Prosecution Insights
Last updated: April 19, 2026
Application No. 18/253,252

SUBSTITUTED PYRROLO [2, 3-b] PYRIDINE AND PYRAZOLO [3, 4-b] PYRIDINE DERIVATIVES AS PROTEIN KINASE INHIBITORS

Non-Final OA §103
Filed
May 17, 2023
Examiner
TOWNSLEY, SARA ELIZABETH
Art Unit
1629
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Fochon Biosciences Ltd.
OA Round
1 (Non-Final)
25%
Grant Probability
At Risk
1-2
OA Rounds
4y 0m
To Grant
73%
With Interview

Examiner Intelligence

Grants only 25% of cases
25%
Career Allow Rate
95 granted / 381 resolved
-35.1% vs TC avg
Strong +48% interview lift
Without
With
+48.0%
Interview Lift
resolved cases with interview
Typical timeline
4y 0m
Avg Prosecution
50 currently pending
Career history
431
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
40.3%
+0.3% vs TC avg
§102
19.7%
-20.3% vs TC avg
§112
23.5%
-16.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 381 resolved cases

Office Action

§103
NON-FINAL REJECTION This application is a 35 U.S.C. 371 (national stage) application of PCT/CN2021/130897, filed Nov. 16, 2021, which claims benefit of priority to Priority from Provisional Application 63/115,027, filed Nov. 17, 2020. Claims 1-19, as amended, are pending. 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 Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Information Disclosure Statement The information disclosure statements (IDS) submitted on May 17, 2023 and Nov. 7, 2024 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements have been considered by the examiner. 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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action: (a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 pre-AIA 35 U.S.C. 103(a) 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 1-19 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tan et al. (WO2020/239124, cited on the IDS dated 5/17/2023). Tan et al. disclose compounds of formula (I) as a novel class of Bruton's tyrosine kinase (BTK) inhibitors, useful for the treatment of hyper-proliferative diseases like cancer (para. [2]). The compounds of Tan et al. are disclosed in pharmaceutical compositions comprising at least one pharmaceutically acceptable carrier (claim 33), as recited by claim 14. The compounds and compositions of Tan et al. are disclosed for use in methods to treat, ameliorate or prevent conditions which respond to BTK inhibition, comprising administering to a subject in need of such treatment an effective amount of a compound of formula (I), a pharma-ceutically acceptable salt thereof, or pharmaceutical compositions thereof, optionally in combination with a second therapeutic agent (claim 34), as recited by claims 15 and 19. Specifically, the compounds of Tan et al. are disclosed in methods of treating cell proliferative disorders, e.g., B-cell proliferative disorders, which includes B-cell malignancies, B-cell chronic lymphocytic lymphoma, chronic lymphocytic leukemia, B-cell prolymphocytic leukemia, lymphoplasmacytic lymphoma, multiple sclerosis, small lymphocytic lymphoma, mantle cell lymphoma, B-cell non-Hodgkin's lymphoma, activated B-cell like diffuse large B-cell lymphoma, multiple myeloma, diffuse large B-cell lymphoma, follicular lymphoma, primary effusion lymphoma, burkitt lymphoma/leukemia, lymphomatoid granulomatosis, and plasma-cytoma (paras. [20]-[21]), as recited by claims 16-18. In particular, Tan et al. exemplify compounds of formula (I), e.g., compound 161 (Table 1, page 90), having the structural formula, PNG media_image1.png 146 304 media_image1.png Greyscale which reads on claims 1-12 to the extent that R1 is unsubstituted C1-alkyl (methyl); m is 1; and R2 is halogen (fluoro). Compound 161 of Tan et al. differs from independent claims 1 and 13 in that the pyrrolopyridine core is substituted by methoxy rather than fluoro. For comparison, compound 161 of Tan et al. is shown side-by-side with formula (I) of claim 1 and the second-recited compound of claim 13 (Example 2) below: Compound 161 of Tan et al. Formula (I) of Claim 1 PNG media_image1.png 146 304 media_image1.png Greyscale PNG media_image2.png 152 366 media_image2.png Greyscale Compound of Claim 13 (Example 2) PNG media_image3.png 124 260 media_image3.png Greyscale However, Tan et al. explicitly disclose, teach, and suggest that methoxy and fluorine substituents on the pyrrolopyridine core are interchangeable in the definition of formula (I), wherein alkoxy and halogen are claimed as equivalent options at R2 (claim 1). Furthermore, Tan et al. exemplify many more compounds of formula (I) wherein R2 is methoxy (e.g., compounds 72-82, Table 1), as well as many compounds wherein R2 is fluorine (e.g., compounds 114-118, 180, 183, 185, and 187, Table 1), as shown below: Compounds 114-118, 180, 183, 185, and 187 of Tan et al. Fluorine substituent at R2 (on the pyrrolopyridine core) PNG media_image4.png 106 216 media_image4.png Greyscale PNG media_image5.png 112 240 media_image5.png Greyscale PNG media_image6.png 104 224 media_image6.png Greyscale PNG media_image7.png 110 226 media_image7.png Greyscale PNG media_image8.png 104 218 media_image8.png Greyscale PNG media_image9.png 106 230 media_image9.png Greyscale PNG media_image10.png 110 228 media_image10.png Greyscale PNG media_image11.png 100 220 media_image11.png Greyscale PNG media_image12.png 120 244 media_image12.png Greyscale The exemplified species of Tan et al. further include, e.g., hydrogen, ethoxy, and cyano at R2, demonstrating that any or all of these substituents at R2, in particular methoxy and fluoro, function as interchangeable equivalents at that position. Therefore, it would have been predictable to one of ordinary skill in the art before the effective filing date to modify the compounds of Tan et al. to arrive the claimed compounds with a reasonable expectation of success, because the close structural similarity of the exemplified compounds of Tan et al., and their teaching of the same mechanism of action and same the use as the claimed compounds, as BTK inhibitors useful for treating B-cell proliferative disorders, creates a reasonable expectation that modifying compound 161 by replacing methoxy with fluoro as explicitly disclosed, taught, and suggested by Tan et al. would result in compounds exhibiting similar properties, functions, and utilities. The closer the chemical similarities between the claimed species or subgenus and any exemplary species or subgenus disclosed in the prior art, the greater the expectation that the claimed subject matter will function in an equivalent manner to the genus. See, e.g., In re Dillon, 919 F.2d at 693, 696, 16 USPQ2d at 1901, 1904 (and cases cited therein); and In re Deuel, 51 F.3d 1552, 1558, 34 USPQ2d 1210, 1214 (Fed. Cir. 1995). As recognized by MPEP § 2144.09, a prima facie case of obviousness may be made when chemical compounds have (1) very close structural similarities and (2) similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979). Conclusion No claims are allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SARA E. TOWNSLEY whose telephone number is 571-270-7672. The examiner can normally be reached on Mon-Fri from 9:00 am to 6:00 pm (EST). If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Jeff S. Lundgren, can be reached at 571-272-5541. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://portal.uspto.gov/external/portal. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /SARA ELIZABETH TOWNSLEY/Examiner, Art Unit 1629
Read full office action

Prosecution Timeline

May 17, 2023
Application Filed
Nov 15, 2025
Non-Final Rejection — §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
25%
Grant Probability
73%
With Interview (+48.0%)
4y 0m
Median Time to Grant
Low
PTA Risk
Based on 381 resolved cases by this examiner. Grant probability derived from career allow rate.

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