Prosecution Insights
Last updated: April 19, 2026
Application No. 18/264,521

METHOD FOR DIFFERENTIATING PLURIPOTENT STEM CELL-DERIVED HEMOGENIC ENDOTHELIAL CELLS INTO LYMPHOID LINEAGE CELLS

Non-Final OA §103§112
Filed
Aug 07, 2023
Examiner
WILSON, MICHAEL C
Art Unit
1638
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Sungkwang Medical Foundation
OA Round
1 (Non-Final)
42%
Grant Probability
Moderate
1-2
OA Rounds
3y 9m
To Grant
59%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
384 granted / 921 resolved
-18.3% vs TC avg
Strong +18% interview lift
Without
With
+17.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
76 currently pending
Career history
997
Total Applications
across all art units

Statute-Specific Performance

§101
5.1%
-34.9% vs TC avg
§103
25.3%
-14.7% vs TC avg
§102
20.7%
-19.3% vs TC avg
§112
36.5%
-3.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 921 resolved cases

Office Action

§103 §112
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 . Claims 1-12 are pending. Claim Objections The first occurrence of each abbreviation should be spelled out before being abbreviated. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Written Description Claims 1-12 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. The specification lacks written description for making/using any species of “lymphoid lineage blood cell” from any species of pluripotent cell as broadly encompassed by claim 1 other than culturing mammalian pluripotent cells in medium containing bFGF, VEGF, and SCF such that mesodermal cells are obtained; ii) culturing the mesodermal cells in medium containing TPO, EPO, and IGF1 such that hemogenic endothelial (HE) cells are obtained; and iii) culturing the HE cells in medium containing IL5, IL7 and DLL such that T-cells and NK cells are obtained. Claim 1 encompasses obtaining any “lymphoid lineage blood cell” from any species of pluripotent cells. The cells encompass plant, insect, fish, amphibian, reptile, bird, or mammalian cells. The claim requires “differentiating [pluripotent cells] in medium containing bFGF, VEGF, and SCF” but does not say they are in culture or isolated. The specification is limited culturing mammalian pluripotent cells in medium containing bFGF, VEGF, and SCF such that mesodermal cells are obtained; ii) culturing the mesodermal cells in medium containing TPO, EPO, and IGF1 such that hemogenic endothelial (HE) cells are obtained; and iii) culturing the HE cells in medium containing IL5, IL7 and DLL such that T-cells and NK cells are obtained (Examples). The specification does not correlate mammalian cells to any other species. The specification does not correlate culturing one type of cell under certain media conditions to “differentiating” using a medium that is in vivo. Accordingly, the claims lack written description. The specification lacks written description for culturing mesoderm cells in medium containing TPO, EPO, IGF1, bFGF, VEGFA, FLT3L, GCSF and IL6 as required in claim 4. The specification does not teach the concept and does not exemplify the concept. Indefiniteness 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 1-12 are 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. The metes and bounds of “early hemogenic endothelial cells” in claim 1 cannot be determined. The specification and the art at the time of filing do not teach the structures/functions that define when hemogenic endothelial (HE) cells are “early”. The term “early” is relative and at the discretion of the person of skill and may be different for everyone. Accordingly, those of skill would not be able to determine when they were infringing on the claim. The metes and bounds of “late hemogenic endothelial cells” in claim 1 cannot be determined. The specification and the art at the time of filing do not teach the structures/functions that define when hemogenic endothelial (HE) cells are “late”. The term “late” is relative and at the discretion of the person of skill and may be different for everyone. Accordingly, those of skill would not be able to determine when they were infringing on the claim. Claim 5 is indefinite because it is unclear when an EHE cell has “rod-type morphological characteristics”. Claim 1 requires obtaining lymphoid lineage blood cells from mesodermal, EHE, and LHE cells, but rod cells are in the eye and not mesodermal, EHE, LHE, or blood cells. Or perhaps applicants are attempting to set forth the shape, but the metes and bounds of when a “rod-like” shape has been obtained cannot be determined. It is also unclear when cells have “bright yellow light” as required in item b) because cells don’t have lights. If it is simply a color, it is unclear when a yellow cell is “bright yellow” as claimed. Accordingly, those of skill would not be able to determine when they were infringing on the claim. Claim 7 is indefinite because it is unclear when a LHE cell has “cobblestone-type morphological characteristics”. Perhaps applicants are attempting to set forth the shape, but the metes and bounds of when a “cobblestone-like” shape has been obtained cannot be determined, especially when the cell is isolated and not amongst other cells. Accordingly, those of skill would not be able to determine when they were infringing on the claim. 