Prosecution Insights
Last updated: April 19, 2026
Application No. 18/006,668

DRUG-SPECIFIC PHARMACOKINETIC ASSAY FOR IL-15 SUPERAGONIST

Non-Final OA §112
Filed
Jan 24, 2023
Examiner
MCCOLLUM, ANDREA K
Art Unit
1674
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Nantcell Inc.
OA Round
1 (Non-Final)
61%
Grant Probability
Moderate
1-2
OA Rounds
3y 3m
To Grant
93%
With Interview

Examiner Intelligence

Grants 61% of resolved cases
61%
Career Allow Rate
363 granted / 599 resolved
+0.6% vs TC avg
Strong +33% interview lift
Without
With
+32.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
42 currently pending
Career history
641
Total Applications
across all art units

Statute-Specific Performance

§101
6.4%
-33.6% vs TC avg
§103
17.5%
-22.5% vs TC avg
§102
18.1%
-21.9% vs TC avg
§112
36.9%
-3.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 599 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 Status The preliminary amendments filed 1/24/23 are acknowledged. Claims 5-6 and 12-13 are cancelled. New claims 17-20 are added. Claims 1, 3-4, 9, and 11 are amended. Claims 1-4, 7-11, and 14-20 are pending. Claims 1-4, 7-11, and 14-20 are currently under consideration for patentability under 37 CFR 1.104. Information Disclosure Statement The information disclosure statements filed on 1/24/23, 4/21/23, 5/2/24, 5/22/25, and 6/27/25 have been considered. Signed copies are enclosed. Notably, the disclosure statement filed lists a Search Report. The listing of the references cited in a Search Report itself is not considered to be an information disclosure statement (IDS) complying with 37 CFR 1.98. 37 CFR 1.98(a)(2) requires a legible copy of: (1) each foreign patent; (2) each publication or that portion which caused it to be listed; (3) for each cited pending U.S. application, the application specification including claims, and any drawing of the application, or that portion of the application which caused it to be listed including any claims directed to that portion, unless the cited pending U.S. application is stored in the Image File Wrapper (IFW) system; and (4) all other information, or that portion which caused it to be listed. In addition, each IDS must include a list of all patents, publications, applications, or other information submitted for consideration by the Office (see 37 CFR 1.98(a)(1) and (b)), and MPEP § 609.04(a), subsection I. states, "the list ... must be submitted on a separate paper." Therefore, the references cited in the Search Report have not been considered. Applicant is advised that the date of submission of any item of information or any missing element(s) will be the date of submission for purposes of determining compliance with the requirements based on the time of filing the IDS, including all "statement" requirements of 37 CFR 1.97(e). See MPEP § 609.05(a). Note: If copies of the individual references cited on the Search Report are also cited separately on the IDS (and these references have not been lined-through) they have been considered. Claim Objections Claim 1 is objected to because of the following informalities: the claim subparts are designated with a period. Each claim begins with a capital letter and ends with a period. Periods may not be used elsewhere in the claims except for abbreviations. See Fressola v. Manbeck, 36 USPQ2d 1211 (D.D.C. 1995). It is recommended that the claim subparts be designated with parentheses, such as “(i)” or “i)”. Appropriate correction is required. Claim 1 is objected to because of the following informalities: the steps are not all properly indented. For example, the last “wherein” clause is not set forth as applying to steps other than step iii. Appropriate correction is required. Claim 9 is objected to because of the following informalities: the steps are not all properly indented. For example, the “and detecting” clause in the last line of the claim is not set forth as applying to steps other than step iii. Appropriate correction is required. Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked. As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph: (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function; (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function. Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function. Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function. Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Claim Rejections - 35 USC § 112(a) 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 1-4, 7-11, and 14-20 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 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. The MPEP states that the purpose of the written description requirement is to ensure that the inventor had possession, as of the filing date of the application, of the specific subject matter later claimed. The MPEP lists factors that can be used to determine if sufficient evidence of possession has been furnished in the disclosure of the application. These include “level of skill and knowledge in the art, partial structure, physical and/or chemical properties, functional characteristics alone or coupled with a known or disclosed correlation between structure and function, and the method of making the claimed invention.” 