DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicants’ amendments to the claims and arguments filed on July 30, 2026, have been received and entered. Claims 1, 4-6, 8-9, 12-13, 17-19, 24-25, 38 have been amended, while claims 2-3, 7,14-15, 20-23, 26-37, 39-41 have been canceled. Claims 42-47 have been newly added. Claims 1, 4-6, 8-13, 16-19, 24-25, 38, 42-46 and 47 are pending in the instant application.
Election/Restrictions
Applicants’ election without traverse of claims 1-27 (group I) in the reply filed on December 23, 2025, was acknowledged.
Newly submitted claim 47 is directed to an invention that is independent or distinct from the invention originally claimed for the following reasons: The newly added claim 47 is similar to previously withdrawn claims 32-33, 36-37 (group III) that was deemed distinct from the elected invention of group I for the reasons of record (see restriction mailed on 10/31/2025).
Since applicants have received an action on the merits for the originally presented invention, this invention has been constructively elected by original presentation for prosecution on the merits. Accordingly, claim 47 is withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03.
To preserve a right to petition, the reply to this action must distinctly and specifically point out supposed errors in the restriction requirement. Otherwise, the election shall be treated as a final election without traverse. Traversal must be timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are subsequently added, applicant must indicate which of the subsequently added claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
Claims 1, 4-6, 8-13, 16-19, 24-25, 38, 42-45 and 46 are under consideration.
Maintained & New -Claim Rejections - 35 USC § 112- necessitated by amendments
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 4-6, 8-13, 16-19, 24-25, 38, 42-45 and 46 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
In determining whether Applicant’s claims are enabled, it must be found that one of skill in the art at the time of invention by applicant would not have had to perform “undue experimentation” to make and/or use the invention claimed. Such a determination is not a simple factual consideration, but is a conclusion reached by weighing at least eight factors as set forth in In re Wands, 858 F.2d at 737, 8 USPQ 1400, 2d at 1404. Such factors are: (1) The breadth of the claims; (2) The nature of the invention; (3) The state of the art; (4) The level of one of ordinary skill in the art; (5) The level of predictability in the art; (6) The amount of direction and guidance provided by Applicant; (7) The existence of working examples; and (8) The quantity of experimentation needed to make and/or use the invention.
The office has analyzed the specification in direct accordance to the factors outlines in In re Wands. MPEP 2164.04 states: “[W]hile the analysis and conclusion of a lack of enablement are based on factors discussed in MPEP 2164.01(a) and the evidence as whole, it is not necessary to discuss each factor in written enablement rejection.” These factors will be analyzed, in turn, to demonstrate that one of ordinary skill in the art would have had to perform “undue experimentation” to make and/or use the invention and therefore, applicant’s claims are not enabled.
Nature of the Invention:
The claims are directed to a method of producing and using genetically modified (GM) pig organs for xenotransplantation that are personalized to a specific organ recipient and that do not require chronic immunosuppression following xenotransplantation. The specification describes before transplant, cells and factors from the intended human recipient are placed into the fetal pig donor while it is still developing. After the pig is born and develops, some of those recipient-derived cells are collected from the pig, expanded or enriched, and given back to the same human recipient. The specification highlights the concept that the recipient’s immune system becomes more acceptable of that specific pig and its organs.
Breadth of the claims:
The breadth of the claimed invention continues to encompass administering partially CD4+ and CD8+ depleted human cells comprising lymphocytes, hematopoietic stem cells, mesenchymal stem cells, and macrophages into the abdominal cavity and thymus of a pig fetus of any development age that may be homozygous, heterozygous KO of GGTAI, CMAH and B4GALNT2 or knockdown for the expression of GGTAI, CMAH or B4GALNT2 to extract viable human CD4+ T cells, B cells, and dendritic cells from blood, bone marrow, spleen, cord blood and lymph node. Claims further encompass administering any extent of depleted CD4+ CD8+ human cells (5% to 90% CD4CD8 depletion) that would prevent GvHD. The amended claims further encompass delivering partially CD4CD* depleted cells in absence of any survival and/or differentiation to the pig fetus to obtain and extract CD4+ and CD8+ human cell from blood or bone marrow. The specification fails to provide any evidence that such a xenotransplantation method would overcome the art recognized unpredictability. The disclosure provided by the applicant, in view of prior art, must encompass a wide area of knowledge to a reasonably comprehensive extent. In other word each of these, aspect must be shown to a reasonable extent so that one of the ordinary skills in the art would be able to practice the invention without any undue burden being on such Artisan.
