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 .
Status of the Claims
Claims 1-12 are pending and examined herein.
Priority
The present application, filed 09/07/2023, is a 371 of PCT/EP2022/056463, filed 03/14/2022, which claims foreign priority of EP21163172.6, filed 03/17/2021. The priority is acknowledged and the claims examined herein are treated as having an effective filing date of 03/17/2021.
Claim Objections
Claim 1 is objected to because of the following informality: Claim 1 recites “incubated with the at least substrate in suspension” (line 8). The phrase “the at least substrate” is grammatically improper. It appears that Applicant intended to recite “the at least one substrate.” The current wording renders the claim linguistically incorrect. Appropriate correction is required.
Claim 6 is objected to because of the following informality: Claim 6 recites “characterized in that at least one the substrate is provided” (line 1). The phrase “at least one the substrate” is grammatically improper. It appears that Applicant intended to recite “at least one substrate.” The current wording renders the claim linguistically incorrect. Appropriate correction is required.
Claim Rejections - 35 USC § 112
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 10 and 11 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.
Regarding claim 10, it recites “at least ne costimulatory molecule” (line 2). The term “ne” has no recognized meaning in the art and appears to be an incomplete or typographical error. It is therefore unclear whether Applicant intended to recite “one,” “one or more,” or some other limitation. Since the scope of the claim cannot be determined with reasonable certainty due to this error, claim 10 is indefinite. Appropriate correction is required.
Lastly, claim 11 recites the limitation "substrate according to claim 9, characterized in that the primer molecule is SMCC (Succinimidyl-trans-4-(N-maleimidylmethyl)cyclohexane-1-carboxylate)" in lines 1-2. There is insufficient antecedent basis for this limitation in the claim. Claim 11 depends from claim 9, but claim 9 does not recite any “primer molecule.” Claim 9 instead recites that the binding is effected “via an anti-biotin antibody, an anti-Thiamine antibody or via Streptavidin.” The term “primer molecule” is introduced in claim 10, not claim 9. Accordingly, the term “the primer molecule” in claim 11 lacks proper antecedent basis. Since it is unclear to which previously introduced element “the primer molecule” refers, the scope of claim 11 cannot be determined with reasonable certainty. Therefore, claim 11 is indefinite. To overcome this rejection, Applicant may amend claim 11 to depend from claim 10, or otherwise provide proper antecedent basis for “the primer molecule.”
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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) 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.
This application currently names joint inventors. In considering patentability of the claims under pre-AIA 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of pre-AIA 35 U.S.C. 103(c) and potential pre-AIA 35 U.S.C. 102(e), (f) or (g) prior art under pre-AIA 35 U.S.C. 103(a).
Claims 1, 3, 4, 5, 6, 9, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Oelke et al. (WO2017161092A1) in view of Hauskins et al. (WO2018023100A2).
Regarding claim 1, Oelke et al. teaches methods for activating and expanding engineered T cells, including CAR-expressing T cells, using paramagnetic artificial antigen-presenting nanoparticles. In particular, Oelke et al. states that “the invention provides methods for expanding antigen-specific T cell populations for adoptive immunotherapy, including engineered T cells that express a heterologous T cell receptor or a chimeric antigen receptor (CAR)” (paragraph 4, page 3). Oelke et al. further teaches the use of surface-presented ligands on nanoparticles, stating that “the method comprises magnetically enriching and/or magnetically expanding a heterogeneous T cell population with paramagnetic nanoparticles having an MHC-peptide antigen presenting complex on the surface” (paragraph 5, page 8). Furthermore, Oelke et al. discloses incubation in which “in various embodiments, the process of enrichment and expansion includes magnetic activation, in which paramagnetic nano-aAPCs harboring signal 1 and signal 2 (either on the same of different populations of nanoparticles) are incubated in the presence of a magnetic field. The incubation in the presence of a magnetic field generally takes place for at least 5 minutes, or at least 10 minutes, or at least 15 minutes, or at least 30 minutes, or at least one hour, or at least 2 hours” (paragraph 1, page 7). Also, Oelke et al. teaches magnetic clustering during incubation, stating that “incubation of paramagnetic nano-aAPCs in the presence of a magnetic field, either during enrichment and/or expansion steps, activates T cells through magnetic clustering of paramagnetic particles on the T cell surface” (paragraph 3, page 3). Lastly, Oelke et al. teaches costimulatory molecules, stating that “in certain embodiments, signal 2 is a T cell costimulatory molecule. T cell costimulatory molecules contribute to the activation of antigen-specific T cells. Such molecules include, but are not limited to, molecules that specifically bind to CD28 (including antibodies)” (paragraph 2, page 21).
