Prosecution Insights
Last updated: April 19, 2026
Application No. 17/789,374

ARGINASE INHIBITORS AND METHODS OF USE

Non-Final OA §112
Filed
Jun 27, 2022
Examiner
WILSON, JERICA KATLYNN
Art Unit
1621
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Merck Sharp & Dohme LLC
OA Round
2 (Non-Final)
61%
Grant Probability
Moderate
2-3
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 61% of resolved cases
61%
Career Allow Rate
57 granted / 94 resolved
+0.6% vs TC avg
Strong +40% interview lift
Without
With
+39.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
39 currently pending
Career history
133
Total Applications
across all art units

Statute-Specific Performance

§101
1.8%
-38.2% vs TC avg
§103
34.4%
-5.6% vs TC avg
§102
18.6%
-21.4% vs TC avg
§112
27.4%
-12.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 94 resolved cases

Office Action

§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 . DETAILED ACTION Claims 1-23 and 27-28 are pending in the instant application. Claims 1-23 and 27-28 are examined herein. Priority The instant application claims benefit of priority to U.S. Provisional Application No. 62/958056, filed on 07 January 2020 and PCT/US2020/065798, filed on 18 December 2020. The claims to the benefit of priority are acknowledged. As such, the effective filing date of the claims is 07 January 2020. Information Disclosure Statement The information disclosure statements (IDS), submitted on 20 September 2022, 03 October 2022, 09 April 2024, are acknowledged and considered. The submissions are in compliance with the provisions of 37 CFR 1.97. Improper Markush Claims 1-23 and 27-28 are rejected on the basis that it contains an improper Markush grouping of alternatives. See In re Harnisch, 631 F.2d 716, 721-22 (CCPA 1980) and Ex parte Hozumi, 3 USPQ2d 1059, 1060 (Bd. Pat. App. & Int. 1984). A Markush grouping is proper if the alternatives defined by the Markush group (i.e., alternatives from which a selection is to be made in the context of a combination or process, or alternative chemical compounds as a whole) share a “single structural similarity” and a common use. A Markush grouping meets these requirements in two situations. First, a Markush grouping is proper if the alternatives are all members of the same recognized physical or chemical class or the same art-recognized class, and are disclosed in the specification or known in the art to be functionally equivalent and have a common use. Second, where a Markush grouping describes alternative chemical compounds, whether by words or chemical formulas, and the alternatives do not belong to a recognized class as set forth above, the members of the Markush grouping may be considered to share a “single structural similarity” and common use where the alternatives share both a substantial structural feature and a common use that flows from the substantial structural feature. See MPEP § 2117. The Markush grouping of Z, V, and X are improper because the alternatives defined by the Markush grouping do not share both a single structural similarity, as there is no common core, and a common use, as the specification fails to use a combination of these variables for the use as BTK inhibitors. The possible substitution patterns set forth in claim 1 create a genus of compounds that spans classifications due to the changing core. Without a representative number of structures, expressing the range of variability, disclosed in the specification or shown in the prior art, the instant application does not show all the possible structure subtypes to be functionally equivalent and have a common use. There are no representative structures where V is O, X is O, or X is S. Claim 20 is close to a proper Markush grouping excluding two compounds (pictured below). The first excluded compound is the only representative structure of Z being CH2, which is also the only structure where V is CR9R10. And the second is the only structure where X is NR11. This is not representative of the genus claimed and does not demonstrate that other compounds with similar substitutions would share in common utility. PNG media_image1.png 118 130 media_image1.png Greyscale PNG media_image2.png 104 152 media_image2.png Greyscale The remaining compounds of claim 20 are a proper Markush grouping where Z is a bond, V is NR8, and X is CH2 or CR9R10, giving the compounds a common core with a representative number of species to demonstrate a shared utility. To overcome this rejection, Applicant may set forth each alternative (or grouping of patentably indistinct alternatives) within an improper Markush grouping in a series of independent or dependent claims and/or present convincing arguments that the group members recited in the alternative within a single claim in fact share a single structural similarity as well as a common use. Claim Rejections - 35 USC § 112 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. Claims 21-23 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification fails to provide the required enablement for the treatment of all cancer. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims. The instant claims are drawn to a method of treating cancer comprising administering a compound of claim 1. The specification fails to provide information that would allow the one skilled in the art to practice the method of treating all cancers To be enabling, the specification of the patent must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation. In re Wright, 999 F.2d 1557, 1561 (Fed. Cir. 1993). Explaining what is meant by "undue experimentation," the Federal Circuit has stated: The test is not merely quantitative, since a considerable amount of experimentation is permissible, if it is merely routine, or if the specification in question provides a reasonable amount of guidance with respect to the direction in which the experimentation should proceed to enable the determination of how to practice a desired embodiment of the claimed invention. PPG v. Guardian, 75 F.3d 1558, 1564 (Fed. Cir. 1996). The factors that may be considered in determining whether a disclosure would require undue experimentation are set forth by In re Wands, 8 USPQ2d 1400 (CAFC1988) at 1404 where the court set forth the eight factors to consider when assessing if a disclosure would have required undue experimentation. Citing Ex parte Forman, 230 USPQ 546 (BdApls 1986) at 547 the court recited eight factors: the nature of the invention the state of the prior art the predictability of the art the amount of direction or guidance provided the presence or absence of working examples the breadth of the claims the quantity of experimentation necessary the relative skill of those in the art These factors are always applied against the background understanding that scope of enablement varies inversely with the degree of unpredictability involved. In re Fisher, 57 CCPA 1099, 1108, 427 F.2d 833, 839, 166 USPQ 18, 24 (1970). Keeping that in mind, the Wands factors are relevant to the instant fact situation for the following reasons: The nature of the invention - is a method of treating cancer comprising administering a compound of claim 1. The state of the prior art - the pharmacological art requires the screening of potential drug candidates in vitro and in vivo to determine if the drug candidates exhibit the desired pharmacological activities. In order to treat a disease: one would need to precisely identify what the disease is, identify what biological target is connected with the disease, demonstrate that the drug candidate in some way modulates the normal processes of the biological target, and demonstrate that a patient benefited from such modification without detrimental side effects. Typically, this process includes in vitro laboratory screening, preclinical in vivo screening, and three phases of clinical trials. Once this arduous process has been successfully completed by a drug candidate, subsequent drug candidates will benefit from the established proof of concept. The subsequent drug candidates must demonstrate a substantial correlation between their biological activity and that of the known drug candidate. In the instant case, the prior arts recognize that arginase activity is elevated in certain cancers and arginase inhibitors are a therapeutic option in these particular cancers (Ye et al. Am J Cancer Res. 2023 May 15;13(5):1952–1969). The predictability or unpredictability of the art – the law recognizes the pharmaceutical art as an unpredictable art and requires each embodiment to be individually assessed for physiological activity. In re Fisher, 427 F.2d 833, 839, 166 USPQ 18 24 (CCPA 1970). Accordingly, the more unpredictable an area is the more specific disclosure is necessary in order to satisfy the statute. Section 2164.02 of the MPEP provides: "[C]orrelation” as used herein refers to the relationship between in vitro and in vivo animal model assays and a disclosed or a claimed method of use . . . if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. In light of these remarks, the Examiner finds that one of ordinary skill in the art would agree with the court; that is, the pharmaceutical art is unpredictable. Thus, a substantial correlation is necessary for establishing the potential of new therapeutics. Additionally, within pharmaceutics, the art of cancer therapeutics is well known to be unpredictable due to the differing etiologies and mechanisms of action for particular cancers. There are more than 200 known cancers; treatment applicable to one is unlikely to be applicable to another. Bianchi et al. (Current Opinion in Cell Biology. 2020; 63:135-143) attributes this unpredictability to tissue specificity, noting most cancer driver genes are mutated in a tissue-dependent manner, which affects therapeutic response (page 135). For example, BRAF inhibition is an effective therapy for BRAF-mutated melanomas, but not BRAF-mutated colon cancer (page 140); same mutation, different tumors, therefore different therapeutic outcomes. Therefore, from the well-established state of cancer arts, a skilled practitioner would not conclude all cancers could be treated, managed or improved with the same therapeutic agent. The amount of direction or guidance presented – the instant specification briefly provides an explanation of the biological activity of arginase on page 1, and discusses the implication of arginase inhibitors in the treatment of diseases facilitated by arginase overexpression and L-arginine depletion. There is no direction or guidance provided that supports a use of an arginase inhibitor as a drug for treatment of all cancers. The amount of guidance or direction to enable the invention is inversely related to the amount of knowledge in