Prosecution Insights
Last updated: April 19, 2026
Application No. 18/249,192

PNA PROBES FOR PRETARGETED IMAGING AND THERAPY

Non-Final OA §103§112
Filed
Apr 14, 2023
Examiner
MEJIAS, SAMANTHA LEE
Art Unit
1618
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Zytox Therapeutics AB
OA Round
1 (Non-Final)
50%
Grant Probability
Moderate
1-2
OA Rounds
3y 6m
To Grant
99%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
8 granted / 16 resolved
-10.0% vs TC avg
Strong +57% interview lift
Without
With
+57.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 6m
Avg Prosecution
61 currently pending
Career history
77
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
48.3%
+8.3% vs TC avg
§102
21.7%
-18.3% vs TC avg
§112
18.0%
-22.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 16 resolved cases

Office Action

§103 §112
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 . Receipt is acknowledged of IDS filed on 10/23/2025 and 04/14/2023. Claim 29 has been added. Claims 1-5, 7-8, 10-16, 18-20, 22, 24 and 29 are pending. Claims 6, 9, 17, 21, 23 and 25-28 are cancelled. Claims 12-14, 18-20, 22, and 24 are withdrawn. Election/Restrictions Applicant’s election without traverse of group I and species A-B in the reply filed on 12/23/2025 is acknowledged. 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. Claims 1-5, 7, 8, 10, 11, 15, 16 and 29 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. Claim 1 contains the term "PNA", which is not defined by the claims. Claims must stand alone to define the invention, and should not rely on the description or the drawings to give them meaning (see Ex Parte Fressola, 27 USPQ 2d 1608). Thus, claim 1, at the very least, should define " PNA” by its formal name; once " PNA " is defined, the term " PNA " may be subsequently recited. The defendant claims fall therewith. 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 1-5, 7, 8, 10, 11, 15, 16 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over WESTERLUND (Radionuclide Therapy of HER2-Expressing Human Xenografts Using Affibody-Based Peptide Nucleic Acid–Mediated Pretargeting: In Vivo Proof of Principle. The Journal of Nuclear Medicine. 2018.) in view of BARHOUMI (US 2020/0095577 A1). Regarding claim 1, WESTERLUND teaches a conjugate comprising a targeting moiety, such as ZHER2:342, that is attached to a hybridization probe moiety comprising a PNA oligomer, such as HP1 (page 1093, paragraph 6). A second conjugate comprising a second hybridization probe moiety comprising a second PNA oligomer, such as HP2 (page 1093, paragraph 6). HP2 is complementary to HP1 (abstract). 177Lu was attached to HP2 (abstract), which reads on a diagnostic agent or a therapeutic agent moiety. Regarding claims 2-4 and 29, WESTERLUND teaches ZHER2:342 targets the human epidermal growth factor receptor 2 (HER2)–expressing cancer (abstract), which is a mammalian protein which is expressed on the surface of a cell, specifically a tumor cell for breast cancer (page 1093, paragraph 2). Regarding claim 5, WESTERLUND teaches the conjugate utilizes a HER2-targeting Affibody (abstract), which is an engineered scaffold protein, which acts as a mimetic antibody. Regarding claim 15, WESTERLUND teaches the conjugate generates a signal that is detectable via single photon emission computed tomography (SPECT) (page 1095, paragraph 2). Regarding claim 16, WESTERLUND teaches the diagnostic agent used is a radionuclide, such as 177Lu (page 1095, paragraph 2). WESTERLUND does not teach the length of the second PNA oligomer to be between 5 and 12 bases or adding a solubilizing moiety. BARHOUMI teaches conjugates involving PNA oligomers that are used for detection in a sample (abstract), including use for breast cancer (page 26, paragraph 0412). The conjugates are complimentary to each other (page 4, paragraph 0103). BARHOUMI further teaches that PNA hydrophobicity is proportional to the number of bases a PNA sequence has. The more bases a PNA sequence has the higher the hydrophobicity is (Page 11, paragraph 0233). The hydrophobicity can affect how the sequence dissolves in aqueous solutions for conjugation to antibodies, how the PNA loads and the stability of the conjugate (Page 11, paragraph 0233). Regarding claim 7, BARHOUMI teaches the conjugate may comprise a group that increases the water solubility (page 11, paragraph 230), such as a PEG based linker (page 14, paragraph 0300), which reads on a solubilizing moiety. The ability of the sequence to dissolve in aqueous solutions assists in conjugation to antibodies (Page 11, paragraph 0233). It would have been obvious to the person of ordinary skill in the art at the time the invention was made to incorporate a solubilizing moiety. The person of ordinary skill in the art would have been motivated to make those modifications, because it affects the water solubility of the conjugate which affects the ability of the sequence to dissolve in aqueous solutions assists in conjugation to antibodies and reasonably would have expected success because the references are in the same field of endeavor, such as complimentary conjugates comprising PNA oligomers that are used for diagnostic purposes in breast cancer. Furthermore, both references talk about conjugating a form of antibody, WESTERLUND uses an antibody mimetic. Regarding claims 1, 8, 10 and 11, the reference does not specifically teach the amount of bases in the probes as claimed by the Applicant. The amount of bases in the probes is clearly a result effective parameter that a person of ordinary skill in the art would routinely optimize. Optimization of parameters is a routine practice that would be obvious for a person of ordinary skill in the art to employ and reasonably would expect success. It would have been customary for an artisan of the ordinary skill to determine the optimal amount of bases in the probes in order to best achieve desired results, such as having the appropriate hydrophobicity for conjugation to antibodies, PNA loading and the stability of the conjugate. Thus, absent of some demonstration of unexpected results from the claimed parameters, this optimization of amount of bases in the probes would have been obvious at the time of Applicant’s invention. Conclusion No claims are allowable. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SAMANTHA L. MEJIAS whose telephone number is (703)756-5666. The examiner can normally be reached M-F. 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, MICHAEL HARTLEY can be reached at (571) 272-0616. 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. /S.L.M./ Examiner, Art Unit 1618 /JAKE M VU/ Primary Examiner, Art Unit 1618
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Prosecution Timeline

Apr 14, 2023
Application Filed
Feb 23, 2026
Non-Final Rejection — §103, §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

1-2
Expected OA Rounds
50%
Grant Probability
99%
With Interview (+57.1%)
3y 6m
Median Time to Grant
Low
PTA Risk
Based on 16 resolved cases by this examiner. Grant probability derived from career allow rate.

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