Although Oelke et al. teaches a substrate (paramagnetic nanoparticle) having a surface-presented activating ligand and a costimulatory molecule such as anti-CD28 - Oelke et al. does not disclose the specific use of anti-CAR idiotype antibodies as the activating surface ligand.
On the other hand, Hauskins et al. teaches anti-idiotype antibodies that specifically bind chimeric antigen receptors (CARs). In particular, Hauskins et al. discloses that “the present disclosure relates in some aspects to anti-idiotype antibodies that specifically recognize anti-CD19 antibody moieties, in particular, anti-CD19 antibody moieties present in recombinant receptors, including chimeric antigen receptors (CARs)” (paragraph [0003], page 3). Hauskins et al. further teaches stimulation of CAR-expressing cells, stating that “also among the provided methods are methods for stimulating cells using the agents, such as stimulating cells containing a molecule such as a CAR that is or contains the target antibody recognized by the anti-idiotype antibody” (paragraph [0053], page 16). Additionally, Hauskins et al. teaches immobilization of such antibodies on a solid substrate, stating that “in some embodiments, the anti-idiotype antibody or antigen-binding fragment thereof is immobilized to a solid support” (paragraph [0467], page 142). Lastly, Hauskins et al. teaches activation outcomes, stating that “in some embodiments, the methods result in proliferation, activation, stimulation, cytokine release, or other functional outcome such as upregulation of an activation marker or cytokine release or production, of cells expressing the chimeric receptor such as the CAR recognized by the anti-Id antibody” (paragraph [0054], page 16). Thus, Hauskins et al. teaches anti-CAR idiotype antibodies capable of binding CAR receptors and stimulating CAR-expressing T cells, resulting in cytokine release and activation marker upregulation.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Oelke et al. by replacing the MHC-peptide antigen presenting complex on the surface of the paramagnetic nanoparticles with an anti-CAR idiotype antibody as taught by Hauskins et al. in order to directly activate CAR-expressing T cells through engagement of their chimeric antigen receptor. Oelke et al. teaches a nanoparticle-based artificial antigen-presenting cell (aAPC) system designed to activate T cells by presenting a surface ligand (signal 1) together with a costimulatory molecule (signal 2, e.g., anti-CD28). The mechanism described in Oelke et al. relies on receptor engagement and clustering on the T cell surface to trigger activation and expansion. Hauskins et al. teaches that anti-idiotype antibodies specifically bind CAR molecules and can stimulate CAR-expressing T cells, resulting in activation and functional responses. Both references operate within the same field of CAR-T cell activation and expansion and address methods of stimulating engineered T cells through receptor engagement. Substituting one known receptor-binding ligand (MHC-peptide) with another known receptor-binding ligand (anti-CAR idiotype antibody) for the purpose of activating engineered CAR T cells constitutes a predictable design choice within a known activation platform. Oelke et al. explicitly contemplates modular presentation of activation signals on nanoparticles, and Hauskins et al. provides a known ligand capable of specifically engaging CAR receptors. The modification does not change the fundamental operating principle of Oelke et al.’s nanoparticle system; it merely substitutes the identity of the receptor-binding ligand presented on the nanoparticle surface in order to target CAR receptors specifically. Such substitution would have been an obvious variation motivated by the desire to selectively activate CAR-expressing T cells rather than relying on endogenous T cell receptor (TCR) recognition.
