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
Claims 3 and 14 have been cancelled and claims 1, 4, and 10-13 have been amended, as requested in the amendment filed on 01/19/2026. Following the amendment, claims 1-2 and 4-14 are pending in the instant application.
Claims 1-2 and 4-14 are under examination in the instant office action.
It is specifically noted that the amendment of claims 1 and 10 has effectively changed the scope of the independent claims, such that the claims are now limited to extracellular vesicles expressing cytokines and antibodies on its surface wherein, notably, the cytokine is IL-2 having the amino acid sequence represented by SEQ ID NO: 1 and the antibody is an epidermal growth factor receptor (EGFR)-binding scFv having the amino acid sequence represented by SEQ ID NO: 2. As such, the claim amendments have changed the scope of the independent claims, necessitating the new grounds of rejection detailed below.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
It is acknowledged that Applicant has filed English translations of foreign priority documents. However, it is unclear as to which English translations correspond to which foreign priority documents. As such, it remains unclear as to if the claims to foreign priority have been perfected.
In view of the above, claims 1-2 and 10-13 are still regarded as having an effective filing date of September 2, 2021 corresponding to PCT/KR2021/011853.
Drawings - Objection Withdrawn
The drawings were objected to because Figures 2-3 and 6-8 contained text/labels that were blurry and difficult to read. Applicant has submitted replacement drawing sheets for Figures 2-3 and 6-8 wherein all of the text/labels are clear and legible. As such, the objection to the drawings is withdrawn.
Specification - Objections Withdrawn
The abstract of the disclosure was objected to for exceeding 150 words in length and reciting legal phraseology. Applicant has amended the abstract such that it is now between 50 and 150 words in length and does not include legal phraseology. As such, the objection to the abstract is withdrawn.
The specification was objected to for the improper representation of trade names and marks used in commerce. Applicant has amended the specification such that all trade names and marks used in commerce are now properly represented and accompanied by their generic terminology. As such, the objection to the specification is withdrawn.
Claim Objections - Withdrawn
Claim 1 was objected to because of an extra space between "SEQ ID NO:" and "1" in line 3. Applicant has amended claim 1 such that extra space has been removed. As such, the objection to claim 1 is withdrawn.
Claim 12 was objected to for the recitation of "the drug of bioactive substance" and "encapsulated with the extracellular vesicle" in line 3. Applicant has amended claim 1 to recite "the drug or bioactive substance" and "encapsulated within the extracellular vesicle". As such, the objection to claim 12 is withdrawn.
Claim 13 was objected to for the recitation of "[t]he method of composition of claim 12" in line 1. Applicant has amended the claim to recite "[t]he method of claim 12". As such, the objection to claim 13 is withdrawn.
Claim Rejections - 35 USC § 112 - Withdrawn
Claims 10-11 were rejected under 35 USC § 112(a) regarding scope of enablement. Applicant has amended claims 10-11 such that they now recite (i) remove “preventing” language regarding cancer treatment and recite “treating an epidermal growth factor receptor (EGFR)-expressing cancer” and (ii) “wherein the epidermal growth factor receptor (EGFR)-expressing cancer is one selected from the group consisting of colon cancer, skin cancer, non-small cell lung cancer, pancreatic cancer, head or neck cancer, breast cancer, and esophageal cancer”, respectively. The scope of claims 10-11 as amended is considered to be enabled by the instant specification. As such, the rejection of claims 10-11 under 35 USC § 112(a) regarding scope of enablement is withdrawn.
Claims 1-13 were rejected under 35 USC § 112(b) as being indefinite.
With regard to claim 1, the claim has been amended to recite “wherein the cytokine is IL-2 having the amino acid sequence represented by SEQ ID NO: 1”. As such, the claim language is regarded as clear and definite, wherein the claim requires the full-length sequence corresponding to SEQ ID NO: 1.
Claim 3 has been cancelled, rendering its rejection moot.
With regard to claim 4, the claim has been amended to recite “wherein the linker comprises 1-20 repeats of a sequence consisting of any one of SEQ ID NOs: 3 to 13”. As such, the claim language is regarded as clear and definite, wherein the claim requires the 1-20 repeats of one of the full-length sequences corresponding to SEQ ID NOs: 3 to 13.
In view of the instant claim amendments, the rejection of claims 1-11 and 13 under 35 USC § 112(b) as being indefinite is withdrawn.
Claim Rejections - 35 USC § 112 - Maintained
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.
Claim 12 stands as 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.
