DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
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.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 84-95, 97-98 are rejected under 35 U.S.C. 103 as being unpatentable over Zimmermann et al ( WO 2015/025030 A1) in view of Atkins et al ( US 2008/0075750 A1), Vantler et al ( Journal of Molecular and Cellular Cardiology, 2010), Zimmermann et al ( WO 2015/040142 A1) herein after Zimmermann et al 142’, and Lian et al ( Nature protocol, 2013).
Regarding claims 84-85, 92-93, and 100-101, Zimmermann et al teach a method for producing engineered heart muscle ( EHM), and specifically disclose that EHM are produced from hESC-or iPSC-derived cardiac cells. ( See abstract, and page 7-lines (1-25)). The method involves combining cell population comprising of human cardiac myocytes and human non-myocytes with a flowable hydrogel composition under serum-free condition. Zimmermann et al expressly teach that the said cells may be derived from embryonic stem cells or induced pluripotent cells, and may be obtained by serum-free differentiation. Zimmerman et al further identify fibroblasts and endothelial cells as suitable non-myocyte populations. See claim 1, Summary of invention, and page 7-lines (1-25), this reads on step (i) of instant claim. The method of Zimmerman et al further teach the step of loading the mixture comprising the cell suspension and hydrogel , wherein the hydrogel comprises of collagen matrix , into a circular mold before condensation, and the subsequent culturing in serum-free EHM culture medium. ( See summary of invention, and claim 1). Specifically, Zimmermann et al teach culturing the mixture comprising the cell suspension and hydrogel (i.e. collagen matrix) in the mold under serum-free condition whereby the mixture is allowed to condense for at least 15 minutes. This reads on steps (ii) and (iii) of instant claim. Zimmerman et al further teach contacting the said cell population with FGFR1 agonist by culturing the cells in a serum-free EHM culture medium comprising FGF2 ( i.e. FGFR1 agonist), and report that FGF-2 supported non-myocyte growth and increased cardiomyocytes cell size. ( See claims 1, 11, Fig.6A, and section “ Withdrawal and replacement of xenoqenic medium components” on page 29). Accordingly, Zimmerman teach a method of producing an engineered human cardiac tissue comprising mixing hPSC-derived cardiomyocytes and non-cardiomyocytes with flowable gel, molding the resulting mixture in a mold, and culturing the molded mixture in a serum free medium containing FGFR1 agonist, such as FGF-2.
It is submitted that Zimmermann et al do not teach contacting the said cells with PDGF agonist.
Atkins et al supplement Zimmermann et al by teaching methods for producing a three-dimensional (3D) tissue engineered cardiac construct, and teach the use of biologically active agents, including growth factors, in connection with cardiac cell cultures and constructs. [0008-0009]. Specifically, Atkins et al expressly identifies PDGF (i.e. PDGFR agonist) and FGF (FGFR agonist) among the growth factors that may be used as an angiogenic factors and further contemplates supplying such biologically active agents to the culture medium of the cardiac construct. Thus, Atkins et al provide an express teaching to use PDGF and FGF as an exogenous growth factor in a cardiac tissue-engineering culture, and expressly identify it as an angiogenic factor, wherein the angiogenic factors are able to promote endothelial and smooth muscle proliferation leading to the formation of new blood vessels. ([0014] and [0035]). Atkins, therefore, provides an ordinary skill in the art with a reason to consider PDGF when selecting a growth factor for the supplementation of a cardiac-cell culture.
Vantler further supplements Zimmermann and Atkins by characterizing the effect of PDGF-BB ( i.e. PDGFR agonist) stimulation on cardiomyocytes and engineered heart tissue (EHT). Vantler et al report that PDGF-BB was administered to neonatal-rat cardiomyocyte cultures and EHT culture and that PDGF-BB enhanced the contractile performance of the EHT in a concentration-dependent manner, and protected cardiomyocytes in a time- and concentration-dependent manner from apoptosis. ( See abstract, and Fig.7).Vantler et al further teach stimulating EHT culture with PDGF-BB at a concentration ranging from 3-30 ng/ml, which falls within the numerical range recited in claim 93. ( See Fig.1C) Accordingly, Vantler et al provide an ordinary skill in the art with the motivation to further supplement the serum-free medium of Zimmermann with PDGF-BB to improve the properties of the engineered cardiac tissue.
