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 .
Applicant’s amendments to the claims and response to restriction requirement filed on July 2, 2025 have been received and entered. Claim 1 has been amended, while claims 3, 6, 11, 16-18, 21-22, 24, 26-27, 32-50 and 51 have been canceled.
Claims 1-2, 4-5, 7-10, 12-15, 19-20, 23, 25, 28, 30 and 31 are pending in the instant application.
Election/Restrictions
Applicant’s election without traverse of claims 1-2, 4-5, 7-10, 12-15, 19-20, 23, 25, 28 and 30 (group I) in the reply filed on July 2, 2025 is acknowledged.
Claim 31 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on July 2, 2025.
Priority
This application is a 371 of PCT/US2020/062507 filed on 11/27/2020 that claims priority from US provisional application no 62/941,563 filed on 11/27/2019.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 05/03/2023 and 04/24/2024 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements have been considered by the examiner.
Claims 1-2, 4-5, 7-10, 12-15, 19-20, 23, 25, 28 and 30 are under consideration.
Claim Rejections - 35 USC § 103
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.
Claims 1, 4-5, 7-10, 12-15, 19-20, 23, 25, 28 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Delaney (WO2018/140532, dated 08/02/2018) as evidenced by Cimanto (Cytometry Part B, 2016; 90B: 415–423), Bernstein et al (US 20130095079, dated 04/18/2013), Cao et al (US20180236135, dated 08/23/2018) and Kang et al (US20180021378, dated 1/25/2018).
Claims are directed to method of culturing hematopoietic stem and progenitor cells (HSPCs), comprising:
providing at least one HSPC population comprising hematopoietic stem cells (HSCs); having the phenotype of Lin- CD34+ CD38- CD133+ CD45RA- CD90+;
enriching the HSPC population for CD34+ or CD133+ HSPCs to prepare an enriched HSPC population that has been depleted of T cells and red blood cells;
encapsulating the enriched HSPCs in a zwitterionic hydrogel comprising alginate and poly- lysine to form encapsulated HSPCs; and culturing the hydrogel encapsulated HSPCs in a culture medium comprising interleukin-3 (IL-3), interleukin-6 (IL-6), thrombopoietin (TPO), Flt3-Ligand (Flt3-L), and stem cell factor (SCF), for a sufficient time to produce a hydrogel expanded HSPC population,
wherein the percentage of and/or the number of HSCs in the hydrogel expanded HSPC population is the same as or greater than the percentage of and/or number of HSCs in the enriched HSPCs, and wherein the percentage of multi-potent progenitor cells (MPPs); having the phenotype of Lin- CD34+ CD38- CD133+ CD45RA- CD90- in the expanded HSPC population is the same as or greater than the percentage and/or number of MPPs in the enriched HSPCs.
With respect to claim 1, Delaney teaches a method of culturing and expanding hematopoietic stem and progenitor cells comprising, said method comprising
providing a population of HSPC comprising 34+ CD133+HSC (see claim 1 and 8 of ‘532), enriching the cells of (i) for a population of CD34+ HSC (see claim 10 of ‘532, para. 67, 69) that would imply a selection of the cells on the basis of CD34 positive expression that would inherently lead to depletion of T and red blood cells to enrich population of CD34+ CD133+cells as evident from the teaching of Bernstein (see para. 36, 69, 77, 84, 86);
encapsulating the enriched HSPCs in a zwitterionic hydrogel to form encapsulated HSPCs (claim 1 and 27); and
culturing the hydrogel encapsulated HSPCs in a culture medium comprising interleukin-3 (IL-3), interleukin-6 (IL-6), thrombopoietin (TPO), Flt3-Ligand (Flt3-L), and stem cell factor (SCF), for a sufficient time to produce a hydrogel expanded HSPC population (see claims 1 14 of ‘532),
wherein the percentage of and/or the number of HSCs in the hydrogel expanded HSPC
population is the same as or greater than the percentage of and/or number of HSCs in the enriched HSPCs or wherein the increased proportion of HSC versus partially or fully differentiated cells is demonstrated through a difference in (i) a fold increase in HSC having a CD34+, CD38-, CD45RA-, CD49f+, CD90+ phenotype in the ZTG-expanded HSC population (see claims 1, 22-23, 27, 29 of ‘532).
