Prosecution Insights
Last updated: April 17, 2026
Application No. 18/516,928

Deuterium-Enriched Nirmatrelvir as SARS-CoV-2 Mpro Inhibitor for the Treatment of COVID-19

Non-Final OA §102§103
Filed
Nov 21, 2023
Examiner
CHENG, KAREN
Art Unit
1623
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
unknown
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
517 granted / 677 resolved
+16.4% vs TC avg
Strong +28% interview lift
Without
With
+27.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
34 currently pending
Career history
711
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
27.4%
-12.6% vs TC avg
§102
21.5%
-18.5% vs TC avg
§112
30.7%
-9.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 677 resolved cases

Office Action

§102 §103
DETAILED ACTION Claims 1-18 are currently pending in the instant application. 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 . Priority This application was filed 11/21/2023. Information Disclosure Statement The listing of references in the specification is not a proper information disclosure statement. 37 CFR 1.98(b) requires a list of all patents, publications, or other information submitted for consideration by the Office, and MPEP § 609.04(a) states, "the list may not be incorporated into the specification but must be submitted in a separate paper." Therefore, unless the references have been cited by the examiner on form PTO-892, they have not been considered. 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 1-4 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN 114805478, hereafter referred to as CN ‘478, pub. 07/29/2022. CN ‘478 teaches compounds of formula PNG media_image1.png 400 482 media_image1.png Greyscale where R1 to R 15 are each independently hydrogen or deuterium; Y1 to Y14 are each independently hydrogen or deuterium. Furthermore, at least one of R 1 to R 15 and Y 1 to Y 14 is a deuterium atom (see p. 2-3 of enclosed machine translation). CN ‘478 exemplifies compounds such as PNG media_image2.png 170 282 media_image2.png Greyscale which reads on claims 1-2. CN ‘478 teaches the compound may be used to treat disease associated with RNA virus infection, specifically COVID-19. The compound may also be administered in combination with other related drugs, including CYP inhibitors (see p. 22 of machine translation). This reads on claims 3-4. Claims 1, 3, 5-6, 9-10 and 15-16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by OWEN (see US Pub No. 2022/0062232, pub. 03/03/02022) teaches compound PNG media_image3.png 176 214 media_image3.png Greyscale and a method of treating a coronavirus infection wherein the infection is COVID-19 (see p. 17). This corresponds to a compound of claims 1 and 3 wherein R1-R25 are independently H. Regarding claims 5-6, OWEN further teaches the compound may be used in methods in combination with other drugs and names remdesivir (see paragraph [0382], p. 22), monoclonal antibodies such as bamlanivimab (see paragraph [0392], p. 23-24). The compound may also be administered with telmisartan (see paragraph [0386], p. 22), which reads on claims 9-10 as well as nicardipine (see paragraphs [0385]-[0386], p. 22), which reads on claims 15-16. 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. Claims 3-4, 7-8, 11-14 and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over CN ‘478 as applied to claims 3-4 above, and further in view of OWEN (see US Pub No. 2022/0062232, pub. 03/03/02022) and Dhanoa (see US Pub No. 2022/0306646, pub. 09/29/2022 and filed 03/29/2021). The limitations of claim 3-4 are taught as discussed above in the 102(a)(1) rejection. Specifically, CN ‘478 teaches the compounds of claims 3-4 may be administered in combination with other related drugs to treat COVID-19 but does not explicitly name other drugs to be administered. OWEN teaches compounds PNG media_image3.png 176 214 media_image3.png Greyscale and a method of treating a coronavirus infection wherein the infection is COVID-19 (see p. 17), which reads on claim 3. Further OWEN teaches that substitution with heavier isotopes such as deuterium can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically labelled compounds used in the methods of this invention and prodrugs thereof can generally be prepared by carrying out the procedures for preparing the compounds disclosed in the art by substituting a readily available isotopically labelled reagent for a non-isotopically labelled reagent (see paragraph [0380]). Thus, one of ordinary skill in the art would know to substitute the hydrogen atoms on the compound with a deuterium to arrive at compounds of claim 4. Additionally, CN ‘478 teaches examples of compounds substituted with deuterium and positions that may be substituted with deuterium atoms to arrive at additional compounds of claim 4. Regarding the limitations of claims 7-8 and 11-12, OWEN further teaches the compounds in treating a coronavirus infection wherein the infection is COVID-19 may be used in combination with other drugs and names remdesivir (see paragraph [0382], p. 22), monoclonal antibodies such as bamlanivimab (see paragraph [0392], p. 23-24) and telmisartan (see paragraph [0386], p. 22). Thus, it would be obvious to one of ordinary skill in the art to combine compounds taught by CN ‘478 to treat COVID-19 with those of OWEN to arrive at the limitations of claims 7-8 and 11-12. According to MPEP 2144.06, Section I states that it is obvious to combine equivalents known for the same purpose. "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980) (citations omitted) (Claims to a process of preparing a spray-dried detergent by mixing together two conventional spray-dried detergents were held to be prima facie obvious.). (That the two claimed types of active agents, GABA-a agonists and ARBs, were known to be useful for the same purpose—alleviating hypertension—alone can serve as a motivation to combine). Regarding claims 13-14 and 17-18, Dhanoa teaches compounds such as PNG media_image4.png 132 208 media_image4.png Greyscale (see claim 2, p. 8) as ACE-2 inhibitors and useful in treatment of Covid-19. Further Dhanoa teaches ACE inhibitors such as Enalapril, Lisinopril, Captopril, Benazepril, Fosinopril, Ramipril, Quinapril, and Perindopril (see paragraph [0019], p. 2 used in combination as useful in the treatment of the unprecedented pandemic disease Covid-19 caused by the Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2). Thus, it would be obvious to one of ordinary skill in the art to combine compounds taught by CN ‘478 with those of Dhanoa to treat Covid-19. According to MPEP 2144.06, Section I states that it is obvious to combine equivalents known for the same purpose. "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980) (citations omitted) (Claims to a process of preparing a spray-dried detergent by mixing together two conventional spray-dried detergents were held to be prima facie obvious.). (That the two claimed types of active agents, GABA-a agonists and ARBs, were known to be useful for the same purpose—alleviating hypertension—alone can serve as a motivation to combine). Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to KAREN CHENG whose telephone number is (703)756-4699. The examiner can normally be reached M-F, 9AM-6PM PST. 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, Adam Milligan can be reached at 571-270-7674. 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. /KAREN CHENG/Primary Examiner, Art Unit 1623 /ADAM C MILLIGAN/Supervisory Patent Examiner, Art Unit 1623
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Prosecution Timeline

Nov 21, 2023
Application Filed
Feb 12, 2026
Non-Final Rejection — §102, §103 (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
76%
Grant Probability
99%
With Interview (+27.9%)
2y 3m
Median Time to Grant
Low
PTA Risk
Based on 677 resolved cases by this examiner. Grant probability derived from career allow rate.

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