Guidance of the Specification and The Existence of Working Examples:
The specification as filed provides a general description of conditions GM pig fetuses with specific cells and factors collected from the future organ recipient to make the pigs resulting from the treated fetuses more matched to the organ recipient, appearing more like self-tissue to the organ recipient. The specification contemplates that this would greatly reduce the anti-transplant reaction of the recipient and paves the way for xenotransplantation without the need for chronic immunosuppression (para. 8 of the specification). The specification prophetically contemplates the method also conditions the future organ recipient with specific recipient's cells and factors conditioned and collected back from the recipient-matched pig (the future organ donor) to prepare the organ recipient's immune system prior to organ transplantation. This completes the reduction of the anti-transplant reaction of the recipient allowing xenotransplantation without the need for chronic immunosuppression (see para. 8 of the specification). Figure 1 of the specification teaches schematic of Yucatan weight-age chart showing the pig weight varies no more than one standard deviation away from the average over time. Figure 2 is a schematic diagram showing the exemplary method of generating genetically modified pigs including GGTA−/−, CMAH−/−, B4GALNT2−/−, Xeno 3 pigs and GGTA−/−, CMAH−/−, B4GALNT2−/−, hTBM/hCD46/hCD55 Xeno 6 pigs. Figure 3 depicts a schematic diagram showing the transfer of cells and factors from an organ recipient to a fetal donor pig, where the fetal donor pig later serves as a source of both tolerance-inducing immunosuppressive cells and factors and a transplant organ. The specification prophetically contemplates using the cell therapy between human recipients and pig donors (transferring lymphocytes, stem cells and factors from the organ recipient and having those cells populate the GM donor fetus organs and then after delivery of the GM donor piglet and expansion and purification of these recipient's lymphocytes and stem cells, these cells are transferred back to the organ recipient prior to organ transplantation) allows a more humanized pig organ to be transplanted, as the pig organ has been repopulated with the recipient cells, such that the organ recipient develops tolerance and avoids the need for chronic immunosuppression (see para. 132). . Remaining specification discloses definition of terms, general description of biological method, and method of xenotransplant. Furthermore, it is noted that application states recipient subjects are typically, the subject is a human, such a human patient in need of treatment for a disease or disorder and organ failure. In some forms, the recipient has been identified as having, or as being at risk of having a disease. The disease can be chronic or acute. Exemplary diseases include congenital diseases of one or more organs or tissues. For example, in some forms, the recipient is a subject having a disease that causes end-stage failure of an organ, necessitating transplantation (see para. 188). In summary, the specification does not provide any specific guidance for the claimed invention because the specification as filed does not teach how human immune cells would respond to pig signal, how human cells would interact with the pig tissue following gene edit in the pig, how the microenvironment in gene edit pig would affect the human cells. Given this lack of reasonable predictability in specification and the art, the Artisan would require a large amount of information from Applicant’s examples to provide the guidance to provide reasonable predictability. An artisan would have to carry out extensive experimentation to make use the invention, without reasonable expectation of success.
State of the Art and Predictability of the Art and the Amount of Experimentation Necessary:
The claimed method encompasses transfer of a human recipient's cells that can further differentiate into regulatory lymphocytes, into a genetically modified pig fetus in which those human cells will eventually differentiate and mature into one or more of the following cells: foxP3+CD4+CD3+CO25+ natural T regulatory cells, adaptive CD4+CD49b+LAG3+CD226+ regulatory Tri cells, CD4+CD25-CD69+foxP3-LAP+ (TGFl3-producing type 3 helper T cells), and PO-L 1 human dendritic cells. Those cells are then isolated/purified/expanded postnatally and transferred back to the human recipient, in order to elicit immuno-tolerance against a pig organ that is later transplanted from the pig formerly used in the fetal stage into the human recipient. In the instance, neither specification nor prior art provides evidence and/or example that such a transplantation method would work.
