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 .
Claims 1, 3-4, 6-7, 9-21, and 24-28, of record 8/13/2025, are pending. Claims 1, 4, 13-14, and 18 are amended. Claims 22-23 are cancelled. Claims 24-28 are withdrawn.
Declaration by Shahin Rafii and William Schachterle under 37 CFR 1.130
A declaration under 37 CFR 1.130, of record 8/13/2025, was filed to disqualify the prior art reference Schachterle et al. as being the work of the inventors of the instant application. The inventors assert that non-inventor authors on the Schachterle et al. paper were not involved inventing the subject matter of the claimed invention, a method of providing endothelial cells by expressing Sox17 from an exogenous nucleic acid in reprogramming-derived endothelial cells.
The declaration is sufficient to overcome the rejection of the pending claims based upon Schachterle et al. as set forth in the last Office Action.
Status of Prior Rejections/Response to Arguments
RE: Objection to claim 4:
The amendment to claim 4 is effective to obviate the objection. The objection is withdrawn.
RE: Rejection of claims 13-17 under 35 U.S.C. 112(b):
The amendment to claims 13-14 is effective to obviate the rejection. The rejection is withdrawn.
RE: Rejection of claims 1, 3, 6, 11, and 22-23 under 35 U.S.C. 102(a)(1) over Schachterle et al. (Nature Communications, 2017):
The cancellation of claims 22-23 renders the rejection thereto moot.
The declaration submitted under 37 CFR 1.130 is effective to obviate the rejection. The rejection is withdrawn.
RE: Rejection of claims 1, 3, 6-7, 9-11, and 13-23 under 35 U.S.C. 103 over Ginsburg et al. (Nature Protocols, 2015) in view of Nakajima-Takagi et al. (Blood, 2013), Clarke et al. (Nature Cell Biology, 2013), and Lee et al. (Circulation Research, 2014):
RE: Rejection of claims 1, 3-4, 6-7, and 9-23 under 35 U.S.C. 103 over Ginsburg et al. (Nature Protocols, 2015) in view of Nakajima-Takagi et al. (Blood, 2013), Clarke et al. (Nature Cell Biology, 2013), and Lee et al. (Circulation Research, 2014), further in view of Warren et al. (Cell Stem Cell, 2010):
RE: Rejection of claims 1, 3, 6-7, and 9-23 under 35 U.S.C. 103 over Ginsburg et al. (Nature Protocols, 2015) in view of Nakajima-Takagi et al. (Blood, 2013), Clarke et al. (Nature Cell Biology, 2013), and Lee et al. (Circulation Research, 2014), further in view of Cooke et al. (US 20150225699 A1):
The cancellation of claims 22-23 renders the rejection thereto moot.
The applicant asserts that enforced expression of Sox17 is required for the full range of mature endothelial cell functionality (Applicant Remarks, page 8-9). The applicant asserts that none of the prior art references teach, suggest, or provide motivation to express Sox17 in reprogramming-derived endothelial cells (Applicant Remarks, page 9). The applicant asserts that the observations of Nakajima-Takagi et al. do not support a conclusion that Sox17 would have improved engraftment (Applicant Remarks, page 9). The applicant asserts that Clarke et al. teach a different cell type and do not disclose increased engraftment (Applicant Remarks, page 10). The applicant asserts that Lee et al. teach that Sox17 promotes neovascularization rather than engraftment (Applicant Remarks, page 10). The applicant also asserts unexpected results in the form of enhanced engraftment and reperfusion (Applicant Remarks, page 11).
