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 .
DETAILED ACTION
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office Action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s submission filed on March 5, 2026 has been entered.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1 – 2, 4 – 5, 7 – 8, 11 – 12, 15, 17 – 18, 21 - 26 are currently pending. Claims 1 and 11 are independent claims. Claims 1, 11, 21, and 22 have been amended by Applicant’s amendment March 5, 2026. Claims 23 – 26 have been added by Applicant’s amendment filed March 5, 2026. No claims have been canceled by Applicant’s amendment filed March 5, 2026.
Priority
The present application, filed September 21, 2021, claims benefit of the Provisional Application, 63/081,248, 63/081,231, 63/081,250, 63/081,229, 63/081,242, 63/081,256, 63/081,258, and 63/081,237, all filed on September 21, 2020.
Maintained Objections/Rejections
Claim Rejection - 35 USC § 112(a) Scope of Enablement
The rejection of claims 1-2, 4-5, 7-8, 11-12,15, 17-18, 21, and 22 is maintained, and claims 23 and 24 are newly rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the Specification,
while being enabling for engineered immune cells comprising a pair of activating and blocking receptors each comprising a ligand binding domain (LBD), a hinge, a transmembrane domain, and an intracellular domain (ICD), wherein the LBD is a scFV activating receptor for a MAGE-A3 target activating ligand, and the scFV blocking receptor (ESO-Tmod) is a NY-ESO-1 blocking ligand, wherein the hinge of the blocking receptor comprises a peptide having 100% identity to the sequence of a leukocyte immunoglobulin-like receptor subfamily B member I (LILRB I) hinge domain comprising the amino acid of SEQ ID NO: 84 or 78,
does not reasonably provide enablement for using any pair of activating and blocking receptor or target ligand, or using the amino acid sequences with 90% sequence alignment set forth in Seq ID No. 84 or 78, within the hinge of the blocking receptor able to modulate the effect of the blocking signal on the activating signal, and does not reasonably provide enablement for the use of a LILRB1 hinge domain comprising Seq ID NO: 77. Please note: This rejection has been modified as necessitated by the response filed March 5, 2026.
The Specification does not enable any person skill in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims. The claims, when given the broadest possible interpretation, encompass a method of producing an engineered immune cell, wherein the engineered immune cell is produced by introducing a vector into the cell that encodes an activating and blocking receptor, wherein the receptors both comprise a LBD, a hinge, a transmembrane domain, and an ICD, and wherein the hinge of the blocking receptor is a LILRB1 hinge. Further, when the activating receptor binds to a target activating ligand, a cytotoxic response is triggered, and when the blocking receptor binds to a target blocking ligand, an inhibitory signal that blocks the activating signal is triggered.
The test of enablement is whether one skilled in the art could make and use the claimed invention from the disclosures in the patent coupled with information known in the art without undue experimentation (United States v. Telectronics, Inc., 8 USPQ2d 1217 (Fed. Cir. 1988)). Whether undue experimentation is required is not based on a single factor but is rather a conclusion reached by weighing many factors (See Ex parte Forman, 230 USPQ 546 (Bd. Pat. App. & Inter, 1986) and In re Wands, 8USPQ2d 1400 (Fed. Cir. 1988); these factors include the following:
Nature of invention. The invention encompasses a method of producing an
engineered immune cell, wherein the engineered immune cell is produced by introducing a vector into the cell that encodes an activating and blocking receptor, wherein the receptors both comprise a LBD, a hinge, a transmembrane domain, and an ICD, and wherein the hinge of the blocking receptor is a LILRB1 hinge. Further, when the activating receptor binds to a target activating ligand, a cytotoxic response is triggered, and when the blocking receptor binds to a target blocking ligand, an inhibitory signal that blocks the activating signal is triggered.
Scope of the invention. The invention encompasses a method of producing an engineered immune cell.
Number of working examples and guidance. In the instant case, Applicant does not disclose any relevant examples that teach the genus of engineered immune cells comprising any combination of an activating receptor, a blocking receptor and their binding to the activating/blocking ligand (respectively) on a tumor and non-tumor cell, and wherein the hinge of the blocking receptor comprises a LILRB1 hinge.
However, Applicant discloses relevant figures, particularly figure 4, 22, 28, and 29, and example 5.