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. Claims 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Rajesh (20100279403) in view of Themeli (20160009813) and Garelick (WO 2016123100), Valamehr (AU 2016211671) Rajesh cultured pluripotent cells in medium comprising bFGF, VEGF, and SCF as required in step i) of claim 1 (para 112) followed by culturing in TPO and EPO (para 71, 79) and optionally IGF to obtain endothelial cells as required in step ii) of claim 1 (para 92, 103) followed by culturing in IL7 and optionally DLL to obtain T-cells (para 13, claims 46, 47, 48). Rajesh did not teach using IL5 as required in step iii). However, Themeli cultured culturing endothelial cells in IL5, IL7 and DLL to obtain T-cells (para 15, 164) as required in step iii). Garelick cultured pluripotent cells in medium comprising bFGF, VEGF, and SCF as required in step i) of claim 1 (para 13, 16; claim 3) followed by culturing in IL5, IL7 and DLL to obtain T-cells (para 15, 164) as required in step iii). Valamehr (AU 2016211671 = WO 2016/123100) differentiated human iPS cells into hematopoietic lineages (Example 2), intermediate cells (Examples 6-10) and mature T-cells and NK cells using IL5, IL7, DDL (pg 127, para 304) as required in step iii). Thus, it would have been obvious to those of ordinary skill in the art at the time of filing culture pluripotent cells in medium comprising bFGF, VEGF, and SCF, followed by culturing in TPO, EPO and IGF followed by IL7 and DLL to obtain T-cells as described by Rajesh wherein the final step contained IL5, IL7, and DLL as described by Themeli, Garelick, and Valamehr. Those of ordinary skill in the art at the time of filing would have been motivated to use IL5 to improve maturity of T-cells and NK cells as described by Themeli, Garelick, and Valamehr. Rajesh used human iPS cells as required in claim 2. Rajesh used BMP4 in the first medium (claim 1) as required in claim 3. Rajesh used IL6 in the 2nd medium (para 10, 11) as required in claim 3 (it is assumed “and” is a typo because it can also be a “mixture thereof”). The cell obtained by the end of step ii) must inherently have the features in claim 5 because they were made using the exact same protocol in claim 1 and described by applicants as being part of the invention. The third media “may comprise one or more growth factor selected from the list consisting of SCF, IL-6, G-CSF, EPO, TPO, FGF2, IL-7, IL-11, IL-9, IL-13, IL-2, or M-CSF in an amount sufficient to promote expansion or further differentiation of the cells” (para 13) as encompassed by claim 6. The cell obtained by the end of step iii) must inherently have the features in claim 7 because they were made using the exact same protocol in claim 1 and because the teachings of Themeli, Garelick, and Valamehr are exactly the same as those described by applicants as being part of the invention. The iPS cells can be cultured for 1-3 days (para 55, 63, 68, 69, 74) as required in claim 8. The mesodermal cells can be cultured for 6-8 days (para 91, 93, 94, 100, 103) as required in claim 9. The HE cells can be cultured for 12-13 days (Themeli, Garelick, and Valamehr) as required in claim 10. The cells can be matured for an additional 13-28 days (Themeli, Garelick, and Valamehr) as required in claim 11. Themeli, Garelick, and Valamehr described using the proteins in claim 12 in the 3rd medium (claim 3, 84, 97). Thus, Applicants' claimed invention as a whole is prima facie obvious in the absence of evidence to the contrary. Conclusion No claim is allowed. Inquiry concerning this communication or earlier communications from the examiner should be directed to Michael C. Wilson who can normally be reached at the office on Monday through Friday from 9:30 am to 6:00 pm at 571-272-0738. Patent applicants with problems or questions regarding electronic images that can be viewed in the Patent Application Information Retrieval system (PAIR) can now contact the USPTO’s Patent Electronic Business Center (Patent EBC) for assistance. Representatives are available to answer your questions daily from 6 am to midnight (EST). The toll free number is (866) 217-9197. When calling please have your application serial or patent number, the type of document you are having an image problem with, the number of pages and the specific nature of the problem. The Patent Electronic Business Center will notify applicants of the resolution of the problem within 5-7 business days. Applicants can also check PAIR to confirm that the problem has been corrected. The USPTO’s Patent Electronic Business Center is a complete service center supporting all patent business on the Internet. The USPTO’s PAIR system provides Internet-based access to patent application status and history information. It also enables applicants to view the scanned images of their own application file folder(s) as well as general patent information available to the public. For all other customer support, please call the USPTO Call Center (UCC) at 800-786-9199. If attempts to reach the examiner are unsuccessful, the examiner's supervisor, Tracy Vivlemore, can be reached on 571-272-2914. The official fax number for this Group is (571) 273-8300. Michael C. Wilson /MICHAEL C WILSON/ Primary Examiner, Art Unit 1638
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Prosecution Timeline

Aug 07, 2023
Application Filed
Feb 09, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
42%
Grant Probability
59%
With Interview (+17.7%)
3y 9m
Median Time to Grant
Low
PTA Risk
Based on 921 resolved cases by this examiner. Grant probability derived from career allow rate.

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