The limitation of the percentage of MPPs having the phenotype of Lin- CD34+ CD38- CD133+ CD45RA- CD90- in the expanded HSPC population is the same as the percentage and/or number of MPPs in the enriched HSPCs would be obvious to one of ordinary skill in the art because prior art recognized that HSCs are identified by the cell surface marker profile
Lineage- CD341 CD38- CD90+CD45RA- and the first differentiated cell type after HSCs (limitation of claim 29) are multipotent progenitors (MPPs). MPPs are distinguished from HSCs by the lack of CD90 expression and functionally by the loss of self-renewal properties (see Cimato et al page 416, col. 1, para. 1). Cimato teaches further resolving CD34+ CD38- cells into CD45RA- CD90+ and CD90- cell populations (see fig. 1, 5). Given that prior art teaches culturing hydrogel encapsulated HSPCs in the same culture medium (IL-3, IL-6, TPO, Flt3-L, SCF) for same duration as one claimed in the instant application it must necessarily result in same number of HSC and HPP as required by the claims that could be further be characterized by markers known in the prior art as evident from Cimato.
Regarding claim 4-5, Delaney teaches the enriched HSPC population is derived from umbilical cord blood, bone marrow, or peripheral blood (see para. 48, 66).
Regarding claim 10, Delaney teaches culture medium does not comprises exogenous IL-15 (see claim 14 of ‘532).
With respect to claim 12, Delaney teaches that culture medium and hydrogel comprising ZTG that is compared with a control substrate that uses notch agonist substrate or fibronectin (see para. 61).
With respect to claim 14, Delaney teaches ZTG opt expansion methodology do not comprise a notch ligand (see para. 180).
Regarding claim 19, 25, 28, Delaney teaches that ZTG-expanded HSC population comprises at least a 10-fold increase in the total number of HSC having a CD34+, CD38-, CD45RA-, CD49f+, CD90+ phenotype as compared to the starting CD34+ hematopoietic cell population (see claims 18, 22 of ‘532). It is further disclosed that enrichment of CD34+ HSPC from 1- comprises 50-80% of the population of HPSC (see para. 68). Delaney further teaches that the encapsulation results in at least 10-fold expansion of the HSC within the CD34+ hematopoietic cell population as compared to the CD34+ hematopoietic cell population before the encapsulating (see claim 40 of ‘532).
With respect to claim 20, Delaney teaches that the method further comprises genetically modifying cells within the CD34+ HSC population (see claim 25-26).
Regarding claim 23, Delaney teaches method wherein the encapsulated HSPC population is cultured for at least 10 days (see claim 18, 49, 65 of ‘532).
While Delaney as evidenced by Bernstein teaches encapsulating the enriched cells in a zwitterionic hydrogel (ZTG) but differs from claimed invention by not disclosing that (i) the ZTG comprises an alginate and poly-lysine and (ii) wherein the enriched HSPC population is derived from at least two different sources of umbilical cord blood and/or placental blood that have not been immunologically matched to each other and (iii) culture medium does not comprise a serum supplement or serum supplement replacement (limitation of claims 7-10)
However, before the effective filing date of instant application, Cao teaches biocompatible hydrogels for encapsulation of a therapeutic agent such as a cell or stem cells (see para. 203). Cao teaches a hydrogel for encapsulation of cells made of an alginate core surrounded with a zwitterionic shell and coated with a cationic polymer such as poly-L-lysine (278-280). Kang discloses encapsulating the cells in a hydrogel comprising alginate and poly-lysine to form encapsulated cells (cells are suspended in a polysaccharide alginate hydrogel solution suitable for injection, the hydrogel is allowed to harden to form a matrix having cells dispersed or encapsulated for implantation. the cells in such a matrix can be cultured and expanded prior to implantation, cells are seeded onto scaffolds using incubation in poly lysine to enhance cell attachment; paragraphs (493, 500), and further discloses culturing to produce a hydrogel expanded cell population (see para. 500). The combination of references differs from claimed invention by not disclosing wherein the enriched HSPC population is derived from at least two different sources of umbilical cord blood and/or placental blood that have not been immunologically matched to each other and (iii) culture medium does not comprise a serum supplement or serum supplement replacement (limitation of claims 7-10). It is further disclosed that the cells may be expanded in presence of notch ligand (see para. 29, 266) (limitation of claim 15).
Bernstein cure the deficiency by disclosing the enriched HSPC population is derived from at least two different sources of umbilical cord blood that have not been immunologically matched to each other (see para. 34, 66, 266 claims). Bernstein further teaches stem cell culture medium consists of serum free expansion medium supplemented with 10 ng/ml recombinant human Interleukin-3 (rhIL-3), 50 ng/ml recombinant human Interleukin-6 (rhIL-6), 50 ng/ml recombinant human Thrombopoietin (rhTPO), 50 ng/ml recombinant human Flt-3 Ligand (rhFlt-3L), 50 ng/ml and recombinant human stem cell factor (rhSCF) (see para. 85) (limitation of claims 7-10). It is further disclosed that HSC could be further differentiated into (i) myeloid progenitor cells to produce monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes/platelets, dendritic cells, or lymphoid progenitor cells that produce T-cells, B-cells, and lymphocyte-like cells called natural killer cells (NK-cells) (para. 17, limitation of claim 30).