With regard to amended claim 12, it is noted that the claim recites the limitation “the composition” in line 4. There is insufficient antecedent basis for this limitation in the claim. Claim 2 makes no reference to “a composition” and as such it is unclear as to what the limitation “the composition” is referring to. As such, the rejection of claim 12 under 35 U.S.C. 112(b) is maintained. For the purposes of examination, the limitation “the composition” is being interpreted as referring to the drug or bioactive substance encapsulated within the extracellular vesicle of claim 1.
Claim Rejections - 35 USC § 102 - Withdrawn
Claims 1 and 10-13 were rejected under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”).
Applicant argues on Page 11 of Remarks (01/19/2026) that independent claims 1 and 10 have been amended such that they now require an extracellular vesicles that express, on the vesicle surface both, (i) IL-2 having SEQ ID NO: 1 and (ii) an EGFR-binding scFv having SEQ ID NO: 2 and that in view of the amendment, Lewis does not describe the sequence-defined EGFR-binding scFv nor the specific combination of said EGFR-binding scFv with IL-2. In view of the instantly amended claims, Applicant’s arguments are deemed persuasive and the rejection of claims 1 and 10-13 under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by Lewis as evidenced by Q0GK43 is withdrawn.
Claim Rejections - 35 USC § 103 - Withdrawn
Claims 2 and 4-7 were rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis"), as applied to claims 1 and 10-13 as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), and in further view of non-patent literature by Liu et. al. (Cell Chemical Biology, 2017, 24, 767-771; previously cited on PTO-892; herein after referred to as "Liu") and non-patent literature by Chen et. al. (Advanced Drug Delivery Reviews, 2013, 65, 1357-1369; previously cited on PTO-892; herein after referred to as “Chen”).
Claim 3 was rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis"), UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), Liu et. al. (Cell Chemical Biology, 2017, 24, 767-771; previously cited on PTO-892; herein after referred to as "Liu"), and Chen et. al. (Advanced Drug Delivery Reviews, 2013, 65, 1357-1369; previously cited on PTO-892; herein after referred to as “Chen”), as applied to claims 1-2, 4-7, and 10-13 above, and in further view of CN 110845623 A (machine translation of the Description provided; previously cited on PTO-892; herein after referred to as “Xia”).
Claims 8-9 were rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis"), as applied to claims 1 and 10-13 as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), and Liu et. al. (Cell Chemical Biology, 2017, 24, 767-771; previously cited on PTO-892; herein after referred to as "Liu"), and Chen et. al. (Advanced Drug Delivery Reviews, 2013, 65, 1357-1369; previously cited on PTO-892; herein after referred to as “Chen”), as applied to claims 1-2, 4-7, and 10-13 above, and in further view of non-patent literature by Yang et. al. (J. Cancer Re. Clin. Oncol., 2007, 133, 389-399; previously cited on PTO-892; herein after referred to as “Yang”).
With regard to the above-listed claim rejections under 35 U.S.C. 103, Applicant argues on Page 12 of Remarks that the rejections do not take into account the newly added limitation of amended claims 1 and 10 which defines the antibody by EGFR-binding function and the exact amino acid sequence of SEQ ID NO: 2. In view of the amended claims, Applicant’s argument is deemed persuasive and the above-listed claim rejections under 35 U.S.C. 103 are withdrawn.
Claim Rejections - 35 USC § 103 - New As Necessitated By Amendment
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1 and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis"), in view of UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), non-patent literature by Roda et. al. (Clin. Cancer Res., 2007, 13(21), 6419-6428; herein after referred to as "Roda"), CN 110845623 A (machine translation of the Description provided previously; previously cited on PTO-892; herein after referred to as “Xia”), non-patent literature by Chen et. al. (Advanced Drug Delivery Reviews, 2013, 65, 1357-1369; previously cited on PTO-892; herein after referred to as “Chen”), EP 2719706 A1 (herein after referred to as “Tamaskovic”), and non-patent literature by Kooijmans et. al. (Journal of Extracellular Vesicles, 2016, 5, 1-11; herein after referred to as “Kooijmans”).