Firstly, Fig. 4 teaches that the engineered immune cells comprise activating and blocking receptors, and the level of the activating receptor decreases when the immune cells are in the presence of non-target cells (Paragraph [0456]). This figure shows the effect of the activating receptor in the presence of the non-target cell, but not the structure function relation that any and all activating receptors can exist with any and all blocking cells what happens when interacting with a tumor or non-tumor cell, or the use of LILRB1 as the hinge in the blocking receptor.
Fig. 22 shows the experimental results indicating that the blocking receptor provides a blocking signal that dominates and inhibits the activating signal from the activating receptor, wherein Jurkat cells were transfected with an activating receptor (MP1-CAR) for a MAGE-A3 activating ligand and a blocking receptor (ESO-Tmod) for a NY-ESO-1 blocking signal (Paragraph [0462]). This figure shows the structure function relationship between these pairs of activating and blocking receptors or ligands, but not the structure function relation that any and all receptors can exist with any and all ligands, the use of tumor cell, and the use of a LILRB1 hinge.
In fact, Applicant emphasizes that “the identity of the ligand binding domain (LBD) of the activating receptor drives the activity of the receptor.” (Paragraph [0144]). Specifically, in Fig. 26, different binding domains effect the receptors EC50, wherein LBD #1 has the highest EC50, and LBD # 2 – 3 have significantly lower EC50s. Similarly, the identity of the blocking receptor LBD can have large effects on the IC50 of the engineered immune cells (Paragraph [0210]). These figures show that there are specific ligand binding domains in both the activating and blocking receptors that impact the activity of the receptors. Thus, the results indicate a structure function relationship between specific ligand binding domains and the efficiency of the receptor, such that any and all receptors cannot exist with any and all ligands.
Applicant discloses relevant Figures, particularly Figures 28 and 29, and Figure 35. Figures 28 and 29 teach that the immune cells can have various combinations of TCRs (Paragraph [0234]). For example, Fig. 28 teaches a combination of a T cell with (i) an scFV activating receptor with a scFV blocker, (ii) an scFv activator with a Ftcr blocker, (iii) a TCR activator with a scFv blocker, and (iv) a TCR activator with a fTCR blocker. These figures only show the structure function relationship between these pairs of activating and blocking receptors, but not the structure function relation that any and all activating receptors can exist with any and all blocking cells can be used to produce an engineered immune cell that can bind to a tumor or non-tumor cell, the use of tumor or non-tumor cell, or the use of a LILRB1 hinge.
In example 5, the Specification discloses a pair of activating MP1 CAR and blocking receptor (ESO-Tmod) CAR (Paragraph [0462]). Specifically, Jurkat cells were transfected with either an activating receptor (MP1-CAR) for a MAGE-A3 activating ligand or the activating receptor and a blocking receptor (ESO-Tmod) for a NY-ESO-1 blocking ligand. The T2 cells were loaded with titrated amounts of blocker NY-ESO-1 peptide and a fixed amount of activator MAGE-A3 peptide concentration above the Emax concentration (˜0.1 μM). This reveals the inhibition dose-response of the transfected cells. At paragraphs [0465] the Specification teaches in panel C luciferase signal of Jurkat cells transfected with either the activator alone or in combination with the blocker, after 6 hours of co-culture with activator and blocker peptide-loaded T2 cells where “The x-value blocker NY-ESO-1 peptide concentrations from panel B were normalized to the constant activator MAGE peptide concentrations used for each curve and plotted on the x-axis. The ratio of blocker peptide to activator peptide required for 50% blocking (IC50) are indicated for each curve. The B:A peptide ratio required is less than 1 indicating that, for this pair of activator CAR and blocker, similar (or fewer) blocker pMHC antigens may be sufficient on target cells to block activator pMHC antigens.”. The Specification is silent about any other produced immune cells “causing the engineered immune cell to express an amount of the blocking receptor to an amount of the activating receptor at a ratio of less than 1.” as required in claim 1.
State of the art. Although the field of producing an engineered immune cell is highly
developed, the method of producing an engineered immune cell with engineered activating and blocking receptors, and using LILRB1 as a hinge in a receptor is not highly developed. The art must therefore be considered to be poorly developed.