Lastly, a person having ordinary skills in the art (PHOSITA) would have had a reasonable expectation of success in making this modification. First, Oelke et al. demonstrates that nanoparticle-based artificial APC systems activate T cells through surface ligand engagement and magnetic clustering. The activation mechanism depends on receptor binding and costimulation, not on the specific identity of the MHC-peptide ligand itself. Second, Hauskins et al. demonstrates that anti-CAR idiotype antibodies bind CAR receptors and stimulate CAR-expressing cells, resulting in activation, cytokine release, and upregulation of activation markers. This confirms that CAR receptors can be directly stimulated via anti-idiotype antibodies. Third, both references describe well-understood immunological principles: receptor engagement combined with costimulatory signaling leads to T cell activation. Receptor clustering is known to enhance activation signaling. Since Oelke et al. already uses magnetic clustering to enhance activation and Hauskins et al. confirms that anti-idiotype antibodies can stimulate CAR receptors, combining these teachings would have predictably resulted in activation of CAR T cells expressing activation markers and effector molecules. The modification requires no change in the nanoparticle architecture, magnetic field application, or costimulatory signaling disclosed by Oelke et al. It simply substitutes a known CAR-binding ligand in place of an MHC-peptide ligand. Given the routine and predictable nature of receptor-ligand mediated T cell activation in the art at the time of filing, a skilled artisan would reasonably expect successful activation of CAR T cells using anti-CAR idiotype antibody-coated nanoparticles with CD28 costimulation.
Regarding claim 3, Oelke et al. teaches secretion of cytokines (i.e., secreted proteins) upon activation with artificial APC particles. In particular Oelke et al. states that “FIGURE 5 shows that signal 1 and signal 2 can support T cell expansion even when present on separate nanoparticles (A, left panel), and that the resultant CD8 T cells are equivalent to those activated by aAPC presenting both signals (A, right panel). Panel B shows cytokine secretion profiles (number of cytokines or effector molecules secreted) of T cells activated with aAPC presenting both signals, as compared to having signals presented on separate particles” (Figure 5, page 5). Oelke et al. further teaches production of specific inflammatory markers upon stimulation, stating that “In some embodiments, the CD8+ lymphocytes enriched and expanded produce inflammatory markers such as IFNγ, TNFα, IL-2, MIP-1β, GrzB, and/or perforin when stimulated with aAPCs loaded with cognate antigen (paragraph 4, page 8). Lastly, Oelke et al. teaches evaluation and quantification of activation responses, stating that “in other embodiments, T cell response is determined by detecting intracellular signaling (e.g., Ca2+ signaling, or other signaling that occurs early during T cell activation), and thus can be quantified within about 15 minutes to about 5 hours (e.g., within about 15 minutes to about 2 hours) of culture with the nano-aAPCs” (paragraph 3, page 13).
Regarding claim 4, Oelke et al. teaches detection and identification of antigen-specific T cells by flow cytometry following expansion with artificial antigen-presenting nanoparticles. Specifically, Oelke et al. states that “the expanded T cells are then sorted (e.g., by flow cytometry) with the MHC-peptide ligand, to obtain a T cell population that is highly enriched for antigen-specific TCRs” (paragraph 1, page 9). Oelke et al. further discloses that “antigen-specific T cells which are bound to the aAPCs can be separated from cells which are not bound using magnetic enrichment, or other cell sorting or capture technique. Other processes that can be used for this purpose include flow cytometry and other chromatographic means” (paragraph 4, page 30).
Regarding claim 5, Oelke et al. teaches that signal 1 and signal 2 may be provided on separate nanoparticles, stating that “FIGURE 5 shows that signal 1 and signal 2 can support T cell expansion even when present on separate nanoparticles (A, left panel), and that the resultant CD8 T cells are equivalent to those activated by aAPC presenting both signals (A, right panel)” (Figure 5, page 5). Oelke et al. further states that co-stimulatory ligands may be placed on the same or separate nanoparticles. In particular, Oelke et al. states that “combinations of co-stimulatory ligands that may be employed (on the same or separate nanoparticles) include anti-CD28/anti-CD27 and anti-CD28/anti-41BB. The ratios of these co-stimulatory ligands can be varied to effect expansion” (paragraph 3, page 21). Lastly, Oelke et al. discloses that more than one nano-aAPC may be used during incubation, stating that “optionally, a cell population comprising antigen-specific T cells can continue to be incubated with either the same nano-aAPC or a second nano-aAPC for a period of time sufficient to form a second cell population comprising an increased number of antigen-specific T cells relative to the number of antigen-specific T cells in the first cell population” (paragraph 5, page 32).
