Prosecution Insights
Last updated: April 19, 2026
Application No. 18/282,322

ANTI-ALPP/ALPPL2 ANTIBODIES AND ANTIBODY-DRUG CONJUGATES

Non-Final OA §112
Filed
Sep 15, 2023
Examiner
HECK, BRYAN WILLIAM
Art Unit
1643
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Seagen Inc.
OA Round
1 (Non-Final)
47%
Grant Probability
Moderate
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 47% of resolved cases
47%
Career Allow Rate
22 granted / 47 resolved
-13.2% vs TC avg
Strong +71% interview lift
Without
With
+71.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
29 currently pending
Career history
76
Total Applications
across all art units

Statute-Specific Performance

§101
5.2%
-34.8% vs TC avg
§103
29.2%
-10.8% vs TC avg
§102
18.9%
-21.1% vs TC avg
§112
29.9%
-10.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 47 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. Claims Status Claims 1-44 and 55 are pending and are examined on the merits. Nucleotide and/or Amino Acid Sequence Disclosures Summary of Requirements for Patent Applications Filed O n Or After July 1, 2022, T hat Have Sequence Disclosures 37 CFR 1.831(a) requires that patent applications which contain disclosures of nucleotide and/or amino acid sequences that fall within the definitions of 37 CFR 1.831(b) must contain a “Sequence Listing XML”, as a separate part of the disclosure, which presents the nucleotide and/or amino acid sequences and associated information using the symbols and format in accordance with the requirements of 37 CFR 1.831-1.835. This “Sequence Listing XML” part of the disclosure may be submitted: 1. In accordance with 37 CFR 1.831(a) using the symbols and format requirements of 37 CFR 1.832 through 1.834 via the USPTO patent electronic filing system (see Section I.1 of the Legal Framework for Patent Electronic System (https://www.uspto.gov/PatentLegalFramework), hereinafter “Legal Framework”) in XML format, together with an incorporation by reference statement of the material in the XML file in a separate paragraph of the specification (an incorporation by reference paragraph) as required by 37 CFR 1.835(a)(2) or 1.835(b)(2) identifying: a. the name of the XML file b. the date of creation; and c. the size of the XML file in bytes; or 2. In accordance with 37 CFR 1.831(a) using the symbols and format requirements of 37 CFR 1.832 through 1.834 on read-only optical disc(s) as permitted by 37 CFR 1.52(e)(1)(ii), labeled according to 37 CFR 1.52(e)(5), with an incorporation by reference statement of the material in the XML format according to 37 CFR 1.52(e)(8) and 37 CFR 1.835(a)(2) or 1.835(b)(2) in a separate paragraph of the specification identifying: a. the name of the XML file; b. the date of creation; and c. the size of the XML file in bytes. SPECIFIC DEFICIENCIES AND THE REQUIRED RESPONSE TO THIS NOTICE ARE AS FOLLOWS: Specific deficiency - Sequences appearing in the drawings, specifically Figures 5-8, are not identified by sequence identifiers in accordance with 37 CFR 1.831(c). Sequence identifiers for sequences (i.e., “SEQ ID NO:X” or the like) must appear either in the drawings or in the Brief Description of the Drawings. Required response – Applicant must provide: Amended drawings in accordance with 37 CFR 1.121(d) inserting the required sequence identifiers; AND/OR A substitute specification in compliance with 37 CFR 1.52, 1.121(b)(3), and 1.125 inserting the required sequence identifiers (i.e., “SEQ ID NO:X” or the like) into the Brief Description of the Drawings, consisting of: • A copy of the previously-submitted specification, with deletions shown with strikethrough or brackets and insertions shown with underlining (marked-up version); • A copy of the amended specification without markings (clean version); and • A statement that the substitute specification contains no new matter. Claim Rejections - 35 USC § 112 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. Claim 55 is 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. This is a written description rejection . Scope of the claimed genus Claim 55 is drawn to an ALPP/ALPPL2 antigen binding protein that binds to “one or more amino acids of a peptide comprising SEQ ID NO: 73 and/or SEQ ID NO: 74”. Accordingly, the claim is drawn to a vast genus of potential ALPP/ALPPL2 antibodies defined only by functional limitations. State of the relevant art Antibodies that target ALPP and ALPPL2 are known in the art, as are antibody-drug-conjugates thereof for use in targeting cancers such as mesothelioma (See Fig. 2-4 of Su et al. 2020, Cancer research , 80(20), 4552-4564. ; PTO-892). Su, however, does not teach that epitope bound by the ALPP/ALPPL2 antibodies is the same as instantly claimed SEQ ID NO: 73 or 74. As was well known in the antibody art, the formation of an intact antigen binding site in a conventional antibody typically requires the association of the complete heavy and light chain variable regions of a given antibody, each of which comprises three CDRs (or hypervariable regions) which provide the majority of the contact residues for the binding of the antibody to its target epitope (reviewed in Sela- Culang et