The claimed method encompasses use of three gene knock-outs and optionally three human transgenes, without specifying any of those genetic modifications, resulting in a myriad of possibilities. The art teaches substantial knowledge gaps in understanding of adaptive pig-to-human immunity (see page 207, col. 1, para. 3, Schmauch et al Nature, 2026, 650, 205-217). The multi omics data from a genetically modified pig (GGTA KO) shows a complex immune response prior to tissue rejection. The results conclude that a complex network of interactions among diverse infiltrating human immune populations from both innate and adaptive compartments, interact not only with each other but also with resident pig immune cells and injured tubular cells. This multifaceted immune and inflammatory response, evident in both human and pig cells, was detected before histological sign of antibody mediated response (AMR) (See page 214, col. 1, para. 2). This study provides an extensive resource for understanding the dynamics and importance of inflammatory and tissue-repair archetypes, interactions with resident pig immune cells and infiltrating human immune cells comprising both the innate and adaptive immune systems of the recipient (See page 216, col. 1, para. 2). This study is further supported by the teaching of Pan (Med, 2024, 5, 1016-1029) who performed single-cell RNA sequencing and longitudinal RNA-seq analyses of the xenotransplantation using porcine of aGAL-KO kidney to dissect xenotransplantation-associated cellular dynamics and xenograft-recipient interactions (abstract). It is noted that while no hyperacute rejection signal was observed through standard histological analyses, results provide strong evidence that both kidney xenografts presented early signs of an AbMR phenotype at 54 h pXTx. The evidence obtained in this study includes (1) the infiltration and the activation of human macrophage and NK cells in the xenografts (Figures 2 and 3), (2) the detection of AbMR-associated marker gene expression through time-resolved RNA-seq of xenograft biopsies (Figure 3), (3) activation of endothelial cells in xenografts (Figure 3), and (4) the holistic xenograft tissue damage signals (Figure 4). Notably, these expression changes were not observed in the contralateral untransplanted kidneys that also experienced ischemia, indicating that the observed evidence reflects xeno transplantation-induced responses but not ischemic injury-induced effects. (See Med page 1025, para. 2). The breadth of instant claim recites using cells and factors of the organ recipient of any species (human) from blood and bone marrow for transplanting into a genetically modified donor pig fetus of any species, wherein the genetic modifications are limited to three known or yet to identified gene knockouts and, optionally, any three human transgenes. The claims as presented is not enabled because transgenic knock out of gene does not eliminate the immune response. In the instant specification provide prophetic guidance with respect to gene knock out of GGTA1, CMAH and B4GALNT2 in a Yucatan miniature pig (see pages 12-14 of the specification). However, Wang (J Biomed Res, 2018 Jul 11;33(4):235-243) reported “Human serum IgG and IgM binding decreased in some triple knock out (TKO) porcine tissues of heart, lung, and kidney, show that eliminating the reactivity of preformed human antibodies with those tissues can be achieved by gene targeting. However, comparable levels of IgG and IgM binding were observed in the liver, spleen, and pancreas of TKO and WT pig, suggesting that other immunoreactive xenoantigens such as swine leukocyte antigens (SLA) maybe the dominant xenoantigens in those organs (see page 242, col. 1, last para.). In fact, Shim (Transgenic Res 2021;30(5):619–634 ) teaches genetic modification of donor pigs for xenotransplantation should be tailored to the target organ and silencing of additional genes such s CMAH or A3GALT2 based on GTKO might not be essential in Yucatan miniature pigs (see abstract). These results clearly show even a specific GGTA1, CMAH and B4GALNT2 in a Yucatan miniature pig reduces antigen induced rejection but does not fully eliminate immune reactivity (emphasis added). The specification has not provided any specific guidance to use any genetically modified pig that removes all known or yet to be determined immune target and may require additional gene knockout. There is no evidence on record that the triple knockout pig model that is necessary to reduce immune response is sufficient and predictable for xenograft survival. An artisan would have to perform undue experimentation to first identify genes that need to be edited and then determine resulting knockout pig would fully eliminate immune reactivity for xenograft survival, without reasonable expectation of success.
Claims embrace delivering cells in absence of any survival and/or differentiation to the pig fetus to obtain and extract CD4+ and CD8+ human cell from blood. The specification prophetically contemplates transfer of a human recipient's cells (such as hematopoietic stem cells or mesenchymal stem cells) and know or yet to be identified factors, that can further expand and/or differentiate into regulatory lymphocytes. These cells are then isolated/purified/expanded postnatally and transferred back to the human recipient, in order to exert immuno-tolerance against a pig organ that is later transplanted from the pig formerly used in the fetal stage, into the human recipient. The art teaches he barrier to cell and tissue xenotransplantation is nonimmunological (Figure 1A). In fact, the ability of xenogeneic cells to “take” in a foreign microenvironment depends first on the ability to sustain angiogenesis. New growth of blood vessels may be impaired by incompatibility of donor cells and recipient growth factors (see page 439, col. 1, para. 3, to col. 2 to page 440, col. 1).. A cell or tissue xenograft might also fail to sustain angiogenesis due to nonresponsiveness of the recipient endothelium to donor angiogenesis factors (see Cascalho et al Immunity, Vol. 14, 437–446, 2001). The art teaches cell-specific differences on the role of both WNT and Hedgehog pathways in these lymphoid cells in pigs and humans. The art further teaches pig–human receptor–ligand incompatibilities (page 13, col. 1, para. 3) and therefore, it is expected that many of the pig cytokine are not likely to bind efficiently to the human receptor despite of lack of active immune response.