Lewis teaches extracellular vesicles comprising an immunomodulating component and methods for producing the extracellular vesicles and methods for using the extracellular vesicles for treating cancer (Abstract). Lewis teaches that immunotherapy can stimulate the patient's own immune system to attack cancer cells, and cancer immunotherapy usually has fewer side effects than traditional cancer therapies (e.g., chemotherapy and radiation), but that there is a need for improved methods of delivering immunomodulatory molecules to cells and tissues of the body (Paragraph 0003); extracellular vesicles can interact with various cells involved with the modulation of the human immune system and extracellular vesicles that are selected, enriched, or engineered to deliver therapeutic molecules to activate, suppress, or influence the human immune system can be potent therapeutics for cancer and other immune system related diseases (Paragraph 0004). More specifically, compositions of the invention comprise extracellular vesicles selected, enriched, or engineered with immunomodulating components that can up-regulate or down-regulate the human immune system, boosting the patient's immune system to fight cancer (Paragraph 0005). In a first aspect, provided is a composition, comprising: an extracellular vesicle comprising a cell membrane bounding an enclosed volume, the cell membrane having an interior surface and an exterior surface, and a first immunomodulating component associated with the cell membrane or enclosed within the enclosed volume (Paragraph 0007); the first immunomodulating component may a cytokine or a binding partner of a cytokine wherein the cytokine is selected from the group consisting of: IL-2, IL-7, IL-10, IL-12, and IL-15 (Paragraph 0010), the first immunomodulating component is a tumor antigen which may include EGFR (Paragraph 0014), the first immunomodulating component is an agonist or an antagonist of a selected target or activity (Paragraph 0015), or the first immunomodulating component is an antibody or an antigen-binding fragment (Paragraph 0016). In some embodiments, the extracellular vesicle additionally comprises a second immunomodulating component, which may be selected from the same groups as the first immunomodulating components (Paragraphs 0022-0033) and the first and second immunomodulating components may be different (Paragraph 0035). Furthermore, the first and/or second immunomodulating components may be expressed as a fusion protein displayed on the exterior surface of said extracellular vesicle (Paragraphs 0019 and 0034, respectively). Lewis further provides (i) a method of formulating the isolated extracellular vesicles of the invention into a pharmaceutical composition and (ii) a method of treating cancer in a subject comprising administering to the subject a therapeutically effective amount of the composition, wherein the composition is capable of up-regulating an immune response in the subject, thereby enhancing the tumor targeting of the subject's immune system (Paragraphs 0037-0038). To produce the extracellular vesicles of the invention, a producer cell is modified with the immunomodulating component(s), wherein the producer cell may be an immune cell, such as a dendritic cell, a T cell, a B cell, a natural killer cell (NK cell), an antigen presenting cell, a macrophage, a T helper cell, or a regulatory T cell (Treg cell) (Paragraphs 0237-0240) or, alternatively, the immunomodulating component(s) can be introduced directly to the extracellular vesicles after the isolation of the extracellular vesicles (Paragraph 0254) wherein methods for isolating extracellular vesicles from the producer cells (i.e., producer cell derived extracellular vesicles) are also provided (Paragraphs 0268-0271). As such, Lewis reads on T cell derived extracellular vesicles which may be modified to express two immunomodulatory components, wherein said immunomodulatory components may be IL-2 and an antibody, each of which may be expressed as a fusion protein displayed on the exterior surface of said extracellular vesicle and the use of said vesicles in upregulating immune responses to treat cancer in a subject. Lewis further suggests targeting EGFR. However, Lewis does not explicitly teach the sequence(s) corresponding to IL-2. This deficiency is remedied by Q0GK43.
Q0GK43 is the UniProt entry corresponding to human IL-2, wherein the disclosed sequence of IL-2 in Q0GK43, shown below, is a 100% match to instant SEQ ID NO: 1.
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It is further noted that the sequence entry was last updated in 2006; thus, the sequence corresponding to human IL-2 was well known and established in the art prior to the filing date of the instant invention.
It would have been prima facie obvious to one of ordinary skill in the art at the time the invention was filed to utilize the IL-2 sequence of Q0GK43 for the IL-2 expressed by the extracellular vesicle of Lewis. One would have been motivated to, and have a reasonable expectation of success to, because Lewis explicitly teaches the extracellular vesicle expresses IL-2 and Q0GK43 teaches the sequence of IL-2 is known and established.
However, it is noted that the combination of Lewis and Q0GK43 does not explicitly teach that the antibody expressed on the surface of the vesicle in combination with IL-2 is an EGFR-specific antibody. This deficiency is remedied by Roda.