al. Frontiers in Immunology 4 (2013): 302.; PTO-892). It is generally understood that all six CDRs in combination and in a specific order (HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3) are required to convey an antibody’s specificity to its target, and that neither the CDRs themselves nor individual VH and VL domains are interchangeable. Sela- Culang further teaches that antigens lack intrinsic properties that clearly differentiate between epitopic and non- epitopic residues, and any part of the antigen surface my become part of an epitope under some circumstances (“Ab Epitope Prediction”; Pg. 2). In the same vein, Edwards et al. 2003 ( Journal of molecular biology 334.1 (2003): 103-118.; PTO-892) endeavored to uncover the breadth of the structural diversity of antibodies a single antigen can give rise to. Edwards employed a phage display library to screen for antibodies that bind a single protein, BLyS , and isolated over 1000 unique anti- BLyS antibodies, each comprising a different amino acid sequence (Abstract). These antibodies were structurally diverse, resulted from nearly all possible V h , D, and J h , germlines (Pg. 105; “ Vh and Vl germline usage”), and comprised 568 distinct V h CDR3 sequences, ranging in length from 5 to 25 amino acid residues (Fig. 4; “ V h CDR3 sequence diversity”; Pg. 105). Together, these works highlight that neither knowledge of the antigen sequence nor the antibody sequence is necessarily predictive of its function. Description of representative species in the specification MPEP § 2163 states that a “representative number of species” means that the species which are adequately described are representative of the entire genus. Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus. In the instant case, however, the specification discloses but a single structurally defined species of antibody p urportedly belonging to the claimed genus . Reactivity of a humanized version of antibody clone “12F3” (“h12F3”) was tested against a variety of chimeric ALPP sequences in order to determine the region within the ALPP sequence required for h12F3 binding, and it was determined that h12F3 binding requires aa L284-S339 of human ALPP to bind (Pg. 99, Example 8; Fig. 25). However, epitope mapping was not performed with any of the other disclosed antibody clones, and there are no examples of any additional antibodies beyond 12F3 that belongs to the claimed genus. In view of the enormous breadth of the potential antibody repertoire highlighted by Edwards, one of ordinary skill in the art would not reasonably consider a single species representative of the claimed genus. Identifying characteristics and structure/function correlation In the absence of a representative number of species, the written description requirement for a claimed genus may be satisfied 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. To meet this requirement in the instant case, the specification must describe structural features that the skilled artisan as of the effective filing date would have expected to convey the claimed binding activity. As discussed above, only a single antibody clone was subject to epitope mapping. Although the disclosure shows that aa L287-S339 within ALPP are required for interaction with h12F3, there is no discussion of the structural features of the antibody itself responsible for this interaction. Accordingly, o ne of ordinary skill in the art would be unable to envisage an anti-ALPP/ALPPL2 antibody defined only by the epitope to which it binds. Claim s 22, 24-31 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA), first paragraph, because the specification, while being enabling for ADCs containing up to 8 drug conjugates, does not reasonably provide enablement for ADCs having greater than 8. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make the invention commensurate in scope with these claims. Scope of the Claims Each of instant Claims 22, 24, and 31 specify a general ADC structure wherein the number of conjugates (“p”) is between 1 to 16 (Claim 22) or 1 to 12 (Claims 24 and 31). Dependent Claims 25-30 fail to further narrow/specify the maximum number of conjugates represented by “p”. State of the Relevant Art The prior art teaches most ADCs are synthesized by conjugating a cytotoxic compound or “payload” to a monoclonal antibody (Behrens et al. 2015, Molecular pharmaceutics , 12(11), 3986-3998. ; PTO-892) (Pg. 3986, ¶1). Behrens teaches these payloads are conjugated using amino or sulfhydryl specific linkers that react selectively with lysines or cysteines on the antibody surface, wherein a typical antibody contains over 50 lysines but only 8 interchain cysteines as potential conjugation sites (Pg. 3986, ¶1). Behrens teaches ADCs with suboptimal drug antibody ratios (DAR) are prone to aggregation, poor solubility, and instability (Pg. 3986, ¶1), and that conjugation through antibody cysteines minimizes ADC heterogeneity relative to lysine conjugation because there are fewer potential conjugation sites (page 3986, ¶2). The process typically involves partial reduction of four antibody interchain disulfide bonds to generate up to eight reactive cysteine