The specification provides prophetic guidance of factors and cells of the organ recipient that could be repopulated by mature T regulatory cells for eliciting immune tolerance as embraced by the breadth of the claim. Prior to instant invention, Shim (Xenotransplantation 2016: 23: 300-309) states “a well expanded regulatory T cells did not attain long term tolerance and was rejected by activated immune cells, particularly T cells following withdrawal of immunosuppressive drug” (see abstract, page 307, col. 1, last para.). The teaching of Shim clearly shows unpredictability in transplanting T reg cells to develop tolerance in xenotransplantation. Kalscheuer et al (The Journal of Immunology, 2014, 192: 3442–3450) reported suboptimal maintenance and homeostasis of human T cells generated in a porcine thymus graft (see fig. 6). The study shows human T cells generated in porcine thymus grafts are functional, self-tolerant, and specifically tolerant toward the porcine donor. Functional Tregs develop normally in the porcine thymus contribute to tolerance. However, human T cells generated in porcine thymus grafts demonstrate immune defects might be attributable to suboptimal post thymic interactions with human APCs following positive selection on porcine MHC (See page 3450, col. 2, last para.) .Porret ((2025) Front. Immunol. 16:1685682. 1-8) reported Treg therapy involves significant challenge as it is a complex area that is still under evaluation in allotransplantation. This the unique immunological context of xenotransplantation presents an opportunity to study Tregs ability to home to the graft ultimately reducing the burden of immunosuppression. Their efficacy should be confirmed in NHP xenotransplantation models, including the use of repeated infusions, ideally from allogeneic sources (see page 7, col. 1, last para). One of skill in the art would have to perform undue experimentation to make and use the invention, without reasonable expectation of success.
The claims as amended further encompasses administering partially CD4+ and CD8+depleted human cells into the abdominal cavity and thymus of a triple KO genetically modified pig fetus further comprising addition of at least 3 human transgenes including human Thrombomodulin (hTBM), human Membrane Cofactor Protein (hCD46), and human Decay Accelerating Factor for Complement (hCD55). The specification is silent on extent, level and duration of human gene(s) expression in triple knock out pig. It is emphasized that the art reported that “it is crucial to note that more genetic editing does not necessarily equate to better outcome. The selection of gene combinations and the expression levels of genes significantly affect the final results (see Huai Frontiers in Immunology, 2025, 15:1488552, 1-15, page 11, col. 2, para. 2). The art reported “the factors contributing to rejection in the first case of heart xenotransplantation completed by the UMSOM research team were extensive damage to endothelial cells and capillaries, leading to interstitial edema, erythrocyte extravasation, and complement deposition, suggesting antibody-mediated rejection. Although 10-gene pigs were used, the expression levels of CD55 and CD46 may not have been sufficiently high to achieve the desired outcomes (see reference cited therein Griffith et al . N Engl J Med. (2022) 387:35–44). This discrepancy might be related to the expression levels of the transferred genes” (see page 11, col. 2, last para. to page 12, para. 1). Huai concludes that the high level of transferred genes does not inherently guarantee improved outcomes (emphasis added) Further validation is required to elucidate the relationship between expression levels and the efficacy of transferred genes, particularly in the context of multiple gene edits as required by the instant claims. The art continues to teach impact of gene editing on infection risk primarily depends on the specificity of the edited genes. Evidence from existing studies suggests that certain pathogens can exploit complement receptors to invade host cells. For hTM, no literature has yet reported their roles as targets for viral or bacterial pathogens (see page 12, col. 1, para. 1) . In the instant case, neither instant specification nor prior art provided any specific guidance that provides of level of expression from at least 3 transferred genes as required by the claims. It is emphasized that expression level in a specific genetically modified pig disclosed in prior art expressing specific human gene at a specific level was sufficiently unpredictable as evident from the teaching of Huai so that a person skilled in the art would not have believed that the success with any one or more gene in a specific triple KO pig could be extrapolated successfully to at least three gene that could include additional known or yet to be identified gene. The specification does not teach transferring partially depleted CD4+ and CD8+ T human cells into pig fetus of any development state, using a genetically modified pig comprising knockout or down-regulation of GGTA1 , CMAH and B4GALNT2; and further comprising at least one or two or three human transgene that may or may not express transgene or introducing the partially CD4, CD8 depleted cell in absence of any factor/survival/signal into a triple KO pig fetus of any development state such that cell undergo differentiation and maturation in plurality of different cells type in utero, or extracting after completion of gestation and delivery of the pig fetus, viable human CD4+ T cells, B cells, and dendritic cells from the delivered pig. An artisan would have to perform undue experimentation to make and use the invention, without reasonable expectation of success.