Unpredictability of the art. Before the effective filing date of the claimed invention,
it was known in the art that scFv antibodies have poor stability, low solubility, and affinity, which seriously limits their clinical implication, as evidenced by Wang et al. (Wang R. et al. Engineering production of functional scFv antibody in E. coli by co-expressing the molecule chaperone Skp. Front Cell Infect Microbiol. 2013 Nov 6;3:72. PMID: 24224158; PMCID: PMC3818579.) (Abstract). The instant application recites the use of the scFV receptors, however, these receptors are shown to have poor stability, low solubility, and affinity, making them less effective candidates for cell surface receptors.
Further, by introducing a TCR into a T cell, there is decreased expression of the introduced and endogenous TCR, and the introduced and endogenous TCRs can form TCR dimers which can be neoreactive and leads to off-target effects, as evidenced by van Loenen et al. (van Loenen MM. et al. Mixed T cell receptor dimers harbor potentially harmful neoreactivity. Proc Natl Acad Sci U S A. 2010 Jun 15;107(24):10972-7. Epub 2010 Jun 1. PMID: 20534461; PMCID: PMC2890759.) (Abstract). The instant application recites the use of the engineering TCRs in the immune cell, however, when a TCR is introduced into a cell, there can be off-target effects and the formation of neo-reactive dimers.
Additionally, it was known that NK cells express a variety of activating and inhibitory receptors, but NK cells must remain tolerant of healthy tissue, and some of these receptors can also prevent activation of NK cells, as evidenced by Pegram et al. (Pegram HJ. Et al. Activating and inhibitory receptors of natural killer cells. Immunol Cell Biol. 2011 Feb;89(2):216-24. Epub 2010 Jun 22. PMID: 20567250.) (Abstract). Additionally, receptor families contain both “activating receptors” and “blocking receptors,” which can lead to inappropriate NK cell activation and decreased ability of the NK cells to discriminate normal, healthy tissue from infected or malignant tissue (pg. 217, right column, first paragraph).
It was also known in the art the a “switchable” CAR, comprising a first or second CAR that will be expressed based on the number of engagements between the CAR effector cell and target cell, as evidenced by Young et al. (cited in the Final Rejection, mailed 31 December, 2024). This reference teaches that for specific cell surface receptors to be expressed or inhibited, there needs to be a certain minimum amount of binding between the receptor and engineered immune cell.
Thus, the references indicate that there is a lot of unpredictability in the art pertaining to the specific types of receptors that are used in the engineered immune cells, including off-target effects, low expression levels, and inappropriate cell activation.
Additionally, it is known in the art that the D1D2 hinge domain of LILRB1 is involved in the recognition of MHC class 1 proteins, and it is the D1D2 hinge region is used to form the components of the ligand binding site and regulating immune tolerance, as evidenced by Cheng et al. (Previously cited in the Final Rejection mailed 31 December, 2024) (pg. 18014, right column, second paragraph).
Further, there are 6 different isoforms of human LILRB1, as evidenced by Maute et al. (US 20180251558 A1, published 6 September, 2018) (Paragraph [0068]). Further, when LILRB1 is activated, the receptor transduces a negative signal that inhibits stimulation of an immune response in the cells on which it is expressed (Paragraph [0067]).
These two references (Cheng et al. and Maute et al.) show the variability in the human LILRB1 sequences, and the importance of only the specific D1D2 domain that is being used as a ligand binding site and regulating immune tolerance.
Amount of Experimentation Required. Given the unpredictability of the art, the
poorly developed state of the art with regard to the activating receptors and blocking receptors, wherein all activating receptors are compatible with all blocking receptors, and the variability in the LILRB1 sequences and the increased importance of certain components of the LILRB1 sequence, the skilled artisan would have to conduct undue, and unpredictable experimentation to practice the claimed invention using the engineered immune cells with the activating and blocking receptor, and using the LILRB1 as a hinge on the blocking receptor. Further, due to the lack of specific guidance in the specification for producing the engineered immune cell, it would require undue experimentation to practice the breadth of the instant methods as claimed.
Response to Arguments as they apply to rejection of claims 1-2, 4-5, 7-8, 11-12,15, 17-18, 21, 22, and 25 - 26 under 35 USC § 112(a)
Applicant’s arguments filed March 5, 2025 have been fully considered but they are not persuasive. Applicant essentially asserts (a) the claims delineate the genus of blocking receptors to only those that include such a hinge, and the experimental results validate the hinge comprising a peptide derived from a LILRB1 protein (Remarks, pg. 10, fourth and fifth paragraph), and (b) Applicant has not claimed that the use of the recited hinge will produce any particular therapeutic effect (pgs. 12 and 13).
