Prosecution Insights
Last updated: August 14, 2026
Application No. 18/038,673

YEAST-BASED EXPRESSION OF THERAPEUTIC PROTEINS IN VIVO

Final Rejection §112
Filed
May 24, 2023
Priority
Nov 25, 2020 — provisional 63/118,610 +2 more
Examiner
CHEN, STACY BROWN
Art Unit
1672
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Esperovax Inc.
OA Round
2 (Final)
66%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allowance Rate
615 granted / 932 resolved
+6.0% vs TC avg
Strong +40% interview lift
Without
With
+40.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
50 currently pending
Career history
979
Total Applications
across all art units

Statute-Specific Performance

§101
5.7%
-34.3% vs TC avg
§103
30.3%
-9.7% vs TC avg
§102
14.2%
-25.8% vs TC avg
§112
32.2%
-7.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 932 resolved cases

Office Action

§112
DETAILED ACTION Applicant’s amendment, remarks and terminal disclaimer filed April 15, 2026 are acknowledged and entered. The terminal disclaimer has been approved. All prior objections or rejections that are not repeated or addressed below are either moot or withdrawn in view of Applicant’s amendment. Claim Objections (New Objection) Claim 40 is objected to for a minor informality. At line 2, the comma after “99%” should be deleted. 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. (New Rejection) Claims 42-49 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. Regarding claim 42, the phrase "e.g." renders the claim indefinite because it is unclear whether the limitation(s) following the phrase is part of the claimed invention. See MPEP § 2173.05(d). Claims 43-49 are included in this rejection because they depend from claim 42. 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. (New Rejection) Claims 35, 36, 39, 40 and 43-49 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. To provide adequate written description and evidence of possession of a claimed genus, the specification must provide sufficient distinguishing identifying characteristics of the genus. The factors to be considered include disclosure of complete or partial structure, physical and/or chemical properties, functional characteristics, structure/function correlation, methods of making the claimed product, or any combination thereof. Claim 35 is directed to a large genus of fragments of β-1-3-glucanase that are at least 100 contiguous amino acids of SEQ ID NO: 7. Similarly, claim 36 is directed to a large genus of fragments of β-1-3-glucanase that are at least 95% identical to at least 100 contiguous amino acids of SEQ ID NO: 7. SEQ ID NO: 7 is 548-aa. A 100-aa fragment is roughly 1/5th of the enzyme. The specification has not shown which portions of the enzyme are necessary to retain its function as a β-1-3-glucanase, thus there is no structure-function correlation. Only the full-length enzyme appears to have been provided in Table 1. The one species of the full-length enzyme does not represent the genus of 100-aa fragments, nor those that are at least 95% identical to 100-aa fragments. Claim 39 is directed to a large genus of fragments of chitinase that are at least 100 contiguous amino acids of SEQ ID NO: 9. Similarly, claim 40 is directed to a large genus of fragments of chitinase that are at least 95% identical to at least 100 contiguous amino acids of SEQ ID NO: 9. SEQ ID NO: 9 is 487-aa. A 100-aa fragment is roughly 1/5th of the enzyme. The specification has not shown which portions of the enzyme are necessary to retain its function as a chitinase, thus there is no structure-function correlation. Only the full-length enzyme appears to have been provided in Table 1. The one species of the full-length enzyme does not represent the genus of 100-aa fragments, nor those that are at least 95% identical to 100-aa fragments. Accordingly, in the absence of sufficient recitation of distinguishing identifying characteristics, the specification does not provide adequate written description of the claimed genus. Vas-Cath Inc. v. Mahurkar, 19USPQ2d 1111, clearly states “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). Adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method of isolating it. The compound itself is required. See Fiers v. Revel, 25 USPQ2d 1601 at 1606 (CAFC 1993) and Amgen Inc. v. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016. One cannot describe what one has not conceived. Conclusion No claim is 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. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Stacy B. Chen whose telephone number is 571-272-0896. The examiner can normally be reached on M-F (7:00-4:30). If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas Visone, can be reached on 571-270-0684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. /STACY B CHEN/Primary Examiner, Art Unit 1672
Read full office action

Prosecution Timeline

May 24, 2023
Application Filed
Dec 11, 2025
Non-Final Rejection mailed — §112
Apr 13, 2026
Response Filed
Jun 22, 2026
Final Rejection mailed — §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
66%
Grant Probability
99%
With Interview (+40.4%)
3y 1m (~0m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 932 resolved cases by this examiner. Grant probability derived from career allowance rate.

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