Roda teaches that natural killer (NK) cells express an activating Fc receptor (FcγRIIIa) that mediates antibody-dependent cellular cytotoxicity (ADCC) and production of immune modulatory cytokines in response to antibody-coated targets and that Cetuximab is a therapeutic monoclonal antibody directed against the HER1 antigen (i.e., EGFR); the authors hypothesized that the NK cell response to cetuximab-coated tumor cells could be enhanced by the administration of NK cell-stimulatory cytokines (Abstract). It was shown that cetuximab acts as a potent NK cell FcR stimulus and that NK cell activation in response to cetuximab is enhanced in the presence of immune modulatory cytokines wherein NK cells co-stimulated with cetuximab-coated tumor cells, and IL-2, IL-12, or IL-21 secreted elevated levels of IFN-γ and several T cell–recruiting chemokines compared with NK cells stimulated with either agent alone and NK cell ADCC against cetuximab-coated tumor cells was also enhanced in the presence of IL-2, IL-12, or IL-21; the results suggest that that immune modulatory cytokines would be effective adjuvants to administer in combination with cetuximab (Page 6420, Column 1, Third Paragraph). Thus, Roda suggests that co-administration of, for example, IL-2 with cetuximab (an anti-EGFR antibody/EGFR antagonist) is beneficial in the treatment of cancer (e.g., breast cancer, non-small cell lung cancer, and pancreatic cancer; see Figures 1-2, for example) wherein cetuximab and IL-2 work together to increase NK cell response and subsequent ADCC.
It would have been prima facie obvious to one of ordinary skill in the art at the time the invention was filed to modify the extracellular vesicles rendered obvious by the combination of Lewis and Q0GK43 to express the cetuximab antibody of Roda because Roda suggests that the co-administration of IL-2 with anti-EGFR antibody cetuximab promoted NK cell response and subsequent ADCC for increased immune response and tumor cell killing. One would have been motivated to, and have a reasonable expectation of success to, because Roda explicitly teaches the co-administration of IL-2 and cetuximab promotes increased immune response and subsequent tumor cell killing via NK cell activity, and one of ordinary skill in the art would recognize that co-administration of IL-2 and cetuximab would be achievable through co-expression of both agents on the surface of extracellular vesicles, as suggested by Lewis.
However, it is noted that Roda, nor Lewis and Q0GK43, teach an EGFR-specific scFv having the sequence corresponding to instant SEQ ID NO: 2 derived from cetuximab, nor the surface expression of such an antibody construct on the surface of extracellular vesicles. This deficiency is remedied by the combination of Xia, Chen, Tamaskovic, and Kooijmans.
Xia discloses an EGFR-specific chimeric antigen receptor (CAR) and application thereof (Page 3); Xia further indicates that EGFR is highly expressed on the surface of many malignant tumor cells including epidermal squamous cell carcinoma, breast cancer, ovarian cancer, non-cancer small cell lung cancer, kidney cancer, and head and neck malignancies (Page 2). More specifically, the CAR of the invention comprises a transmembrane signal region, an extracellular recognition region, a hinge region, a transmembrane region, and an intracellular signal transduction region connected in sequence wherein, in preferred embodiments, the extracellular recognition region is derived from anti-EGFR cetuximab, and its amino acid sequence is shown in SEQ ID NO: 2 (Page 3); it is further noted that Xia SEQ ID NO: 2 is an scFv wherein the heavy chain and light chain of cetuximab (known by the brand name Erbitux) are connected via a linker (i.e., GGGGSGGGGSGGGGS or (G4S)3). As such, Xia SEQ ID NO: 2 is a 99.2% match to instant SEQ ID NO: 2. Notably, the difference between the scFv of Xia and the instantly claimed scFv of SEQ ID NO: 2 is that the instantly claimed scFv comprises the amino acid residues “KL” immediately preceding the linker (i.e., the instantly claimed linker is KLGGGGSGGGGSGGGGS). However, the inclusion of “KL” immediately preceding the (G4S)3 is taught/suggested by the combination of Chen and Tamaskovic.
Chen discloses that linkers have shown increasing importance in the construction of stable, bioactive fusion proteins; besides the basic role in linking the functional domains together (as in flexible and rigid linkers) or releasing the free functional domain in vivo (as in in vivo cleavable linkers), linkers may offer many other advantages for the production of fusion proteins, such as improving biological activity, increasing expression yield, and achieving desirable pharmacokinetic profiles (Abstract). Flexible linkers are usually applied when the joined domains require a certain degree of movement or interaction. They are generally composed of small, non-polar (e.g. Gly) or polar (e.g. Ser or Thr) amino acids; the small size of these amino acids provides flexibility, and allows for mobility of the connecting functional domains wherein the incorporation of Ser or Thr can maintain the stability of the linker in aqueous solutions by forming hydrogen bonds with the water molecules, and therefore reduces the unfavorable interaction between the linker and the protein moieties (Page 1359, Column 2, Flexible Linkers”). Flexible linkers may be rich in small or polar amino acids such as Gly and Ser, but can contain additional amino acids such as Thr and Ala to maintain flexibility, as well as polar amino acids such as Lys and Glu to improve solubility (Page 1360, Column 2, Paragraph 1). Flexible linkers are suitable choices when certain movements or interactions (e.g. scFv) are required for fusion protein domains. In addition, although flexible linkers do not have rigid structures, they can serve as a passive linker to keep a distance between functional domains. The length of the flexible linkers can be adjusted to allow for proper folding or to achieve optimal biological activity of the fusion proteins (Page 1361, Column 1, Paragraph 2). Thus, Chen explicitly suggests the incorporation of lysine to improve solubility and suggests that small, non-polar residues, which one of ordinary skill in the art would recognize as including leucine, maintain flexibility.