These arguments are not found persuasive. Ginsberg et al. teach the rAC-VECs generated by their methods are functionally durable and capable of long-term engraftment in mice (See page 1984, Anticipated Results, ¶3). As Ginsberg et al. do not use Sox17, it would appear that this transcription factor is not required for yielding endothelial cells that can engraft. Further, Ginsberg et al. are not required to suggest the use of Sox17. Motivation for the use of Sox17 is found in the teachings of Lee et al. and Clarke et al. Lee et al. are not relied upon for showing improved engraftment but rather for other advantages in expressing Sox17 in endothelial cells. Motivation to combine teachings need not be the same as the applicant’s. See MPEP 2144(IV). Additionally, Clarke et al. teach that Sox17 promotes the development and expansion of hemogenic endothelium from embryonic stem cells as well as its engraftment ability (See Abstract). Because hemogenic endothelial cells are a subset of vascular endothelial cells (See Antas et al., page 692, col. 1, ¶1), it would be reasonable for one of ordinary skill in the art, based on the teachings of Clarke et al., to conclude that increasing expression of Sox17 in developing endothelial cells may confer added benefits, particularly with respect to engraftment.
The instant claims require only an end product of endothelial cells that have enhanced engraftment via Sox17 expression. The lone difference between the method of Ginsberg et al. and the method of independent claim 1 is the constitutive expression of Sox17 from an exogenous nucleic acid for at least 20 days. A role in endothelial development, with a creditable link to engraftment, had already been ascribed to Sox17 expression prior to the effective filing date of the claimed invention, nullifying any assertion of unexpected results. One of ordinary skill would have had sufficient motivation for incorporating Sox17 into methods of generating endothelial cells, given the combined teachings of the prior art. Further, as Ginsberg et al. had already demonstrated that vessels formed from engraftment of implanted amniotic cell-derived endothelial cells generated in the absence of exogenous nucleic acid-expressed Sox17 were functional and perfused (See Ginsberg et al., 2012, page 567, col. 1, ¶1-2, of record in IDS dated 9/3/2019), one could readily anticipate that enhanced engraftment would likely be associated with enhanced reperfusion.
The rejections are maintained.
Maintained Rejections
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 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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, 3, 6-7, 9-11, and 13-21 remain rejected under 35 U.S.C. 103 as being unpatentable over Ginsburg et al. (Nature Protocols, 2015), of record, in view of Nakajima-Takagi et al. (Blood, 2013), of record, Clarke et al. (Nature Cell Biology, 2013), of record, and Lee et al. (Circulation Research, 2014), of record.
Regarding claims 1, 11, and 21: Ginsburg et al. teach a method of generating endothelial cells by reprogramming amniotic cells. The amniotic cells (which read on “non-vascular cells”) are transduced using lentiviral vectors for the expression of ETV2, FLI1, and ERG1 (which reads on “ERG”), with culturing in the presence of SB-431542 (which reads on “a TGF-β signaling inhibitor”) (See fig. 1 legend, lines 1-6). The reprogrammed vascular endothelial cells are termed rAC-VECs (See abstract and Fig. 1A). The rAC-VECs read on “reprogramming-derived endothelial cells”. The rAC-VECs express VE-cadherin, CD31, and VEGFR2 (See fig. 1 legend, lines 7-9). Ginsburg et al. do not teach constitutive expression of Sox17 in the cells for at least 20 days or the resulting characteristic of enhanced engraftment.
Lee et al. teach that Sox17 facilitates vascular sprouting by embryonic and post-natal endothelial cells, which suggests that Sox17 promotes neovascularization (See page 216, col. 2, full ¶5; page 218, col. 1, ¶1-2; and fig. 1-2). Lee et al. thus provide motivation for one to induce Sox17 expression in the rAC-VECs of Ginsburg et al.