In conclusion, in view of breadth of the claims and absence of a strong showing by Applicant, in the way of specific guidance and direction, and/or working examples demonstrating the same, such invention as claimed by Applicant is not enabled for the claimed inventions. An artisan of skill would have required undue experimentation to practice the invention, without reasonable expectation of success as supported by the observations in the art record.
Response to arguments
Applicants disagree with the rejection arguing the process involves producing chimeric pig organs and chimeric immune cells, i.e., viable human cells derived from a subject ("recipient"), that have been partially depleted of CD8+ T cells and CD4+ T cells and transported into and matured within the immune-privileged environment of a fetal donor pig. The fetal environment, together with the genetic modifications required by the claims, will permit growth, maturation and expansion of the human cells as the fetus develops and is delivered. The guidance in the specification is clear that, following gestation and birth, viable human cells can readily be isolated from the piglet, depleted of pig cells, and the remaining human cells expanded in vitro. Applicant argues that there is a reasonable amount of predictability that the claimed methods will provide a population of modified "chimeric" immune cells that have been exposed to/matured within the antigenic environment of the donor and can be given back to the human subject prior to receiving the chimeric pig organ from the donor pig. Applicants continue to argue that amended claims do not require any specific response to "pig signal," nor do they require that the human cells interact in any specific manner with any specific tissues associated with a specific genotype or microenvironment. All that is required is that a population of viable human cells is isolated from a recipient, partially depleted of specific (CD4+/CD8+) cell types, and then administered into a pig fetus in utero, subsequently extracted from the same pig from one or more of blood, bone marrow, spleen, cord blood and lymph nodes following birth. Applicants’ arguments have been fully considered but are not found persuasive.
In response, the breadth of the claims continue to encompass administering partially CD4+ and CD8+ depleted human cells comprising lymphocytes, hematopoietic stem cells, mesenchymal stem cells, and macrophages into the abdominal cavity and thymus of a pig fetus of any development age that may be homozygous, heterozygous KO of GGTAI, CMAH and B4GALNT2 or knockdown for the expression of GGTAI, CMAH or B4GALNT2 to extract viable human CD4+ T cells, B cells, and dendritic cells from blood, bone marrow, spleen, cord blood and lymph node. In the instant case, specification fails to enable administering viable human cells derived from a subject ("recipient"), that have been partially depleted of CD8+ T cells and CD4+ T cells and matured within the immune-privileged environment of a fetal donor pig of any development age as embraced by the breadth of the claims. The fetal immune system of fetal pigs is functional and active at late gestational stage of development. It is expected that any delivery of viable human cells into a late gestational stage pig having active functional immune system would reject CD4+ and CD8+ depleted viable human cells. It is relevant to note that the prophetic guidance provided in the specification is limited to using a genetically modified pig whose genome comprises (i) a homozygous inactivation of (i) GGTA −/−, (ii) CMAH−/−, B4GALNT2−/−, and a nucleic acid encoding human thrombomodulin, human CD46. None of the pending claims are so limited. It is emphasized that pigs that are heterozygous for inactivation of GGTA, CMAH and B4GALNT or down-regulated for GGTA, CMAH and B4GALNTexpression would continue to express different levels of glycan xeno antigen (alpha-Gal, Neu5Gc ad Sda carbohydrate) on its vascular endothelium thereby eliciting unpredictable cascade of immune responses. In the instant case, none of the pending methods requires use of a pig whose genome comprises (i) a homozygous inactivation of (i) GGTA −/−, (ii) CMAH−/−, B4GALNT2−/−, and a nucleic acid encoding human gene such as human thrombomodulin, human CD46 and human CD55 to make and use the invention. In fact, prior art summarized by the reference of Wang (J Biomed Res, 2018 Jul 11;33(4):235-243, art of record) reported “Human serum IgG and IgM binding decreased in some triple knock out (TKO) porcine tissues. However, comparable levels of IgG and IgM binding were observed in the liver, spleen, and pancreas of TKO and WT pig, suggesting that other immunoreactive xenoantigens such as swine leukocyte antigens (SLA) maybe the dominant xenoantigens in those organs (see page 242, col. 1, last para.)., Shim (Transgenic Res 2021;30(5):619–634, art of record) teaches genetic modification of donor pigs for xenotransplantation should be tailored to the target organ and silencing of additional genes that might not be essential in Yucatan miniature pigs (see abstract). These results clearly show even a specific GGTA1, CMAH and B4GALNT2 in a Yucatan miniature pig that reduces antigen induced rejection but does not fully eliminate immune reactivity (emphasis added). Additionally, the specification fails to provide any guidance for the required minimal threshold of partially depleted CD4+ CD8+ human cells that would prevent GvHD. Further, there is no evidence on record that a partially depleted CD4+ CD8+ human cell population would prevent the human xenograft from an immunocompetent late-stage heterozygous or homozygous KO (triple knockout) pig fetus as embraced by the breadth of the claims. In the instant case, neither specification nor prior art provide any specific guidance to overcome this art recognized unpredictability. An artisan would have to perform undue experimentation to make and use the invention, without reasonable expectation of success.
