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 Claims
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
This action is in response to the papers filed on October 28, 2025. Claims 1, 3, 6- 24 are currently pending. Claims 3, 6, and 8 have been amended and claims 2, and 4 – 5 have been canceled in the Applicant’s amendment filed October 28, 2025. No claims have been added in the Applicant’s amendment filed October 28, 2025.
Applicant's election, in the reply filed 6 June, 2025 of Group I, claims 1 – 10 and 24, directed to a method for the production of human regulatory T cells (Tregs); and the following election of Species is acknowledged:
Species (A): the medium further comprises IL-6 and IL-1beta (instant claim 5);
Species (B): wherein step b) does not comprises use of anti-CD3 antibody (instant claim 1).
Claims 11 - 23 were previously withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a non-elected invention, there being no allowable generic or linking claim.
Claim 9 was previously withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a non-elected species, there being no allowable generic or linking claim.
Please Note: claim 10 refers to back to withdrawn claim 9 and, therefore, claim 10 has not been examined on the merits.
Because Applicant did not distinctly and specifically point out the supposed errors in the examiner’s action, and further, did not specifically traverse the election requirement, the election was treated as an election without traverse (MPEP § 818.03(a)).
The restriction requirement was previously made FINAL.
Therefore, claims 1 3, 6 – 8, and 24 are under consideration to which the following grounds of rejection are applicable.
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on August 27, 2025 have been considered. Initialed copies of the IDSs accompany this Office Action.
Priority
The present application filed 28 October, 2021, is a 35 U.S.C. 371 national stage filing of International Application No. PCT/US2020/030869, filed 30 April, 2020; which claims the benefit of Provisional Application 62/841,215, filed 30 April, 2019.
Therefore, the earliest priority date is 30 April, 2019.
Maintained Objections/Rejections
Claim Rejection - 35 USC § 112(b)
The rejection of claims 1, 3, 6- 8, and 24 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 is maintained. The rejection has been modified as necessitated by the response filed October 28, 2025.
Claim 1 is indefinite for the recitation of “CD4+, CD25+, CD127-/low T cells” in line 5. There is a lack of antecedent basis for the term “CD4+, CD25+, CD127-/low T cells” in line 5, as line 3 teaches CD4+, CD25+, CD127 cells”.
Claim 1 is indefinite as being incomplete for omitting essential steps, such omission amounting to a gap between the steps. See MPEP § 2172.01. The omitted steps include staining and/or selecting the CD4+, CD25+, CD127 -/low T cells after isolating the CD4+, CD25+, CD127 cells. A claim that does not set forth any steps involved in the method/process is unclear as to what method/process applicant is intending to encompass. A claim is indefinite where it merely recites a use without any active, positive steps delimiting how this use is actually practiced.
Claim 1 is indefinite for the recitation of “CD4+, CD25+, CD127 cells” in line 3. It is unclear whether three separate cells are cultured, or whether the cell is positive for all 3 markers. For compact prosecution, this has been interpreted as CD4+, CD25+, CD127 T cells.
Claim 1 is indefinite for the recitation of “a lymphocyte containing biological sample comprising mononuclear cells” in lines 3 – 4. It is unclear what is meant by this term, as lymphocytes are a type of mononuclear cell. Thus, it is unclear what the biological sample is, and hence, the metes and bounds of the claim cannot be determined.
Claims 3, 6 – 8, and 24 are indefinite insofar as they ultimately depend from claim 1.
Claim Rejection - 35 USC § 112(a) Scope of Enablement
The rejection of claims 1, 3, 6 – 8, and 24 is maintained under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the Specification, while being enabling for
A method for the production of human regulatory T cells (Tregs), comprising isolating CD4+, CD25+, CD127-low T cells from mononuclear cells isolated from peripheral blood samples, and culturing these T cells under the Bead-Free Treg stimulation conditions shown in Table 1-1 of the as-Filed Specification,
does not reasonably provide enablement for any lymphocyte-containing biological sample comprising mononuclear cells from a human subject. This rejection has been modified as necessitated by the response filed October 28, 2025.
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 for the production of human Tregs that are isolated from a lymphocyte-containing biological sample comprising mononuclear cells, are CD4+, FOXP3+, and HELIOS+, and have a demethylated TSDR, comprising isolating CD4+CD25+CD127-/low T cells, and culturing the T cells in a medium under conditions effective to produce these Treg cells.
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 production of Tregs that are CD4+, FOXP3+, HELIOS+, and have a demethylated Treg specific demethylation region (TSDR).
Scope of the invention. The invention encompasses a method for the production of Tregs, wherein Tregs produced in this this method are suitable for use in various immunotherapy regiments.
