Prosecution Insights
Last updated: April 19, 2026
Application No. 18/555,180

FLUORESCENT NUCLEOSIDE PHOSPHATES

Non-Final OA §101§102§112
Filed
Oct 12, 2023
Examiner
LAU, JONATHAN S
Art Unit
1693
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Stealth Labels Biotech AB
OA Round
1 (Non-Final)
64%
Grant Probability
Moderate
1-2
OA Rounds
3y 0m
To Grant
45%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
654 granted / 1028 resolved
+3.6% vs TC avg
Minimal -19% lift
Without
With
+-18.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
41 currently pending
Career history
1069
Total Applications
across all art units

Statute-Specific Performance

§101
1.9%
-38.1% vs TC avg
§103
40.1%
+0.1% vs TC avg
§102
17.9%
-22.1% vs TC avg
§112
22.4%
-17.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1028 resolved cases

Office Action

§101 §102 §112
DETAILED ACTION 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 . This application is the national stage entry of PCT/EP2022/059666, filed 11 April 2022; and claims benefit of foreign priority document UNITED KINGDOM 2105194.1, filed 12 April 2021. This foreign priority document is in English. Claims 1-25 are pending in the current application and are examined on the merits herein. Information Disclosure Statement The IDS filed 12 Oct 2023 misspells the name of the author Pradere, Ugo, et al. of the NPL document Chem. Rev., 2014, 114, p9154-9218. This author’s name has been corrected in the considered IDS attached herein. 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 and 9-25 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. Claim 1 recites “A compound of formula (I), a physiologically cleavable precursor or a salt thereof…” The phrase “a physiologically cleavable precursor” renders the claimed indefinite because it is unclear what compounds are encompassed within the scope of the claim and what compounds are excluded from the scope of the claim. The specification at page 19, paragraph 83-87 provides non-limiting examples of a physiologically cleavable precursor, for example at paragraph 87 referencing the prior art Pradere et al. which discloses a phosphoramidate as a possible prodrug approach. See also MPEP 2173.05(g) providing “Notwithstanding the permissible instances, the use of functional language in a claim may fail “to provide a clear-cut indication of the scope of the subject matter embraced by the claim” and thus be indefinite. In re Swinehart, 439 F.2d 210, 213 (CCPA 1971). For example, when claims merely recite a description of a problem to be solved or a function or result achieved by the invention, the boundaries of the claim scope may be unclear. Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244, 1255, 85 USPQ2d 1654, 1663 (Fed. Cir. 2008)” In this case the structure of the claimed compound is described in terms of a function of being a physiologically cleavable precursor, and fails to provide a clear-cut indication of the scope of the subject matter embraced by the claim. As detailed below, each of claims 19-23 recite “The use of a compound of formula (I), a physiologically cleavable precursor or a salt thereof…” which is an improper definition of a process. Further, if claims 19-23 are interpreted as drawn to the statutory category of a process, it unclear what the scope of the claimed process would be because the claim does not set forth any steps involved in the process. See MPEP 2173.05(q). Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claims 19-23 are rejected under 35 U.S.C. 101 because the claimed invention is directed to non-statutory subject matter. The claim(s) does/do not fall within at least one of the four categories of patent eligible subject matter because each of claims 19-23 recite “The use of a compound of formula (I), a physiologically cleavable precursor or a salt thereof…” which is an improper definition of a process. See also MPEP 2173.05(q) providing ‘“Use” claims that do not purport to claim a process, machine, manufacture, or composition of matter fail to comply with 35 U.S.C. 101. In re Moreton, 288 F.2d 708, 709, 129 USPQ 227, 228 (CCPA 1961)’ In contrast, claims 24 and 25 appear to provide a proper definition of the process. Claim Rejections - 35 USC § 102 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. Claims 1-5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wypijewska del Nogal et al. (Nucleic Acids Research, 2020, 48(14), p7640-7652, provided by Applicant in IDS filed 12 Oct 2023). Wypijewska del Nogal et al. discloses a new fluorophore analogue of adenine, 2CNqA, which can be incorporated into both DNA and RNA (page 7460, abstract). The compound 2CNqA (12) is converted to the phosphoramidite building block (13): PNG media_image1.png 190 290 media_image1.png Greyscale (page 7642, scheme 1). As the scope of “a physiologically cleavable precursor” is unclear for the reasons detailed above, claims 12 and 13 are interpreted as such physiologically cleavable precursors of the claimed compound of formula (I), where either R1 is hydro and R2 is cyano as in the disclosed compound, or a precursor of the compound where R1 and R2 together form a 6-membered carboaromatic ring. Therefore the compounds (12) and (13) disclosed in Wypijewska del Nogal et al. are interpreted to meet the limitations of “a physiologically cleavable precursor” of the compound of claims 1-5. Allowable Subject Matter Claims 6-8 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claims 9-18 and 24-25 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. The following is a statement of reasons for the indication of allowable subject matter: The closest prior art is Wypijewska del Nogal et al. (Nucleic Acids Research, 2020, 48(14), p7640-7652, provided by Applicant in IDS filed 12 Oct 2023) in view of Pradere et al. (Chem. Rev., 2014, 114, p9154-9218, provided by Applicant in IDS filed 12 Oct 2023). Wypijewska del Nogal et al. teaches as above. Wypijewska del Nogal et al. does not specifically disclose a compound of formula (I) or a salt thereof, or a method of making or using the compound. Pradere et al. teaches the state of the art regarding nucleoside phosphate and phosphonate prodrugs. Pradere et al. teaches nucleoside triphosphates cannot be considered as viable drug candidates as they usually have poor chemical stability along with high polarity that hinders them from transporting across cell membranes. Further, nucleoside monophosphates are known to have no or low cell penetration (page 9154, right column, paragraph 1; page 9155, figure 1). It would not have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Wypijewska del Nogal et al. in view of Pradere et al. to arrive at the claimed invention. Wypijewska del Nogal et al. teaches the 2CNqA for use in incorporating into DNA or RNA, and the use of nucleotide mono-, di-, or tri-phosphates in the synthesis DNA or RNA would have been well known to one of ordinary skill in the art based on the knowledge of biology and these fundamental molecules of life. However, the application in Examples 8-10 at page 48-51 shows evidence that the claimed invention possesses advantageous properties of cellular uptake, which would not have been reasonably predicted based on the teachings of Pradere et al. Therefore the claimed subject matter including those properties necessarily present would not have been obvious to one of ordinary skill in the art based the teachings of the closest prior art. Conclusion No claim is currently in condition for allowance. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jonathan S Lau whose telephone number is (571)270-3531. The examiner can normally be reached Monday-Friday 9a-5p Eastern. 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, Scarlett Goon can be reached at (571)270-5241. 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. /JONATHAN S LAU/ Primary Examiner, Art Unit 1693
Read full office action

Prosecution Timeline

Oct 12, 2023
Application Filed
Feb 05, 2026
Non-Final Rejection — §101, §102, §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
64%
Grant Probability
45%
With Interview (-18.8%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 1028 resolved cases by this examiner. Grant probability derived from career allow rate.

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