Regarding claim 6, as discussed above, Oelke et al. discloses a substrate (nanoparticle/bead) having on its surface: an activation ligand and a costimulatory molecule (e.g., anti-CD28). While, Hauskins et al. teaches anti-idiotype antibodies (e.g., anti-CD19), specific binding to CAR extracellular domains, and immobilization of such antibodies on a solid substrate. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nanoparticle substrate of Oelke et al. by replacing the MHC-peptide antigen presenting complex (signal 1) with the anti-CAR idiotype antibody of Hauskins et al., while retaining Oelke et al.’s disclosed costimulatory ligand (e.g., anti-CD28) on the nanoparticle surface. This modification would have been motivated by the shared objective of both references: controlled activation and expansion of engineered T cells. Oelke et al. teaches a nanoparticle platform that presents activation and costimulatory ligands on a surface to stimulate T cells. Hauskins et al. teaches anti-idiotype antibodies that specifically bind CAR extracellular domains and stimulate CAR-expressing cells, and further teaches immobilizing those antibodies on a solid support. Since Oelke et al. already teaches a dual-ligand nanoparticle structure (signal 1 + signal 2), and Hauskins et al. teaches an alternative activation ligand (anti-CAR idiotype antibody) that binds engineered CARs and can be immobilized, a skilled artisan would have recognized that the activation ligand in Oelke et al.’s nanoparticle system could be substituted with Hauskins et al.’s anti-CAR idiotype antibody to create a substrate specifically tailored for CAR cell activation rather than TCR/MHC-mediated activation. This is a predictable substitution of one known activation ligand for another, within an expressly taught dual-signal nanoparticle architecture.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification for several reasons. First, Oelke et al. demonstrates that nanoparticles bearing both an activation ligand and anti-CD28 costimulatory ligand are capable of stimulating T cells when those ligands are presented on the nanoparticle surface. Second, Hauskins et al. teaches that anti-idiotype antibodies bind CAR extracellular domains and stimulate CAR-expressing cells, and that such antibodies may be immobilized on solid supports. Third, immobilization of antibodies on beads or solid substrates for cell stimulation was well-established in the art. Oelke et al.’s nanoparticle surface is designed to present ligands in a functional orientation. Hauskins et al. confirms that anti-idiotype antibodies are suitable for binding CARs and can be bound to a solid support. Thus, there would have been no technical incompatibility or unpredictability in attaching Hauskins et al.’s anti-CAR idiotype antibody to Oelke et al.’s nanoparticle surface. Since both references disclose surface-bound ligands that function to activate T cells (via TCR or CAR), substituting Hauskins et al.’s’ anti-CAR idiotype antibody for Oelke et al.’s MHC-peptide activation ligand would have predictably yielded a substrate having: at least one anti-CAR idiotype on its surface; and at least one costimulatory molecule on its surface.
Regarding claim 9, Oelke et al. teaches coupling molecules to nanoparticles via streptavidin-based affinity binding. In particular, Oelke et al. discloses that “in other embodiments, a molecule can be coupled to a nanoparticle through affinity binding such as a biotin-streptavidin linkage or coupling, as is well known in the art. For example, streptavidin can be bound to a nanoparticle by covalent or non-covalent attachment, and a biotinylated molecule can be synthesized using methods that are well known in the art” (paragraph 2, page 24).