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, disclosure of drawings, or by disclosure of relevant identifying characteristics, for example, 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 Applicants were in possession of the claimed genus. The instant claims are directed to a composition comprising an IL-15/IL-15RαSu complex comprising a first IL-15RαSu domain; a second IL-15RαSu domain wherein the first and second IL-15RαSu domains are directly or indirectly joined by a disulfide bond; a first IL-15 domain bound by electrostatic interactions to the first IL-15RαSu domain to form the first IL-15/IL-15RαSu complex; a second IL-15 domain, bound by electrostatic interactions to the second IL-15RαSu domain to form a second IL-15/ IL-15RαSu complex, a first monoclonal antibody bound to an epitope on the first IL-15/ IL-15RαSu complex, wherein the first monoclonal antibody comprises a means for conjugation to a polymeric surface; and a second monoclonal antibody bound to the second IL-15/ IL-15RαSu complex wherein the second antibody comprises a detection means, and wherein the first and second antibody comprise the same epitope binding domain. The claims further recite a method for detecting heterotrimeric IL-15/ IL-15RαSu complex with a first complex with a first antibody conjugated to a polymeric surface, wherein the complex comprises two IL-15 domains and two IL-15RαSu domains, wherein each IL-15 domain is bound electrostatically to an IL-15RαSu domain, and wherein two IL-15RαSu domains are directly or indirectly bound to each other by a disulfide bond, and wherein the Fab portion of the mAb binds to an epitope on the IL-15/ IL-15RαSu complex with an affinity between 500 nM and 1fM, and contact a biological sample with second antibody that binds to an identical epitope on the IL-15/ IL-15RαSu complex, wherein the second antibody comprises a detection means. The instant specification defines an "interleukin-15 protein" or "IL-15" as including “any of the recombinant or naturally-occurring forms of the interleukin-15(IL-15) protein or variants or homologs thereof that maintain IL-15 protein activity (e.g. within at least 50%, 80%, 90%, 95%,96%, 97%,98%, 99% or 100% activity compared to IL-15 protein)” (see e.g. paragraph [0050] of the instant specification). The specification also states that “the variants or homologs have at least 90%, 95%, 96%, 97%, 98%, 99% or 100% amino acid sequence identity across the whole sequence or a portion of the sequence (e.g. a 50, 100, 150 or 200 continuous amino acid portion) compared to a naturally occurring IL-15 protein” (see e.g. paragraph [0050] of the instant specification). Therefore, the IL-15 protein can include at least 10% variation from any one of multiple possible IL-15 parent proteins, and the IL-15 variant protein is defined entirely by its functional characteristics. The instant specification defines an "interleukin-15 receptor subunit alpha protein" or "IL-15Rα" as including “any of the recombinant or naturally-occurring forms of the interleukin-15 receptor subunit alpha (IL-15Ra) protein or variants or homologs thereof that maintain IL-15Ra protein activity (e.g. within at least 50%, 80%, 90%, 95%,96%, 97%,98%, 99% or 100% activity compared to JL-15Rax protein)” (see e.g. paragraph [0051] of the instant specification). The specification also states that “the variants or homologs have at least 90%, 95%, 96%, 97%, 98%, 99%o or 1000% amino acid sequence identity across the whole sequence or a portion of the sequence (e.g. a 50, 100, 150 or 200 continuous amino acid portion) compared to a naturally occurring IL-15Rax protein” (see e.g. paragraph [0051] of the instant specification). Therefore, the IL-15Rα protein can include at least 10% variation from any one of multiple possible IL-15Rα parent proteins, and the IL-15Rα variant protein is defined entirely by its functional characteristics. The claims recite “IL-15” and “IL-15Rα” but these terms encompass proteins with variation in the protein sequence. The specification provides some embodiments that have 10% or less variation, but notably the specification offers this level of variation as merely an example of possible embodiments, meaning that the terms “IL-15” and “IL-15Rα” can encompass any possible variation, such as substitutions, additions, and deletions, as long as the variants possess the required activity. This means that the genera of proteins encompassed by the instant claims are defined entirely by their functions. These proteins have no correlation between their structure and function, and the specification has not provided a representative number of species for the breadth of the claimed genera. The claims further recite two antibodies, each of which can bind to an epitope on the IL-15/IL-15Rα complex. This epitope is not defined in the specification or the claims. However, the antibody is defined entirely by its function of binding to a specific protein and having a specific affinity for the complex, without identifying a corresponding structure that would correlate to this function. Further, the specification does not provide a