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 .
Continued Examination Under 37 CFR 1.114
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/4/26 has been entered.
Claim Amendment
2. Applicant’s response to the Final Action dated 11/5/25 is acknowledged (paper filed 2/4/26). In the reply filed therein claim 27 was amended. Claims 1-26, 34-60, and 63 have been canceled without prejudice or disclaimer. Currently claims 27-33 and 61-62 are pending and under consideration.
3. Rejections and/or objections of record not reiterated herein have been withdrawn.
Priority
4. The priority date for the instant application is March 21, 2019. This application is a continuation of PCT Application No. PCT/US2020/023747, filed March 20, 2020, where the PCT claims priority to US Provisional Application No. 62/821,641, filed on March 21, 2019.
NEW GROUNDS OF REJECTIONS NECESSITATED BY AMENDMENTS
Claim Rejections - 35 USC § 103
5. 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.
I. Claims 27-33 is/are rejected under 35 U.S.C. 103 as being unpatentable over Diamond et al. (W097/12035) in view of Hara et al. (Transplant International 21, 2008, pages 1163-1174) and further in view of Wang et al. (Clinical Immunology, Vol.162, 2016, pages 37-44) and Stites et al. (The Journal of Immunology, Vol.195, Issue 12, 12/2015, pages 5525-5531).
Diamond et al. teach methods for the preparation and use of transgenic animals and recombinant xenogeneic cells so as to reduce or prevent antibody-mediated and complement-mediated rejections, including hyperacute rejection, following xenotransplantation, and specifically for reducing or preventing antibody-mediated and complement-mediated rejection following xenotransplantation which comprises the preparation of transgenic animals whose cells and tissues express a gene coding for an enzyme such as α(1,2)fucosyltransferase, α(2,6)sialyltransferase, β(1,3)N-acetylglucosaminyltransferase, or other suitable glycosyltransferase that will mask or reduce the level of the antigenic gal epitope, along with a gene that is capable of expressing a complement inhibiting protein, such as CD59, DAF, and/or MCP or other complement inhibitors, so as to produce organs, tissues, cells and non-viable
components that reduce or eliminate antibody- or complement-mediated rejections following xenotransplantation. The invention also relates to the transgenic organs, tissues, cells and non-viable components produced by this method which express a plurality of complement inhibiting proteins and to methods of xenotransplantation using organs, tissues, cells and non-viable components from the transgenic animals prepared in accordance with the invention.
Diamond et al. disclose that hyperacute rejection in transplants of organs from pigs to humans or other primates, is the initiation of antibody-mediated rejection usually characterized by thrombosis, hemorrhage and edema, and almost invariably result in a decline in graft function and irreversible rejection within a period of a few minutes to a few hours following transplantation. It has been generally observed that this process is initiated by the binding of xenoreactive natural antibodies (or XNAs) to the carbohydrate structures present on the endothelial cells of the graft which in turn leads to the activation of the complement cascade.
Therefore the researchers provided transgenic animals that are useful in xenotransplantation because of their ability to achieve substantial reductions in both XNA binding and subsequent complement activation following transplantation, and thus reduce or prevent antibody-mediated rejections, such as hyperacute rejection, and complement-mediated rejection when transplanted into human patients.
Diamond et al. also disclose that it is known that complement activation plays a critical role in antibody-mediated rejections. And the involvement of complement in the antibody-mediated rejection process has been dramatically demonstrated by exogenous inhibition of host complement activity prior to xenotransplantation.
“Two independent groups have shown that inhibition of host complement prior to transplantation leads to prolonged xenograft survival”. Xenografts which would normally be rejected in a few hours have been maintained for days and weeks if the host complement is continuously suppressed.
Diamond et al. differ from the instant invention in not specifically conducting CDC analysis on the genetically modified non-human donor cells and/or a sample isolated from the patient.
However, Hara et al. teach that successful xenotransplantation requires pigs with multiple genetic modifications. In their research, sera from healthy humans were tested by (i) flow cytometry for binding of IgM/IgG, and (ii) CDC assay against peripheral blood mononuclear cells and porcine aortic endothelial cells from five types of pigs – WT, GTKO, GTKO transgenic for H-transferase (GTKO/HT), WT transgenic for human complement regulatory protein CD46 (CD46) and GTKO/ CD46. There was significantly higher mean CDC to WT than to GTKO, GTKO/HT, CD46, and GTKO/CD46 cells. Lysis of GTKO/CD46 cells was significantly lower than that of GTKO or CD46 cells. CD46 expression provided partial protection against serum from a baboon sensitized to a GTKO pig heart. GTKO/CD46 cells were significantly resistant to lysis by human serum and sensitized baboon serum.