Regarding claim 12, as discussed above, Oelke et al. teaches distributing ligands across separate nanoparticles. Oelke et al. states that “combinations of co-stimulatory ligands that may be employed (on the same or separate nanoparticles) include anti-CD28/anti-CD27 and anti-CD28/anti-41BB. The ratios of these co-stimulatory ligands can be varied to effect expansion” (paragraph 3, page 21). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nanoparticle substrate of Oelke et al., as combined with Hauskins et al., so that the at least one anti-CAR idiotype antibody (as taught by Hauskins et al.) and the at least one costimulatory molecule are provided on the surfaces of at least two different substrates, as contemplated by Oelke et al. As discussed in the rejection of claim 6, Hauskins et al. teaches the use of anti-CAR idiotype antibodies for engaging CAR-expressing cells. Oelke et al. teaches nanoparticle substrates bearing activation and costimulatory ligands, and discloses that co-stimulatory ligands may be employed “on the same or separate nanoparticles.” Thus, once Hauskins et al.’s anti-CAR idiotype antibody is incorporated into the Oelke et al. nanoparticle activation platform, Oelke et al. itself provides an express teaching that such ligands may be presented on separate nanoparticles. A skilled artisan would have recognized that distributing the activation ligand and the costimulatory molecule across separate nanoparticle substrates represents an alternative configuration expressly contemplated by Oelke et al. Oelke et al.’s disclosure of “same or separate nanoparticles” demonstrates that the art recognized both configurations as interchangeable design options within the same immune activation framework. Moreover, distributing ligands across separate particle populations would have provided practical advantages known in the art, including independent control of ligand density, adjustable ratios of activation to costimulation, and tunable receptor clustering effects. In immune activation systems, the magnitude and quality of signaling depend on ligand density and spatial organization. Using distinct nanoparticle populations bearing different ligands allows modulation of signal strength without altering the underlying chemistry or materials. Accordingly, modifying the combined Oelke et al.– Hauskins et al. system to distribute the anti-CAR idiotype antibody and the costimulatory molecule across at least two different substrates would have been an obvious implementation of an expressly taught alternative configuration within the same nanoparticle-based activation platform.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because Oelke et al. teaches that co-stimulatory ligands may be employed “on the same or separate nanoparticles,” thereby confirming operability of the separate-substrate configuration. The modification does not introduce new chemistry, new materials, or new biological mechanisms. The nanoparticle substrates remain those taught by Oelke et al. The anti-CAR idiotype antibody remains that taught by Hauskins et al. The costimulatory molecules remain those taught by Oelke et al. The only modification concerns the spatial allocation of these known ligands onto separate nanoparticle populations. In practice, T cells interacting with nanoparticle suspensions encounter multiple particles simultaneously. Receptor engagement and clustering can occur through contact with adjacent particles in solution. Since Oelke et al. explicitly teaches that ligands may be provided on separate nanoparticles, it demonstrates that such a configuration does not impair functionality and is operable for immune activation. Thus, given Oelke et al.’s express teaching of separate nanoparticles and Hauskins et al.’s teaching of anti-CAR idiotype antibodies for CAR engagement, a skilled artisan would reasonably expect successful activation using at least two different substrates without undue experimentation.
Claims 2 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Oelke et al. and Hauskins et al., as applied to claims 1 and 6 above, and further in view of Shen et al. (Frequency and Reactivity of Antigen-Specific T Cells Were Concurrently Measured through the Combination of Artificial Antigen-Presenting Cell, MACS and ELISPOT. Scientific Reports. Vol. 7, No. 1, November 2017).
With respect to the teachings of Oelke et al. and Hauskins et al., see the discussion above, which applies equally here. These references differ from the instant claim in failing to teach or specify that the particles have a mean diameter of at least 0.4 µm.
However, Shen et al. teaches cell-sized magnetic beads having a diameter well above 0.4 µm. In particular, Shen et al. discloses that “the magnetic Dynabead M-450 Epoxy with a diameter of 4.5 μm is hydrophobic and covered with surface epoxy groups” (Results, paragraph 1, page 2). Shen et al. further teaches using such beads as artificial antigen-presenting cell beads by coupling activation and costimulatory ligands onto the bead surface, stating that “we developed an artificial antigen-presenting cell microplate (termed AAPC-microplate) by co-coupling pMHC multimers and anti-CD28 mAbs onto magnetic beads” (paragraph 2, page 2). Lastly, Shen et al. teaches incubation of the beads with cells under conditions consistent with a bead/cell suspension, stating that “AAPC-beads were seeded into the microplate containing CD8+ T cells and co-incubated for 2 hrs on a mild shaker at RT” (Materials and Methods, paragraph 4, page 11).