Therefore, it would have been prima facie obvious to one with ordinary skill in the art at the time the invention was filed to supplement the serum-free medium of Zimmerman with PDGFR agonist (i.e. PDGF-BB) in order to improve the properties of the engineered cardiac tissue. Because Zimmerman et al teach a method of producing engineered human cardiac tissue (EHT) comprising the steps of combining cardiomyocytes and non-cardiomyocyte cells with a flowable hydrogel, casting the mixture in a mold, and then culturing the mixture under serum free medium containing FGFR1 agonist, but fail to teach further supplementing the medium with PDGFR agonist. Atkins et al supplement Zimmerman et al by establishing that PDGF, an PDGFR agonist, is a suitable exogenous factor for use with tissue-engineered cardiac construct, and expressly identify PDGF as an angiogenic factor that can be used to induce angiogenesis (i.e. formation of blood vessels). Vantler et al further support Atkins by providing a specific teaching that PDGF-BB, an PDGFR agonist, can be supplied during the construction of engineered heart tissue, where it acts through the PDGFR pathway to produce beneficial effect on the engineered construct. Therefore, an ordinary skill in the art would be motivated to further supplement the serum- free medium of Zimmermann with PDGFR agonist to improve the properties of the engineered cardiac tissue. An ordinary skill in the art would have a reasonable expectation of success in using PDGF-BB as a PDGFR agonist because Vantler et al experimentally demonstrated that treatment of engineered heart tissue with PDGF-BB produces a measurable biological effect. Specifically, PDGF-BB enhanced EHT contractile performance and protected cardiomyocytes from apoptosis. In other words, instant claims are an example of combining prior art elements according to known methods to yield predictable results. See MPEP 2143 (I)(A).
As per the recitation “ to thereby provide engineered human cardiac tissue wherein said tissue comprises cardiomyocytes, stromal cells/fibroblasts and endothelial cells”, it is noted that the presence of these cells population is not a separate step process requiring additional modification of the combined teachings, but rather is a functional outcome that flows from carrying out the disclosed cell composition, hydrogel casting, and culturing steps. Therefore, the recited functional outcome is considered prima facie present per natural law of cell biology in the combined teachings of the cited prior arts and they reasonably fulfill the functional limitations that are being claimed. In other words, the recited functional limitations are considered to be an inherent property as it flows from performing the active steps of the method as taught by the combined teachings of Zimmermann, Atkins and Vanlter, and even if the functional limitations were not recognized by the prior arts at the time the invention was filed, according to the MPEP, the functional outcome would flow naturally from following the suggestion of the prior art and 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).
Regarding claims 86-87, following the discussion of claim 84 above, the combined teachings of Zimmermann, Atkins, and Vantler render obvious the method of claim 84. Zimmermann et al expressly teach culturing the cell containing hydrogel after casting in a mold in a serum-free EHM culture medium comprising FGF. (See claims 1, and 11). Vantler et al further teach administration of PDGF-BB during EHT culture and demonstrate that PDGF-BB stimulation produces a concentration dependent improvement in EHT contractile performance with the effect being dependent on the duration of exposure.( See abstract). Accordingly, incorporating PDGF-BB into the serum free FGF containing medium of Zimmermann would have been obvious modification of known EHM culture conditions, and determining the appropriate timing and duration would have involved routine optimization of known culture parameters. Therefore, an ordinary skill in the art would have relied on routine experimentation to find the appropriate timing for supplementing the serum-free medium with the PDGFR agonist and FGFR agonist in order to find the appropriate timing that provides the desired effect . Optimization of such variables would have been within the ordinary skill in the art. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum of workable ranges by routine experimentation. The "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Application of Boesch, 617 F.2d 272, 276, 205 USPQ 215, 218-219 (C.C.P.A. 1980). See MPEP 2144.05.
Regarding claim 88, Zimmermann et al expressly teach mixtures containing 20-80% cardiac myocytes, with progressively narrower preferred ranges of 30-70%, and about 50% cardiac myocytes. Zimmermann et al further identifies fibroblast and endothelial cells as nonmyocytes populations. ( See page 7-lines-15-25). Thus, Zimmermann et al teach the claimed range for the cardiomyocytes with the remainder being the non-myocytes. Thus, Zimmermann et al render obvious instant claim.