Therefore, it would have been prima facie obvious for a person of ordinary skill in the art to combine the teachings of prior art by modifying the method of Delaney by substituting the ZTG hydrogel used in the encapsulation of HSPC with alginate and poly-lysine made ZTG hydrogel as disclosed by Cao and Kang, in the method of culturing and expanding HSPC cells, as instantly claimed, with a reasonable expectation of success, before the effective filing date of the instant invention. Said modification amounting to combining prior art elements according to known methods to yield predictable results. One of ordinary skill in the art would be motivated to use alginate core that is incubated with poly-L-lysine in order to minimizes the size of pores of the core eliminating potential transport of undesirable materials during transplantation (see 280). Other limitation of further including notch ligand attached to hydrogel would be obvious modification of known method to expand the HSC in a given field as per the teaching of Bernstein (see para. 29). Absent evidence of any unexpected and/or superior result with ZTG comprising alginate and poly-lysine for cell encapsulation, one of skill in the art would have been expected to have a reasonable expectation of success in replacing/substituting the ZTG hydrogel used to encapsulate HSPC as in Delaney with functionally equivalent an alginate/poly-lysine made ZTG as an obvious alternative intended for the same purpose as used and suggested in prior art. It should be noted that the KSR case forecloses the argument that a specific teaching, suggestion, or motivation is required to support a finding of obviousness See the recent Board decision Smith, --USPQ2d--, slip op. at 20, (Bd. Pat. App. & Interf. June 25, 2007) (citing KSR, 82 USPQ2d at 1396) (available at http: www. uspto.gov/ web/offices/dcom/bpai/prec/fd071925.pdf).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Delaney (WO 2018/140532, dated 08/02/2018), Bernstein et al (US 20130095079, dated 04/18/2013), Lansdorp (US5514340, dated 5/7/1996). Cao et al (US20180236135, dated 08/23/2018) and Kang et al (US20180021378, dated 1/25/2018).
Claim is directed to a method of culturing hematopoietic stem and progenitor cells (HSPCs), comprising:
providing at least one enriched CD34+ or CD133+ HSPC population comprising hematopoietic stems cells (HSCs; Lin- CD34+ CD38- CD133+ CD45RA- CD90+), less than 2% T cells and less than 2% red blood cells;
encapsulating the enriched HSPCs in a zwitterionic hydrogel comprising alginate and poly- lysine to form hydrogel encapsulated HSPCs; and
culturing the hydrogel encapsulated HSPCs in a culture medium comprising interleukin-3 (IL-3), interleukin-6 (IL-6), thrombopoietin (TPO), Flt3-Ligand (Flt3-L), and stem cell factor (SCF), for a sufficient time to produce a hydrogel expanded HSPC population, wherein the percentage and/or number of HSCs in the hydrogel expanded HSPC population is the same or greater than the percentage and/or number of HSCs in the enriched HSPCs.
Claim interpretation: limitation recited within parenthesis is interpreted as optional and therefore not given any patentable weight.
With respect to claim 1, Delaney teaches a method of culturing and expanding hematopoietic stem and progenitor cells comprising, said method comprising
providing an enriched population of CD34+ HPSC (see claim 10 of ‘532, para. 67, 69) that would imply a selection of the cells on the basis of CD34 positive expression that would inherently lead to depletion of T and red blood cells to enrich population of CD34+ cells as evident from the teaching of Bernstein (see para. 77, 84, 86);
encapsulating the enriched HSPCs in a zwitterionic hydrogel to form encapsulated HSPCs (claim 1 and 27); and
culturing the hydrogel encapsulated HSPCs in a culture medium comprising interleukin-3 (IL-3), interleukin-6 (IL-6), thrombopoietin (TPO), Flt3-Ligand (Flt3-L), and stem cell factor (SCF), for a sufficient time to produce a hydrogel expanded HSPC population (see claims 1 14 of ‘532),
wherein the percentage of and/or the number of HSCs in the hydrogel expanded HSPC
population is the same as or greater than the percentage of and/or number of HSCs in the enriched HSPCs or wherein the increased proportion of HSC versus partially or fully differentiated cells is demonstrated through a difference in 10 a fold increase in HSC in the ZTG-expanded HSC population (see claims 1, 22-23, 27, 29 of ‘532).
While Delaney teaches providing an enriched population of CD34+ HPSC (see claim 10 of ‘532, para. 67, 69) that would imply a selection of the cells on the basis of CD34 positive expression that would inherently lead to depletion of T and red blood cells as evident from the teaching of Bernstein who teaches a method to enrich population of CD34+ cells that is then encapsulated in a zwitterionic hydrogel (ZTG) but differs from claimed invention by not disclosing that (i) enriched CD34+ or CD133+ HSPC population comprising hematopoietic stems cells less than 2% T cells and less than 2% red blood cells and (ii) the ZTG comprises an alginate and poly-lysine.