The greatest protection from CDC was obtained by the combination of an absence of Gal expression and the presence of CD46 expression. Organs from GTKO/CD46 pigs are likely to be significantly less susceptible to CDC. See abstract and figures 2-4. Less than 25% cytotoxicity was seen in GTKO/CD46 cells. See figure 6.
The research suggests that GTKO pigs (non-human) transgenic (genetically engineered) for human CD46 are likely to be less susceptible to human serum CDC as a result of both reduced binding of antibody and increased resistance to complement-mediated injury. Page 1172, 2nd paragraph.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to utilize a CDC analysis on cells involved in transplant procedures as taught by Hara et al. in the transplant assay methods of Diamond et al. because Hara et al. suggests that GTKO pigs (non-human) transgenic (genetically engineered) for human CD46 are likely to be less susceptible to human serum CDC as a result of both reduced binding of antibody and increased resistance to complement-mediated injury. Page 1172, 2nd paragraph.
One skilled in the art would have been motivated to reduce CDC cytotoxicity on the genetically modified cells as a means for improving organ transplantation.
Diamond et al. in view of Hara et al. differ from the instant invention in not specifically teaching steps (b), (i) and (ii).
However, Wang et al. teach a method of utilizing an SV40-immortalized porcine aortic endothelial cell line iPEC as a target and human or NHP sera as sources of xenoreactive natural antibodies and complement to test the feasibility and effectiveness of the porcine cell lysis model in evaluating the complement inhibitory activity of Cp40 in human serum and have also compared the effects of Cp40 in different primate species. Page 38, 1st column.
Wang et al. disclose that “in the situation of pig-to-human xenotransplantation, the complement cascade is mainly activated via the classical pathway”. In their in vitro CDC model, the researchers monitored the deposition of C3b/iC3b, C4b/iC4b, and C5b-9 on iPECs after incubation with Cp40-treated or untreated NHS. The results showed that Cp40 pretreatment almost completely inhibited the deposition of C3b/iC3b and C5b-9 but not of C4b/iC4b, confirming inhibition at the level of C3. Page 43.
The assay used in this study most closely reflects the clinical context of xenotransplantation, in which perfusion of non-human organs with human blood typically induces a strong inflammatory reaction that leads to rejection. To overcome the shortage of human donor organs, a large body of research has been performed to establish pigs as suitable donors. However, the binding of natural antibodies to α-Gal epitopes on endothelial cells with subsequent activation of complement and downstream inflammatory reactions remains a critical complication.
Besides the use of genetically modified pigs that do not express α-Gal and/or express human complement regulators, therapeutic intervention at the complement level is considered a promising strategy to enable xenotranplantation.
Compstatin analogs, including Cp40, have previously shown efficacy in ex vivo and in vitro models of xenotransplantation. See pages 43-44.
Pretreatment of the human serum with Cp40 almost completely inhibited the deposition of C3 fragments and C5b-9 on the cells, resulting in a dose-dependent inhibition of CDC against the iPECs. See abstract.
Wang et al. demonstrated that a simple and reliable method based on an in vitro xenoantibody-mediated complement dependent cell lysis with a porcine aortic endothelial cell line as targets can be used to evaluate the complement inhibitory activity of complement-directed drug candidates. The method was found to be highly reproducible and could be successfully translated for evaluating inhibitory efficacy.
Besides the efficacy monitoring of complement inhibitors, the method may also be used to study functional mechanisms of complement activation and modulation as revealed by the differential effect on C3, C4, and C5 fragment deposition in the presence and absence of Cp40. And human endothelial cells often become targets of complement activation under disease conditions, for example during allotransplantation and ischemia–reperfusion injury but also as part of thrombotic microangiopathies and C3 glomerulopathies. See page 44.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to utilize the method taught by Wang et al. to analyze the genetically engineered cells and/or patient cells exemplified by Diamond et al in view of Hara et al. because Wang et al. teaches that their method based on an in vitro xenoantibody-mediated complement dependent cell lysis with a porcine aortic endothelial cell line as targets was simple and reliable. The method was found to be highly reproducible and could be successfully translated for evaluating inhibitory efficacy, monitoring the efficacy of complement inhibitors, to study functional mechanisms of complement activation and modulation as revealed by the differential effect on C3, C4, and C5 fragment deposition in the presence and absence of Cp40.
And because human endothelial cells often become targets of complement activation under disease conditions, for example during allotransplantation and ischemia–reperfusion injury but also as part of thrombotic microangiopathies and C3 glomerulopathies), the method has broader clinical impact. See page 44.