On page 15 of applicants’ argument, applicants assert that ultimate aim of the claimed methods is to develop a population of modified host-derived immune cells, which are matured within a fetal donor pig, extracted and expanded in vitro. The modified immune cells, once administered into the transplant recipient from which they were initially derived, provide an interface between the transplant and the donor, with a view to providing improved immunomodulation within the recipient. Applicants continue to argue that the specification as filed, the long-term prognosis for organ transplant recipients receiving contemporary standard or care treatment regimens is extremely poor, with intensive immunosuppressive therapy required to prevent rejection, often leading to fatal infections. Each of these aspects of the claimed methods are shown to a reasonable extent so that one of the ordinary skills in the art would be able to practice the invention without any undue burden. Applicants’ arguments have been fully considered but are not found persuasive.
In response, it is noted that amended claims recite administering partially CD4+ and CD8+ depleted human cells into the abdominal cavity and thymus of the triple KO pig fetus of any development stage. The specification fails to enable the claimed method of administering partially CD4+ and CD8+depleted human cells without administering specific survival signal/factors. The art teaches he barrier to cell and tissue xenotransplantation is nonimmunological (Figure 1A). In fact, the ability of xenogeneic cells to “take” in a foreign microenvironment depends first on the ability to sustain angiogenesis. New growth of blood vessels may be impaired by incompatibility of donor cells and recipient growth factors (see page 439, col. 1, para. 3, to col. 2 to page 440, col. 1).. A cell or tissue xenograft might also fail to sustain angiogenesis due to non-responsiveness of the recipient endothelium to donor angiogenesis factors (see Cascalho et al Immunity, Vol. 14, 437–446, 2001). The art teaches cell-specific differences on the role of both WNT and Hedgehog pathways in these lymphoid cells in pigs and humans. The art further teaches pig–human receptor–ligand incompatibilities (page 13, col. 1, para. 3) and therefore, it is expected that many of the pig cytokine are not likely to bind efficiently to the human receptor despite of lack of active immune response. In view of foregoing, it is apparent that absence of specific factors, the administered human cells in the pig fetus of any developmental stage is likely to respond inefficiently to the environmental cues in the recipient organism (pig fetus) (see page 13, col. 1, para. 3, Bailey et al Experimental Hematology, 2026, 1-17). This is further evidenced by Rashid et al (Cell Stem Cell, 2014, 15, 406-409) who reported presence of very small numbers of donor human cells in pig tissue will in our opinion never make a humanized pig unless the relevant organ niche is provided” (see page 408, col. 3, last para). Further, as stated in previous office action, prior to instant invention, Shim (Xenotransplantation 2016: 23: 300-309) states “a well expanded regulatory T cells did not attain long term tolerance and was rejected by activated immune cells, particularly T cells following withdrawal of immunosuppressive drug” (see abstract, page 307, col. 1, last para.). The teaching of Shim clearly shows unpredictability in transplanting T reg cells to develop tolerance in xenotransplantation. Kalscheuer et al (The Journal of Immunology, 2014, 192: 3442–3450) reported suboptimal maintenance and homeostasis of human T cells generated in a porcine thymus graft (see fig. 6). The study shows human T cells generated in porcine thymus grafts are functional, self-tolerant, and specifically tolerant toward the porcine donor. Functional Tregs develop normally in the porcine thymus contribute to tolerance. However, human T cells generated in porcine thymus grafts demonstrate immune defects might be attributable to suboptimal post thymic interactions with human APCs following positive selection on porcine MHC (See page 3450, col. 2, last para.). Porret (2025) Front. Immunol. 16:1685682. 1-8) reported Treg therapy involves significant challenge as it is a complex area that is still under evaluation in allotransplantation. The instant specification does not provide additional guidance to overcome art recognized unpredictability. An artisan would have to perform undue experimentation to first identify specific survival signal/factors/cytokine and growth factors to facilitate survival and differentiation of partially CD4CD8 depleted human cells as embraced by the breadth of the claims, without reasonable expectation of success.