the state of the art as well as the predictability in the art. MPEP § 2164.03 (quoting In re Fisher, 427 F.2d 833, 839, 166 USPQ 18 24 (CCPA 1970)). As identified supra, the pharmaceutical art is recognized as unpredictable. Thus, in order to support a claim for treating all cancer a vast amount of evidence is required because such a claim is not supported by the prior art or the instant specification. The presence or absence of working examples - there are no working or prophetic examples in the specification that demonstrate that the instant compounds or compositions thereof may treat all cancers. The assays in the specification demonstrate that the instant compounds were tested for their ability to inhibit the enzyme in vitro (page 152 of the instant specification). The breadth of the claims – is incommensurate in scope with the disclosure because a fair reading of the specification fails to support a finding that the compounds of instant formula (I) may treat all cancers in a patient. The quantity of experimentation necessary – generally speaking, the amount of experimentation to transform a molecule into medicine is vast and the success thereof is low. Recent statistics indicate that the attrition rates during drug development remain high. Schafer et al. Drug Discovery Today 2008, 13 (21/22), 913-916. The article makes clear that there are many steps necessary to promote a new molecular entity toward its clinical use, any one of which is cumbersome. For instance, Schafer et al. discloses: "proof of concept trials have failed when the decision to enter clinical development was based on preclinical experiments using the wrong compound, the wrong experimental model, or the wrong endpoint.” It can be gleaned from this article that a plethora of experimentation is needed to identify the lead compound (i.e. one among many in a Markush-type claim), to establish which preclinical tests are predictive of clinical success, and to establish which diseases are the best to target for each lead compound. There is generally a vast amount of experimentation to take a drug from bench to the clinic. See e.g., Horig et al. Journal of Translational Medicine 2004, 2(44) (“Successful drug development requires satisfying a matrix of domains from relevance to the disease and the drug-ability of the target through feasibility and convenience of drug delivery, demonstration of favorable benefit-risk profile in order to achieve a drug label that reflects physician and patent acceptance.") The Examiner finds that one of ordinary skill in the art would agree with the statements in these articles; that is, the amount of experimentation required to enable a pharmaceutical drug is extensive. The level of skill in the art - the level of ordinary skill in the art may be found by inquiring into: (1) the type of problems encountered in the art; (2) prior art solutions to those problems; (3) the rapidity with which innovations are made; (4) the sophistication of the technology; and (5) the education level of active workers in the field. Custom Accessories, Inc. v. Jeffrey-Allan Industries, Inc., 807 F.2d 855, 962 (Fed. Cir. 1986). All of those factors may not be present in every case, and one or more of them may predominate. Envtl. Designs, Ltd. v. Union Oil Co., 713 F.2d 693, 696 (Fed. Cir. 1983). Based on the typical education level of the active workers in the field of pharmaceuticals and/or medicine, as well as the high degree of sophistication required to solve problems encountered in the art, the Examiner finds that a person of ordinary skill in the art would have at least a college degree in a field related to medicine and/or the pharmaceutical art and at least four years of work experience, i.e. a masters or doctorate level scientist/clinician. Therefore, claims 21-23 are rejected because the Examiner finds that the Wands factors suggest a conclusion that the skilled artisan would not be able to make and use the instant invention without undue experimentation, although the level of skill for an ordinary person in the art is high. That is, due to the breadth of the claims, the unpredictability of the art, the lack of guidance or direction from the disclosure, the lack of any working examples, and the amount of experimentation needed illustrate that a person having ordinary skill in the art would not be able to treat all cancer. Conclusion Claims 1-23 and 27-28 are rejected. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jerica K Wilson whose telephone number is (703)756-4690. The examiner can normally be reached Monday-Friday 9:00-5:00. 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, Clinton Brooks can be reached at (571)270-7682. 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. /J.K.W./Examiner, Art Unit 1621 /CLINTON A BROOKS/Supervisory Patent Examiner, Art Unit 1621
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Prosecution Timeline

Jun 27, 2022
Application Filed
Jun 04, 2025
Non-Final Rejection — §112
Aug 25, 2025
Response Filed
Dec 19, 2025
Non-Final Rejection — §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

2-3
Expected OA Rounds
61%
Grant Probability
99%
With Interview (+39.5%)
3y 3m
Median Time to Grant
Moderate
PTA Risk
Based on 94 resolved cases by this examiner. Grant probability derived from career allow rate.

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