Prosecution Insights
Last updated: April 19, 2026
Application No. 18/039,027

MEDIUM COMPOSITION FOR DERMAL PAPILLA CELL GROWTH, CONTAINING ROTENONE AND ALBUMIN AS ACTIVE INGREDIENTS

Final Rejection §101§102§103
Filed
May 26, 2023
Examiner
PYLA, EVELYN Y
Art Unit
1633
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Xcell Therapeutics Inc.
OA Round
2 (Final)
55%
Grant Probability
Moderate
3-4
OA Rounds
3y 9m
To Grant
99%
With Interview

Examiner Intelligence

Grants 55% of resolved cases
55%
Career Allow Rate
296 granted / 538 resolved
-5.0% vs TC avg
Strong +48% interview lift
Without
With
+47.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
42 currently pending
Career history
580
Total Applications
across all art units

Statute-Specific Performance

§101
5.5%
-34.5% vs TC avg
§103
40.2%
+0.2% vs TC avg
§102
16.8%
-23.2% vs TC avg
§112
27.0%
-13.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 538 resolved cases

Office Action

§101 §102 §103
DETAILED ACTION Applicant’s response filed 12/16/2025 has been received and entered into the application file. All arguments have been fully considered. Claims 1 and 5-10 are currently pending. Claims 2-4 are cancelled. Claim 1 is amended. 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 . Claim Interpretation Claim 1 recites the phrase “for culturing dermal papilla cells”. It is noted the claims are to the composition, per se. Although claim 1 states that the composition is “for culturing dermal papilla cells”, this limitation is considered only to be directed to intended use which does not further define or limit the composition, per se. Compositions are defined by their physical, structural, and chemical properties, not by an intended use or application. Please note that it is well settled that “intended use” of a composition or product, e.g., “for culturing dermal papilla cells”, will not further limit claims drawn to a composition or product. See, e.g., Ex parte Masham, 2 USPQ2d 1647 (1987) and In re Hack 114, USPQ 161. See MPEP 2111.02 Further regarding claim 5 and the limitation “the dermal papilla cells are derived from humans”, this limitation is likewise directed to the intended use of the claimed composition and does not further limit the composition. REJECTION(S) MAINTAINED Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claims 1 and 5-9 are rejected under 35 U.S.C. 101 because the claimed invention is directed to a natural phenomenon without significantly more. The rejection has been updated in view of Applicant’s amendment submitted 12/16/2025. The rationale set forth below conforms to current Office practice for examination of claims under § 101. These claims are analyzed for eligibility in accordance with their broadest reasonable interpretation. All of the claims are directed to a statutory category, e.g., a composition (Step 1: YES). The next part of the analysis involves whether the claimed invention recites or is directed to one or more judicial exceptions (Step 2A, prong one). Claim 1: Claim 1 is directed to a culture medium additive for culturing dermal papilla cells, comprising rotenone and albumin. The claim recites rotenone is present at a concentration ranging from 10 to 100 pM and albumin is present at a concentration ranging from 0.1 g/L to 0.5 g/L. As is recognized by the instant specification (page 8, lines 4-5]), rotenone is a chemical component obtained from the root of Derris elliptica, which is a leguminous plant. As is further recognized by the instant specification (page 8, lines 4-5]), albumin is a blood plasma protein that can be obtained from human plasma or serum. Thus, claim 1 recites a combination of two products of nature. Although rotenone and albumin are not found in combination in nature, and specifically where rotenone is present at a concentration ranging from 10 to 100 pM and albumin is present at a concentration ranging from 0.1 g/L to 0.5 g/L, there is no indication in the specification that in combining rotenone with albumin at the recited concentrations, that any characteristics (structural, functional, or otherwise) are developed by either the rotenone or the albumin that are not present in the individual parts. The combination does not improve or change in any way each components natural functioning. Thus, the claimed composition does not have markedly different characteristic from what occurs in nature and is a "product of nature" exception. Accordingly, the claims are directed to an exception (Step 2A, prong one: YES). Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101. The claim as a whole, considering all claim elements, does not amount to significantly more than the natural product of rotenone. Thus, the claimed composition does not have markedly different characteristic from what occurs in nature and is a "product of nature" exception. Accordingly, the claims are directed to an exception (Step 2A, prong one: YES). Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101. Claim 5: Claim 5 further defines the dermal papilla cells are derived from humans. It is noted, as set forth above at Claim Interpretation, this limitation is directed to the intended use of the culture medium additive, i.e., “for culturing dermal papilla cells”, and therefore does not limit the claimed rotenone composition in such a way that is markedly different in structure or biological and/or pharmacological function from the natural counterpart. Claim 6: Claims 6 is directed to a culture medium composition for culturing dermal papilla cells, comprising the culture medium additive of claim 1 and a basal medium. It is noted that there is no indication in the specification that in combining rotenone with a basal medium, that any characteristics (structural, functional, or otherwise) are developed by the rotenone that are not present in the individual part. The combination does not improve or change in any way the natural functioning of retenone. Thus, the claimed composition does not have markedly different characteristic from what occurs in nature and is a "product of nature" exception. Accordingly, the claims are directed to an exception (Step 2A, prong one: YES). Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101. Claims 7 and 8: Claim 7 further defines the culture medium as a serum-free medium. Claim 8 further defines the type of basal medium. These limitations do not limit the claimed rotenone in such a way that is markedly different in structure or biological and/or pharmacological function from the natural counterpart. Thus, the claimed composition does not have markedly different characteristics from what occurs in nature and is a "product of nature" exception. Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101. Claim 9: Claim 9 further defines that the medium composition maintains the characteristics of dermal papilla cells for at least 10 passages. However, said limitation does not limit the claimed rotenone in such a way that is markedly different in structure or biological and/or pharmacological function from the natural counterpart. Accordingly, the claims are directed to an exception (Step 2A, prong one: YES). Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101. The next part of the analysis involves whether the claimed invention recites additional elements that integrate the judicial exception into a practical application (Step 2A, prong two). Given the claims are directed to a composition, the claims do not recite additional steps that integrate the judicial exception into a practical application (Step 2A, prong two: No). The final part of the analysis involves whether the claimed invention, as a whole, recite something “significantly more” than the judicial exceptions (Step 2B). In view of the above and considered as a whole, the claimed composition does not have markedly different characteristics from what occurs in nature and such elements discussed above are not significantly more than the indicated judicial exceptions. Thus, the claims do not qualify as eligible subject matter, and are rejected under 35 U.S.C. 101 (Step 2B: NO). REJECTION(S) WITHDRAWN Claim Rejections - 35 USC § 102 RE: Rejection of Claim(s) 1, 3, 5-7, 9-10 under 35 U.S.C. 102(a)(1) as being anticipated by Zheng: Due to the claim amendments the rejection under 35 U.S.C. 102(a)(1) has been withdrawn, however the amendments have necessitated a new ground of rejection, as set forth below. Claim Rejections - 35 USC § 103 RE: Rejection of Claim(s) 2, 4 and 8 under 35 U.S.C. 103 as being unpatentable over Zheng, in view of Bakkar: For the reasons discussed above, the anticipation rejection over Zheng is withdrawn, and thus the obviousness rejection that is based on the same basis is likewise withdrawn. However, the amendment submitted 12/16/2025 has necessitated new grounds of rejection, as set forth below. NEW GROUND(S) OF REJECTION, NECESSITATED BY AMENDMENT Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1 and 5-10 are rejected under 35 U.S.C. 103 as being anticipated by Zheng et al., (British Journal of Dermatology (2019) 181, pp523-534; IDS 8/8/2023, previously cited) (“Zheng”), in view of Bakkar et al., (US 2020/0255801; previously cited) (“Bakkar”). Zheng is directed to a study investigating the mitogenic and hair inducing