Tamaskovic is drawn to bispecific targeting agents, particularly to antibodies, antibody fragments or other polypeptide ligands targeting HER2, and their use in cancer therapy (Paragraph 0001). Embodiments of the invention include: (1) a bispecific agent comprising a first ligand that binds HER2 extracellular domain 1, a second ligand that binds HER2 extracellular domain 4, and a linker that connects said first ligand to said second ligand; (2) a bispecific agent comprising a first binding site that binds HER2 extracellular domain 1, a second binding site that binds HER2 extracellular domain 4, and a linker that connects said first binding site to said second binding site; and (3) a bispecific agent comprising a first polypeptide ligand that binds HER2 extracellular domain 1, a second polypeptide ligand that binds HER2 extracellular domain 4, and a linker that connects said first polypeptide ligand to said second polypeptide ligand (Paragraphs 0021-0026). Exemplary bispecific binding agents are characterized by amino acid sequences corresponding to SEQ ID NOs: 03-09 (Paragraph 0096). Notably, Tamaskovic SEQ ID NO: 8 comprises a linker sequence of KLGGGGSGGGGSGGGS at residues 166-182. Thus, Tamaskovic discloses a linker of KLGGGGSGGGGSGGGS wherein said linker is utilized in the context of, generally, polypeptide fusion.
Kooijmans discloses that extracellular vesicles (EVs) are attractive candidate drug delivery systems due to their ability to functionally transport biological cargo to recipient cells, but the apparent lack of target cell specificity of exogenously administered EVs limits their therapeutic applicability (Abstract). The authors transfected EV-producing cells with vectors encoding for anti-epidermal growth factor receptor (EGFR) nanobodies, which served as targeting ligands for tumor cells, fused to glycosylphosphatidylinositol (GPI) anchor signal peptides derived from decay-accelerating factor (DAF) and subsequent EV-tumor cell interactions were analyzed (Id.). Study data shows that (i) GPI-anchors can be used to display nanobodies on EV surfaces, without affecting other EV characteristics (i.e. protein composition, size and morphology) (Pages 4-5, Characterization of EVs Derived from DAF-Nanobody Expressing Cells); (ii) control EVs and EV-DAF-R2 were not efficiently captured by the cells over the course of the experiment, while EV-DAF-EGa1 rapidly associated with cell surfaces wherein the rate of association was approximately 2-fold higher for EV-DAF-EGa1 (Pages 6-7, Cell Association Under Flow Conditions). Thus, Kooijmans discloses the successful surface expression of anti-EGFR antibody constructs on EVs and the increased association of such EVs with EGFR-expressing cells.
