DETAILED ACTION
A non-final Office action was mailed 11 September 2025 (“Office Action”).
Applicant’s reply to the Office Action was received 8 December 2025 (“Reply”).
Status of the Claims
The listing of claims filed with the Reply has been examined.
Claims 1–4, 11–16, 26, 27, 29, 30, 33, 35, 37, and 40–45 are pending.
Claims 1 and 37 are amended. Claims 42–45 are new.
Claims 5–10, 17–25, 28, 31, 38, and 39 are canceled.
Status of Rejections and Objections
The text of those sections of Title 35, U.S. Code and/or text providing the basis for non-statutory double patenting rejections not included in this action are set forth in the Office Action.
Unless repeated herein, any objection or rejection in the Office Action is withdrawn.
Claim Rejections - 35 U.S.C. § 112
(i) Claims 1–4, 11–16, 26, 27, 29, 30, 33, 35, 37, and 40–45 are rejected under 35 U.S.C. § 112(a) as failing to comply with the written description requirement. The claims contain subject matter (i.e., prodrugs) that was not described in the Specification in such a way as to reasonably convey to one of ordinary skill in the art that Applicant, at the time the application was filed, had possession of the claimed invention.
In Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc), the Federal Circuit stated “the hallmark of written description is disclosure.” A specification adequately describes an invention when it “reasonably conveys to those skilled in the art the inventor had possession of the claimed subject matter as of the filing date.” (Id.). “A ‘mere wish or plan’ for obtaining the claimed invention is not adequate written description.” Centocor Ortho Biotech, Inc. v. Abbott Labs., 636 F.3d 1341, 1348 (Fed. Cir. 2011).
What is required to meet the written description requirement “varies with the nature and scope of the invention at issue, and with the scientific and technologic knowledge already in existence.” Capon v. Eshhar, 418 F.3d 1349, 1357 (Fed. Cir. 2005). In Ariad, the Federal Circuit explained what is required to meet the written description requirement:
This inquiry, as we have long held, is a question of fact. Ralston Purina, 772 F.2d at 575. Thus, we have recognized that determining whether a patent complies with the written description requirement will necessarily vary depending on the context. Capon v. Eshhar, 418 F.3d 1349, 1357–58 (Fed. Cir. 2005). Specifically, the level of detail required to satisfy the written description requirement varies depending on the nature and scope of the claims and on the complexity and predictability of the relevant technology. Id. For generic claims, we have set forth a number of factors for evaluating the adequacy of the disclosure, including “the existing knowledge in the particular field, the extent and content of the prior art, the maturity of the science or technology, [and] the predictability of the aspect at issue.” Id. at 1359.
(Ariad, at 1351).
The written description of a genus, such as a chemical genus, “requires a precise structure, formula, [or] chemical name” of the claimed subject matter sufficient to distinguish it from other materials. Regents of the Univ. of Cal. v. Eli Lilly & Co., 199 F.3d 1559, 1568 (Fed. Cir. 1997). The Federal Circuit commented on that case in the Ariad decision:
We held that a sufficient description of a genus instead requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can “visualize or recognize” the members of the genus. Id. at 1568-69. We explained that an adequate written description requires a precise definition, such as by structure, formula, chemical name, physical properties, or other properties, of species falling within the genus sufficient to distinguish the genus from other materials. Id. at 1568 (quoting Fiers v. Revel, 984 F.2d 1164, 1171 (Fed. Cir. 1993)). We have also held that functional claim language can meet the written description requirement when the art has established a correlation between structure and function. See Enzo, 323 F.3d at 964 (quoting 66 Fed. Reg. 1099 (Jan. 5, 2001)). But merely drawing a fence around the outer limits of a purported genus is not an adequate substitute for describing a variety of materials constituting the genus and showing that one has invented a genus and not just a species.
(Ariad, at 1350).
The factors outlined in the above Federal Circuit cases are analyzed in turn below with respect to the claimed invention.