representative number of species for the genus of antibodies. The claim requires that the IL-15 and IL-15Rα proteins and the recited antibodies exhibit specific functions, but the specification provides no guidance regarding which protein variants or encompassed antibody species are capable of the recited functions. Therefore, the specification provides insufficient written description to support the genus encompassed by the claim. Vas-Cath Inc. v. Mahurkar, 19 USPQ2d 1111, makes clear that "applicant must convey with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention. The invention is, for purposes of the 'written description' inquiry, whatever is now claimed." (See page 1117.) The specification does not "clearly allow persons of ordinary skill in the art to recognize that [he or she] invented what is claimed." (See Vas-Cath at page 1116.) The skilled artisan cannot envision the detailed chemical structure of the encompassed polypeptides, regardless of the complexity or simplicity of the method of isolation. Adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method for isolating it. See Fiers v. Revel, 25 USPQ2d 1601, 1606 (CAFC 1993) and Amgen Inc. V. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016. In Fiddes v. Baird, 30 USPQ2d 1481, 1483, claims directed to mammalian FGF's were found unpatentable due to lack of written description for the broad class. The specification provided only the bovine sequence. University of California v. Eli Lilly and Co., 43 USPQ2d 1398, 1404. 1405 held that: ...To fulfill the written description requirement, a patent specification must describe an invention and does so in sufficient detail that one skilled in the art can clearly conclude that "the inventor invented the claimed invention." Lockwood v. American Airlines Inc. , 107 F.3d 1565, 1572, 41 USPQ2d 1961, 1966 (1997); In re Gosteli , 872 F.2d 1008, 1012, 10 USPQ2d 1614, 1618 (Fed. Cir. 1989) (" [T]he description must clearly allow persons of ordinary skill in the art to recognize that [the inventor] invented what is claimed."). Thus, an applicant complies with the written description requirement "by describing the invention, with all its claimed limitations, not that which makes it obvious," and by using "such descriptive means as words, structures, figures, diagrams, formulas, etc., that set forth the claimed invention." Lockwood, 107 F.3d at 1572, 41 USPQ2datl966. Protein chemistry is one of the most unpredictable areas of biotechnology. This unpredictability prevents prediction of the effects that a given number or location of mutation will have on a protein (such as TNF or a cytokine) As taught by Skolnick et al (Trends Biotechnol. 2000 Jan;18(1):34-9), sequence based methods for predicting protein function are inadequate because of the multifunctional nature of proteins (see e.g. abstract). Further, just knowing the structure of the protein is also insufficient for prediction of functional sites (see e.g. abstract). Sequence to function methods cannot specifically identify complexities for proteins, such as gain and loss of function during evolution, or multiple functions possible within a cells (see e.g. page 34, right column). Skolnick advocates determining the structure of the protein, then identifying the functionally important residues since using the chemical structure to identify functional sites is more in line with how a protein actually works (see e.g. page 34, right column). The sensitivity of proteins to alterations of even a single amino acid in a sequence are exemplified by Burgess et al. (J. Cell Biol. 111:2129-2138, 1990) who teach that replacement of a single lysine reside at position 118 of acidic fibroblast growth factor by glutamic acid led to the substantial loss of heparin binding, receptor binding and biological activity of the protein and by Lazar et al. (Mol. Cell. Biol., 8:1247-1252, 1988) who teach that in transforming growth factor alpha, replacement of aspartic acid at position 47 with alanine or asparagine did not affect biological activity while replacement with serine or glutamic acid sharply reduced the biological activity of the mitogen. These references demonstrate that even a single amino acid substitution will often dramatically affect the biological activity and characteristics of a protein. Further, Miosge (Proc Natl Acad Sci U S A. 2015 Sep 15;112(37):E5189-98) teach that Short of mutational studies of all possible amino acid substitutions for a protein, coupled with comprehensive functional assays, the sheer number and diversity of missense mutations that are possible for proteins means that their functional importance must presently be addressed primarily by computational inference (see e.g. page E5189, left column). However, in a study examining some of these methods, Miosge shows that there is potential for incorrect calling of mutations (see e.g. page E5196, left column, top paragraph). The authors conclude that the discordance between predicted and actual effect of missense mutations creates the potential for many false conclusions in clinical settings where sequencing is performed to detect disease-causing mutations (see e.g. page E5195, right column, last