Number of working examples and guidance. In the instant case, Applicant provides one relevant working example. In Example 1, the as-Filed Specification teaches the development of a bead-free method of producing Tregs, wherein human peripheral mononuclear cells were isolated from peripheral blood samples and stained for CD4+, CD25+, and CD127 T regs, and then subjected to FACS to isolate CD44+CD25+CD127-/low T regs (Paragraph [0069]). These CD44+CD25+CD127-/low T regs were cultured in T cell media, anti-CD28 antibody, and IL-2 (Paragraph [0071]). These cells were also cultured using beads (anti-CD3/CD28 beads, or various bead free (BF) conditions, as shown in Table 1-1. Treg expansion was found to be dependent on concentration of CD28S Ab and the presence of IL-2, and that there was an absence of activation-associated cell clustering in the absence of IL-2(Paragraph [0078]). Additionally, it was observed that CD28SA antibody preferentially activates CD4+CD25+CD127-low Treg cells, whereas preferential activation of Tregs was not observed when anti-CD3/CD28 beads were employed (Paragraph [0079]). The addition of TNFα alone did not significantly affect the expansion rate of the CD28SA stimulated Tregs, whereas the addition of IL-6 and TNFα did enhance the expansion rate of the CD28SA stimulated T regs (Paragraph [0081 and 0081]). This example teaches that peripheral mononuclear cells were isolated from peripheral blood samples. The mononuclear cells are not isolated from any other “lymphocyte containing biological sample.”
State of the art. Although the field of expressing of culturing T cells is highly developed, the
method of producing Tregs from PBMCs 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 that the purity of the Tregs can be improved, as the currently available GMP-grade isolation strategies result in a Treg cell below 50%, as evidenced by Ukena et al. (Ukena SN et al. Isolation strategies of regulatory T cells for clinical trials: phenotype, function, stability, and expansion capacity. Exp Hematol. 2011 Dec;39(12):1152-60. doi: 10.1016/j.exphem.2011.08.010. Epub 2011 Aug 22. PMID: 21864487.) (pg. 1158, left column, first paragraph).
Further, it was known in the art that the global T cell transcriptome is sensitive to changes induced by magnetic or flow sorting, and thus, the naïve T cells need to be rested before stimulating the T cells, as evidenced by Schmidt et al. (Schmidt, A. et al. Time-resolved transcriptome and proteome landscape of human regulatory T cell (Treg) differentiation reveals novel regulators of FOXP3. BMC Biol 16, 47 (2018).) (pg. 19, right column, first paragraph).
It was also known in the art that Tregs are extremely sensitive to variations in temperature, which can affect viability, recovery, and functionality, such that temperature control is a critical aspect of Treg sample handling, as evidenced by Ehrhardt and Thompson. (Ehrhart and Thompson, Innovative Temperature Standardization Technology supports Cell Therapy Clinical Trials, March, 2015, https://drug-dev.com/standardization-technology-innovative-temperature-standardization-technology-supports-cell-therapy-clinical-trials/). (Regulatory T cells, second paragraph).
Amount of Experimentation Required. Given the unpredictability of the art, the poorly
developed state of the art and the sensitivity of the Tregs in regards to culturing and handling, and the low levels of purity of the Tregs produced in using GMP-grade isolation strategies, the skilled artisan would have to conduct undue, and unpredictable experimentation to practice the claimed invention to produce Tregs from CD4+,CD25+,CD127-/low T cells. Further, due to the lack of specific guidance in the specification for the culture conditions that produce the Tregs that are CD4+,FOXP3+,HELIOS+ and have demethylated TSDR, 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 1-3, 5-8,and 24 under 35 USC § 112(a)
Applicant’s arguments filed 10 June, 2025 have been fully considered but they are not persuasive. Applicant essentially asserts (a) the claims have been amended to overcome the rejection, and the specification also teaches one skilled in the art how to isolate these cells from a biological sample comprising mononuclear cells (Remarks, pg. 8 and 9).
Regarding (a), Applicant’s arguments are not persuasive. The as-Filed Specification only teaches how to isolate these mononuclear cells from peripheral blood. One of ordinary skill in the art would know that mononuclear cells can also be isolated from tissues, as evidenced by Ryon. (Ryon, J.J. (1991), Isolation of Mononuclear Cells From Tonsillar Tissue. Current Protocols in Immunology, 00: 7.8.1-7.8.3.). Ryon teaches the isolation of mononuclear cells from tonsillar tissue, spleen, and lymph nodes (Abstract). The as-Filed Specification only teaches the isolation of mononuclear cells from peripheral blood samples. Thus, the rejection is maintained.
Conclusion
Claims 1, 3, 6- 8, and 24 remain rejected.
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 extension fee 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VYOMA SHUBHAM TIWARI whose telephone number is (571)272-2954. The examiner can normally be reached M-F 8:30 - 5:30 EST.
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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.
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Examiner Suggestions
In order to advance prosecution, Examiner suggests amending the claim 1 to include the source of the mononuclear cells that are used to produce the Tregs.
/VYOMA SHUBHAM TIWARI/Examiner, Art Unit 1634
/MARIA G LEAVITT/Supervisory Patent Examiner, Art Unit 1634
Prosecution Insights