Prosecution Insights
Last updated: April 19, 2026
Application No. 18/155,650

BIOACTIVE CONJUGATE, PREPARATION METHOD THEREFOR AND USE THEREOF

Final Rejection §103§112§DP
Filed
Jan 17, 2023
Examiner
SKOKO III, JOHN JOSEPH
Art Unit
1643
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Sichuan Kelun-Biotech Biopharmaceutical Co. Ltd.
OA Round
2 (Final)
52%
Grant Probability
Moderate
3-4
OA Rounds
3y 7m
To Grant
99%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
53 granted / 102 resolved
-8.0% vs TC avg
Strong +60% interview lift
Without
With
+59.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
37 currently pending
Career history
139
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
32.2%
-7.8% vs TC avg
§102
11.6%
-28.4% vs TC avg
§112
25.0%
-15.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 102 resolved cases

Office Action

§103 §112 §DP
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 92-100, 102, 106-109, 116-124, and 129-133 are pending. Claims 101, 103-105, and 110-115 are canceled. Claims 116-124 and 129-131 remain withdrawn. Claims 132-133 are new. Objections and Rejections Withdrawn The objections and rejections to claims 101, 103-105, and 110-115 are moot in view of claim cancelation. The rejections to claim 92-100 and 102 under 35 USC §112(b) are withdrawn in view of claim amendment. The rejections to claims 92-98 under 35 USC §103 are withdrawn in view of claim amendment. Claim Status Applicant previously elected Group I and the drug linker: PNG media_image1.png 194 418 media_image1.png Greyscale in the reply filed on 7/21/2025. Claims 92-100, 102, 106-109, and 132-133 are pending for the Applicant elected species. The Applicant elected species is free of prior art except for non-statutory double patenting issues. The Applicant has amended the Application to remove the Examiner elected species of: PNG media_image2.png 170 797 media_image2.png Greyscale The next Examiner elected species is: PNG media_image3.png 167 626 media_image3.png Greyscale Claims 92-95, 97-100, and 132 contain the next Examiner elected species. Claim Rejections – 35 USC § 112(b) The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. The rejection of claim 98 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention is maintained. Regarding instant claim 98, the abbreviations of Oms and OTs are unclear. Thus, the meets and bounds of the claim are unclear. Response to arguments Applicant respectfully disagrees that the abbreviations of OMs, OTs, and OTf are unclear, and notes that these abbreviations are commonly used in the art and a person of ordinary skill in the art would understand what these abbreviations mean, especially in view of the disclosure in the specification, which provides the meanings for these abbreviations as shown below (see e.g., paragraph [0262] of US 2023/0357259, which is the publication of the instant application): PNG media_image4.png 277 428 media_image4.png Greyscale In response, Applicant's arguments filed 12/19/2025 have been fully considered but they are not persuasive. Section 2173.05(s) of the M.P.E.P. states that, when possible, claims are to be complete in themselves. Claim 98 relies on the specification for the identity of OMs and OTs. The claim requires amendment with the defined abbreviations of OMs and OTs. Regarding the Examiner elected species of PNG media_image3.png 167 626 media_image3.png Greyscale and instant claims 92-95, 97-100, and 132. 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 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. 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 92-95, 97-100, and 132 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2014/092804 (Govindan SV et al. IDS reference), WO 2009/117531 (Senter P et al. IDS reference), and WO 2018/025168 (Dushin RG et al. IDS reference). Govindan taught an effective method of treating cancer comprising administering a pharmaceutical composition comprising of the ADC hRS7-CL2A-SN-38 (page 89, [0232] and Fig. 2), wherein the antibody was conjugated to the CLA2A-SN-38 linker of PNG media_image5.png 158 588 media_image5.png Greyscale (page 85 and pages 87-88 [0231]). Govindan did not teach the species of: PNG media_image3.png 167 626 media_image3.png Greyscale , but this is obvious in view of Senter, and Dushin. Senter taught a comparison of potency of aryl and alkyl auristain-h1F6 conjugates resulted in conjugates with similar potency against cancer cells in a cell-based assay (pages 120-121, [0365], Example 71, and Table 10). Senter taught administration of a pharmaceutical composition comprising the aryl maleimide ADC cAC10-AM-Asn-(D)Lys-aryl to a subject with cancer was effective in vivo (page 123, [0365], Example 74, and Fig. 17), wherein the drug linker structure was PNG media_image6.png 192 491 media_image6.png Greyscale (page 120, Example 69). Dushin taught non-maleimide-based ADC linkers and linker components, their preparation, and their use in preparing ADCs more stable than corresponding maleimide-based