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method and nanoparticle substrate of Oelke et al., as combined with Hauskins et al., to provide the claimed substrate as particles having a mean diameter of at least 0.4 µm as taught by Shen et al. As discussed above, Oelke et al. teaches nanoparticle-based artificial antigen-presenting systems that present activation and costimulatory ligands on particle surfaces to stimulate immune cells. Hauskins et al. teaches the use of anti-CAR idiotype antibodies to activate CAR-expressing cells. Shen et al. likewise teaches artificial antigen-presenting particles that present activation and costimulatory ligands on magnetic beads to stimulate T cells. Since both Oelke et al. and Shen et al. operate within the same field of particle-based immune activation systems, a PHOSITA would recognize that particle size represents a known and routinely adjustable design parameter that can be selected based on desired cell-particle characteristics. Shen et al. teaches that magnetic beads having a diameter of approximately 4.5 µm can be used as artificial antigen-presenting cell particles that present activation and costimulatory ligands to immune cells. These particles are substantially larger than the minimum size recited in claims 2 and 7. A PHOSITA would have understood that larger particle sizes can improve the physical interaction between particle substrate and immune cells by increasing available ligand presentation surface area and facilitating multivalent receptor engagement. Since receptor clustering and signal strength in immune activation systems depend on ligand density and spatial organization, selecting particle sizes within the micrometer range would have been recognized as a practical approach to improving or maintaining effective receptor engagement. Furthermore, particle size selection in nanoparticle-based immune activation systems is a routine engineering consideration that can be modified without altering the underlying chemistry or biological mechanism of activation. The same ligands, surface chemistries, and coupling methods taught by Oelke et al. can be applied to particles of varying sizes. Shen et al. demonstrates that micrometer scale beads can successfully function as artificial antigen-presenting cells. Thus, a skilled artisan would have been motivated to implement particles sizes equal to or greater than 0.4 µm in the Oelke et al. system as a predictable variation within the same particle-based immune activation platform. Accordingly, modifying the particle substrates of Oelke et al. to have a mean diameter of at least 0.4 µm as taught by Shen et al. would have been a routine and predictable design choice motivated by the desire to provide effective immune cell engagement in artificial antigen-presenting particle systems.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because both systems (Oelke et al. and Shen et al.) rely on the same fundamental biological mechanism: immune cell activation through receptor engagement with ligands presented on particle surfaces. The modification does not involve introducing new ligands, new coupling chemistries, or new biological pathways. Rather, it merely involves adjusting the physical size of the particle substrate used to present the activation and costimulatory ligands. The ligands themselves, the surface attachment methods, and the receptor-mediated signaling mechanisms remain unchanged. Since the activation mechanism depends on ligand-receptor interaction rather than on a specific particle size, changing the particle diameter within the range taught by Shen et al. would not disrupt the function of the system. Shen et al. further demonstrates that beads with diameters of approximately 4.5 µm successfully present activation and costimulatory ligands, and stimulate T cells when incubated together in suspension. A PHOSITA would therefore reasonably expect that particles meeting the claimed minimum size requirement would function effectively within the Oelke et al. system. Moreover, particle fabrication methods capable of producing particles within defined size ranges were well known in the art at the time of the invention. Thus, modifying the particle size of the Oelke et al. substrates to meet the size parameter taught by Shen et al. would have represented a straightforward and predictable implementation of known particle design principles without requiring undue experimentation. Therefore, a skilled artisan would have had a reasonable expectation of success in implementing particles having a mean diameter of at least 0.4 µm in the Oelke et al. activation system.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Oelke et al. and Hauskins et al., as applied to claim 6 above, and further in view of Sunshine et al. (Particle Shape Dependence of CD8+ T Cell Activation by Artificial Antigen Presenting Cells. Biomaterials. Vol. 35, No. 1, January 2014).
With respect to the teachings of Oelke et al. and Hauskins et al., see the discussion above, which applies equally here. These references differ from the instant claim in failing to collectively teach that the particles comprise silica, polystyrene, polyolefins, polysaccharides, polyesters, polyacrylates, and polylactic and/or iron oxide.
Oelke et al. already teaches particles comprising iron oxide, stating that “the nanoparticles can be made of any material, and materials can be appropriately selected for the desired magnetic property, and may comprise, for example, metals such as iron, nickel, cobalt, or alloy of rare earth metal. Paramagnetic materials also include magnesium, molybdenum, lithium, tantalum, and iron oxide” (paragraph 2, page 22).
