Prosecution Insights
Last updated: October 25, 2026
Application No. 17/426,813

A CONJUGATE OF AN AMANITA TOXIN WITH BRANCHED LINKERS

Final Rejection §112
Filed
Jul 29, 2021
Priority
Jan 31, 2019 — nonprovisional of PCTCN2019074176
Examiner
CANELLA, KAREN A
Art Unit
1643
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Hangzhou Dac Biotech Co. Ltd.
OA Round
3 (Final)
62%
Grant Probability
Moderate
4-5
OA Rounds
0m
Est. Remaining
95%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allowance Rate
711 granted / 1142 resolved
+2.3% vs TC avg
Strong +33% interview lift
Without
With
+32.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
49 currently pending
Career history
1198
Total Applications
across all art units

Statute-Specific Performance

§101
6.7%
-33.3% vs TC avg
§103
24.2%
-15.8% vs TC avg
§102
16.6%
-23.4% vs TC avg
§112
33.0%
-7.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1142 resolved cases

Office Action

§112
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 . Claim 24-27, and 36 have been amended. Claims 49-54 have been added. Claims 24-42 and 44-54 are pending and under consideration to the extent that they encompass the elected species (vi) of formula II, wherein the toxin is linked to the cell binding agent through conjugation at position R10 together with R11.. The rejection of claims 24, 25 and 36 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or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention is withdrawn in light of applicant’s amendments of the claims to remove reference to Tradenames. The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 49-54 are rejected and claims 24-42 and 44-48 remain rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Section 2163 of the M.P.E.P. states that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species by actual reduction to practice, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus. A “representative number of species” means that the species which are adequately described are representative of the entire genus. See, e.g., AbbVie Deutschland GMBH v. Janssen Biotech, 111 USPQ2d 1780, 1790 (Fed. Cir. 2014). Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus to provide a “representative number” of species. The “structural features common to the members of the genus” needed for one of skill in the art to ‘visualize or recognize’ the members of the genus takes into account the state of the art at the time of the invention. Applicant has reduced to practice the amanita toxin drug linkers 71, 145, 111, 152, 153, 166, 195, 196, 213, 214, 215, 239, S-1 and S-2. It is noted that in all the examples, with the exception of “71” the core structure is identical, the difference being in the linker structures. Compound 71 differs from compounds 145, 111, 152, 153, 166, 195, 196, 213, 214, 215, 239, S-1 and S-2 in having an R5 of OH rather than NH2 and a X of S rather than SO. However, the core structures claimed are highly variant encompassing R.sub.1 and R.sub.2 are independently selected from H, OH, CH.sub.2OH, CH(OH)CH.sub.2OH, CH(CH.sub.3)CH.sub.2OH, CH(OH)CH.sub.3, C.sub.1-C.sub.8 alkyl, —OR.sub.12 (ether), C.sub.2-C.sub.8 alkenyl, alkynyl, heteroalkyl, —OCOR.sub.12 (ester), —OC(═O)OR.sub.12 (carbonate), —OC(═O)NHR.sub.12(carbamate); C.sub.3-C.sub.8 aryl, heterocyclic, carbocyclic, cycloalkyl, heterocycloalkyl, heteroaralkyl, alkylcarbonyl; R.sub.3 and R.sub.4 are independently selected from H, OH, —OR.sub.12 (ether), —OCOR.sub.12 (ester), —OCOCH.sub.3 (acetate), —OCOOR.sub.12 (carbonate), —OC(═O)NHR.sub.12(carbamate), —OP(O)(OR.sub.12)(OR.sub.12′) (phosphate), OP(O)(NHR.sub.12)(NHR.sub.12′) (phosphamide), O—SO.sub.3.sup.