Please note: on pg. 13 of the Remarks, Applicant notes that the claims are rejected under 35 USC § 112(a) as lacking adequate written description. The Examiner notes that in the Office Actions mailed May 6, 2025, and November 5, 2025 claims 1-2, 4-5, 7-8, 11-12,15, 17-18, 21, and 22 are rejected under 35 USC § 112(a) for scope of enablement, not written description.
Regarding (a), Applicant argues that the genus is limited to only those that include the hinge comprising a peptide derived from a LILRB1 protein; however, this argument is not found persuasive. As noted above, as shown from the figures, there is a structure function relationship shown between specific activating and blocking receptors. It is not clear whether any and all activating blocking can exist with this “genus of blocking receptors comprising a peptide derived from a LILRB1 protein” to produce an engineered cell that can bind to a tumor and non-tumor cell. As noted above, the Specification discloses a pair of activating MP1 CAR and blocking receptor (ESO-Tmod) CAR. The Specification is silent about any other produced immune cells “causing the engineered immune cell to express an amount of the blocking receptor to an amount of the activating receptor at a ratio of less than 1.” as required in claim 1. Though Applicants states at page 12 of the remarks that “as evidenced by the voluminous citations provided by the Office, the components methods for making engineered immune cells with activating and inhibitory receptors was well known in the art.”, there is no evidence provided by Applicants to support his assertion and the scope of the claimed invention in relation to the genus of combinations of CAR and engineered blocking receptor wherein (i) binding of the activating receptor to a target activating ligand expressed on the surface of a tumor cell and a non-tumor cell of a patient triggers an activating signal that promotes a cytotoxic response by the engineered immune cell and (ii) binding of the blocking receptor to a target blocking ligand on a nontumor cell of the patient causes the blocking receptors to trigger an inhibitory signal that blocks the activating signal.
The examiner also notes that example 8 teaches engineered immune cells with one of five different activating receptors CT479, CT482, CT486, CT487, CT 488, e.g, titrated amounts of activator MAGE-A3 peptide, each targeted the same activating ligand, epidermal growth factor receptor (EGFR) and the same C1765, e.g, fixed amount of blocker NY-ESO-1 peptide concentration, where “Addition of the blocker caused some of the immune cells, like CT486-containing cells, to decrease their ability to kill target cells.”.
Further, the as-Filed Specification cites Fig. 25, which shows that lengthening a hinge from 25 amino acids to 35 amino acids confers a significant increase in blocker strength, and the increase becomes more dramatic as the hinge length approaches 65 amino acids in length (As filed Specification, pg. 35, lines 17 – 18). Fig. 25 does teach that the hinge of LILRB1 (referred to as “2B1” has been tested. However, as noted in Figure 25, the length of this hinge is 64 amino acids. It is unclear which Seq. ID refers to the LILRB1 of hinge length of 64 amino acids, as Seq ID No: 84 (the LILRB1 hinge domain as given by instantly filed application) is 63 amino acids long. Fig. 25 teaches a variety of different hinges that were tested, but does not teach the effect of varying the sequence of these hinges to yield the same result. As such, there is no way of knowing whether a hinge that is 90% aligned to Seq ID No:84 will also confer a similar blocker strength.
In sum, the instant specification does not provide any guidance that would steer the skilled practitioner toward engineered immune cells that express activating and blocking receptors that can be used to carry out the claimed methods -- an essential element of every claim of the application -- and has not provided evidence that any such activating and blocking receptors were otherwise within the knowledge of a person of ordinary skill in the art at the relevant time. The disclosure is limited to the examples specified above and does not define any particular activating and blocking receptors that would facilitate the claimed effect of the methods.
The examiner notes that the applicant has amended the claims to recite that the LILRB1 hinge domain as set forth in Seq ID No: 84, 77, and 78. Seq ID Nos: 84 and 78 are LILRB1 hinge domains, whereas Seq ID No: 77 refers to a D3D4 domain. The hinge domain is separate from the D3D4 domain of a receptor. Thus, it is still unclear what exactly is the sequence of the LILRB1 hinge domain and how it relates to the blocking capacity of the blocking receptor.
