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 .
DETAILED ACTION
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
This Action is in response to the papers filed on November 24, 2025. Pursuant to the amendment filed on November 24, 2025, claims 3 and 11 are currently pending of which claim 3 has been amended, claims 4 and 5 have been cancelled, and claim 11 is newly filed.
Therefore, claims 3 and 11 are currently under examination to which the following grounds of rejection are applicable.
Response to Arguments
Withdrawn Objections/Rejections in response to Applicants’ arguments or amendments:
Claim Rejections - 35 USC § 103
In view of Applicants’ amendment to the claims dated November 24, 2025, wherein claim 3 has been amended, claims 4 and 5 have been cancelled, and claim 11 is newly filed, the rejection to claim 3 rejected under 35 U.S.C. 103 as being unpatentable over Tsumaki et al. (WO 2016/133208) in view of Correa et al. (2015, Osteoarthritis and Cartilage 23:443-453) and Sennett et al. (Journal of Orthopaedic Research® 36.10 (2018): 2648-2656), has been withdrawn.
In view of Applicants’ amendment to the claims dated November 24, 2025, wherein claim 3 has been amended, claims 4 and 5 have been cancelled, and claim 11 is newly filed, the rejection to claims 4 and 5 rejected under 35 U.S.C. 103 as being unpatentable over Tsumaki et al. (WO 2016/133208) in view of Correa et al. (2015, Osteoarthritis and Cartilage 23:443-453) and Sennett et al. (Journal of Orthopaedic Research® 36.10 (2018): 2648-2656), further in view of Zhang et al. (Stem Cells International 2014.1 (2014): 125683), have been rendered moot.
The withdrawn rejection is in view of the amendments to claim 3 now stating the culturing of step 2 as occurring in a permeable vessel, and furthermore under flow conditions as opposed to a frame in now cancelled claim 4; and furthermore not being limited to culturing with FGF18. Applicants’ arguments are moot in view of the withdrawn rejections.
New Grounds of Rejection
Claim Rejections - 35 USC § 103
Claims 3 is newly rejected under 35 U.S.C. 103 as being unpatentable over Tsumaki et al. (WO 2016/133208; publication date August 25, 2016; citations are from US2018/0251732A1; of record) in view of Gilbert et al. (Processes 2.3 (2014): 658-674).
This is a new rejection necessitated by Applicants' amendments to the claims in the response filed on November 24, 2025.
Claim 3 is directed to a method for producing a pluripotent stem cell-derived cartilage comprising a layer of a plurality of pluripotent stem cell-derived cartilage consisting of pluripotent stem cell-derived chondrocytes, cartilage extracellular matrix produced by the chondrocytes, and perichondrium-like membranes, said method comprising;
step 1: producing pluripotent stem cell-derived cartilage by inducing pluripotent stem cells to differentiate into the chondrocytes and to produce the cartilage extracellular matrix, and
step 2: culturing the pluripotent stem cell-derived cartilage in a culture medium contained in a liquid permeable vessel in a culture medium, wherein adjacent pluripotent stem cell-derived cartilage integrates in contact with one another thereby forming said layer, wherein the culturing is performed in culture medium under flow conditions.
Regarding claim 3, Tsumaki teaches “A method for producing a pluripotent stem cell-derived cartilage comprising a layer of a plurality of pluripotent stem cell-derived cartilage consisting of pluripotent stem cell-derived chondrocytes and cartilage extracellular matrix produced by the chondrocytes, and perichondrium-like membranes, said method comprising; step 1: producing pluripotent stem cell-derived cartilage by inducing pluripotent stem cells to differentiate into the chondrocytes and to produce the cartilage extracellular matrix (“The iPS cell clusters obtained by the above method were collected, and the whole or half of them were seeded on a 10-cm culture dish (Iwaki) with 5 mL of chondrogenic differentiation medium…During the culture period, the iPS cell clusters gradually adhered on the dish and ultimately formed nodules…The results show that cell clusters (cartilaginous particles) intensely stained with safranin O, i.e., cell clusters composed of an extracellular matrix and chondrocytes were obtained (FIG. 1).” (par 0077-0078); “As a result, both in the human iPS cell-derived cartilaginous particles and in the mouse embryonic cartilage primordia, a type II collagen-positive cartilage tissue was surrounded by a type I collagen-positive membrane as shown in FIG. 2. The surrounding membrane of the cartilage primordium is called perichondrium. The results show that the human iPS cell-derived cartilaginous particles are morphologically similar to the embryonic cartilage consisting of cartilage and perichondrium.”(par 0078));