−, or O-glycoside; R.sub.5 is selected from H, OH, NH.sub.2, NHOH, NHNH.sub.2, —OR.sub.12, —NHR.sub.12, NHNHR.sub.12, —NR.sub.12R.sub.12′, or N(H)(R.sub.12)R.sub.13CO(Aa).sub.p, (an amino acid or peptide), wherein Aa is an amino acid or a polypeptide, p represents 0-6; R.sub.6 is selected from H, OH, CH.sub.2OH, CH(OH)CH.sub.2OH, CH(CH.sub.2OH).sub.2, CH(CH.sub.3)OH, CH.sub.2CH.sub.2OH, PrOH, BuOH, C.sub.1-C.sub.8 alkyl, —OR.sub.12 (ether), C.sub.2-C.sub.8 alkenyl, alkynyl, heteroalkyl, —OCOR.sub.12 (ester); C.sub.3-C.sub.8 aryl, heterocyclic, or carbocyclic; R.sub.7, R.sub.8 and R.sub.9 are independently selected from H, OH, CH.sub.3, CH(CH.sub.3).sub.2, CH (CH.sub.3)CH.sub.2CH.sub.3, CH.sub.2OH, CH(OH)CH.sub.2OH, CH.sub.2CH(OH)CH.sub.2OH, CH(CH.sub.2OH).sub.2, CH.sub.2C(OH)(CH.sub.2OH).sub.2, CH.sub.2C(OH)(CH.sub.3)(CH.sub.2OH), CH.sub.2C(OH)(CH(CH.sub.3).sub.2)(CH.sub.2OH), CH.sub.2CH.sub.2OH, PrOH, BuOH, CH.sub.2COOH, CH.sub.2CH.sub.2COOH, CH(OH)COOH, CH.sub.2CONH.sub.2, CH.sub.2CH.sub.2CONH.sub.2, CH.sub.2CH.sub.2CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2CH.sub.2NHC(═NH)NH.sub.2, C.sub.1-C.sub.8 alkyl, CH.sub.2Ar, CH.sub.2SH, CH.sub.2SR.sub.12, CH.sub.2SSR.sub.12, CH.sub.2SSAr, CH.sub.2CH.sub.2SCH.sub.3, —OR.sub.12(ether), C.sub.2-C.sub.8 alkenyl, alkynyl, heteroalkyl, —OCOR.sub.12 (ester); C.sub.3-C.sub.8 aryl, heterocyclic, or carbocyclic and wherein “X” is S, O, NH, SO, SO2 or CH2. Further, the linker structures represented in compounds 71, 145, 111, 152, 153, 166, 195, 196, 213, 214, 215, 239, S-1 and S-2 do not describe the genus of linker structures encompassed by the claims wherein L.sub.1 and L.sub.2 are, the same or different, and are independently selected from O, NH, N, S, P, NNH, NHNH, N(R.sub.3), N(R.sub.12), N(R.sub.12)N(R.sub.12), CH, CO, C(O)NH, C(O)O, NHC(O)NH, NHC(O)O, a polyethyleneoxy unit of formula (OCH.sub.2CH.sub.2).sub.pOR.sub.12, (OCH.sub.2CH—(CH.sub.3)).sub.pOR.sub.12, NH(CH.sub.2CH.sub.2O).sub.pR.sub.12, NH(CH.sub.2CH(CH.sub.3)O).sub.pR.sub.12, N[(CH.sub.2CH.sub.2O).sub.pR.sub.12]—[(CH.sub.2CH.sub.2O).sub.pR.sub.12], (OCH.sub.2CH.sub.2).sub.pCOOR.sub.12, or CH.sub.2CH.sub.2(OCH.sub.2CH.sub.2).sub.pCOOR.sub.12, wherein p and p′ are independently an integer selected from 0 to about 1000, or a combination of two or more of above; C.sub.1-C.sub.8 alkyl; C.sub.2-C.sub.8 heteroalkyl, alkylcycloalkyl, heterocycloalkyl; C.sub.3-C.sub.8 aryl, Ar-alkyl, heterocyclic, carbocyclic, cycloalkyl, heteroalkylcycloalkyl, alkylcarbonyl, heteroaryl; or (Aa).sub.r, r=1-12 (one to 12 amino acid units), which is composed from natural or un-natural amino acids, or a same or different sequence of dipeptide, tripeptide, tetrapeptide, pentapeptide, hexapeptide, heptapeptide, octapeptide, nonapeptide, decapeptide, undecapeptide or dodecapeptide unit, or formula I-q1, wherein Q.sub.1, Q.sub.2, L.sub.1, L.sub.2, V.sub.1, or V.sub.2, can be independently absent but Q.sub.1 and Q.sub.2 are not absent at the same time; V.sub.1 and V.sub.2 are independently a spacer unit selected from O, NH, S, C.sub.1-C.sub.8 alkyl, C.sub.2-C.sub.8 heteroalkyl, alkenyl, alkynyl, C.sub.3-C.sub.8 aryl, heterocyclic, carbocyclic, cycloalkyl, alkylcycloalkyl, heterocycloalkyl, heteroaralkyl, heteroalkylcycloalkyl, or alkylcarbonyl, or (Aa).sub.r, r=1-12 (one to 12 amino acid units), which is composed from a natural or unnatural amino acid, or a same or different sequence of dipeptide, tripeptide, tetrapeptide, pentapeptide, hexapeptide, heptapeptide, octapeptide, nonapeptide, decapeptide, undecapeptide or dodecapeptide unit; or (CH.sub.2CH.sub.2O).sub.p, p is 0-1000; v.sub.1 and v.sub.2 are independently 0, 1 or 2, but v.sub.1 and v.sub.2 are not 0 at the same time; n is 1 to 30. Written description issues may arise if the knowledge and level of skill in the art would not have permitted the ordinary artisan to immediately envisage the claimed product arising from the disclosed process (Fujikawa v. Wattanasin, 93 F.3d 1559, 1571, 39 USPQ2d 1895, 1905 (Fed. Cir. 1996) (a "laundry list" disclosure of every possible moiety does not necessarily constitute a written description of every species in a genus because it would not "reasonably lead" those skilled in the art to any particular species; MPEP 2162.1(A)). Further, the criteria for a “representative number of species” to be described requires that the species which are reduced to practice are representative of the entire genus. The description of the conjugates reduced to practice with only a limited number of moieties of “R” groups attached to the core structure are not representative of the compounds required in the instant claimed conjugates and thus, it cannot be concluded that the disclosure "indicates that