(A) The nature and scope of the claim invention in view of the specification: relates generally to the chemical art and more specifically to the pharmaceutical art; and even more specifically to a compound of Formula (X), including a salt, enantiomer, diastereomer, racemate, solvate, hydrate, polymorph, prodrug, or isotope thereof; a pharmaceutical composition comprising the compound; a kit comprising the compound, and a method of administering the compound to a subject to treat a disease.
A salt, enantiomer, diastereomer, racemate, solvate, hydrate, polymorph, or isotope of a compound of Formula (X) would be represented by essentially the same chemical structure as the base compound; however, a prodrug requires a modification to the structure of the compound of Formula (X) and the modification may involve the deletion and/or addition of an atom or functional group that changes the structure of a compound of Formula (X).
Formula (X) includes variables R, R’, A2, A3, A4, R1, R2, R3, and ring A. In view of such variability, the scope of Formula (X) therefore encompasses hundreds to thousands of different compounds. Modifying such compounds into a one or more prodrugs could multiple the scope to millions of different compounds.
The Specification does not provide any guidance or examples for preparing a prodrug of a compound of Formula (X). Such guidance may include, for example, the identification of which atom or functional group on the structure of Formula (X) would be targeted for modification, what the structure of the prodrug moiety would be, and how the prodrug compound would be prepared from the compound of Formula (X). The specification merely describes what a “prodrug” is and identifies references that discuss prodrugs, but those references are not directed to a compound of Formula (X). (Spec., 46:24–47:4) (page:lines).
(B) The extent and content of the prior art: The compounds of Formula (X) appear to be free of the prior art. Prodrugs are known in the prior art. Considered as a whole, while the prior art may provide general guidance as to which prodrugs may be useful for certain compounds, the prior art does not specifically inform one of ordinary skill in the art how a compound of Formula (X) should be modified or how to make and use a prodrug of such a compound. Accordingly, Applicant’s disclosure is critical to show possession.
(C) The maturity of the science or technology: While prodrugs have existed for decades, the claims are specifically directed to a prodrug of a compound of Formula (X). When considered as a whole, the science relevant to making and using prodrugs of the compound of Formula (X) is in its infancy because the compounds appear to be novel.
(D) The predictability of the aspect at issue: the chemical and pharmaceutical arts are generally recognized as unpredictable. In re Fisher, 427 F.2d 833, 839 (CCPA 1970). The art requires, for example, each potential drug candidate to be assessed for physiological activity. (Id.). Applications in unpredictable arts require more specific disclosures to satisfy the statutory requirement. In this case, there is no evidence suggesting the claimed invention is more predictable than the chemical and pharmaceutical arts are generally.
The question of written description
After considering the above factors and evidence discussed therein, Examiner finds the specification does not adequately describe a representative number of prodrug species for a compound of Formula (X), or provide sufficient guidance for making such a prodrug. As such, the specification does not reasonably convey to those skilled in the art that applicant had possession of the claimed subject matter as of the filing date.
Examiner recommends deleting “prodrug” from the claims.
(ii) Claims 37 and 42 are rejected under 35 U.S.C. § 112(a) as failing to comply with the written description requirement. The claims contain subject matter (i.e., diseases) that was not described in the Specification in such a way as to reasonably convey to one of ordinary skill in the art that Applicant, at the time the application was filed, had possession of the claimed invention.
(A) The nature and scope of the claim invention in view of the specification: relates generally to the chemical art and more specifically to the pharmaceutical art; and even more specifically to a compound of Formula (X), including a salt, enantiomer, diastereomer, racemate, solvate, hydrate, polymorph, prodrug, or isotope thereof; a pharmaceutical composition comprising the compound; a kit comprising the compound, and a method of administering the compound to a subject to treat a disease.
Claim 37 is directed to a method of treating CDK-mediated diseases in a subject.
Claim 42 is directed to a method of treating cell proliferative diseases.
The specification does not define either of the claim terms.