paragraph). The findings in their study show underscore the importance of interpreting variation by direct experimental measurement of the consequences of a candidate mutation, using as sensitive and specific an assay as possible (see e.g. page E5197, left column, top paragraph). Additionally, Bork (Genome Research, 2000,10:398-400) clearly teaches the pitfalls associated with comparative sequence analysis for predicting protein function because of the known error margins for high-throughput computational methods. Bork specifically teaches that computational sequence analysis is far from perfect, despite the fact that sequencing itself is highly automated and accurate (p. 398, column 1). One of the reasons for the inaccuracy is that the quality of data in public sequence databases is still insufficient. This is particularly true for data on protein function. Protein function is context dependent, and both molecular and cellular aspects have to be considered (p. 398, column 2). Conclusions from the comparison analysis are often stretched with regard to protein products (p. 398, column 3). Further, although gene annotation via sequence database searches is already a routine job, even here the error rate is considerable (p. 399, column 2). Most features predicted with an accuracy of greater than 70% are of structural nature and, at best, only indirectly imply a certain functionality (see legend for table 1, page 399). As more sequences are added and as errors accumulate and propagate it becomes more difficult to infer correct function from the many possibilities revealed by database search (p. 399, paragraph bridging columns 2 and 3). The reference finally cautions that although the current methods seem to capture important features and explain general trends, 30% of those features are missing or predicted wrongly. This has to be kept in mind when processing the results further (p. 400, paragraph bridging cols 1 and 2). Kulmanov et al (Bioinformatics, 34(4), 2018, 660–668), teach that there are key challenges for protein function prediction methods (see e.g. page 661, left column). These challenges arise from the difficulty identifying and accounting for the complex relationship between protein sequence structure and function (see e.g. page 661, left column). Despite significant progress in the past years in protein structure prediction, it still requires large efforts to predict protein structure with sufficient quality to be useful in function prediction (see e.g. page 661, left column). Another challenge is that proteins do not function in isolation. In particular higher level physiological functions that go beyond simple molecular interactions will require other proteins and cannot usually be predicted by considering a single protein in isolation (see e.g. page 661, left column). Due to these challenges it is not obvious what kinds of features should be used to predict the functions of a protein and whether they can be generated efficiently for a large number of proteins, such as the vast genus of proteins encompassed by the instant claims (see e.g. page 661, left column). Given the teachings of these references that point out the limitations and pitfalls of using sequence to predict functions, and the lack of a representative number of species across the breadth of the genus, one of skill in the art would reasonably that the recited composition of the instant claims does not meet the written description provision of 35 USC 112(a). Regarding the encompassed antibodies and fragments thereof, the functional characteristics of antibodies (including binding specificity and affinity are dictated on their structure. Amino acid sequence and conformation of each of the heavy and light chain CDRs are critical in maintaining the antigen binding specificity and affinity which is characteristic of the parent immunoglobulin. For example, Vajdos et al. (J Mol Biol. 2002 Jul 5;320(2):415-28 at 416) teaches that, “ … Even within the Fv, antigen binding is primarily mediated by the complementarity determining regions (CDRs), six hypervariable loops (three each in the heavy and light chains) which together present a large contiguous surface for potential antigen binding. Aside from the CDRs, the Fv also contains more highly conserved framework segments which connect the CDRs and are mainly involved in supporting the CDR loop conformations, although in some cases, framework residues also contact antigen. As an important step to understanding how a particular antibody functions, it would be very useful to assess the contributions of each CDR side-chain to antigen binding, and in so doing, to produce a functional map of the antigen-binding site." The art shows an unpredictable effect when making single versus multiple changes to any given CDR. For example, Brown et al. (J Immunol. 