effects of hypoxia on dermal papilla cells (DPCs) and subsequently learned that hypoxia significantly increased proliferation and delayed senescence of DPCs (Summary). Regarding claims 1 and 10, Zheng specifically teaches conducting culturing of dermal papilla cells (i.e., a method for culturing dermal papilla cells) using low concentrations of reactive oxygen species (ROS) donors, including rotenone at concentrations ranging from 1 pM to 1000 pM (claimed range lies within the prior art range), wherein the presence of low concentrations of rotenone significantly increased DPCs proliferation and migration (Fig. 5 a-b; and page 529-530, Low concentrations of reactive oxygen species donors activate dermal papilla cells). Zheng’s Supplementary Materials and Methods, Proliferation assay teaches the cells were incubated for 48 hours in serum-free basal medium containing 1% antibiotics (page 1 of Supplementary Materials and Methods). Zheng does not further teach the culture medium additive further comprises albumin at a concentration ranging from 0.1 g/L to 0.5 g/L. However, Bakkar is directed to methods of culturing dermal papilla equivalents using dermal papilla fibroblasts (i.e., dermal papilla cells) (Abstract). Bakkar’s Example 3 specifically teaches culturing the dermal papilla fibroblasts using basal medium comprising DMEM Glutamax supplemented with various ingredients including 400 mg/l (0.4 g/l) of BSA (bovine serum albumin) ([0210]-[0220]). Thus, Bakkar has established it was known that dermal papilla fibroblasts were successfully cultured in medium comprising albumin (BSA) at a concentration of 400 mg/l (prior art range lies within the claimed range). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include albumin as a culture medium additive. The person of ordinary skill in the art would have been motivated to modify the culture composition of Zheng to include albumin (BSA), as taught by Bakkar, for the predictable result of successfully promoting growth and proliferation of the dermal papilla fibroblasts, thus meeting the limitation of claim 1. The skilled artisan would have had a reasonable expectation of success in combining the teachings of Zheng and Bakkar because each of these teachings are directed at cultivation of dermal papilla cells. Regarding claim 5, and the limitation “the dermal papilla cells are derived from humans”, it is noted, as discussed above at Claim Interpretation, this limitation is likewise directed to the intended use of the claimed composition and does not further limit the composition of claim 1. Therefore, claim 5 is included in the rejection of claim 1. Regarding claim 6, Zheng teaches the basal medium comprises Follicle Dermal Papilla Cell Growth Medium, thus meeting the limitation of claim 6. Regarding claim 7, Zheng’s Supplementary Materials and Methods, Proliferation assay, teaches the cells were incubated for 48 hours in serum-free basal medium containing 1% antibiotics (page 1 of Supplementary Materials and Methods), thus meeting the limitation of claim 7. Regarding claim 8, although Zheng does not further teach the basal medium comprises any one of those recited in claim 8, e.g., DMEM, it is noted that Bakkar, as discussed above regarding claim 1, has shown that DMEM is successfully employed for the culturing of the dermal papilla fibroblasts ([0212]). Therefore, it would have been prima facie obvious to one having ordinary skill in the art at the time of filing the invention to substitute DMEM, as taught by Bakkar, for the culture medium of Zheng, since both cell types are known to provide successful cultivation and proliferation of dermal papilla cells. Therefore, one of ordinary skill in the art would recognize this as simply substituting one type of dermal papilla culture medium for another useful for the same purpose ((KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398 (2007) pg 14 and 12). Regarding claim 9 and the limitation “the medium composition maintains the characteristics of dermal papilla cells for at least 10 passages”, it is noted this limitation is interpreted as functional language and is not given patentable weight because the said functional recitation does not appear to add additional structural limitations to the instant claimed product. See MPEP 2106 (II) (C) and 2111.02 (II). Additionally, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977).” See MPEP 2112.01 (I). Moreover, the prior teaches the same rotenone and albumin components as disclosed in the instant specification, thus any properties exhibited by or benefits provided by the composition are inherent and are not given