Nakajima-Takagi et al. teach transduction of embryoid body cells with a retrovirus vector for the expression of Sox17 in order to promote hemogenic activity (See page 448, col. 2, full ¶2 and fig. 2-4). Nakajima-Takagi et al. teach lentiviral vector-mediated expression of Sox17 (which reads on “expressed constitutively”) from day 6 of culture to day 27 (which reads on “for at least 20 days”) for chromatin immunoprecipitation (See page 454, col. 1, ¶1). Chromatin immunoprecipitation data show enrichment of Sox17 occupancy at a number of genes involved in vasculogenesis in Sox17-transduced cells compared to control cells following 21 days of culture (See page 454, col. 2, ¶1; fig. 6a; and table 1). It would have been prima facie obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method of Ginsburg et al. to include a step of transducing the rAC-VECs with a Sox17 expression vector, such as is taught by Nakajima-Takagi, for improving functionality in endothelial cells. In addition to the motivation provided by Lee et al., one would have been further compelled to make this modification because Clarke et al. teach that expression of Sox17 is necessary for transplanted hemogenic endothelial cells to generate hematopoietic progeny cells (See page 504, col. 1, full ¶3 and fig. 2d). Clarke et al. demonstrate that progeny of Sox17-expressing donor cells can be detected in recipient mice 16 weeks after transplantation but Sox17-negative cell progeny are undetectable, which reads on “enhanced engraftment”, as donor cells must be able to integrate into existing blood vessels in order for their progeny to populate the hematopoietic niche (See page 504, col. 1, full ¶3 and fig. 2d). Given that Sox17 is required for the engraftment of at least one subset of endothelial cells, one would have been motivated to express it in other endothelial cells, such as rAC-VECs, to enhance engraftment. There would have been a reasonable expectation of success in modifying the method of Ginsburg et al. because the Sox17 expression vector of Nakajima-Takagi could be readily used to transduce the rAC-VECs of Ginsburg et al., followed by a duration of 21 days in culture to enhance the effects of Sox17. The rAC-VECs of Ginsburg et al. would be expected to respond to Sox17 similarly as the embryonic and post-natal endothelial cells of Lee et al. because Ginsburg et al. teach that amniotic cell-derived rECs possess an angiogenic and vascular functional profile and transcriptome that matches mature bona fide endothelial cells (See page 1976, col. 1, ¶2 and col. 2, ¶1). The teachings of Clarke et al. and Lee et al., therefore, indicate that the endothelial cells produced by the method of Ginsburg et al., modified by Nakajima-Takagi et al., would display enhanced engraftment by virtue of Sox17 expression.
Regarding claim 3: Following the discussion of claims 1, 11, and 21, Nakajima-Takagi et al. teach transduction of cells with a retroviral Sox17 vector (which reads on “transduced with a vector comprising a nucleic acid encoding Sox17 to achieve expression of Sox17”) (See page 448, col. 2, full ¶2 and fig. 2-4).
Regarding claims 6-7: Following the discussion of claims 1, 11, and 21, Ginsburg et al. teach culturing of rECs for 3-4 weeks (which reads on “cultured for a total duration of at least 28 days”) (See page 1976, col. 2, full ¶1). Ginsburg et al. also teach that rECs can be stably cultured through more than 15 passages (which reads on “cultured for a total duration of at least 42 days”, since the conversion protocol takes 21-28 days) (See page 1984, Anticipated Results, ¶3).
Regarding claims 9-10: Following the discussion of claims 1, 11, and 21, Ginsburg et al. teach transient expression of ETV2 for two weeks (which reads on “13-15 days”) and constitutive expression of FLI1 and ERG1 (which reads on “ERG”) (See page 1975, Abstract).
Regarding claim 13: Following the discussion of claims 1, 11, and 21, Ginsburg et al. teach culturing of the cells with a TGF-β inhibitor for three weeks (which reads on “present in the cell culture of the non-vascular cells for 20-24 days”) (See page 1975, Abstract).
Regarding claims 14-17: Following the discussion of claims 1, 11, 13, and 21, Ginsburg et al. teach treatment of the cells with the TGF-β signaling inhibitor SB-431542 (which reads on “specific for type I TGF-β receptors” and “small molecule compound”) (See fig. 1 legend, lines 1-6).
Regarding claim 18: Following the discussion of claims 1, 11, and 21, Ginsburg et al. teach culture of non-vascular cells with transient expression of ETV2 for the first two weeks (which reads on “for the first 13-14 days”), SB-431542 treatment for the first three weeks (which reads on “presence of a TGF-β signaling inhibitor for the first 20-21 days”), and constitutive expression of FLI1 and ERG (which reads on “ERG”) (See page 1975, Abstract).
