Prosecution Insights
Last updated: April 19, 2026
Application No. 18/247,152

METHODS OF TREATING VIRAL INFECTIONS WITH PiRNAS OR EXTRACELLULAR VESSICLES RELEASED FROM NEURAL STEM CELLS OR NEURAL PROGENITOR CELLS

Non-Final OA §112
Filed
Mar 29, 2023
Examiner
POLIAKOVA-GEORGAN, EKATERINA
Art Unit
1637
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Albert Einstein College of Medicine
OA Round
1 (Non-Final)
65%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
81%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
434 granted / 668 resolved
+5.0% vs TC avg
Strong +16% interview lift
Without
With
+16.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
55 currently pending
Career history
723
Total Applications
across all art units

Statute-Specific Performance

§101
5.4%
-34.6% vs TC avg
§103
28.6%
-11.4% vs TC avg
§102
22.8%
-17.2% vs TC avg
§112
24.2%
-15.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 668 resolved cases

Office Action

§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 . Election/Restrictions Applicant’s election without traverse of Group I, claims 1-6, 8-10, 14, 16 in the reply filed on 12/23/2025 is acknowledged. Election of species of VSV virus and the following 10 RNAs of SEQ ID NOs: 526, 550, 586, 594, 598, 604, 638, 658, 690, and 669 is acknowledged. Claims 14, 17, 21, 23, 25, 27, 30-31, 33, 35 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group or species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12/23/2025. 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. Claims 1-6, 8-10 and 16 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for treatment by administering extracellular vesicles comprising specific piRNAs, does not reasonably provide enablement for treatment with any extracellular vesicles. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims. The claimed invention is not supported by an enabling disclosure taking into account the Wands factors. In re Wands, 858/F.2d 731, 8 USPQ2d 1400 (Fed. Cir. 1988). In re Wands lists a number of factors for determining whether or not undue experimentation would be required by one skilled in the art to make and/or use the invention. These factors are: the quantity of experimentation necessary, the amount of direction or guidance presented, the presence or absence of working examples of the invention, the nature of the invention, the state of the prior art, the relative skill of those in the art, the predictability or unpredictability of the art, and the breadth of the claim. Claims are broadly drawn to methods of treating an individual in need of treatment or prevention of infection with a virus, comprising administering to the individual a therapeutically effective amount of extracellular vesicles released from neural stem cells and/or neural progenitor cells. Claims encompass treatment of any individual at risk of viral infection by administering any possible extracellular vesicles released from neural stem or progenitor cells, in some embodiments such vesicles comprising piRNAs. Instant specification teaches that presence of groups of specific piRNAs in exosomes purified from neural stem cells provides antiviral effects, defining such groups of piRNAs for HIV and VSV viruses (see Examples 3 and 5). It is notable that such antiviral activity of exosomes is provided by not any one of piRNAs as instantly claimed, but by a large number of specific piRNAs (see, for example, Table 2). There is no evidence that the presence of only one piRNA from the group provides enough antiviral effect to treat viral infection. Also, there is no evidence in the specification of any activity of any other extracellular vesicles than exosomes. Instant specification does not provide any working examples of actual treatment or prevention of any viral infection by administering exosomes isolated from neural stem cells. Prior art related to studies of extracellular vesicles derived from neural stem cell teaches that some such vesicles actually deliver viruses into cells (see, for example, Vogel et al (EBioMedicine, 2018, 38: 273-282) on page 279, first column). Sims et al (International Journal of Nanomedicine, 2014, 4893-4897) clearly state that neural stem cells derived exosomes mediate viral entry (see Title, Abstract). Therefore, according to teachings of prior art administration of neural stem cells derived exosomes is expected to bring in more viruses into an organism, instead of treating a viral infection. Thus, the guidance provided in the specification is insufficient for actual treatment or prevention of viral infections by administering neural stem cells derived extracellular vesicles. In the absence of guidance, undue trial and error experimentation would have been required by one skilled in the art at the time invention was made to treat a subject for viral infection by administering neural stem cells derived extracellular vesicles as instantly claimed. Given the breadth of the claims, unpredictability of the art and lack of guidance of the specification, as discussed above, undue experimentation would be required by one skilled in the art to make and use the claimed invention commensurate in scope with the claims. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to EKATERINA POLIAKOVA whose telephone number is (571)270-5257. The examiner can normally be reached Mon-Fri 8-5. 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, Jennifer Dunston can be reached at (571)272-2916. 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. /EKATERINA POLIAKOVA-GEORGANTAS/Primary Examiner, Art Unit 1637
Read full office action

Prosecution Timeline

Mar 29, 2023
Application Filed
Mar 06, 2026
Non-Final Rejection — §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
65%
Grant Probability
81%
With Interview (+16.2%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 668 resolved cases by this examiner. Grant probability derived from career allow rate.

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