and step 2: culturing the pluripotent stem cell-derived cartilage in a culture medium contained in in a culture medium, wherein adjacent pluripotent stem cell-derived cartilage integrates in contact with one another thereby forming said layer, wherein the culturing is performed in culture medium under flow conditions. (“During the culture period, the iPS cell clusters gradually adhered on the dishes and ultimately formed nodules. The formed nodules were detached using a cell scraper, transferred to a 6-cm suspension culture dish (Sumitomo), and cultured under the conditions of 37° C. and 5% CO2… Cell clusters obtained 28 days from the start of differentiation induction, i.e., culture in chondrogenic differentiation medium, were examined by safranin O staining. The results show that cell clusters (cartilaginous particles) intensely stained with safranin O, i.e., cell clusters composed of an extracellular matrix and chondrocytes were obtained” (par 0082-0084); “Two human iPS cell-derived cartilaginous particles obtained 90 days after the start of the differentiation induction in Example 1 were cultured in contact with each other in medium for 60 days. As a result, the two particles were integrated to form a single particle as shown in FIG. 4. Originally, the two particles were independent cartilage tissues surrounded by their respective perichondria, but in the integrated part, the perichondria disappeared and the cartilage tissues started integrating with each other.” (par 0092); “The chondrocytes obtained by the method of the present invention may be obtained as a cartilaginous tissue (also called a cartilaginous particle) containing chondrocytes and an extracellular matrix. The cartilaginous tissue is composed of an outer membrane and inner components surrounded by the outer membrane.” (par 0054)). Tsumaki teaches “flow conditions” based on teaching suspension culturing wherein a bioreactor is used (par 0050)
Tsumaki does not teach in relation to step 2 culturing the pluripotent stem cell-derived cartilage in a liquid permeable vessel.
Gilbert teaches using perfusion bioreactor to generate scaffold-free tissue engineered cartilage constructs, wherein flow of culture media was restricted through the transwell which comprises a 0.22 micron membrane filter, and thus the cell constructs (abstract, Sec. 2.1; Fig. 2). Chondrocytes were isolated and inserted into transwell inserts, and then tested under different flow conditions, e.g. flow directions (Methods 1&2), and static culture before perfusion (Method 3) (Sec. 2.2). The study concludes, “In summary, our novel through-thickness perfusion bioreactor has shown the capacity to successfully generate a 24 mm diameter scaffold-free tissue engineered cartilage construct with superior biochemical and biomechanical properties to a statically cultured cartilage construct.” (Conclusion). In reference to forming a layer, the obtained constructs formed thicker layers when using perfusion system as opposed to static culturing (Table 1, Fig. 5).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of culturing cartilage in suspension taught by Tsumaki to incorporate a liquid permeable vessel (as taught by Gilbert) because it would have been obvious to combine prior art elements according to known methods to yield predictable results. The incorporation of a liquid permeable vessel in the suspension culture taught by Tsumaki would have led to predictable results with a reasonable expectation of success because both Gilbert and Tsumaki. teach successful generation of cartilage formation after culturing of chondrocytes in suspension culture. In particular, Gilbert teaches improved outcomes for cartilage formation when using suspension culture with a liquid permeable vessel, e.g. perfusion with a mesh filter, as opposed to static conditions; and moreover, Tsumaki teaching suspension culture conditions to obtain cartilage with a culture vessel suitable for three-dimensional suspension culture.
Claim 11 is newly rejected under 35 U.S.C. 103 as being unpatentable over Tsumaki et al. (WO 2016/133208; publication date August 25, 2016; citations are from US2018/0251732A1; of record) in view of Gilbert et al. (Processes 2.3 (2014): 658-674), as applied to claim 1, and further in view of Davidson et al. (
Regarding claim 3, the disclosure of Tsumaki in view of Gilbert is applied as in the 103 rejections above, the content of which is incorporated above, in its entirety.
Regarding claim 11, Tsumaki does not teach step 2, specifically culturing the pluripotent stem cell-derived cartilage in a culture medium comprising FGF18.