ADCs (page 3-4, bridging paragraph). Dushin taught this improved stability will result in ADCs having improved therapeutic indices and/or other advantageous properties (page 3-4, bridging paragraph). Dushin taught antibodies conjugated to maleimide linker comprising ADCs H-(380C)-mcMMAD and H-(380C)-mcValCitPABC-Aur0101 were less stable in the presence of GSH compared to an antibody conjugated to a pyrimidylene linker comprising ADC of H-(380C)-#26 (pages 115-116, Table 3), wherein the #26 pyrimidylene comprising linker comprised a methylsulfonyl substituent attached to the pyrimidylene PNG media_image7.png 65 71 media_image7.png Greyscale prior to antibody conjugation PNG media_image8.png 143 650 media_image8.png Greyscale (page 71, Scheme for Compound #26). Dushin taught an ADC comprising an antibody conjugated to a pyrimidylene linker #26 was effective against cancer cells expressing the antibody target (pages 117-118, Table 4). Thus, antibody conjugation via pyrimidylene is known to be stable and effective. Regarding instant claims 92-95, 97-100, and 132, it would have been obvious for a person having ordinary skill in the art to take the effective drug linker of Govindan comprising the CL2A-SN-38 linker compound of PNG media_image5.png 158 588 media_image5.png Greyscale – and modify it to: Exchange the methyl cyclohexane moiety for an aryl hexane in view of Senter; and Exchange the maleimide moiety which can be used for cysteine conjugation to an antibody for a methylsulfonyl substituent attached to a pyrimidylene moiety PNG media_image7.png 65 71 media_image7.png Greyscale which can be used for cysteine conjugation to an antibody. This is obvious because: 1) Senter taught a comparison of potency of aryl and alkyl auristain-h1F6 conjugates resulted in conjugates with similar potency against cancer cells in a cell-based assay and administration of a pharmaceutical composition comprising an aryl hexane linked maleimide moiety in ADC cAC10-AM-Asn-(D)Lys-aryl to a subject with cancer was effective in vivo. Thus, an aryl hexane moiety next to a cysteine conjugating moiety in a linker produces an effective linker for cancer treatment; and 2) Dushin taught antibodies conjugated to a pyrimidylene linker comprising ADC of H-(380C)-#26 was more stable in the presence of glutathione (GSH) and an ADC comprising an antibody conjugated to a pyrimidylene linker #26 was effective against cancer cells expressing the antibody target. Thus, exchange of maleimide with PNG media_image7.png 65 71 media_image7.png Greyscale would beneficial. There is a reasonable expectation of success because: 1) Senter taught a comparison of potency of aryl and alkyl auristain-h1F6 conjugates resulted in conjugates with similar potency against cancer cells in a cell-based assay and administration of a pharmaceutical composition comprising an aryl hexane linked maleimide moiety in ADC cAC10-AM-Asn-(D)Lys-aryl to a subject with cancer was effective in vivo. Thus, an aryl hexane moiety next to a cysteine conjugating moiety in a linker would produce an effective linker for cancer treatment; and 2) Dushin taught antibodies conjugated to a pyrimidylene linker comprising ADC of H-(380C)-#26 was more stable in the presence of glutathione (GSH) and an ADC comprising an antibody conjugated to a pyrimidylene linker #26 was effective against cancer cells expressing the antibody target. Thus, exchange of maleimide with PNG media_image7.png 65 71 media_image7.png Greyscale would beneficial. This would produce a linker compound of: PNG media_image9.png 213 613 media_image9.png Greyscale which meets the claim limitations of instant claims 92-95, 97-100, and 132. Response to arguments Applicant has amended the claims to exclude the previous Examiner’s elected species. The updated rejection is above for the next Examiner’s elected species. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Regarding the Applicant elected species of PNG media_image1.png 194 418 media_image1.png Greyscale The provisionally rejected claims 92-100, 102, 106-109, and 132-133 on the ground of nonstatutory double patenting as being unpatentable over claims 1-18, 21, and 23-26 of copending Application No. 18/558,201 are maintained. Although the claims at issue are not identical, they are not patentably distinct from each other because: ‘201 taught an antibody-drug conjugate that binds ROR1 with the formula Ab-[M-L-E-Dx] in claims 1-15, 18, and 23-26. ‘201 claim 16 taught a drug-linker of M’-L-E-D. ‘201 claim 17 taught a drug linker with the structure of the elected species of PNG media_image10.png 195 503 media_image10.png Greyscale which anticipates the Applicant elected species in instant claims 92-100, 102, 106-109, and 132-133. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Response to arguments Applicant respectfully points out that according to MPEP Section 1490(VI)(D)(2)(a), "[i]f a provisional nonstatutory double patenting rejection is the only rejection remaining in an application having the earlier patent term filing date, the examiner should withdraw the rejection in the application having the earlier patent term filing date and permit that application to issue as a patent ... ". In response, Applicant's arguments filed 12/19/2025 have been fully considered but they are not persuasive. While the instant application has an earlier patent term filing date, there are still rejections remaining in the instant application. Thus, the rejection is maintained. The provisionally rejected claims 92-100, 102, 106-109, and 132-133 on the ground of nonstatutory double patenting as being unpatentable over claims 1-2, 6, 11, 16, 20-21, 30, 32, 36-37, 40, 44-47, 50-52, and 72-76 of copending Application No. 18/859,078 are maintained. Although the claims at issue are not identical, they are not patentably distinct from each other because: ‘078 taught an antibody-drug conjugate that binds HER3 with the formula Ab-[M-L-E-Dx] in claims 1-2, 6, 11, 16, 20-21, 30, 32, 36, 45-47, 50, 52, and 72-76. ‘078 claims 37 and 40 taught a drug-linker of M’-L-E-D, wherein a pharmaceutical composition of the drug linker with a pharmaceutically acceptable excipient is taught in claim 51. Claim 44 taught a drug linker with the structure of the elected species of PNG media_image1.png 194 418 media_image1.png Greyscale , which anticipates the Applicant elected species in instant claims 92-100, 102, 106-109, and 132-133. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Response to arguments Applicant respectfully points out that according to MPEP Section 1490(VI)(D)(2)(a), "[i]f a provisional nonstatutory double patenting rejection is the only rejection remaining in an application having the earlier patent term filing date, the examiner should withdraw the rejection in the application having the earlier patent term filing date and permit that application to issue as a patent ... ". In response, Applicant's arguments filed 12/19/2025 have been fully considered but they are not persuasive. While the instant application has an earlier patent term filing date, there are still rejections remaining in the instant application. Thus, the rejection is maintained. The provisionally rejected claims 92-100, 102, 106-109, and 132-133 a on the ground of nonstatutory double patenting as being unpatentable over claims 1-29 of copending Application No. 18/688,265 are maintained. Although the claims at issue are not identical, they are not patentably distinct from each other because: ‘265 claims 1-29 taught a method of improving the product quality of an antibody drug conjugate which includes a drug-linker in claims 3 and 16 that comprises the Applicant elected species of: PNG media_image11.png 198 581 media_image11.png Greyscale which anticipates the Applicant elected species in instant claims 92-100, 102, 106-109, and 132-133. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Response to arguments Applicant respectfully points out that according to MPEP Section 1490(VI)(D)(2)(a), "[i]f a provisional nonstatutory double patenting rejection is the only rejection remaining in an application having the earlier patent term filing date, the examiner should withdraw the rejection in the application having the earlier patent term filing date and permit that application to issue as a patent ... ". In response, Applicant's arguments filed 12/19/2025 have been fully considered but they are not persuasive. While the instant application has an earlier patent term filing date, there are still rejections remaining in the instant application. Thus, the rejection is maintained. Conclusion Claims 92-100, 102, 106-109, and 132-133 are rejected. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 JOHN J SKOKO III whose telephone number is (571)272-1107. The examiner can normally be reached M-F 8:30 - 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, Julie Z Wu can be reached at (571)272-5205. 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.J.S./Examiner, Art Unit 1643 /Karen A. Canella/Primary Examiner, Art Unit 1643
Read full office action

Prosecution Timeline

Jan 17, 2023
Application Filed
Sep 17, 2025
Non-Final Rejection — §103, §112, §DP
Dec 19, 2025
Response Filed
Mar 05, 2026
Final Rejection — §103, §112, §DP (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12590977
ANTI-CERULOPLASMIN ANTIBODIES AND USES THEREOF
2y 5m to grant Granted Mar 31, 2026
Patent 12576154
CONJUGATES OF PSMA-BINDING MOIETIES WITH CYTOTOXIC AGENTS
2y 5m to grant Granted Mar 17, 2026
Patent 12540190
ANTI-BCMA ANTIBODY, ANTIGEN-BINDING FRAGMENT THEREOF AND MEDICAL USE THEREOF
2y 5m to grant Granted Feb 03, 2026
Patent 12534541
ANTI-PTK7 ANTIBODY AND USES THEREOF
2y 5m to grant Granted Jan 27, 2026
Patent 12492264
ANTI-ROR1 ANTIBODY AND ROR1-TARGETING ENGINEERED CELLS
2y 5m to grant Granted Dec 09, 2025
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
52%
Grant Probability
99%
With Interview (+59.9%)
3y 7m
Median Time to Grant
Moderate
PTA Risk
Based on 102 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month