdeZ is a proteolytic enzyme produced by Streptococcus equii which cleaves IgG with a degree of specificity similar to IdeS (Introduction, pg. 44, right column). Those of skill in the art would have had reason to use the IdeZ of Hulting as a substitute for the Ig protease domain, AK183 taught in Xie et al because, like the Ig protease domain taught in Xie et al , IdeZ binds and cleaves immunoglobulins. Substituting a known element for another, to yield the known result, is obvious. See KSR, 550 U.S. at 416, 421 (2007). "[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result." KSR Int'l v. Teleflex Inc., 550 U.S. 398,416 (2007). "Structural similarity, alone, may be sufficient to give rise to an expectation that compounds similar in structure will have similar properties." In re Merck & Co., Inc., 231 USPQ 375,379. From the combined teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. 14. Claims 1-6, 10 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (Xie et al. (JASN 33: 918-935 (Feb. 16, 2022)) in view of Brown (US 20190262434 A1, “Brown”). The teachings of Xie have been discussed, supra. The claimed invention differs from the reference by the recitation of a Mycoplasma bacterial strain (claim 10), wherein the Ig protease domain is of IdeMC protease (claim 14). Brown teaches that IdeMC is a proteolytic enzyme produced by Mycoplasma which cleaves IgG with a unique degree of specificity (See Figure 6). The purpose of Brown study was investigating the potential of IdeMC for the treatment of conditions involving pathogenic IgG antibodies. Those of skill in the art would have had reason to use the IdeMC of Brown as a substitute for the Ig protease domain, AK183 taught in Xie et al because, like the Ig protease domain taught in Xie et al , IdeMC binds and cleaves immunoglobulins. Substituting a known element for another, to yield the known result, is obvious. See KSR, 550 U.S. at 416, 421 (2007). "[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result." KSR Int'l v. Teleflex Inc., 550 U.S. 398,416 (2007). "Structural similarity, alone, may be sufficient to give rise to an expectation that compounds similar in structure will have similar properties." In re Merck & Co., Inc., 231 USPQ 375,379. From the combined teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. 15. Claims 1-7, 11 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (Xie et al. (JASN 33: 918-935 (Feb. 16, 2022)) in view of Lood-Alayon et al. (US 20250320480 A1, filed 04/22/2022, “Lood-Alayon”) or Selecta Biosciences Press Release, October 21, 2021. The teachings of Xie have been discussed, supra. The claimed invention differs from the reference by the recitation of a Streptococcus krosus bacterial strain (claim 11), wherein the Ig protease domain is of IdeSORK (claim 15). Lood-Alayon teaches that IdeSORK is a proteolytic enzyme produced by Streptococcus krosus which cleaves IgG with a unique degree of specificity, and that the full-length sequence of IdeSORK is considerably different to that of other known IgG cysteine proteases (paragraphs 0006 and 0007). Lood-Alayon further characterize a version of IdeSORK called IdeSORK2.0 or Xork (with the addition of N-terminal methionine and a C-terminal protein purification tag – His6) which has very little pre-existing immunity against it. This creates an advantage which potentially allows the treatment of patients that are currently excluded from treatment due to pre-existing immunity to IdeS/IdeZ (paragraph 0009). The Selecta Biosciences Press Release teaches that most IgG proteases are derived from human pathogens and have a high prevalence of pre-existing antibodies. Xork is derived from a Streptococcal bacterial strain that does not infect humans. The pre-clinical data generated to date highlights Xork’s differentiated profile - demonstrating very low cross-reactivity with naturally occurring antibodies in human sera while retaining efficient and specific cleavage of human IgG antibodies (paragraph 2). Those of skill in the art would have had reason to use the IdeSORK of Lood-Alayon or the Xork of Selecta Biosciences Press Release as a substitute for the Ig protease domain, AK183 taught in Xie et al because, like the Ig protease domain taught in Xie et al , IdeSORK/Xork binds and cleaves immunoglobulins. Substituting a known element for another, to yield the known result, is obvious. See KSR, 550 U.S. at 416, 421 (2007). "[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result." KSR Int'l v. Teleflex Inc., 550 U.S. 398,416 (2007). "Structural similarity, alone, may be sufficient to give rise to an expectation that compounds similar in structure will have similar properties." In re Merck & Co., Inc., 231 USPQ 375,379. From the combined teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. 16. Claim 42 is rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Sleep et al. (Biochimica et Biophysica Acta 1830: 5526-5534 (2013), “Sleep”). The teachings of Xie have been discussed, supra. The claimed invention differs from the reference by the recitation of a Fc fusion where the Ig protease domain is fused to the human serum albumin protein (claim 42). Sleep teaches that conjugation of drugs to albumin is an ideal strategy to increase the circulatory half-life of therapeutic protein-based drugs. It would have been obvious to one of ordinary skill in the art at the time the invention was made to substitute the Fc region of the fusion protein as taught by Xie with human serum albumin as taught by Sleep. One of ordinary skill in the art at the time the invention was made would have been motivated to do so because like the Fc region taught by Xie et al references, HSA increased half-life of the fusion protein as taught by Sleep. Substituting a known element for another, to yield the known result, is obvious. See KSR, 550 U.S. at 416, 421 (2007). From the combined teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. Conclusion 17. No claim is allowable. 18. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALAN ALFANO whose telephone number is (571)272-3092. The examiner can normally be reached M-F 8-5 EST. 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. /ALAN ALFANO/Examiner, Art Unit 1641 /MAHER M HADDAD/Primary Examiner, Art Unit 1641
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Prosecution Timeline

Aug 11, 2023
Application Filed
Mar 10, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Expected OA Rounds
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Median Time to Grant
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