Regarding claims 90-91, it is also noted that the recitation of the particular cell composition and relative percentage does not require any additional step or modification of the combined teachings of Zimmermann, Atkins, and Vantler. Rather, the recited cellular composition and their relative percentage are properties of the engineered tissue that results from carrying out the disclosed method steps, including combining the cardiomyocytes with non-cardiomyocyte with hydrogel, casting the resulting cell containing composition and culturing the construct under disclosed conditions. In other words, the recited cells and cellular composition are functional limitations which are considered to be prima facie present per natural law of cell biology in the combined teachings of the cited prior arts and they reasonably fulfill the functional limitations that are being claimed. As such, the recited functional limitations are considered to be an inherent property as it flows from performing the active steps of the method as taught by the combined teachings of Zimmermann, Atkins and Vanlter, and even if the functional limitations were not recognized by the prior arts at the time the invention was filed, according to the MPEP, the functional outcome would flow naturally from following the suggestion of the prior art and 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). For a method claim comprising a functional outcome, it is not required that a prior art would disclose/recognize the functional outcome before a prima facie case of anticipation or obviousness would be established. While the references do not show a specific recognition of the recited functional outcome, its discovery by appellants is tantamount only to finding an inherent property. As per the MPEP “ there is no requirement that a person of ordinary skill in the art would have recognized the inherent disclosure at the time of invention, but only that the subject matter is in fact inherent in the prior art reference. Schering Corp. v. Geneva Pharm. Inc., 339 F.3d1373, 1377, 67 USPQ2d 1664, 1668 (Fed. Cir. 2003).
Regarding claim 94, Zimmermann et al teach the use of a serum-free culture medium comprising albumin and transferrin. ( See claim 1). Zimmerman et al further recognize calcium concentration as a controllable parameter of the culture medium and describe media having different concentration of calcium concertation, including media having substantially low free-calcium concentration. For example, Zimmermann et al evaluate different calcium concentration in connection with culture of engineered heart muscle and demonstrate that calcium concentration was a variable that could be selected and adjusted in practicing the disclose method. ( See Fig.7A, Fig.8A-B, and page 34-lines ( 18-26)). Thus, an ordinary skill in the art would have recognized that the calcium concentration is a result effective variable that could be adjusted according to the desired characteristic of the resulting engineered cardiac tissue. Optimization of such variable would have been within the ordinary skill in the art. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum of workable ranges by routine experimentation. The "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Application of Boesch, 617 F.2d 272, 276, 205 USPQ 215, 218-219 (C.C.P.A. 1980). See MPEP 2144.05
Regarding claim 95, it should be noted that the recited limitations are functional limitations which are considered to be prima facie present per natural law of cell biology in the combined teachings of the cited prior arts and they reasonably fulfill the functional limitations that are being claimed. In other words, the recited functional limitations are considered to be an inherent property as it flows from performing the active steps of the method as taught by the combined teachings of Zimmermann, Atkins and Vanlter, and even if the functional limitations were not recognized by the prior arts at the time the invention was filed, according to the MPEP, the functional outcome would flow naturally from following the suggestion of the prior art and 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). For a method claim comprising a functional outcome, it is not required that a prior art would disclose/recognize the functional outcome before a prima facie case of anticipation or obviousness would be established. While the references do not show a specific recognition of the recited functional outcome, its discovery by appellants is tantamount only to finding an inherent property. As per the MPEP “ there is no requirement that a person of ordinary skill in the art would have recognized the inherent disclosure at the time of invention, but only that the subject matter is in fact inherent in the prior art reference. Schering Corp. v. Geneva Pharm. Inc., 339 F.3d1373, 1377, 67 USPQ2d 1664, 1668 (Fed. Cir. 2003).