On the other hand, Sunshine et al. teaches polymeric artificial antigen-presenting particles, stating that “T cell activation requires two sets of receptor-receptor interactions. One interaction, Signal 1, is the binding of major histocompatibility complexes (MHC) or a surrogate, such as anti-CD3, to bind the T cell receptor (TCR). A second interaction, Signal 2, is the binding of costimulatory receptors on the APC, such as B7.1, to ligands on the T cell, such as CD28. aAPCs have been generated by coupling proteins, that deliver Signals 1 and 2 to cells, to the surface of particles (Fig. 1A) made from a range of materials, including magnetic microparticles, polystyrene particles, and PLGA microparticles” (Introduction, paragraph 2, page 269). Sunshine et al. further discloses that “we hypothesized that non-spherical aAPCs would offer improved activation of CD8+ T cells. To test this hypothesis, we adapted a film-stretching method for controlling the shape of microparticles made from poly(lactic-co-glycolic) acid (PLGA) to generate ellipsoidal aAPCs with varying long axis lengths and aspect ratios (ARs)” (Introduction, paragraph 3, page 271). Here Sunshine et al. teaches artificial antigen-presenting microparticles comprising polymer bead materials including PLGA and polystyrene. PLGA ((poly(lactic-co-glycolic acid)) is a polyester and contains polylactic components, directly corresponding to the “polyesters” and “polylactic” materials recited in claim 8.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nanoparticle substrate of Oelke et al., as combined with Hauskins et al., by utilizing polymer bead materials such as polystyrene or PLGA as taught by Sunshine et al. Oelke et al. teaches that artificial antigen-presenting particles function by presenting activation ligands (e.g., MHC complexes and co-stimulatory molecules) on a particulate surface to stimulate antigen-specific T cells. The operative principle in Oelke et al. is surface presentation of ligands on a particle substrate capable of interacting with T cells. The specific material of the particle serves as a structural scaffold to support surface functionalization and facilitate T cell engagement. Sunshine et al. teaches that artificial antigen-presenting cells can be generated from multiple particle materials, expressly including magnetic microparticles, polystyrene particles, and PLGA microparticles. Sunshine et al. thereby demonstrates that the particle material is a selectable design parameter in aAPC construction, and that polymeric microparticles such as PLGA and polystyrene are known and suitable scaffolds for surface coupling of activation ligands. Since both Oelke et al. and Sunshine et al. operate in the same field of artificial antigen-presenting particle systems, and both disclose the same functional architecture, the substitution of one known particle substrate (iron oxide magnetic nanoparticles) with another known particle substrate (polymeric microparticles such as PLGA or polystyrene) would have represented a routine optimization and material selection within the ordinary skill in the art. The modification does not alter the fundamental mode of operation of Oelke et al.’s system. Rather, it involves selecting from among known art-recognized particle materials capable of supporting surface functionalization and T cell activation. The art explicitly recognizes that artificial APCs have been generated from a range of materials , thereby affirming that particle composition was known to be variable and interchangeable depending on design considerations such as biodegradability, size, shape, or in vivo application. Accordingly, selection of polymer bead materials such as PLGA or polystyrene in place of, or in addition to, iron oxide particles would have been an obvious design choice motivated by known benefits such as biodegradability (PLGA), established biocompatibility, tunable size and shape control, and established use in immunotherapy contexts.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because Sunshine et al. demonstrates that polymeric microparticles such as PLGA and polystyrene can be successfully functionalized with activation ligands to create artificial antigen-presenting cells capable of inducing antigen-specific CD8+ T cell activation and proliferation. Sunshine et al. does not merely suggest polymer particles in the abstract; it demonstrates functional aAPCs constructed from PLGA microparticles that successfully stimulate CD8+ T cell proliferation in vitro and exhibit activity in vivo. Thus, the art confirms that polymer bead substrates are fully capable of performing the same functional role as the iron oxide nanoparticles disclosed by Oelke et al. Moreover, both Oelke et al. and Sunshine et al. rely on the same mechanistic principle: covalent or surface coupling of activation ligands to a particulate scaffold. Since polymeric microparticles were already shown to support ligand coupling and T cell activation, there would have been no technical barrier or unpredictability in substituting the particle material while maintaining the same surface-bound ligand architecture. The substitution therefore would have been predictable, would have required only routine surface functionalization techniques already disclosed in the art, and would not have required undue experimentation.
Claims 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Oelke et al. and Hauskins et al., as applied to claim 6 above, and further in view of McCarthy et al. (Multifunctional Magnetic Nanoparticles for Targeted Imaging and Therapy. Advanced Drug Delivery Reviews. Vol. 60, No. 11, August 2008).