1996 May;156(9):3285-91 at 3290 and Tables 1 and 2), describes how the VH CDR2 of a particular antibody was generally tolerant of single amino acid changes, however the antibody lost binding upon introduction of two amino changes in the same region. Recently, the U.S. Court of Appeals for the Federal Circuit (Federal Circuit) decided Amgen v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017), which concerned adequate written description for claims drawn to antibodies. The Federal Circuit explained in Amgen that when an antibody is claimed, 35 U.S.C. § 112(a) requires adequate written description of the antibody itself even when preparation of such an antibody would be routine and conventional. Amgen, 872 F.3d at 1378-79. A key role played by the written description requirement is to prevent “attempt[s] to preempt the future before it has arrived.” Ariad at 1353, (quoting Fiers v. Revel, 984 F.2d at 1171). Upholding a patent drawn to a genus of antibodies that includes members not previously characterized or described could negatively impact the future development of species within the claimed genus of antibodies. In the instant application, neither the art nor the specification provide a sufficient representative number of antibodies or a sufficient structure-function correlation to meet the written description requirements. The prior art recognizes that antigen binding by antibodies requires precise orientation of the complementarity determining region (CDR) loops in the variable domain to establish the correct contact surface. For example, Vattekatte, (PeerJ. 2020 Mar 6:8:e8408. doi: 10.7717/peerj.8408. eCollection 2020.) teach that antigen binding in heavy chain only antibodies, (HCAbs) is mediated by only three CDR loops from the single variable domain (VHH) at the N-terminus of each heavy chain, (see abstract). The Vattekatte et al further teach that the amino acid length distribution in different regions of VHH (see Fig. S7) shows diversity in CDR lengths, and that most diversity in CDR3, (see page 7 and 19). However, the prior art also recognizes that a single protein can be bound by a very large and structurally diverse genus of antibodies (i.e., there is no common structural relationship even for antibodies that bind to the same protein, epitope, or overlapping epitopes). For example, Edwards et al. (Mol Biol. 2003 Nov 14;334(1):103-18) teach that over 1,000 different antibodies to a single protein can be generated, all with different sequences, and representative of almost the entire extensive heavy and light chain germline repertoire (42/49 functional heavy chain germlines and 33 of 70 V-lambda and V-kappa light chain germlines), and with extensive diversity in the HCDR3 region sequences (that are generated by VDJ germline segment recombination) as well (see table 2, figure 2). Lloyd et al. (Protein Eng Des Sel. 2009 Mar;22(3):159-68. Epub 2008 Oct 29.) teach that a large majority of VH/VL germline gene segments are used in the antibody response to an antigen, even when the antibodies were selected by antigen binding, (abstract). The Lloyd et al reference further teaches that in their studies, of the 841 unselected and 5,044 selected antibodies sequenced, all but one of the 49 functional VH gene segments was observed, and that there are on average about 120 different antibodies generated per antigen (page 167, column 1). Said reference also teaches that a wide variety of VH and VL pairings further increase diversity. (page 159, column 2). Goel et al. (J Immunol. 2004 Dec 15;173(12):7358-67) teach that three mAbs that bind to the same short (12-mer) peptide, exhibit diverse V gene usage, indicating their independent germline origin. Said reference further teaches that two of these mAbs recognize the same set of amino acid residues defining the epitope (alternate amino acid residues spread over the entire sequence), however, the relative contribution of each set of residues in the peptide showed significant variation. The reference notes that all of the mAbs do not show any kind of V gene restriction among themselves, implying variable paratope structure, despite that two of these mAbs bind to the peptide through a common set of residues. (See entire reference). Khan et al. (J Immunol (2014) 192 (11): 5398–5405) teach that two structurally diverse germline mAbs recognizing overlapping epitopes of the same short peptide do so in different topologies, the antibodies possessing entirely different CDR sequences. Said reference teaches that unrelated mAbs structurally adjust to recognize an antigen, indicating that the primary B cell response is composed of BCRs having a high degree of structural adaptability. Said reference also teaches that the common epitope(s) also adopt distinct conformations when bound to different mAbs, with the higher degree of structural plasticity inherent to the mAbs. Said reference further teaches “It has been shown that both the framework region and the CDRs have a considerable amount of inherent conformational plasticity...Therefore, it is not surprising that distinct germline Abs recognize the same epitope by rearranging the CDR conformations. This may well have implications of Ag specificity beyond the naive BCR repertoire, because Kaji et al... .have shown in a recent report that the B cell memory can contain both germline-encoded and somatically mutated BCRs.” (See entire reference). Poosarla et al. (Biotechnol Bioeng. 