The specification includes examples of a CDK-mediated disease and cell proliferative disease. (Spec., 5:35–6:8). The same examples are recited in claims 43–45. Each of those examples relates to a tumor or cancer.
No other types of diseases are mentioned in the specification.
In view of the claims and specification, one of skill in the art would consider the nature of the claimed invention to be directed to the treatment of cancer, which is sophisticated.
(B) The extent and content of the prior art: The background explains that over 20 CDK inhibitors have entered the clinical stage as new anti-tumor drugs. (Spec., 1:14–18). The specification does not discuss other types of diseases (non-cancer) or associated drugs.
Lukasik et al., Int. J. Mol. Sci. (2021), 22, 2935, 35 pages (“Lukasik”), explains that CDKs are involved in various diseases that are distinct from cancer, including neurodegenerative diseases and viral infections:
There are 20 members of CDK family known to this day regulating the cell cycle, transcription and splicing. The kinases are organized in a pathway to ensure that, during cell division, each cell accurately replicates its DNA, and ensures its segregation equally between the two daughter cells. Deregulation of any of the stages of the cell cycle or transcription lead to apoptosis, but if uncorrected, can result in a series of diseases, such as cancer, neurodegenerative diseases (Alzheimer’s or Parkinson’s disease), and stroke. They also play a key role in the spread of some viral infections, including HIV.
(Lukasik, p.1).
In view of Lukasik, one of skill in the art would appreciate the members of the CDK family are diverse in the types of diseases in which they may be involved.
(C) The maturity of the science or technology: While methods of treating diseases such as tumors and cancers are known in the art, the claims are specifically directed to treating any disease that could be considered a CDK-mediated disease or cell proliferative disease with a compound of Formula (X). The scope of such diseases is diverse and includes cancer and other diseases that are not even mentioned in the specification. Thus, when considered as a whole, the science relevant to administering a compound of Formula (X) to a subject for the purpose of treating cancer may be advanced (with anti-tumor compounds in the clinic); but, for treating unknown diseases, the science is in its infancy.
(D) The predictability of the aspect at issue: the chemical and pharmaceutical arts are generally recognized as unpredictable. In re Fisher, 427 F.2d 833, 839 (CCPA 1970). The art requires, for example, each potential drug candidate to be assessed for physiological activity. (Id.). Applications in unpredictable arts require more specific disclosures to satisfy the statutory requirement.
In this case, the instant specification states: “Some CDK inhibitor drugs lack selectivity for CDK subtypes, resulting in greater toxicity.” (Spec., 1:14–18). The specification also provides a table of results for different assays, and shows that some compounds are relatively selective for CDK2/A2 or CDK4/D3/ or CDK6/D3, whereas other compounds have no selectivity. (Spec., 85:29–86). Thus, the evidence would suggest to one of skill in the art the claimed invention is unpredictable, which is consistent with the pharmaceutical art generally.
The question of written description
After considering the above factors and evidence discussed therein, Examiner finds the specification does not adequately describe a representative number of species for treating an undefined genus like CDK-mediated disease or cell proliferative disease. Although undefined, the genus of diseases encompasses diverse and sophisticated diseases like cancer, Alzheimer’s disease, and HIV, as evidenced by Lukasik. By contrast, the examples and guidance provided by the specification are limited to cancer. Further, the pharmaceutical art is unpredictable and the claimed method relevant to treating a CDK-mediated disease or cell proliferative disease is in its infancy. As such, the specification does not reasonably convey to those skilled in the art that applicant had possession of the claimed subject matter as of the filing date.
Examiner recommends canceling claims 37 and 42 in view of claims 43–45.
Conclusion
No claims are allowed.
Communication
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jason Nolan at (571) 272-2480. The examiner can normally be reached Monday through Friday between 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 submit an Automated Interview Request: http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Adam Milligan, can be reached on 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.
/JASON M. NOLAN/Patent Examiner, Art Unit 1623
/ADAM C MILLIGAN/Supervisory Patent Examiner, Art Unit 1623