patentable weight over the prior art. A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties Applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ 1655, 1658 (Fed. Cir. 1990). See MPEP 2112.01. The burden is shifted to Applicant to show that the prior art product does not inherently possess the same properties as instantly claimed product. Response to Remarks Rejection under 35 USC 101: Applicant has traversed the rejection of record on the grounds that the specification provides direct experimental evidence that the claimed combination and concentration ranges impart new and markedly different functional characteristics to dermal papilla cell cultures, as compared to the presence of rotenone and albumin alone. Applicant asserts the interplay between rotenone and albumin produces a functional behavior that neither component yields by itself, specifically sustained high proliferation with preserved inductive markers over at least 10 passages, as discussed at Applicant’s remarks (pages 4-5). It is noted that Applicant’s remarks have been fully considered, but are not found persuasive since the claims are not directed to methods of cell proliferation. The claims do not require the presence of cells, or any limitations regarding passage number. There is no indication in the specification that, in combining rotenone with albumin at the recited concentrations, any characteristics (structural, functional, or otherwise) are developed by the rotenone or albumin that are not present in the individual part. The combination does not appear to improve or change in any way the natural functioning of rotenone or albumin. Rejection under 35 USC 102: As set forth above, the rejection has been withdrawn in view of Applicant’s amendment submitted 12/16/2025. Rejection under 35 USC 103: For the reasons discussed above, the anticipation rejection over Zheng is withdrawn, and thus the obviousness rejection that is based on the same basis is likewise withdrawn. However, the amened limitations are addressed above under the new ground of rejection. Applicant has traversed the rejection of record on the grounds that Bakkar et al do not provide motivation to add albumin to the dermal papilla culture medium of Zheng, that Bakkar’s inventive examples use medium B without albumin to form well-defined dermal papilla spheroids and Bakkar only demonstrates use of albumin (BSA) in the comparative examples, and Bakkar characterizes the use of BSA results in poor quality dermal papilla spheroids, as discussed at Applicant’s remarks (pages 6-7). Applicant’s remarks have been carefully considered, but are not found persuasive. In response, it is noted that Bakkar does not recite the terms “poor” or “failure” in characterizing the comparative culture supplemented with albumin. Bakkar, at [0222], merely concludes the morphology of the obtained dermal papilla comprised very heterogeneous cell aggregates of different sizes with irregular edges, as illustrated in FIG. 11. Bakkar does not teach that the use of albumin results in a failure of obtaining dermal papilla. On the contrary, Bakkar demonstrates successful culturing in the presence of 0.4 g/L of BSA (albumin). Applicant further asserts the claimed concentration ranges are not arbitrary and provide unexpectedly superior results when the culture medium additive comprises 10 pM of rotenone and 0.1 g/L of albumin, as discussed at Applicant’s remarks (pages 7-8). Applicant’s remarks have been carefully considered, but are not found persuasive given the claims are not limited to the specific concentrations of 10 pM of rotenone and 0.1 g/L of albumin. Conclusion No claim is allowed. No claim is free of prior art. 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. Examiner Contact Information Any inquiry concerning this communication or earlier communications from the examiner should be directed to E. YVONNE PYLA whose telephone number is (571)270-7366. The examiner can normally be reached M-F 9am - 6pm. 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, CHRISTOPHER BABIC can be reached at 571-272-8507. 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. E. YVONNE PYLA Primary Examiner Art Unit 1633 /EVELYN Y PYLA/ Primary Examiner, Art Unit 1633
Read full office action

Prosecution Timeline

May 26, 2023
Application Filed
Sep 24, 2025
Non-Final Rejection — §101, §102, §103
Dec 16, 2025
Response Filed
Mar 25, 2026
Final Rejection — §101, §102, §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
55%
Grant Probability
99%
With Interview (+47.8%)
3y 9m
Median Time to Grant
Moderate
PTA Risk
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