the patentee has invented species sufficient to constitute the gen[us]." See Enzo Biochem, 323 F.3d at 966, 63 USPQ2d at 1615; Noelle v. Lederman, 355 F.3d 1343, 1350, 69 USPQ2d 1508, 1514 (Fed. Cir. 2004) (Fed. Cir. 2004) ("[A] patentee of a biotechnological invention cannot necessarily claim a genus after only describing a limited number of species because there may be unpredictability in the results obtained from species other than those specifically enumerated."). Regarding the description of the genus by partial structure combined with a specific function, the specification fails to provide such a correlation. It would be expected that the plethora of different linkers having different formats attached to different parts of the amanita molecule would provide conjugates with different properties the drug being delivered with different kinetics under different microenvironmental conditions. It would also be expected that the released linkers would not in all cases provide the free drug (Casi and Neri, Journal of Controlled Release, 2012, Vol. 161, pp. 422-428, see Table 2). Thus, the resulting drug would be modified by the residue of the linker which can affect the toxicity or behavior of the drug. The compounds described in the specification do not provide a description of (i) all the compounds having the numerous linkers that could be generated from all the variables recited in the instant claims pertaining to the linkers, (i) all the modifications of the amanita toxin core encompassed by the instant claims, and (iii) the amanita toxin -linker structures attached to the large genus of cell-binding agents, T. Thus, the specification fails to provide adequate written description for the genus of compounds claimed and does not reasonably convey to one of skill in the art that he inventors, at the time the application was filed, had possession of the genus of conjugates, methods of making said conjugates and pharmaceutical composition comprising said conjugates. Applicant argues that the recent decision in Teva Pharmaceuticals v Eli Lilly pertains to the instant rejection because. In Teva Pharmaceuticals v Eli Lily the Court distinguished between claims to a genus and claims to a known genus. The Court determined that the disclosure of a specific example of the humanized anti-CGRP antibody was an adequate written description for purpose of that claimed invention which was a method of reducing or treating headache in a human. This has been considered but not found persuasive. The instant claims are drawn to a multitude of previous unknown amanita analogs. Any R group, X group, alteration in the size of the ring (m=0 or1), or combinations thereof is an analog. In the Teva Pharmaceuticals case, the prior art provided the other members of the genus of anti-CGRP antagonists. In the instant case, the prior art does not provide a description of a genus of PNG media_image1.png 76 279 media_image1.png Greyscale wherein T is the cell binding agent ; Q1and Q2 are: PNG media_image2.png 67 402 media_image2.png Greyscale and D is PNG media_image3.png 169 301 media_image3.png Greyscale All claims are rejected/ Conclusion 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 KAREN A CANELLA whose telephone number is (571)272-0828. The examiner can normally be reached M-F 10-6:30. 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 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. KAREN A. CANELLA Examiner Art Unit 1643 /Karen A. Canella/Primary Examiner, Art Unit 1643
Read full office action

Prosecution Timeline

Jul 29, 2021
Application Filed
May 29, 2025
Examiner Interview Summary
May 29, 2025
Applicant Interview (Telephonic)
Feb 13, 2026
Non-Final Rejection mailed — §112
Apr 24, 2026
Response Filed
Jul 01, 2026
Non-Final Rejection mailed — §112
Aug 13, 2026
Response Filed
Oct 16, 2026
Final Rejection mailed — §112 (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

4-5
Expected OA Rounds
62%
Grant Probability
95%
With Interview (+32.8%)
3y 5m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 1142 resolved cases by this examiner. Grant probability derived from career allowance rate.

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