2017 June ; 114(6): 1331–1342) teach substantial diversity in designed mAbs (sharing less than 75% sequence similarity to all existing natural antibody sequences) that bind to the same 12-mer peptide, binding to different epitopes on the same peptide. Said reference further teaches “most B-cell epitopes... in nature consist of residues from different regions of the sequence and are discontinuous...de novo antibody designs against discontinuous epitopes present additional challenges...". (See entire reference.) Rabia, et al. (Biochem Eng J. 2018 Sep 15:137:365-374. Epub 2018 Jun 5) teach what effects mutations can have on an antibody's stability, solubility, binding affinity and binding specificity. Rabia et al. report that an increase in antibody affinity can be associated with a decrease in stability (p. 366, col. 2 last paragraph; Fig. 2). Rabia et al. thus teach that affinity and specificity are not necessarily correlated and that an increase in affinity does not indicate an increase in specificity (Fig. 3; p. 368, col. 1, section 3,1st full paragraph to col. 2, 2nd full paragraph). Therefore, neither the art nor the specification provide a sufficient representative number of antibodies or a sufficient structure-function correlation to meet the written description requirements. Applicant is reminded that generally, in an unpredictable art, adequate written description of a genus which embraces widely variant species cannot be achieved by disclosing only one species within the genus (Enzo Biochem, Inc. v. Gen- Probe Inc., 323 F.3d 956 (Fed. Cir. 2002); Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004); Regents of the University of California v. Eli Lilly Co., 119 F.3d 1559 (Fed. Cir. 1997)). A patentee must disclose “a representative number of species within the scope of the genus of structural features common to the members of the genus so that one of skill in the art can visualize or recognize the member of the genus” (see Amgen Inc. v. Sanofi, 124 USPQ2d 1354 (Fed. Cir. 2017) at page 1358). An adequate written description must contain enough information about the actual makeup of the claimed products — “a precise definition, such as structure, formula, chemic name, physical properties of other properties, of species falling with the genus sufficient to distinguish the gene from other materials”, which may be present in “functional terminology when the art has established a correlation between structure and function” (Amgen page 1361). MPEP § 2163.02 states, “[a]n objective standard for determining compliance with the written description requirement is, 'does the description clearly allow person of ordinary skill in the art to recognize that he or she invented what is claimed’”. The courts have decided: the purpose of the "written description" requirement is broader than to merely explain how to "make and use"; the Applicant must convey with reasonable clarity to those skilled in the art, that as of the filing date sought, he or she was in possession of the invention. The invention is for purposes of the “written description” inquiry, whatever is now claimed. See Vas-Cath, Inc v. Mahurkar, 935 F.2d 1555, 1563-64, 19 USPQ2d 1111, 1117 (Federal Circuit, 1991). Furthermore, the written description provision of 35 USC §112 is severable from its enablement provision; and adequate written description requires more than a mere statement that it is part of the invention and reference to a potential method for isolating it. Fiers v. Revel, 25 USPQ2d 1601, 1606 (CAFC 1993). And Amgen Inc. v. Chugai Pharmaceutical Co. Ltd., 18 USPQ2d 1016. Moreover, an adequate written description of the claimed invention must include sufficient description of at least a representative number of species by actual reduction to practice, reduction to drawings, or by disclosure of relevant, identifying characteristics sufficient to show that Applicant was in possession of the claimed genus. However, factual evidence of an actual reduction to practice has not been disclosed by Applicant in the specification; nor has Applicant shown the invention was “ready for patenting” by disclosure of drawings or structural chemical formulas that show that the invention was complete; nor has the Applicant described distinguishing identifying characteristics sufficient to show that Applicant were in possession of the claimed invention at the time the application was filed. Therefore for all these reasons the specification lacks adequate written description, and one of skill in the art cannot reasonably conclude that Applicant had possession of the claimed invention at the time the instant application was filed. 