thiol groups, followed by conjugation of payloads containing thiol-specific maleimide linkers (Pg. 3986-3987, ¶2). Thus, linker-drug conjugates would conjugate up to 8 cysteines on the antibody. Examples of the instant disclosure According to the instant specification, the drug payloads are attached through a cysteine residue of the antibody (¶0279), which is reflected by the sulfur present on the claimed ADC structure (see instant Claims 22, 24, and 31). The ADCs reduced to practice in Example 4 were conjugated to either 8 loads of MDpr -PEG(12)- gluc -MMAE or 4 loads of either mc- vc -PABC-MMAE or mp - dLAE -PABC-MMAE (¶0333). There are no examples of ADCs with loads greater than 8 nor is there guidance provided in the instant specification on how to achieve loads of up to 12 or up to 16 drugs per antibody, as indicated in the claims. Accordingly, one of ordinary skill in the art would be subject to an undue amount of experimentation to make and use the ADCs of the instant claims with drug loads greater than 8. Claims 22-31 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. It is apparent that the monoclonal antibody clone h12F3 is required to practice the invention of Claims 22-31 . Although the heavy chain and light chain sequences comprised within the h12F3 clone are disclosed, antibody clones are specific to the particular clone of cells used to make them, and may comprise undisclosed post-translational modifications. As required elements, they must be known and readily available to the public or obtainable by a repeatable method set forth in the specification. If they are not so obtainable or available, the enablement requirements of 35 USC 112, first paragraph, may be satisfied by a deposit of the antibody clones. See 37 CFR 1.801-1.809. In addition to the conditions under the Budapest Treaty, applicant is required to satisfy that all restrictions imposed by the depositor on the availability to the public of the deposited material will be irrevocably removed upon the granting of a patent in U.S. patent applications. Amendment of the specification to recite the date of deposit and the complete name and address of the depository is required. As an additional means for completing the record, applicant may submit a copy of the contract with the depository for deposit and maintenance of each deposit. If the original deposit is made after the effective filing date of an application for patent, the applicant should promptly submit a verified statement from a person in a position to corroborate the fact, and should state, that the biological material which is deposited is a biological material specifically identified in the application as filed, except if the person is an attorney or agent registered to practice before the Office, in which the case the statement need not be verified. See MPEP 1.804(b). Affidavits and declarations, such as those under 37 C.F.R. § 1.131 and 37 C.F.R. § 1.132, filed during prosecution of the parent application do not automatically become a part of this application. Where it is desired to rely on an earlier filed affidavit, the applicant should make the remarks of record in the later application and include a copy of the original affidavit filed in the parent application. Alternatively, applicant is invited to make the record clear whether satisfaction of the requirements under 35 USC 112, first paragraph, enablement for biological materials has been satisfied in a current U.S. Patent for h12F3 in order to make the record of the instant application complete. Allowable Subject Matter Claims 1-21 and 32-44 are allowed. The following is a statement of reasons for the indication of allowable subject matter: Antibodies that bind ALPP/ALPPL2 comprising the instantly claimed CDR sequences are free of the prior art of record . The nearest prior art is considered to be Su et al. 2020 ( Cancer research , 80(20), 4552-4564. ; PTO-892) , which teaches an ALPP/ALPPL2 antibody, ADCs comprising said antibody, and methods of treating cancer comprising said ADCs. However, Su neither teaches nor suggests the CDR sequences required by each of Claims 1-21 and 32-44. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILLIN "Examiner name" \* MERGEFORMAT BRYAN WILLIAM HECK whose telephone number is FILLIN "Phone number" \* MERGEFORMAT (703)756-4701 . The examiner can normally be reached FILLIN "Work Schedule?" \* MERGEFORMAT Mon-Fri 8:00am - 5:30pm . 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, FILLIN "SPE Name?" \* MERGEFORMAT Julie Wu can be reached at FILLIN "SPE Phone?" \* MERGEFORMAT (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. /BRYAN WILLIAM HECK/ Examiner, Art Unit 1643 /GARY B NICKOL/ Primary Examiner, Art Unit 1643
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Prosecution Timeline

Sep 15, 2023
Application Filed
Mar 11, 2026
Non-Final Rejection — §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
47%
Grant Probability
99%
With Interview (+71.4%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 47 resolved cases by this examiner. Grant probability derived from career allow rate.

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