It would have been prima facie obvious to one of ordinary skill in the art at the time the invention was filed to (i) produce extracellular vesicles derived from T cells expressing cytokines and antibodies on at their surface, wherein the cytokine is IL-2 having the amino acid sequence represented by instant SEQ ID NO: 1 and wherein the antibody is an epidermal growth factor receptor-binding scFv having the amino acid sequence represented by SEQ ID NO: 2 and (ii) administer said vesicles to a subject for the treatment of cancer. One would have been motivated to combine the teachings of Lewis, Q0GK43, Roda, Xia, Chen, Tamaskovic, and Kooijmans: (1) in order to produce extracellular vesicles derived from T cells expressing cytokines and antibodies on at their surface, wherein the cytokine is IL-2 having the amino acid sequence represented by instant SEQ ID NO: 1 and wherein the antibody is an epidermal growth factor receptor-binding scFv having the amino acid sequence represented by SEQ ID NO: 2 and use such vesicles in the treatment of cancer, (2) because Lewis discloses vesicles engineered to express immunomodulatory components at their surfaces (including cytokines, tumor antigens, target antagonists, antibodies, and/or combinations thereof), and their use in the treatment of cancer for upregulating immune response and Roda demonstrates the co-administration of IL-2 and EGFR antagonistic antibody cetuximab improves NK cell response/activity in treating cancer and (3) Q0GK43 discloses the IL-2 cytokine sequence, the combination of Xia, Chen, and Tamaskovic suggest the EGFR-binding scFv of instant SEQ ID NO: 2 derived from cetuximab, and Kooijmans discloses surface expression of anti-EGFR antibody constructs on EVs for increased EV interactions/association with EGFR-expressing cells such that, when taken together, the resultant extracellular vesicles expressing IL-2 and an epidermal growth factor receptor-binding scFv would be reasonably expected to function in the context of targeting EVs to EGFR-expressing cells (i.e., cancer cells), increasing immune response via NK cells through the simultaneous actions of IL-2 and the anti-EGFR scFv, and subsequently treating cancer. One of ordinary skill in the art would have a reasonable expectation of success because: (1) the cited references teach the established, successful methods of treating cancer with engineered, T cell derived vesicles expressing immunomodulatory components on their surface, teach the known benefits of combining immunomodulatory components such as EGFR-targeting antibody constructs (e.g., cetuximab and/or scFv thereof) and cytokine IL-2, and that surface expression of anti-EGFR antibody constructs on EVs increases the association of said EVs with EGFR-expressing cells (i.e., cancer cells).
In the test of whether it is “obvious to try” there must be:
(1) a finding in the art at the time of filing of the invention that there had been a recognized problem or need in the art;
(2) a finding that there had been a finite number of identified, predictable potential solutions to the recognized need or problem;
(3) a finding that one of ordinary skill in the art could have pursued the known potential solutions with a reasonable expectation of success.
In the instant case: (1) Lewis recognizes the need for improving the delivery of immunomodulatory molecules to tissues/cells and recognizes that extracellular vesicles can interact with various cells involved with the modulation of the human immune system;
(2) Roda recognizes that the co-administration of IL-2 and cetuximab enhances NK cell response/activity and subsequently enhances ADCC (i.e., antibody-dependent cellular cytotoxicity) for improved treatment of various EGFR-expressing cancers, and Q0GK43 discloses the IL-2 cytokine sequence and the combination of Xia, Chen, and Tamaskovic suggest the EGFR-binding scFv of instant SEQ ID NO: 2 derived from cetuximab, and Kooijmans discloses surface expression of anti-EGFR antibody constructs on EVs for increased EV interactions/association with EGFR-expressing cells such that, when taken together, the resultant extracellular vesicles expressing IL-2 and an epidermal growth factor receptor-binding scFv would be reasonably expected to function in the context of targeting EVs to EGFR-expressing cells (i.e., cancer cells), increasing immune response via NK cells through the simultaneous actions of IL-2 and the anti-EGFR scFv, and subsequently treating cancer; and (3) one of skill in the art could have pursued the production of extracellular vesicles derived from T cells expressing cytokines and antibodies on at their surface, wherein the cytokine is IL-2 having the amino acid sequence represented by instant SEQ ID NO: 1 and wherein the antibody is an epidermal growth factor receptor-binding scFv having the amino acid sequence represented by SEQ ID NO: 2 and their subsequent administration to a subject for the treatment of cancer with a reasonable expectation of success.
With regard to claims 9 and 12-13, Lewis further teaches that extracellular vesicles of the invention may further comprise a third immunomodulatory component, which may be different from the first and second immunomodulatory components (Paragraphs 0036-0037). It is noted that an immunomodulatory component may be an activator of a T-cell receptor or co-receptor, wherein in certain embodiments the activator of a T-cell receptor or co-receptor is an activator of CD3, optionally an agonist antibody of CD3 (Paragraphs 0013 and 0028). It is noted that there is no special definition of “bioactive substance” provided in the instant specification, and as such an agonist antibody of CD meets the definition of a bioactive substance, and more specifically a bioactive substance that is a protein. Additionally, Lewis teaches that immunomodulatory components may be either (i) associated with the surface of the extracellular vesicle or (ii) encapsulated within the extracellular vesicle (Paragraph 0007); Lewis does not teach the expression of the third immunomodulatory component as a fusion protein for surface expression, and as such the third immunomodulatory component is encapsulated within the extracellular vesicle. As such, the extracellular vesicles of claim 1 may further comprise a bioactive substance (e.g., a bioactive protein), wherein said bioactive substance is encapsulated within the extracellular vesicle and is delivered to a subject (e.g., a subject having cancer) via administration of said extracellular vesicles. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the effective filing date of the invention as evidenced by the references.