Regarding (b), Applicant states that they have not claimed use of the recited hinge will produce any particular therapeutic effect. However, in the same paragraph, Applicant notes that the hinge domain of the blocking receptor can be used to provide a strong signal that can be modulated. The instantly recited claims recite that binding of the blocking receptor on the engineered immune cell to the blocking receptor triggers an inhibitory signal that blocks the activating signal. Thus, the blocking receptor, comprising the LILRB1 hinge domain, must be able to bind to the blocking ligand on the non-target cell, and trigger an inhibitory signal that blocks the activating signal. From the examples and figures provided in the as-Filed Specification, only specific blocking receptors are able to successfully bind to the blocking ligand on the non-target cell, and trigger an inhibitory signal that blocks the activating signal. The Applicant is reminded that rather than the instant claims are directed to a method of producing engineered immune cells that are being used for cancer treatment. Thus, the Applicant needs to show the relationship between the activating and blocking receptors that comprise the novel hinge domain.
Claim Rejection - 35 USC § 112(d)
The rejection of claims 21 and 22 is maintained, and claims 23 – 26 are newly rejected under 35 U.S.C. 112(d) as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claims 21 – 26 are rejected for the recitation of “wherein said blocking receptor comprises an amino acid sequence having at least 90% identity with an amino acid sequence set forth in Seq ID No: 79 or 80,” such as recited in claim 21, lines 1 – 5. Claim 21 depends from claim 1, and claim 22 depends from claim 11, which teaches that the hinge of the blocking receptors comprise a peptide of at least 20 to 63 amino acids having at least 90% identity with an amino acid of Seq ID No: 84, 77, and 78. The blocking receptor sequence, Seq ID No: 80, does not include any of the hinge domain sequences. Thus, claims 21 – 26 are improper dependent claims for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Response to Applicants’ Arguments as they apply to the rejection of claims 21 – 26 under 35 USC § 112(d)
At pg. 8 of the remarks, Applicant argues that Seq ID No: 79 and 80 include, as subsequences, each one of Seq ID No: 84, 77, and 78.
However, this argument is not found persuasive.
PNG
media_image1.png
816
630
media_image1.png
Greyscale
Supra is the alignment of Seq ID No: 80 and Seq ID No: 77. As can be seen from this alignment, the hinge domain of Seq ID No: 77 is not included in the hinge-transmembrane-intracellular domain of Seq ID No: 80.
PNG
media_image2.png
800
622
media_image2.png
Greyscale
Supra is the alignment of Seq ID No: 80 and Seq ID No: 78. As can be seen from this alignment, the hinge domain of Seq ID No: 78 is not included in the hinge-transmembrane-intracellular domain of Seq ID No: 80.
PNG
media_image3.png
806
584
media_image3.png
Greyscale
Supra is the alignment of Seq ID No: 80 and Seq ID No: 84. As can be seen from this alignment, the hinge domain of Seq ID No: 84 is not included in the hinge-transmembrane-intracellular domain of Seq ID No: 80.
New Objections/Rejections
Claim Rejection - 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, 2, 4 – 5, 7 – 8, 12, 15, 17 – 18, and 21 – 26 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.
Claims 1 and 11 are indefinite for the recitation of “an amino acid sequence of a LILRB1 hinge domain as set forth in Seq ID No: 84, Seq ID No: 77, or Seq ID No: 78, such as recited in claim 11, lines 24 – 27. Seq ID No: 77 refers to a D3D4 domain, while Seq ID Nos: 84 and 78 refer to a hinge domain. Thus, Seq ID No: 77 does not refer to a LILRB1 hinge domain, and thus, the metes and bounds of the claim cannot be determined.
Claims 2, 4 – 5, 7 – 8, 21, 23 – 24 are indefinite insofar as they ultimately depend on claim 1.
Claim 12, 15, 17, 18, 22, and 25 – 26 are indefinite insofar as they ultimately depend on claim 11.
Conclusion
Claims 1, 2, 4 – 5, 7 – 8, 12, 15, 17 – 18, and 21 – 26 remain rejected.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VYOMA SHAILESH THAKKER whose telephone number is (571)272-2954. The examiner can normally be reached M-F 8:30 - 5:30 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, Maria Leavitt can be reached on (571) 272-1085. 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.
/VYOMA SHUBHAM TIWARI/Examiner, Art Unit 1634
/MARIA G LEAVITT/Supervisory Patent Examiner, Art Unit 1634
Prosecution Insights