With respect to the teachings of Oelke et al. and Hauskins et al., see the discussion above, which applies equally here. These references differ from the instant claim in failing to teach that the ligands are bound to the substrate specifically via a primer molecule (claim 10) nor that the primer molecule is SMCC (Succinimidyl-trans-4(N-maleimidylmethyl)cyclohexane-1-carboxylate) (claim 11).
However, McCarthy et al. discloses the use of SMCC as a heterobifunctional linker for modifying nanoparticle surfaces and appending biomolecules thereto. In particular, McCarthy et al. states that “ligands bearing sulfhydryl groups, such as those present in peptides, antibodies, and oligonucleotides, can also be appended to the surface of amine-coated particles once the surface is modified with heterobifunctional linkers such as succinimidyl iodoacetate (SIA), N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP), or succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC)” (paragraph 8, page 1242). Here McCarthy et al. directly teaches binding biomolecules to nanoparticles via SMCC, which satisfies the limitations of claim 11 and inherently satisfies claim 10’s requirement of binding via a primer molecule.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nanoparticle substrate of Oelke et al., as combined with Hauskins et al., so that the activation ligand and/or costimulatory molecule is bound via a primer molecule, and specifically via SMCC, as taught by McCarthy et al. Oelke et al. already establishes that nanoparticle surfaces may be functionalized using crosslinking chemistries to attach proteins and other biomolecules. The purpose of such crosslinking is to create stable, oriented, and reproducible immobilization of ligands on the nanoparticle surface. McCarthy et al. provides a specific, well-known heterobifunctional crosslinker—SMCC—that is expressly used to modify amine-coated nanoparticles and append sulfhydryl-bearing ligands such as antibodies. Since Oelke et al.’s nanoparticle system requires surface immobilization of antibodies and/or antigens, and because McCarthy et al. teaches SMCC specifically for this exact purpose in nanoparticle systems, a skilled artisan would have recognized SMCC as a particularly suitable and predictable choice of crosslinker. The modification would simply implement a known heterobifunctional linker in place of other known crosslinkers, all serving the same established function of nanoparticle–protein conjugation. The substitution of SMCC for other small-molecule crosslinkers represents a routine selection from among known coupling reagents within the same technical field. SMCC was commercially available, widely used, and recognized as a standard reagent for amine-to-thiol coupling. Accordingly, there would have been a clear motivation to employ SMCC in the Oelke et al. nanoparticle system to achieve controlled and stable ligand immobilization.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because McCarthy et al. demonstrates that SMCC is compatible with amine-coated nanoparticles and can be used to append antibodies to particle surfaces. The underlying chemistry of SMCC-mediated conjugation—NHS ester reaction with primary amines and maleimide reaction with sulfhydryl groups—was well characterized and widely practiced well before the effective filing date. The modification does not introduce any new or unpredictable chemistry. Rather, it applies a standard heterobifunctional crosslinking strategy to achieve the same objective already contemplated by Oelke et al: covalent immobilization of ligands onto nanoparticles. The nanoparticle surface chemistry remains fundamentally the same, the ligand remains the same, and the functional objective—presentation of activation and/or costimulatory molecules—is unchanged. Only the specific crosslinking reagent is selected from a known class of reagents. Since McCarthy et al. demonstrates successful nanoparticle functionalization using SMCC, and because SMCC chemistry was routine and well understood, a skilled artisan would reasonably expect successful attachment of the claimed ligands via SMCC without undue experimentation.
Ultimately, for the reasons set forth above, claims 1–12 are rejected under 35 U.S.C. 103 as being unpatentable over the cited prior art combinations. The cited references collectively teach or render obvious each and every limitation of the claimed substrate and its configurations, including nanoparticle-based presentation of activation and costimulatory ligands, particle diameter, distribution across separate substrates, and attachment via primer molecules such as SMCC. The proposed combinations involve the predictable use of known elements according to their established functions, and a PHOSITA would have had both a motivation to combine the teachings and a reasonable expectation of success in doing so. Accordingly, the claims, when viewed as a whole, would have been obvious to PHOSITA at the time of the invention.
For the reasons stated above, all claims are rejected.
Conclusion
No claims are allowable.
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/E.O./Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677 March 4, 2026