Claims 2 and 4-7 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis"), UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), non-patent literature by Roda et. al. (Clin. Cancer Res., 2007, 13(21), 6419-6428; herein after referred to as "Roda"), CN 110845623 A (machine translation of the Description provided previously; previously cited on PTO-892; herein after referred to as “Xia”), non-patent literature by Chen et. al. (Advanced Drug Delivery Reviews, 2013, 65, 1357-1369; previously cited on PTO-892; herein after referred to as “Chen”), and EP 2719706 A1 (herein after referred to as “Tamaskovic”), as applied to claims 1 and 8-13 above, and in further view of non-patent literature by Liu et. al. (Cell Chemical Biology, 2017, 24, 767-771; herein after referred to as "Liu").
The extracellular vesicle of instant claim 1 is rendered obvious by Lewis, Q0GK43, Roda, Xia, Chen, and Tamaskovic. It is further noted that Lewis discloses that the first and/or second immunomodulating components may be expressed as a fusion protein displayed on the exterior surface of said extracellular vesicle (Paragraphs 0019 and 0034, respectively). In an exemplary embodiment, the immunomodulatory component introduced into an exosome (i.e., extracellular vesicle) is IL-15, which is fused to the transmembrane domain of PDGFR (platelet-derived growth factor receptor) (Paragraph 0355). Lewis also teaches that to produce the extracellular vesicles of the invention, a producer cell is modified with the immunomodulating component(s), wherein the producer cell may be an immune cell, such as a dendritic cell, a T cell, a B cell, a natural killer cell (NK cell), an antigen presenting cell, a macrophage, a T helper cell, or a regulatory T cell (Treg cell) (Paragraphs 0237-0240) or, alternatively, the immunomodulating component(s) can be introduced directly to the extracellular vesicles after the isolation of the extracellular vesicles (Paragraph 0254) wherein methods for isolating extracellular vesicles from the producer cells (i.e., producer cell derived extracellular vesicles) are also provided (Paragraphs 0268-0271).Thus, Lewis suggests (i) extracellular vesicles derived from T helper cells, (ii) production of the extracellular vesicles of the invention, and (iii) fusions of immunomodulatory components to transmembrane proteins. However, Lewis does not suggest the use of linkers in such fusions.
Liu discloses transforming TF-1 cells via lentiviral transduction to expression fusion proteins composed secreted proteins (including cytokines) linked to TMD of RTK platelet- derived growth factor (PDGFR) through long, flexible peptide linker identical to GSTSGSGKPGSGEGSTKG, which is a 100% match to instant SEQ ID NO: 12 (Page 769, Column 2, Paragraph 1). Liu validates active autocrine signaling using cytokines known to stimulate TF1 proliferation (including IL3 and IL6) via proliferation assay (Figure 4B); thus Liu demonstrates that said TM-linker-cytokine fusions retain functionality.
Furthermore, it is noted that Chen teaches that flexible linkers are suitable choices when certain movements or interactions (e.g. scFv) are required for fusion protein domains; although flexible linkers do not have rigid structures, they can serve as a passive linker to keep a distance between functional domains wherein the length of the flexible linkers can be adjusted to allow for proper folding or to achieve optimal biological activity of the fusion proteins (Page 1361, Column 1, Paragraph 2).
Thus, it would have been prima facie obvious to one of ordinary skill in the art that the extracellular vesicles disclosed by Lewis could be modified such that the fusion proteins for surface expression of the immunomodulatory components comprising cytokines (e.g., IL-2) fused to transmembrane domains (e.g., PDGFR), disclosed by Lewis, could be modified such that the fusions further comprise a flexible linker, suggested by both Liu and Chen, wherein said flexible linker may be that of instant SEQ ID NO: 12, as suggested by Liu, wherein the resulting TM-linker-cytokine fusion protein expressed at the surface of the extracellular vesicles of claim 1 would reasonably be expected to retain biological activity, as suggested by Liu and Chen, wherein the use of such a flexible linker may reduce unfavorable interactions between the transmembrane domain and the cytokine by keeping distance between the two domains and achieve optimal/improved biological activity of the cytokine, as suggested by Chen.
Double Patenting - Withdrawn
Claims 1-2, 4-7, and 10-13 were provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 10, and 16 of copending Application No. 17/439,124 (herein after referred to as "first reference application") in view of US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”).
Claim 3 was provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 10, and 16 of copending Application No. 17/439,124 (herein after referred to as "first reference application") and US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), as applied to claims 1-2, 4-7, and 10-13 above, and in further view of CN 110845623 A (machine translation of the Description provided; previously cited on PTO-892; herein after referred to as “Xia”).