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. Claims 1-4, 7-11, and 14-20 are rejected 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. Claim 1 limitation “means for conjugation to a polymeric surface” invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. However, the written description fails to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function. The specification provides no species or structures described as “means for conjugation to a polymeric surface.” Therefore, the claim is indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. Applicant may: (a) Amend the claim so that the claim limitation will no longer be interpreted as a limitation under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph; (b) Amend the written description of the specification such that it expressly recites what structure, material, or acts perform the entire claimed function, without introducing any new matter (35 U.S.C. 132(a)); or (c) Amend the written description of the specification such that it clearly links the structure, material, or acts disclosed therein to the function recited in the claim, without introducing any new matter (35 U.S.C. 132(a)). If applicant is of the opinion that the written description of the specification already implicitly or inherently discloses the corresponding structure, material, or acts and clearly links them to the function so that one of ordinary skill in the art would recognize what structure, material, or acts perform the claimed function, applicant should clarify the record by either: (a) Amending the written description of the specification such that it expressly recites the corresponding structure, material, or acts for performing the claimed function and clearly links or associates the structure, material, or acts to the claimed function, without introducing any new matter (35 U.S.C. 132(a)); or (b) Stating on the record what the corresponding structure, material, or acts, which are implicitly or inherently set forth in the written description of the specification, perform the claimed function. For more information, see 37 CFR 1.75(d) and MPEP §§ 608.01(o) and 2181. In claims 2 and 10, the recited amino acid substitutions are identified by a specific residue location. However, no parent sequence is provided, and therefore it is impossible to determine which protein variants would be encompassed based only on a single point mutation at a site that could vary according to sequence. For example, if one were to delete or add amino acids, the exact location of the required modifications would be called into question, since the numbering of the amino acids would change. Therefore it is impossible to determine which locations would have the required substitutions, resulting in an indefinite claim scope. The term “same affinity” in claim 9 is a relative term which renders the claim indefinite. The term “same affinity” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. In particular, it is unclear to what the “same affinity” is compared. The term “substantially the same” in claim 15 is a relative term which renders the claim indefinite. The term “substantially the same” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Claims depending from the rejected claims do not remedy the deficiency and therefore are also rejected. Statement Regarding Prior Art A search of the art indicates that the claimed products are novel. The closest available prior art identified in the Examiner’s search is: 1. Wong et al (WO 2012/040323 A2; filed 9/21/11; published 3/29/12) teaches a fusion protein complex having two soluble fusion proteins. The first fusion protein is a biologically active polypeptide covalently linked to an IL-15 polypeptide, and the second fusion protein is linked to a soluble IL-15 receptor alpha polypeptide (see e.g. abstract). The first and/or second fusion proteins can further include an immunoglobulin Fc domain (see e.g. abstract). Figure 64 shows an Il-15N72D and an IL-15RαSu domain attached to an IgG1 Fc domain. However, Wong does not teach a first and second antibody that binds to the complex, wherein the binding is at the same epitope on the two fusion proteins, while the antibodies have different functions of conjugating to a polymeric surface or serving as detection means, as required by the instant claims. Therefore, Wong does not read on the instant claims. 2. Han et al (Cytokine. 2011 December ; 56(3): 804–810) teaches a method for detecting N-803 (ALT-803) using a capture antibody and a detection antibody that recognize different epitopes of IL-15, i.e. anti-IL-15 Ab capture and HRP-conjugated donkey anti-human lgG Ab (see e.g. abstract and section 3.3 on pages 7-8). Han does not teach an assay that distinguishes between a heterotetrameric IL-15/IL-15RaSu complex, e.g. N-803, TxM or N-820, and native IL-15 in a biological sample, and may potentially measure IL-15 levels in the biological sample in addition to the target heterotetrameric IL-15/IL-15RaSu complex. Therefore, Han does not read on the instant claims. Conclusion No claim is allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREA MCCOLLUM whose telephone number is (571)272-4002. The examiner can normally be reached 9:00 AM to 6:00 PM 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, VANESSA FORD can be reached at (571)272-0857. 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. /ANDREA K MCCOLLUM/Examiner, Art Unit 1674
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Prosecution Timeline

Jan 24, 2023
Application Filed
Feb 27, 2026
Non-Final Rejection — §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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1-2
Expected OA Rounds
61%
Grant Probability
93%
With Interview (+32.6%)
3y 3m
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