The claims as amended further encompasses administering partially CD4+ and CD8+depleted human cells into the abdominal cavity and thymus of a triple KO genetically modified pig fetus further comprising addition of at least 3 human transgenes including human Thrombomodulin (hTBM), human Membrane Cofactor Protein (hCD46), and human Decay Accelerating Factor for Complement (hCD55). The guidance provided in the specification is limited to use a prophetic as genetically engineered pigs lacking the expression of GGTA1, CMAH, and B4GALNT2 are further modified to express one or more human transgenes such as human thrombomodulin, CD46, and CD55 (see page 6 of the specification). It is relevant to note that specification is silent on extent, level and duration of human gene(s) expression in triple knock out pig. It is emphasized that the art reported that “it is crucial to note that more genetic editing does not necessarily equate to better outcome. The selection of gene combinations and the expression levels of genes significantly affect the final results (see Huai Frontiers in Immunology, 2025, 15:1488552, 1-15, page 11, col. 2, para. 2). The art reported “the factors contributing to rejection in the first case of heart xenotransplantation completed by the UMSOM research team were extensive damage to endothelial cells and capillaries, leading to interstitial edema, erythrocyte extravasation, and complement deposition, suggesting antibody-mediated rejection. Although 10-gene pigs were used, the expression levels of CD55 and CD46 may not have been sufficiently high to achieve the desired outcomes (see reference cited therein Griffith et al . N Engl J Med. (2022) 387:35–44). This discrepancy might be related to the expression levels of the transferred genes” (see page 11, col. 2, last para. to page 12, para. 1). In our 6GE pigs, the expression level of hCD55 in Peripheral blood is seven times higher than in humans, with in vitro results showing a CDC close to zero, suggesting that the higher expression levels of hCD55 can indeed reduce CDC. For coagulation system, the expression of hTM and hEPCR is also varied and controversial. (see references cited therein, page 12, col. 1, para. 1). Huai concludes that the high level of transferred genes does not inherently guarantee improved outcomes (emphasis added) Further validation is required to elucidate the relationship between expression levels and the efficacy of transferred genes, particularly in the context of multiple gene edits as required by the instant claims. The art continues to teach impact of gene editing on infection risk primarily depends on the specificity of the edited genes. Evidence from existing studies suggests that certain pathogens can exploit complement receptors to invade host cells. For hTM, no literature has yet reported their roles as targets for viral or bacterial pathogens (see page 12, col. 1, para. 1) . In the instant case, neither instant specification nor prior art provided any specific guidance that provides of level of expression from at least 3 transferred genes as required by the claims. It is emphasized that expression level in a specific genetically modified pig disclosed in prior art expressing specific human gene at a specific level was sufficiently unpredictable as evident from the teaching of Huai so that a person skilled in the art would not have believed that the success with any one or more gene in a specific triple KO pig could be extrapolated successfully to at least three gene that could include additional known or yet to be identified gene. The specification does not teach transferring partially depleted CD4+ and CD8+ T human cells into pig fetus of any development state, using a genetically modified triple KO pig; and further comprising at least one or two or three human transgene that may or may not express said human transgene or introducing the partially CD4, CD8 depleted cell in absence of any factor/survival/signal into a triple KO pig fetus of any development state such that cell undergo differentiation and maturation in plurality of different cells type in utero, or extracting after completion of gestation and delivery of the pig fetus, viable human CD4+ T cells, B cells, and dendritic cells from the delivered pig. The specification is silent on producing any enriched, expanded and/or purified viable human cells and fail to transplant any cell into any subject or harvest any chimeric pig organ or transplant any pig organ to any subject to treat or prevent any disease or co relates to reduce any pathology associated with any known or yet to identified disease of heart, kidney, liver, lung, eye, pancreatic, congenital of one or more organ in any subject to enable the method as claimed. An artisan would have to perform undue experimentation to make and use the invention, without reasonable expectation of success.