Regarding claim 97, with respect to the recited cell concentration, Zimmermann et al disclose that the relative cell composition may be provided at 20-80% cardiac myocytes, with the balance being human non-myocytes, and state “Depending on the size of the EHM, the cell density can easily be adapted”. ( See page 7-lines 27-31, and page 31-line 10). Thus, Zimmermann et al recognize that the cell concentration is an optimizable parameter as they provide a range of cell concentration for use in producing the engineered heart construct. Thus, an ordinary skill in the art would have recognized that the cell concentration is a result effective variable that could be adjusted according to the desired characteristic of the resulting engineered cardiac tissue. Optimization of such variable would have been within the ordinary skill in the art. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum of workable ranges by routine experimentation. The "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Application of Boesch, 617 F.2d 272, 276, 205 USPQ 215, 218-219 (C.C.P.A. 1980). See MPEP 2144.05
Regarding claims 89 and 98, following the discussion of claim 84 above, Zimmermann et al expressly teach cardiomyocytes and non-cardiomyocyte may be obtained by serum-free differentiation.( See claim 1, Summary of invention, and page 7-lines (1-25)). However, Zimmermann et al do not expressly teach that the cell suspension is derived from a single differentiation process or the particular steps of hPSC cardiac-lineage differentiation recited in claim 98. Zimmermann et al 142’ supplement the cited prior arts by teaching sequential steps for directing pluripotent stem cells (PSC) toward cardiac differentiation in a single differentiation process, and the subsequent production of engineered human engineered cardiac tissue. In particular, the method of Zimmermann et al 142’ involves culturing hPSC in a medium comprising an effective amount of BMP4, Activin A, FGF2, and GSK3B inhibitor, together with serum free supplement comprising albumin and transferrin for 72 hours, thereby inducing mesoderm differentiation. Zimmermann et al 142’ further teach culturing the cells obtained from first step in a basal medium comprising an effective amount of Wnt inhibitor for 10 days, thereby inducing cardiac differentiation. Zimmermann et al 142’ further teach that cells obtained form the Wnt inhibition stage are subsequently cultured under conditions promoting cardiac maturation, and that the resulting cell population comprises of cardiomyocyte and stromal cells which would subsequently progress to a more mature cardiac tissue. ( see claim 1, and page 3-lines 10-22 ). It is submitted that Zimmermann et al 142’ do not expressly teach the particular durations recited in steps (a)-(d) of claim 98 nor do they specify when insulin is to be added to the serum free medium. For example, Zimmermann et al describe the use of B27 supplement, as well as B27 supplement minus insulin, thereby leaving to the person of ordinary skill in the art the choice of whether to employ a medium containing insulin or insulin-free medium ( see claim 9); however, such duration and the choice when to add insulin are a result effective process variables as evidenced by Lian et al. For example, Lian et al teach a fully defined growth factor and serum free hPSC cardiomyocytes differentiation protocol based on temporal modulation of canonical Wnt signaling. Lian et al expressly employ temporal control of the differentiation process, including treatment with a GSK3 inhibitor at the beginning of differentiation and subsequent introduction of a Wnt inhibitor after approximately 72 hours. Lian et al further proceed through subsequent differentiation and maturation stages, with transition to insulin-containing medium at a later stage of the differentiation process. Lian et al further report that the timing of Wnt pathway modulation is important to cardiomyocyte differentiation and establish that temporal adjustment of the differentiation stages affect the resulting cardiomyocyte yield, and further state that “ insulin, present in B-27 supplement, greatly inhibits cardiomyocyte yield during the first 5 d of differentiation, which is consistent with previous reports that insulin inhibits cardiac differentiation of hPSCs” and clearly suggest optimizing the insulin concentration during the first 5 days of differentiation. ( See section “ Methods to differentiate hPSCs into cardiomyocytes” on page 162, and Fig.3). Accordingly, an ordinary skill in the art would have been motivated to adjust the duration of each stage, as well as the timing to add insulin, based on the recognized effect of Wnt modulation as well as insulin on cardiomyocyte differentiation. Such adjustment would have been obtained by an ordinary skill in the art through routine experimentation applied to the method of Zimmermann et al 142’. As per the limitation wherein “ the basal medium used in each of steps a) - d) has a calcium concentration of less than about 1.2 mM”. As discussed previously, Zimmerman et al further recognize calcium concentration as a controllable parameter of the culture medium and describe media having different concentration of calcium concertation, including media having substantially low free-calcium concentration. For example, Zimmermann et al evaluate different calcium concentration in connection with culture of engineered heart muscle and demonstrate that calcium concentration was a variable that could be selected and adjusted in practicing the disclose method. ( See Fig.7A, Fig.8A-B, and page 34-lines ( 18-26)). Thus, an ordinary skill in the art would have recognized that the calcium concentration is a result effective variable that could be adjusted according to the desired characteristic of the resulting engineered cardiac tissue.
Claim(s) 96, 99-103 are rejected under 35 U.S.C. 103 as being unpatentable over Zimmermann et al, in view of Atkins et al, and Vantler et al as applied to claim 84-95, 97-98 above, and further in view of Gao et al ( Circulation, 2018).
