Prosecution Insights
Last updated: April 19, 2026
Application No. 18/276,812

ENGINEERED EXTRACELLULAR VESICLES AND THEIR USES

Non-Final OA §103
Filed
Aug 10, 2023
Examiner
NICOL, ALEXANDER W
Art Unit
1634
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Wake Forest University Health Sciences
OA Round
1 (Non-Final)
41%
Grant Probability
Moderate
1-2
OA Rounds
4y 7m
To Grant
87%
With Interview

Examiner Intelligence

Grants 41% of resolved cases
41%
Career Allow Rate
71 granted / 172 resolved
-18.7% vs TC avg
Strong +46% interview lift
Without
With
+45.8%
Interview Lift
resolved cases with interview
Typical timeline
4y 7m
Avg Prosecution
53 currently pending
Career history
225
Total Applications
across all art units

Statute-Specific Performance

§101
2.7%
-37.3% vs TC avg
§103
40.2%
+0.2% vs TC avg
§102
18.9%
-21.1% vs TC avg
§112
20.7%
-19.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 172 resolved cases

Office Action

§103
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 . Status of Application/Restriction/Claims Applicant’s election with traverse of Group I (Claims 1-4, 6 and 40) in the reply filed om 1/14/2026 is acknowledged. Applicant’s traversal is on the grounds that group I shares the common technical features with Groups II, III, IV, V and VI and can be examined together without undue burden. This is not found persuasive because the common technical feature was known in the art at the time of the invention, Briefly, Leonard describes a plasmid and extracellular vesicle thereof comprising an expression cassette encoding a fusion protein comprising CD63 and at least one cargo RNA with specific embodiments to RNA-motifs that bind the fusion protein with additional functional RNA sequences like sgRNAs (Leonard, para 37, 39). As the common technical feature was known in the art at the time of the invention, this cannot be considered a common special technical feature that would otherwise unify the groups. Furthermore, the search and examination of methods (Groups III and IV) is not coextensive with the search for compositions (Group I, II, V and VI), since the methods have manipulative steps that the compositions don’t have, and are evaluated differently under certain statues (i.e. 35 U.S.C 101 and 112 in particular). Accordingly, unity of invention is lacking and the requirement is still deemed proper and is therefore made FINAL. Claims 1-4, 6, 14-17, 19, 21, 23-24, 28-29, 35 and 40-43 are pending. Claims 14-17, 19, 21, 23-24, 28-29, 35 and 41-43 are currently 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. Claims 1-4, 6 and 40 are the subject of the present Official action. Priority Applicant’s claim for the benefit of a prior-filed application PRO 63/148,872 and 371 of PCT/US2022/016053 filed on 2/12/2021 and 2/11/2022, respectively, under 35 U.S.C 119(e) or under 35 U.S.C 120, 121 or 365(c) is acknowledged. Accordingly, the effective priority date of the instant application is granted as 2/12/2021. Information Disclosure Statement The information disclosure statement (IDS) submitted on 12/11/2024, 7/18/2025 and 1/14/2026 were received. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement was considered by the examiner. Claim Interpretation The claims describe a plasmid system comprising several expression plasmids and an envelope plasmid. It is emphasized that the current claim language broadly encompasses ANY delivery system which comprises the plasmid system including both extracellular vesicles, lentiviral vector systems among others. 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 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. Claims 1-4 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Lu et al. WO 2019/213257, published 11/7/2019 (hereinafter Lu) in view of Leonard et al. US 2020/0390700, published 12/17/2020 (hereinafter Leonard). Claim 1: Lu describes lentivirus-like particles for delivering a plasmid system comprising a first mammalian expression plasmid comprising a eukaryotic promoter operably linked to a nucleic acid sequence comprising a CRISPR-associated endonuclease and a gRNA comprising at least one aptamer coding sequence (Lu, abstract and para 7, 9, 11). Lu further describes a second mammalian expression plasmid comprising a eukaryotic promoter operably linked to a nucleic acid sequence encoding a modified viral protein that is a fusion protein with an aptamer-binding protein (Lu, para 62, 74, 121, 143). Lu does not expressly describe that the aptamer binding protein is a fusion with CD63 in the second expression plasmid which binds to the aptamer coding sequence of the fist expression plasmid. Claim 2: Lu describes the system further comprising an envelope plasmid which encode vesicular stomatis virus G (VSV G) protein (Lu, para 117 and 229). Claim 3: Lu provides a preferred embodiment towards the CRISPR-associated endonuclease being a Cas9 protein (Lu, para 1 and 99). Claim 4: Lu