In response to applicant’s argument that claimed cell-based methods require only techniques that are commonly practiced by those of ordinary skill is not found persuasive, because the omission of minor details does not cause a specification to fail to meet the enablement requirement, however, when there is lack of or no disclosure of any specific conditions and the resulting outcome of an unpredictable art as discussed above under which a process can be carried out, undue experimentation is required; there is a failure to meet the enablement requirement that cannot be rectified by asserting that all the disclosure related to the process is within the skill of the art. It is emphasized that it is the specification, not the knowledge of one skilled in art, that must supply the novel aspects of condition that lead to the claimed outcome from the process as claimed in order to constitute adequate enablement. It should be further noted that while a later dated publication cannot supplement an insufficient disclosure in a prior dated application to make it enabling, an applicant can offer the testimony of an expert based on the publication(s) as evidence of the level of skill in the art at the time the application was filed. Gould v. Quigg, 822 F.2d 1074, 1077, 3 USPQ2d 1302, 1304
In conclusion, in view of breadth of the claims and absence of specific guidance and direction, and/or working examples demonstrating the same, such invention as claimed by applicant is not enabled for the claimed inventions.
Withdrawn-35 USC § 112-written description
Claims 1, 4-6, 8-13, 16-19, 24-25, 38, 42-45 and 46 were rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. Applicants’ amendments to the claims obviate the basis of the rejection. Applicants’ arguments with respect to the withdrawn rejections are thereby rendered moot.
Maintained-Claim Rejections - 35 USC § 112
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 6 remains 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. In view of applicants’ amendments to claims to claim 1, 17, 21, 22-25, previous rejection of claims 1-5, 7-27 are hereby withdrawn. Applicants’ arguments with respect to the withdrawn rejections are thereby rendered moot.
Regarding claim 6, the phrase "e.g. for example" renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Response to arguments
Applicant disagrees with the rejection and assert recitation of e.g for example has been deleted. Applicants’ arguments have been fully considered but are not found persuasive.
In response, claim 6 continue to recite phrase “e.g. for example" renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. Absent any amendment to claim deleting the phrase, instant rejection is maintained for the reasons of record.
Conclusion
No claims allowed.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Sper et al (Front Vet Sci, . 2022 4; 9:965316, 1-21.) teaches intrauterine injection at day 42–45 of gestation, fetuses were allowed to gestate to term and analyzed postnatally for the presence of pig (allogeneic) and human (xenogeneic) B cells, T-cells and NK cells in peripheral blood and other lymphoid tissues (abstract). It is further disclosed that in utero hematopoietic stem cell transplantation of human T-cell-depleted bone marrow and umbilical cord blood into wild type pig fetuses.
Ogle et al (TISSUE ENGINEERING: Part A, 2009, 1031-1040) teaches T cell–depleted human bone marrow cells into fetal swine and tested the swine for human T cells at various times after birth (abstract).
Kalscheuer (The Journal of Immunology, 2014, 3442-3450) teaches peripheral T cells are specif ically tolerant to the mouse and to the human and porcine donors, with robust responses to nondonor human and pig Ags. Specific tolerance is observed to pig skin grafts sharing the THY donor MHC. SW THY–generated peripheral (abstract).
Rothblatt (US2022211018) teaches a transgenic pig comprising at least six transgenes, wherein the at least six transgenes are incorporated and expressed at a single locus under the control of at least two promoters, and the at least six transgenes are selected from: (i) CD46, DAF, EPCR, HO-1, TBM, and CD47; (ii) EPCR, HO1, TBM, CD46, DAF and TFPI; (iii) EPCR, CD55, CD46, TFPI, HO-1 and CD47; (iv) EPCR, DAF, CD46, TFPI, CD59, and CD47; or (v) EPCR, CD55, CD46, TBM, HO-1, and CD39; and wherein the transgenic pig lacks expression of alpha 1, 3-galactosyltransferase (GGTA1) gene, growth hormone receptor (GHR) gene, β-1,4-N-acetyl-galactosaminyltransferase 2 (βGalNT2) gene, and cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.
Hearing (US20180092338) teaches genetically modified pig comprising an exogenous polynucleotide encoding a human leukocyte antigen G (HLA-G) polypeptide, wherein the HLA-G is HLA-G1, HLA-G2, HLA-G3, HLA-G4, HLA-G5, HLA-G6, or HLA-G7.
Conclusion
No claims allowed.
Applicants’ amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicants are 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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/ANOOP K SINGH/ Primary Examiner, Art Unit 1632
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