One skilled in the art would have been motivated to employ the method of Wang et al. in order to evaluate possible drug candidates for disease treatments.
Although, Diamond et al. in view of Hara et al. and further in view of Wang et al. disclose procedures for evaluating lysis in transplant procedures, they do not specifically recite that said “lysis indicates the potential transplant recipient patient expresses donor reactive antibodies that could prevent transplant acceptance by the patient”.
However, Stites et al. teach that (Abs) antibody-mediated rejection (AMR) is a clinical and histopathologic diagnosis based on detection of allograft dysfunction with evidence of endothelial inflammation, and it is mediated by circulating Abs directed against donor Ags (antigens) in the allograft. Recipients of organs that are mismatched can develop Abs (referred to as donor-specific Abs, or DSA) that bind Ags (antigens) on the surface of endothelial cells in the microvasculature and activate the classical pathway of complement (Fig. 1A). page 5525. Stites et al. also disclose that DSA lymphocyte lysis is critical in determining transplant success. See page 5527, 2nd column – page 5528. “Consequently, the overall tendency of DSA to cause injury varies over time, and the diagnosis of AMR requires the detection of DSA in serum and microvascular injury and/or C4d deposition within the allograft.” Page 5529.
Absent evidence to the contrary it would have been prima facie obvious to measure DSA lysis to analyze transplant possible rejection/success as taught by Stites et al. because Stites et al. taught that DSA is a necessary tool for transplant analysis. See page 5529.
II. Claims 61-62 is/are rejected under 35 U.S.C. 103 as being unpatentable over Diamond et al. (WO 97/12035) in view of Hara et al. (Transplant International 21, 2008, pages 1163-1174) and further in view of Wang et al. (Clinical Immunology, Vol.162, 2016, pages 37-44), Stites et al. (The Journal of Immunology, Vol.195, Issue 12, 12/2015, pages 5525-5531) and Nguyen et al. (Xenotransplantation. 2011 ; 18(2): 94–107).
Please see Diamond et al. (WO 97/12035) in view of Hara et al. (Transplant International 21, 2008, pages 1163-1174) and further in view of Wang et al. (Clinical Immunology, Vol.162, 2016, pages 37-44) and Stites et al. (The Journal of Immunology, Vol.195, Issue 12, 12/2015, pages 5525-5531) as set forth above.
Diamond et al. (WO 97/12035) in view of Hara et al. (Transplant International 21, 2008, pages 1163-1174) and further in view of Wang et al. (Clinical Immunology, Vol.162, 2016, pages 37-44) and Stites et al. (The Journal of Immunology, Vol.195, Issue 12, 12/2015, pages 5525-5531) differ from the instant invention in not specifically teaching that the donor is a pig or flow cytometry analyses.
However, Nguyen et al. disclose that galactosyl transferase gene knock-out (GalTKO) swine offer a unique tool to evaluate the role of the Gal antigen in xenogenic lung hyperacute rejection.
The amount of antibodies inducing complement-dependent lysis of GalTKO cells was measured in peripheral blood mononuclear cells isolated from wild-type and GalTKO pigs then incubated with heat inactivated serum followed by complement, and cytotoxicity was quantified at various dilutions (1:2 to 1:512) by staining with 7-amino-actinomycin D (7-AAD).
Results were expressed as the per cent of cell lysis determined at the 1:2 serum dilution, corrected for background cytotoxicity in the absence of complement. See page 4. Antibodies were measured by flow cytometry, ELISA, or protein arrays. See pages 4-6.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to evaluate pig donors in flow cytometry measurements in the transplant techniques of Diamond et al. in view of Hara et al. and Wang et al. and Stites et al. because Nguyen et al. demonstrated that galactosyl transferase gene knock-out (GalTKO) swine offer a unique tool to evaluate the role of the Gal antigen in xenogenic lung hyperacute rejection. See abstract and page 1.
One skilled in the art would have been motivated to access GalTKO swine as a means to promote successfully transplants.
Response to Arguments
6. Applicant argues filed 2/4/26 were carefully considered but were not found persuasive for the following reasons:
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007).
In this case, Applicant contends that the cited references are directed to a patient that has already received a transplant. However, the reference to Diamond et al. teaches that Diamond et al. discloses that the involvement of complement in the antibody-mediated rejection process has been dramatically demonstrated by exogenous inhibition of host complement activity prior to xenotransplantation. And “two independent groups have shown that inhibition of host complement prior to transplantation leads to prolonged xenograft survival”. Xenografts which would normally be rejected in a few hours have been maintained for days and weeks if the host complement is continuously suppressed.
Stites et al. teaches that DSR (donor specific antibodies) can be detected in patients prior to transplant, patients with a previous transplant, or after a transplant. See page 5525, 2nd column, 1st paragraph.