However, Lansdorp discloses method of depletion of T cell from peripheral blood comprising cell population comprising less than 2% T cells (as shown in table 1, the technique allows 3 log or 1000-fold depletion of the T-cells with 73 percent recovery of the negative or other cells, thus, providing less than 2% T cells in the purified sample; col.15, lines 10-20; col. 20, lines 1-15) and less than 2% red blood cells (see col. 19, lines 20-35). The combination of references differs from claimed invention by not disclosing that the ZTG comprises an alginate and poly-lysine.
However, before the effective filing date of instant application, Cao teaches biocompatible hydrogels for encapsulation of a therapeutic agent such as a cell or stem cells (see para. 203). Cao teaches a hydrogel for encapsulation of cells made of an alginate core surrounded with a zwitterionic shell and coated with a cationic polymer such as poly-L-lysine (278-280). Kang discloses encapsulating the cells in a hydrogel comprising alginate and poly-lysine to form encapsulated cells (cells are suspended in a polysaccharide alginate hydrogel solution suitable for injection, the hydrogel is allowed to harden to form a matrix having cells dispersed or encapsulated for implantation. the cells in such a matrix can be cultured and expanded prior to implantation, cells are seeded onto scaffolds using incubation in poly lysine to enhance cell attachment; paragraphs (493, 500), and further discloses culturing to produce a hydrogel expanded cell population (see para. 500).
Therefore, it would have been prima facie obvious for a person of ordinary skill in the art to combine the teachings of prior art by modifying the method of Delaney by substituting the ZTG hydrogel used in the encapsulation of HSPC with alginate and poly-lysine made ZTG hydrogel as disclosed by Cao and Kang, in the method of culturing and expanding HSPC cells, as instantly claimed, with a reasonable expectation of success, before the effective filing date of the instant invention. Said modification amounting to combining prior art elements according to known methods to yield predictable results. One of ordinary skill in the art would be motivated to use alginate core that is incubated with poly-L-lysine in order to minimizes the size of pores of the core eliminating potential transport of undesirable materials during transplantation (see 280) Other limitation of cell population comprising less than 2%T cells and less than 2% red blood cells would have been obvious to a person of ordinary skill in the art, before the effective filing date of the invention, to modify the method of Delaney to provide extent of CD34+ cell enrichment by removing T cells and red blood cells from blood using contemporary techniques as suggested in Lansdorp. It is relevant to note that both Delaney as evidenced by Bernstein and Lansdorp disclose the methodology of depletion of T cells and red blood cells from the blood samples to provide an enriched cell population comprising CD34+ cell having less than 2% T cells and less than 2%red blood cells. Absent evidence of any unexpected and/pr superior result with ZTG comprising alginate and poly-lysine for cell encapsulation, one of skill in the art would have been expected to have a reasonable expectation of success in replacing/substituting the ZTG hydrogel used to encapsulate HSPC as in Delaney with functionally equivalent an alginate/poly-lysine made ZTG as an obvious alternative intended for the same purpose as used and suggested in prior art. It should be noted that the KSR case forecloses the argument that a specific teaching, suggestion, or motivation is required to support a finding of obviousness See the recent Board decision Smith, --USPQ2d--, slip op. at 20, (Bd. Pat. App. & Interf. June 25, 2007) (citing KSR, 82 USPQ2d at 1396) (available at http: www. uspto.gov/ web/offices/dcom/bpai/prec/fd071925.pdf).
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.
Claims 2 and 19 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 2 recite, hematopoietic stems cells (HSCs; Lin- CD34+ CD38- CD133+ CD45RA- CD90+)-". The limitations intended to be captured by placing the term " Lin- CD34+ CD38- CD133+ CD45RA- CD90+" in parentheses are not apparent. Parenthesis are used in claims to delineate an abbreviation of a term that is recited just prior to the parentheses and does not further impart limitations to the claim. However, in this instant, case, no term is recited prior to the parentheses. As such, it is not apparent how the parentheses are to be interpreted or if the term in the parenthesis is intended to be further limiting to the claim. For art purposes, the term "(- HSCs; Lin- CD34+ CD38- CD133+ CD45RA- CD90+)-" will be interpreted as a structural limitation as if the parentheses were not present. Amending the claim to remove the parentheses and explicitly reciting that HSCs having the phenotype of Lin- CD34+ CD38- CD133+ CD45RA- CD90+ would be remedial.
Claim 19 is vague and indefinite because of the multiple "and/or" phrases withinclaim. This is because given the broadest reasonable interpretation, the HSC and/or MPP within HSPC could embrace multiple combination of phenotype, and hence the metes and bounds of the claim is uncertain. Appropriate correction is required.
Conclusion
No claims allowed.
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/ANOOP K SINGH/ Primary Examiner, Art Unit 1632