Prosecution Insights
Last updated: April 19, 2026
Application No. 17/262,133

IMAGING AGENTS FOR RADIOLABELING EXOGENOUS AND ENDOGENOUS ALBUMIN

Final Rejection §103
Filed
Jan 21, 2021
Examiner
SCHLIENTZ, LEAH H
Art Unit
1618
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Ladrx Corporation
OA Round
6 (Final)
42%
Grant Probability
Moderate
7-8
OA Rounds
4y 0m
To Grant
81%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
248 granted / 589 resolved
-17.9% vs TC avg
Strong +39% interview lift
Without
With
+39.0%
Interview Lift
resolved cases with interview
Typical timeline
4y 0m
Avg Prosecution
67 currently pending
Career history
656
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
48.7%
+8.7% vs TC avg
§102
22.3%
-17.7% vs TC avg
§112
15.1%
-24.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 589 resolved cases

Office Action

§103
DETAILED ACTION 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 . Acknowledgement of Receipt Applicant’s Response, filed 9/24/2025, in reply to the Office Action mailed 3/24/2025, is acknowledged and has been entered. Claims 20, 24, 25, 27, 29-39, 43 and 44 are pending and are examined herein on the merits for patentability. Response to Arguments Applicant’s arguments have been fully considered. The rejection of claims 20, 24, 25 and 44 under 35 U.S.C. 103 as being unpatentable over Kobayashi et al. (Anal. Chem., 2011, 83, p. 9123-9130) in view of Lehmann et al. (US 2012/0064002) has been withdrawn in view of Applicant’s argument that Kobayashi does not teach a metal complex that is not bound to an antibody. The rejection of claims 20, 24, 25, 27, 29-39, 43 and 44 under 35 U.S.C. 103 as being unpatentable over Kobayashi et al. (Anal. Chem., 2011, 83, p. 9123-9130) in view of Lehmann et al. (US 2012/0064002), in further view of Driver (US 2017/0296684) and Kratz (US 2015/0023912) is maintained. The Examiner’s response to Applicant’s arguments is incorporated below. 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. Claims 20, 24, 25, 27-39, 43 and 44 are rejected under 35 U.S.C. 103 as being unpatentable over Kobayashi et al. (Anal. Chem., 2011, 83, p. 9123-9130) in view of Lehmann et al. (US 2012/0064002), in further view of Driver (US 2017/0296684) and Kratz (US 2015/0023912), for reason set forth in the previous Office Action. Response to arguments Applicant argues that Kobayashi does not disclose, teach or suggest an 111In labeled EMCS-Bz-DTPA that is not bound to an antibody, nor does Kobayashi teach or suggest the specific compounds recited in the instant claims. Applicant asserts that the antibody-maleimide conjugate in Kobayashi is not a conjugate acid and nothing in Lehmann remedies the deficiencies of Kobayashi. Applicant further argues that nothing in Driver and Kratz remedies the deficiencies of Kobayashi and Lehmann. Applicant asserts that Driver does not teach or suggest the specific metal complexes as recited in the instant claims, and that while Kratz discloses various therapeutic agents, it does not teach or suggest any metal complexes, let alone the specific metal complexes as recited in the instant claims. Moreover, Applicant has demonstrated that upon administration of the instantly recited complexes, they are detected in tumor tissues. Applicant asserts that nothing in the combination of Kobayashi, Lehmann, Driver and Kratz would have led the skilled worker to the specific metal complexes and methods of use thereof as recited in the instant claims. Applicant’s arguments have been fully considered but are not found to be persuasive. While it is acknowledged that Kobayashi does not teach a 111In labeled EMCS-Bz-DTPA or conjugate acid thereof that is not bound to an antibody, it is respectfully submitted that Driver is incorporated to teach provision of a radiolabeled proconjugate comprising a reactive maleimide moiety, see in particular an exemplary proconjugate comprising a radiolabeled chelator and maleimide for reaction with a protein shown on page 13 of Driver. Lehman teaches enantiomeric resolution of DTPA derivatives. With regard to the argument that Kratz does not remedy the deficiencies of Kobayashi and Driver, Applicant's arguments have been fully considered but are not found to be persuasive because Kratz teaches administration of a maleimide bearing active agent in order to bind the Cys-34 position of circulating albumin and accumulation in solid tumors due to passive targeting for tumor detection and monitoring. While the active agent bearing a reactive maleimide groups are not the same active agent in Kobayashi/Driver and Kratz, it is considered that one of ordinary skill in the art would have recognized that a given active agent bearing a reactive maleimide would be capable of reacting with albumin as shown by Kratz using an active agent bearing a reactive maleimide for the desired purpose of targeting for albumin and accumulation in tumor for detection and monitoring; for example Kratz teaches that a drug may be radioactive. Conclusion No claims are allowed at this time. THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to LEAH H SCHLIENTZ whose telephone number is (571)272-9928. The examiner can normally be reached Monday-Friday, 8:30am - 12:30pm EST. 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, MICHAEL HARTLEY can be reached at 571-272-0616. 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. /LHS/ /Michael G. Hartley/Supervisory Patent Examiner, Art Unit 1618
Read full office action

Prosecution Timeline

Jan 21, 2021
Application Filed
Mar 12, 2022
Non-Final Rejection — §103
Aug 24, 2022
Response Filed
Dec 11, 2022
Final Rejection — §103
Jun 13, 2023
Request for Continued Examination
Jun 16, 2023
Response after Non-Final Action
Nov 16, 2023
Non-Final Rejection — §103
Jun 04, 2024
Response Filed
Sep 12, 2024
Final Rejection — §103
Mar 13, 2025
Request for Continued Examination
Mar 17, 2025
Response after Non-Final Action
Mar 18, 2025
Non-Final Rejection — §103
Sep 24, 2025
Response Filed
Jan 13, 2026
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

7-8
Expected OA Rounds
42%
Grant Probability
81%
With Interview (+39.0%)
4y 0m
Median Time to Grant
High
PTA Risk
Based on 589 resolved cases by this examiner. Grant probability derived from career allow rate.

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