Prosecution Insights
Last updated: April 18, 2026
Application No. 18/945,768

CELASTROL SALTS, CRYSTALLINE FORMS, AND USES THEREOF

Non-Final OA §103
Filed
Nov 13, 2024
Examiner
HUTTER, GILLIAN A
Art Unit
1625
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Erx Pharmaceuticals Inc.
OA Round
3 (Non-Final)
55%
Grant Probability
Moderate
3-4
OA Rounds
3y 0m
To Grant
99%
With Interview

Examiner Intelligence

Grants 55% of resolved cases
55%
Career Allow Rate
62 granted / 113 resolved
-5.1% vs TC avg
Strong +45% interview lift
Without
With
+44.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
49 currently pending
Career history
162
Total Applications
across all art units

Statute-Specific Performance

§101
2.4%
-37.6% vs TC avg
§103
39.5%
-0.5% vs TC avg
§102
21.1%
-18.9% vs TC avg
§112
20.4%
-19.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 113 resolved cases

Office Action

§103
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 . A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 10/10/2025 has been entered. Current Status of 18/945,768 This Office Action is responsive to the amended claims of 8/12/2025. Claims 1-2, 5-7, 9-14, 16-24, 28-35, 37 are examined on the merits. Priority This Application is a national stage entry of PCT/US23/80122, filed 11/16/2023, which claims priority to US provisional application 63/384,153, filed 11/17/2022, filed 11/17/2022. The instant claims find support from the provisional application. Therefore, the effective filing date is 11/17/2022. Response to Arguments Applicants’ claim amendments and Remarks of 8/12/2025 are acknowledged and have been considered. Applicants’ arguments with respect to the previously raised objections and rejections of record have been considered, but are moot due to the claim amendments and the new rejection(s) applied as a result of said amendments. Response to Amendment Claim Rejections - 35 USC § 103 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. Claim(s) 1-2, 5-7, 9-14, 16-24, 28-35 and 37 are rejected under 35 U.S.C. 103 as being unpatentable over WANG (Wang et al., “Assembly of Celastrol to Zeolitic Imidazolate Framework-8 by coordination as a Novel Drug Delivery Strategy for Cancer Therapy”, Pharmaceuticals, August 29, 2022) in view of NEWMAN (Newman et al., “Parts per Million Powder X-ray Diffraction”, Anal Chem. November 3, 2015). NEWMAN teaches “The detection limits for PXRD are typically on the order of a few percent crystallinity by mass…. Currently, the detection limits for percent crystallinity range from 0.2 to 5% for existing methods” (page 2). This teaches that XRPD can detect impurities from 0.2-5%. NEWMAN does not teach the crystalline form of compound I. WANG teaches the crystalline form of compound I (the compound is also known as celastrol; Figure 1e “PXRD results of Cel”). PNG media_image1.png 183 529 media_image1.png Greyscale Examiner has measured (to the best of her ability) the X-ray power diffraction pattern comprising 9.51o, 14,81o, and 16.84o. For the purification, WANG is silent to the purity. Because WANG does not mention any impurities, one cannot discount that the purity of the crystalline form might be 100%. Since the Office does not have the facilities for examining and comparing Applicants’ composition with the composition of the prior art, the burden is on applicant to show a novel or unobvious difference between the claimed product and the product of the prior art. See In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977) and In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980), and “as a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). This teaches claim 1. WANG does not use ethyl acetate, methanol, ethanol, or dichloromethane as solvents for CEL. Absent to evidence to the contrary, there is no ethyl acetate, methanol, ethanol, or dichloromethane. This teaches claims 7, 9-14, 17, and 20-24. Examiner finds no mention of solvents in WANG. Absent evidence to the contrary, WANG teaches 4000 ppm or less of residual solvents (claim 15). WANG teaches that celastrol is dissolved in DMSO (page 6). This teaches claims 5 and 19. Examiner has included instant application’s figure 21 (Figure 21 is a graph of the XRPD pattern of Compound 1 Form III paragraph [0049]) compared to WANG’s figure 1e (just CEL). [AltContent: rect] PNG media_image2.png 373 585 media_image2.png Greyscale PNG media_image1.png 183 529 media_image1.png Greyscale Examiner has pointed out a peak around 18.74 (with an arrow above on Fig. 21). This teaches claims 2 and 18. WANG teaches a pharmaceutical composition comprising the crystalline form of compound 1 (Cel-ZIF-8) and a pharmaceutically acceptable excipient (DMSO) (2.4 Cellular Uptake and Abstract). This teaches claims 29-30. The artisan would have been motivated to purify the crystalline form of compound I. XRPD can detect impurities from 0.2-5% (Newman page 2); the artisan would be motivated to obtain 95-99.8% crystalline purity before characterization. Additionally, Crystallization in itself is a purification technique. Furthermore, “Purer forms of known products may be patentable, but the mere purity of a product, by itself, does not render the product nonobvious.” See MPEP 2144.04 VII. This teaches up to a purity of 99.8%. Conclusion No claims are allowed as written. Any inquiry concerning this communication or earlier communications from the examiner should be directed to GILLIAN A HUTTER whose telephone number is (571)272-6323. The examiner can normally be reached M-F 7:30-5. 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, Andrew Kosar can be reached at 571-272-0913. 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. /G.A.H./ Examiner, Art Unit 1625 /Andrew D Kosar/Supervisory Patent Examiner, Art Unit 1625
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Prosecution Timeline

Nov 13, 2024
Application Filed
Feb 14, 2025
Non-Final Rejection — §103
Apr 07, 2025
Interview Requested
Apr 14, 2025
Examiner Interview Summary
May 07, 2025
Response Filed
Jun 10, 2025
Final Rejection — §103
Aug 12, 2025
Response after Non-Final Action
Oct 10, 2025
Request for Continued Examination
Oct 14, 2025
Response after Non-Final Action
Mar 27, 2026
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

3-4
Expected OA Rounds
55%
Grant Probability
99%
With Interview (+44.9%)
3y 0m
Median Time to Grant
High
PTA Risk
Based on 113 resolved cases by this examiner. Grant probability derived from career allow rate.

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