Sennett teaches using recombinant human FGF18 (sprifermin) for cartilage defect repairs wherein cartilage explants with created defects were cultured in control or sprifermin-containing medium (changed weekly with 24 hour exposure of 100 ng/ml sprifermin) for 4 weeks. The results showed greater adhesive strength (Fig. 3), increased collagen content, i.e. ECM (Fig. 4), and larger contact areas between core and annular cartilage in the sprifermin-treated group (Fig. 5 and 6), and stating “These findings present a novel treatment for cartilage injuries that have potential to enhance defect healing and lateral cartilage–cartilage integration.” (abstract; Fig. 1).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of culturing cartilage, particularly the culture media taught by Tsumaki to incorporate FGF-18 (as taught by Sennett) because it would have been obvious to combine prior art elements according to known methods to yield predictable results. The incorporation of FGF-18 in the culture media taught by Tsumaki would have led to predictable results with a reasonable expectation of success because both Sennett and Tsumaki teach successful generation of cartilage formation after tissue culturing. In particular, Sennett teaches improved outcomes for cartilage formation when using FGF-18 as describes as having greater adhesive strength, increased collagen content, and larger contact areas between core and annular cartilage. Moreover, Tsumaki teaching suspension culture conditions that would allow the incorporation of FGF-18 in the culture media as it allows incorporation of other growth factors (par 0055), and therefore the outcome observed by Sennett would subsequently be expected.
Response to Applicants’ Arguments as they apply to the rejection of claim 3-5 under 35 USC § 103
Starting on page 3 of the remarks filed on November 24, 2025, Applicants essentially argue the following:
“(i) Distinctions between the invention of claim 3 and the cited references”
“(ii) Effects of the invention of independent method claim 3” Applicant argues improved properties observed in the claimed invention for suspension culturing versus static conditions (example 1 versus 2 of the instant application). Applicant cites Figure 11 and 12 for support.
“(iii) General state of the art as of the priority date for present application”
Applicant's arguments filed on November 24, 2025 have been fully considered but they are not persuasive for the following reasons:
In response to the first argument, the previous rejection for claim 3 has been withdrawn, and the new grounds of rejection is made obvious over Tsumaki et al. (same reference) in view of Gilbert et al., as opposed to Tsumaki et al. in view of Correa et al. and Sennett et al.. Therefore in view of the amended claim 3, the new rejection makes obvious the amendments to the claim, particularly Gilbert teaches the limitation of a liquid permeable vessel and flow conditions by teaching culturing cartilage/chondrocytes in perfusion system on a filter membrane wherein the outcome of cartilage formation were improved in comparison to only static culture conditions. Therefore this argument that depends on the withdrawn rejection is considered moot. It is acknowledged that the Tsumaki reference is still used, yet the new limitations presented in the amended claim 3 are currently taught in view Gilbert.
In response to the second argument, describing the claimed invention leads to improved properties, it is noted that the features upon which applicant relies, for example, “a mesh bag containing pluripotent stem cell-derived cartilage was placed into a bioreactor containing the chondrogenic medium, and culture was performed under the conditions of 37°C and 5% CO2 with stirring of the medium for 4 weeks”, are not recited in the rejected claim(s). Moreover, the main limitation for which this comparison is made is based on static versus dynamic culture conditions as seen in suspension culturing, e.g. perfusion. The Gilbert reference explicitly teaches this improved outcome when using a perfusion system for cartilage formation when culturing chondrocyte as opposed to static culture conditions. Therefore, the argued improved properties were effectively known in the art, and therefore the incorporation of such step would have been clearly obvious. Lastly, based on Tsumaki in view of Gilbert teaching the entirety of the claimed method steps recited in claim 1, the outcomes related to these methods are expected, i.e. wherein adjacent pluripotent stem cell-derived cartilage integrates in contact with one another thereby forming said layer. Regardless, both references clearly teach such outcome as Tsumaki teaches the integration of the membranes and Gilbert teaching thicker layer formation during cartilage formation.
Regarding the third presented argument, Applicant states,
“However, it was believed that the flowing culture medium during the integration of two pieces of cartilage would prevent them from maintaining contact, thereby being detrimental to the integration process. Therefore, the effect of promoting formation of the layer of the pluripotent stem cell derived cartilage by flowing the culture medium is a remarkable effect that could not be reasonably predicted based on the common technical knowledge at the time of the priority date of the present application. Applicant respectfully submits that the cited references, including those newly cited, do not provide the proper reason or rationale that would allow one of ordinary skill in the art to arrive at the claimed invention.”;
However, this rationale is not accurate since Gilbert clearly teaches the effect of promoting formation of the layer of cartilage by flowing the culture medium as seen in the perfusion system wherein outcomes were improved over static conditions for which the Applicant points to as more common at the time of filing. It is acknowledged that the starting cells for Gilbert are different than the claimed invention as they are not derived from pluripotent stem cells, yet Tsumaki fills this gap in teaching the differentiation of these cells for cartilage formation.
Conclusion
Claims 3 and 11 are rejected. No claims are allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/MICHAEL ANGELO RIGA/Examiner, Art Unit 1634
/TERESA E KNIGHT/Primary Examiner, Art Unit 1634