describes provides a preferred embodiment towards catalytically impaired CRISPR-associated endonucleases like dCas9 (Lu, para 102). Claim 20: Lu describes cells containing the expressed plasmid system (Lu, para 105, 120). Claim 1: Leonard describes a secreted extracellular vesicle that contains an engineered targeting membrane fusion protein (Leonard, para 3-4). Leonard describes targeting membrane fusion proteins comprising CD63 and at least one cargo RNA with specific embodiments to RNA-motifs that bind the fusion protein with additional functional RNA sequences like sgRNAs (Leonard, para 34, 37, 39). Leonard states that CD63 fusions significantly enhance cargo loading into exosomes (Leonard, para 112). It would have been prima facie obvious to one of ordinary skill in the art to create a fusion protein comprising a CD63 as described by Leonard and at least one aptamer binding protein targeting the CRISPR expression plasmid as described by Lu. It would have been a matter of combining prior art elements according to known methods to yield predictable results since Leonard states that CD63 fusions significantly enhance cargo loading into exosomes (Leonard, para 112). Thus, one of ordinary skill would have been motivated to make this combination in order to enhance cargo loading into the lentivirus-like particles described by Lu. This is particularly important given that Lu describes loading multiple plasmids into a single lentivirus-like particles. One would have a reasonable expectation of success given that CD63- ABP systems can direct specific plasmids or RNA into exosomes via an active packing mechanism which is particularly advantageous. Accordingly, in the absence of evidence to the contrary, one of ordinary skill in the art would have considered claims 1-4 and 40 to have been prima facie obvious to at the time the invention was made. Claims 1-4, 6 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Lu (supra) in view of Leonard (supra) as applied to claims 1-4 and 40 above in further view of Sun et al. "Recent advances of genome editing and related technologies in China." Gene Therapy 27.7 (2020): 312-320 (hereinafter Sun). A description of claims 1-4 and 40 can be found above. Neither Lu nor Leonard describes a first expression plasmid encoding for an adenosine base pair editor (ABE) which is fused to a catalytically impaired CRISPR endonuclease. Claim 6: Sun describes the use of base editing for generating precise nucleotide changes in target DNA without introducing DNA double stranded breaks (Sun, pg 314). Sun describes the use of adenine base editors capable of converting A-T and G-C by fusing a catalytically impaired dCas9 to an adenine deaminase (Sun, pg 314). Sun describes the advantages of a system in achieving targeted DNA editing without double stranded breaks and reduced indels (Sun, pg 314). It would have been prima facie obvious to one of ordinary skill in the art to deliver an ABE fused to a dCas9 as described by Sun using the plasmid delivery system described by Lu in view of Leonard. It would have been a matter of combining prior art elements according to known methods to yield predictable results since adenine base editors are known in the art and are able to in achieving targeted DNA editing without double stranded breaks and reduced indels. One of ordinary skill would have been motivated to make this combination in order to deliver ABEs using the lentivirus-like particles described by Lu given their low toxicity and high carrying capacity, especially when utilizing the CD63 fusions disclosed by Leonard. One would have a reasonable expectation of success given the high editing efficiency of ABEs and programable targeting of ABEs to gene targets. Accordingly, in the absence of evidence to the contrary, one of ordinary skill in the art would have considered the claimed invention have been prima facie obvious to at the time the invention was made. Conclusion No claims allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Dr. ALEXANDER NICOL whose telephone number is (571)272-6383. The examiner can normally be reached on M-F 8-5 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, Maria Leavitt can be reached on (571)272-1085. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. Alexander Nicol Patent Examiner Art Unit 1634 /ALEXANDER W NICOL/Examiner, Art Unit 1634
Read full office action

Prosecution Timeline

Aug 10, 2023
Application Filed
Aug 10, 2023
Response after Non-Final Action
Feb 21, 2024
Response after Non-Final Action
Mar 03, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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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
41%
Grant Probability
87%
With Interview (+45.8%)
4y 7m
Median Time to Grant
Low
PTA Risk
Based on 172 resolved cases by this examiner. Grant probability derived from career allow rate.

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