While, Hara et al. disclose that GTKO pigs (non-human) transgenic (genetically engineered) for human CD46 are likely to be less susceptible to human serum CDC as a result of both reduced binding of antibody and increased resistance to complement-mediated injury [possibly allowing for successful xenotransplants]. Page 1172, 2nd paragraph.
Applicant contends that the cited prior art does not teach a pre-transplant screening method measuring sensitized donor cell to evaluate recipient antibodies to determine xenotransplant potential for a recipient. This argument was not found persuasive because Stites et al. has been added to disclose the limitation. In particular, Stites et al. disclose that DSA lymphocyte lysis is critical in determining transplant success. See page 5527, 2nd column – page 5528. “Consequently, the overall tendency of DSA to cause injury varies over time, and the diagnosis of AMR requires the detection of DSA in serum and microvascular injury and/or C4d deposition within the allograft.” Page 5529. Additionally, Stites et al. teaches that DSR (donor specific antibodies) can be detected in patients prior to transplant, patients with a previous transplant, or after a transplant. See page 5525, 2nd column, 1st paragraph.
Applicant contends that the motivation provided by Wang was a motivation “to employ the method of Wang to evaluate possible drug candidates for disease treatments.” However, the presently claimed methods are not methods of evaluating possible drug candidates.
Rather, the presently claimed methods provide a solution to a different problem, that is the problem of determining whether a potential human transplant recipient patient expresses donor reactive antibodies (pre-transplant measurements). Thus, the Office Action does not establish a motivation relating to the actual subject matter claimed.
In response to applicant's argument that the motivation to combine is different from Applicant, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the 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).
In response to applicant's arguments, it is noted that the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, Diamond et al. teach methods for the preparation and use of transgenic animals and recombinant xenogeneic cells so as to reduce or prevent antibody-mediated and complement-mediated rejections, including hyperacute rejection, following xenotransplantation,… Therefore the researchers provided transgenic animals that are useful in xenotransplantation because of their ability to achieve substantial reductions in both XNA binding and subsequent complement activation following transplantation, and thus reduce or prevent antibody-mediated rejections, such as hyperacute rejection, and complement-mediated rejection when transplanted into human patients. Diamond et al. differ from the instant invention in not specifically teaching CDC analysis. However, the reference to Hara et al. demonstrates increased sensitivity of genetically engineered animals over WT analysis. While, Wang et al. contemplate “pig-to-human xenotransplantation” (Applicant’s non-human donor to a potential human transplant recipient). The method uses an immortalized porcine aortic endothelial cell line (iPEC) as target (non-human donor cells) to evaluated the feasibility and effectiveness of an in vitro xenoantibody-mediated complement-dependent cytotoxicity (CDC) model for evaluating the complement inhibitory activity of Cp40, a potent analog of the peptidic C3 inhibitor compstatin.
The binding of human xenoantibodies (patient samples) to iPECs led to serum dilution-dependent cell death. Pretreatment of the human serum (patient samples) with Cp40 almost completely inhibited the deposition of C3 fragments and C5b-9 on the cells, resulting in a dose-dependent inhibition of CDC against the iPECs. See abstract and pages 43-44.
And Stites et al. discloses that DSA lymphocyte lysis is critical in determining transplant success. See page 5527, 2nd column – page 5528.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to utilize the CDC method taught by Wang et al. to analyze the genetically engineered cells exemplified by Diamond et al in view of Hara et al. because Wang et al. teaches that their method based on an in vitro xenoantibody-mediated complement dependent cell lysis with a porcine aortic endothelial cell line as targets was simple and reliable. And Stites et al. discloses that DSA lymphocyte lysis is critical in determining transplant success. See page 5527, 2nd column – page 5528.
One skilled in the art would have been motivated to employ the method of Stites et al. in order to evaluate the transplant procedures in Diamond et al. (Journal of Immunological Methods, Vol.456, 2018, pages 15-22) in view of Hara et al. (Transplant International 21, 2008, pages 1163-1174) and further in view of Wang et al. (Clinical Immunology, Vol.162, 2016, pages 37-44).
7. For reasons aforementioned, no claims are allowed.
8. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Lisa Cook whose telephone number is 571-272-0816. The examiner works a flexible Part-Time schedule but can normally be reached on Monday, Thursday, and Friday from 9am to 5pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Samira Jean-Louis, can be reached at telephone number 571-270-3503.
The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Lisa V. Cook
Patent Examiner
Art Unit 1642
Remsen
571-272-0816
6/8/26
/LISA V COOK/Primary Examiner, Art Unit 1642
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