Claims 1, 3-4, 6-7, and 9-21 remain rejected under 35 U.S.C. 103 as being unpatentable over Ginsburg et al. (Nature Protocols, 2015), of record, in view of Nakajima-Takagi et al. (Blood, 2013), of record, Clarke et al. (Nature Cell Biology, 2013), of record, and Lee et al. (Circulation Research, 2014), of record, further in view of Warren et al. (Cell Stem Cell, 2010), of record.
The teachings of Ginsburg et al., Nakajima-Takagi et al., Clarke et al., and Lee et al. are set forth above and are incorporated herein in their entirety.
Regarding claims 4 and 12: Following the discussion of claims 1, 3, 6-7, 9-11, and 13-21, Ginsburg et al., modified by Nakajima-Takagi et al., Clarke et al., and Lee et al. teach the production of endothelial cells from non-vascular cells but fail to teach the delivery of exogenous mRNA for the expression of Sox17, ETV2, FLI1, and ERG1 (which reads on “ERG”).
Warren et al. teach a method for making mRNA from plasmid DNA and its use in transfection (See page 626, col. 2, full ¶1; page 627, col. 1, ¶1-2; and fig. 1-2 and 5). It would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to modify the vector-generating DNA constructs of Ginsburg et al. and Nakajima-Takagi et al. encoding Sox17, ETV2, FLI1, and ERG1 for mRNA transfection. One would have been motivated to make this modification because Warren et al. teach that the use of mRNA is non-mutagenic, unlike some viral vectors, and is highly controllable for reprogramming cells (See page 619, col. 1, full ¶2). There would have been a reasonable expectation of success in doing so because the mRNAs could be readily used in place of lentiviral vectors and because Warren et al. demonstrate that their methods could be applied to multiple transcription factors and diverse cell types (See page 621, col. 1, full ¶2; page 627, col. 2, full ¶2; and fig. 2D and S2).
Claims 1, 3, 6-7, and 9-21 remain rejected under 35 U.S.C. 103 as being unpatentable over Ginsburg et al. (Nature Protocols, 2015), of record, in view of Nakajima-Takagi et al. (Blood, 2013), of record, Clarke et al. (Nature Cell Biology, 2013), of record, and Lee et al. (Circulation Research, 2014), of record, further in view of Cooke et al. (US 20150225699 A1), of record.
The teachings of Ginsburg et al., Nakajima-Takagi et al., Clarke et al., and Lee et al. are set forth above.
Regarding claim 12: Following the discussion of claims 1, 3, 6-7, 9-11, and 13-21, Ginsburg et al., modified by Nakajima-Takagi et al., Clarke et al., and Lee et al., teach the production of endothelial cells from non-vascular cells but do not teach the delivery of exogenous mRNA for the expression of ETV2, FLI1, and ERG1 (which reads on “ERG”).
Cooke et al. teach transfection with mRNAs encoding ETV2, FLI1, and ERG1 (which reads on ERG”) (See ¶0039). It would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method Ginsburg et al., modified by Nakajima-Takagi et al., Clarke et al., and Lee et al., by using mRNAs to express ETV2, FLI1, and ERG1, such as are taught by Cooke et al., for generating endothelial cells. One would have been motivated to make this modification because Cooke et al. teach that the use of mRNA avoids the risk of foreign DNA integration and provides greater control over transcription factor concentration and timing (See ¶0007). There would have been a reasonable expectation of success in doing so because the mRNAs could be readily used in place of lentiviral vectors and because Cooke et al. demonstrate that the mRNAs can be used to reprogram somatic cells into endothelial cells (See ¶0039 and 0078).
Conclusion
THIS ACTION IS MADE FINAL. 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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/J.S.S./Examiner, Art Unit 1633
/CHRISTOPHER M BABIC/Supervisory Patent Examiner, Art Unit 1633