Claims 8-9 were provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 10, and 16 of copending Application No. 17/439,124 (herein after referred to as "first reference application") and US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), as applied to claims 1-2, 4-7, and 10-13 above, and in further view of non-patent literature by Yang et. al. (J. Cancer Re. Clin. Oncol., 2007, 133, 389-399; previously cited on PTO-892; herein after referred to as “Yang”).
Claims 1-2, 4-8, and 10-13 were provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-14 of copending Application No. 17/621,234 (herein after referred to as "second reference application") in view of US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”).
Claim 3 was provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-14 of copending Application No. 17/621,234 (herein after referred to as "second reference application") and US 2019/0202892 A1 (previously cited on PTO-892; herein after referred to as "Lewis") as evidenced by UniProt Entry Q0GK43 (previously cited on PTO-892; herein after referred to as “Q0GK43”), as applied to claims 1-2, 4-7, and 10-13 above, and in further view of CN 110845623 A (machine translation of the Description provided; previously cited on PTO-892; herein after referred to as “Xia”).
With regard to the above-listed claim rejections under nonstatutory double patenting, Applicant argues on Page 15 of Remarks that the reference applications in view of Lewis (and the additionally cited prior art) fail to recognize the claimed extracellular vesicle co-expressing IL-2 and the now recited, sequence-defined EGFR-binding scFv of independent claims 1 and 10. In view of the amended claims, Applicant’s argument is deemed persuasive and the above-listed claim rejections under nonstatutory double patenting are withdrawn.
Response to Arguments
Applicant argues on Pages 13 and 15 of Remarks that:
In vitro data shows that expressing both IL-2 and the instantly claimed EGFR-binding scFv results in marked cytotoxicity against EGFR-positive A549 cancer cells while producing essentially no cytotoxicity in normal HEK cells under the same conditions;
IL-2 alone does not induce cytotoxicity in either cancer cells or normal cells under comparable conditions;
Masking EGFR with competitive antibodies blocks vesicle association with cancer cells and the in vivo xenograft data shows tumor-selective accumulation of the instantly claimed extracellular vesicles following systemic administration;
The above detailed results evidence synergistic and a selective functional profile that goes beyond what the previously cited prior art had described.
In response to Applicant's argument that the invention of the presently amended claims functions as a cancer-cell specific cytotoxic platform with a selectivity profile not suggested by the references (see Pages 13 and 15 of Remarks), the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the newly cited prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Furthermore, MPEP 716.02b indicates that evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992) (Mere conclusions in appellants’ brief that the claimed polymer had an unexpectedly increased impact strength "are not entitled to the weight of conclusions accompanying the evidence, either in the specification or in a declaration."); Ex parte C, 27 USPQ2d 1492 (Bd. Pat. App. & Inter. 1992) (Applicant alleged unexpected results with regard to the claimed soybean plant, however there was no basis for judging the practical significance of data with regard to maturity date, flowering date, flower color, or height of the plant.). See also In re Nolan, 553 F.2d 1261, 1267, 193 USPQ 641, 645 (CCPA 1977) and In re Eli Lilly, 902 F.2d 943, 14 USPQ2d 1741 (Fed. Cir. 1990) as discussed in MPEP § 716.02(c). None of the data referenced by Applicant comprises any statistical analysis and as such does not clearly support or evidence the argued result of synergy. Furthermore, the newly cited Roda reference explicitly suggests that the combination of EGFR-specific antibody cetuximab (the antibody from which the instantly claimed scFv is derived) and IL-2 enhances NK cell activity and subsequent ADCC activity in various cancer cell models; additionally, Lewis indicates that the extracellular vesicles of the invention would be effective in delivering immunomodulatory molecules to cells and tissues, wherein one of ordinary skill in the art would further recognize that engineering an extracellular vesicle to comprise surface expression of an EGFR-binding antibody construct would preferentially delivery said extracellular vesicles to EGFR-expressing tissues (i.e., EGFR-positive cancerous tissues) as is supported by Kooijmans.
Thus, in view of the new grounds of rejection presented above relying on newly cited prior art and in view of the arguments presented above, Applicant’s argument of nonobviousness by way of unexpected results is deemed not persuasive.
Conclusion
Claims 1-2 and 4-14 are pending. Claims 1-2 and 4-14 are rejected. No claims are allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/ALYSSA RAE STONEBRAKER/Examiner, Art Unit 1642
/Laura B Goddard/Primary Examiner, Art Unit 1642