Regarding claim 96, the teachings of Zimmermann, Atkins, and Vantler et al are set forth above. The cited prior arts render obvious claim 84. It is submitted that none of the cited prior art teach that the hydrogel composition comprises of fibrin hydrogel. Gao et al supplement the cited prior arts by teaching the fabrication of engineered human cardiac muscle patches using cardiac muscle cells differentiated from human iPSCs. Specifically, Gao et al teach suspending hiPSCs-derived cardiomyocytes, endothelial cells, and smooth muscle cells in a fibrinogen solution, mixing the cell- containing fibrinogen with a solution comprising thrombin, quickly poring the resulting mixture in a mold, and culturing the resulting construct. ( See section “ Fabrication and Characterization of Large, Thick, hiPSC-Derived hCMPs” on page 1714). Accordingly, Gao et al expressly teach fibrin-based hydrogel. Thus, an ordinary skill in the art would be motivated to use the fibrin-based hydrogel of Gao et al because fibrin was a known and widely used biomaterial for cardiac tissue engineering, and Gao et al demonstrated that fibrin-based hydrogel can successfully be used to generate a functional cardiac construct. An ordinary skill in the art would have had a reasonable expectation of success that using a fibrin-based hydrogel would provide a suitable three-dimensional environment for cardiac cell. In other words, instant claim is combining prior art elements according to known methods to yield predictable results. See MPEP 2143 (I)(A).
Regarding claims 99-103, following the discussion above Zimmermann, Atkins, and Vantler et al render obvious claim 84. Atkins et al further recognize the suitability of employing the generated engineered heart construct for the treatment of heart damage. Specifically, Atkins et al state that “the tissue engineered cardiac constructs may be implanted into a subject for the treatment of conditions involving tissue damage or dysfunction in accordance with standard surgical procedures. In particular, the tissue-engineered cardiac construct may be implanted directly into, for example, damaged (or other) areas of a heart during heart surgery in order to augment contractile function”.[0049]. Gao et al further demonstrate the use of engineered human cardiac tissue for treatment of damaged cardiac tissue. Gao et al describe human cardiac muscle patches generated from cardiomyocytes, smooth muscle cells, and endothelial cells differentiated from human induced pluripotent stem cells. The cells were incorporated into fibrin scaffold and cultured to form engineered human cardiac muscle patches. ( See section “Fabrication and Characterization of Large, Thick, hiPSC-Derived hCMPs”, on page 1714). Gao et al further disclose transplantation of the engineered human cardiac muscle patches onto the site of myocardial infraction in a porcine model. Gao et al report that transplantation of the patches was associated with significant improvements in left-ventricular function, infraction size, and myocardial wall stress. ( See section “ hiPSC-Derived Cardiac Cells Engraft and Survive After hCMP Transplantation Into a Porcine Model of MI” on page 1717). Accordingly, Gao et al demonstrate the generation of human cardiac tissue in a form of tissue patches, as well as the administration/ transplantation of the engineered cardiac tissue to a subject suffering from a cardiac tissue injury (i.e. myocardial infraction) and report improved recovery following transplantation. Therefore, it would have been prima facie obvious to one with ordinary skill in the art at the time the invention was filed to generate the human cardiac tissue in a form of patches according to the teachings of Zimmermann, Atkins, and Vantler et al and further to use them for the treatment of cardiac tissue injury as taught by Gao et al. Because Gao et al provide an express teaching of making engineered human cardiac tissue in the form of patches and demonstrate that transplantation of the engineered human tissue into injured myocardium can reduce the consequences of myocardial infraction. An ordinary skill in the art would have a reasonable expectation of success when transplanting the engineered human cardiac tissue into a subject with a cardiac tissue injury that the transplanted cells would migrate, integrate, and probably would improve the recovery after transplantation. In other words, instant claims are combining prior art elements according to known methods to yield predictable results. See MPEP 2143 (I)(A).
Conclusion
No claim is allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to FATIMAH KHALAF MATALKAH whose telephone number is (703)756-5652. The examiner can normally be reached Monday-Friday,7:30 am-4:30 pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tracy Vivlemore can be reached on 571-272-2914. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/FATIMAH KHALAF MATALKAH/Examiner, Art Unit 1638
/Tracy Vivlemore/Supervisory Primary Examiner, Art Unit 1638
Prosecution Insights