Prosecution Insights
Last updated: April 19, 2026
Application No. 18/576,244

IONIZABLE LIPID COMPOUND FOR NUCLEIC ACID DELIVERY AND LNP COMPOSITION THEREOF

Non-Final OA §102§103
Filed
Jan 03, 2024
Examiner
SHOMER, ISAAC
Art Unit
1612
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Cansino (Shanghai) Biological Research Co. Ltd.
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
2y 11m
To Grant
94%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
733 granted / 1164 resolved
+3.0% vs TC avg
Strong +31% interview lift
Without
With
+31.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
62 currently pending
Career history
1226
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
44.9%
+4.9% vs TC avg
§102
12.2%
-27.8% vs TC avg
§112
23.5%
-16.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1164 resolved cases

Office Action

§102 §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 . 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. Election/Restrictions Applicant’s election without traverse of the following species PNG media_image1.png 94 572 media_image1.png Greyscale in the reply filed on 21 January 2026 is acknowledged. No claim is withdrawn due to the species election, and all claims are subject to substantive examination. Claim Interpretation Regarding claim 30, the examiner understands this claim as requiring that each of R1 and R2 separately have the following structure. PNG media_image2.png 122 80 media_image2.png Greyscale The examiner notes that “a” has a minimum value of 2. This results in a minimum of four separate groups that are R7a and R7b. The presence of four R7a and R7b groups occur in the case wherein the value of “a” that is part of R1 is 2 and the value of “a” that is part of R2 is also 2. If “a” exceeds 2, there are more than four R7a and R7b groups. The examiner further clarifies that a linear hydrocarbon chain would appear to read on the requirements of claim 30. In such a hydrocarbon chain, “a” is equivalent to the number of carbon atoms in the chain, and all R7a and R7b groups are hydrogen. Additionally, the case wherein there is a branching on the carbon atom adjacent to the carbonyl group, such as in the following structure PNG media_image3.png 96 286 media_image3.png Greyscale would also appear to be within the claim scope. In the above-reproduced structure, “a” is 9, all values of R7a and R7b are hydrogen with the exception of an R7a group attached to the first carbon atom, which is a C8 hydrocarbyl group. Claim Rejections - 35 USC § 102 – Anticipation The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claim(s) 24-33, 35-37 and 41-43 is/are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Benenato et al. (WO 2021/055835 A1). Benenato et al. (hereafter referred to as Benenato) is drawn to carbonate containing lipid compounds, as of Benenato, title and abstract. Benenato teaches various compounds including compound 22 on page 16 at the bottom right corner of the page, which is reproduced below with annotation by the examiner clarifying how each feature of this compound reads on the claimed invention. PNG media_image4.png 125 406 media_image4.png Greyscale This reads on the claimed invention in the following manner, as of the table on the next page. Claimed Variable Equivalent in Benenato Compound 22 G3 C2 alkylene R3 Hydroxyl G1 and G2 Both C6 alkylene L1 and L2 Both -O(C=O)O- R1 C9 alkyl R2 Branched alkyl group having 17 carbons As such, the above-reproduced compound from Benenato reads on the structure required by instant claim 24. As to claim 25, both L1 and L2 are-O(C=O)O- in structure #22 of Benenato. As to claim 26, both L1 and L2 are-O(C=O)O- in structure #22 of Benenato. As to claim 27, the above-reproduced structure of Benenato would appear to read on the claimed invention wherein R3 is hydroxyl, R6 is hydrogen and n is 2. As to claim 28, the above-reproduced structure of Benenato would appear to read on the claimed invention wherein R3 is hydroxyl, R6 is hydrogen, n is 2, y is 6 and z is 6. As to claim 29, this claim is rejected for essentially the same reason that claim 28 is rejected. As to claim 30, in the case of R1, this reads on the claim in the manner that “a” is 9 and all values of R7a and R7b are hydrogen. In the case of R2, this reads on the claimed requirements such that “a” is 9, all but one value of R7a and R7b are hydrogen; however, a single R7b group attached to the carbon atom closest to the carbonate oxygen is a C8 hydrocarbyl group. See the section above entitled “Claim Interpretation” for more detailed explanation as to how claim 30 is being interpreted. As to claim 31, there are multiple occurrences of R7a and R7b as hydrogen. See the explanation above. As to claim 32, there is a single occurrence of R7b as C8 hydrocarbyl. See the explanation above regarding why claim 30 is rejected. As to claim 33, the structure of compound 22 of Benenato reads on this moiety as R2, which is recited by claim 34. PNG media_image5.png 86 270 media_image5.png Greyscale As to claim 35, Benenato teaches a lipid nanoparticle in the abstract, which reads on the required delivery system. As to claim 36, Benenato teaches mRNA as of pages 81-82, paragraph 00263. As to claim 37, Benenato teaches a mRNA vaccine in at least page 90, paragraphs 00286-00287. As to claim 41, Benenato teaches mRNA as of pages 81-82, paragraph 00263. The mRNA reads on the required bioactive substance. As to claims 42-43, Benenato teaches the following lipid nanoparticle, as of page 85, top paragraph, relevant text reproduced below. PNG media_image6.png 144 598 media_image6.png Greyscale These formulations would appear to read on the claimed structure. The examiner also notes here that there are other chemical structures in Benenato that would appear to anticipate claim 24 but not claim 25 because these structures comprise a carbonate group that reads on L1 and an ester group that reads on L2; see e.g. Benenato, page 16, structure #21 at the bottom left of the page. Note Regarding Reference Date: Benenato was published on 25 March 2021. This is less than a year prior earlier than the earliest possible effective filing date of the instant application, which is 7 July 2021, based upon a foreign priority claim. As such, Benenato is prior art under AIA 35 U.S.C. 102(a)(1). Benenato was also effectively filed earlier than the effective filing date of the instant application and is thereby prior art under AIA 35 U.S.C. 102(a)(2). There are no common inventors, and there does not appear to be a common assignee between Benenato et al. (WO 2021/055835 A1) and the instantly claimed invention. As such, the AIA exceptions would not appear to be applicable here. Claim(s) 24-28 and 30-31 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Furaya et al. (JP 2005015377 A). As an initial matter, Furaya et al. (JP 2005015377 A) has been written in Japanese. The examiner has provided an English translation, which was obtained from https://patents.google.com/patent/JP2005015377A/en?oq=JP+2005015377+ on 19 February 2026. All page and paragraph citations are to the English translation unless otherwise noted. With that being said, the original document, while written in Japanese, includes various chemical structures in the original Japanese document that are comprehensible to an English speaker and are cited herein. Furaya et al. (hereafter referred to as Furaya) is drawn to a cationic surfactant, as of Furaya, title and abstract. Furaya teaches the following compound, as of page 11 of the original Japanese publication, relevant structure reproduced below. PNG media_image7.png 200 644 media_image7.png Greyscale The above-reproduced chemical structure reads on the requirements of claim 24 in the following manner, as of the table set forth on the next page. Claimed Variable Equivalent in Furaya prior art G3 C1 alkylene R3 Hydrogen G1 and G2 Both C2 alkylene L1 and L2 Both -O(C=O)O- R1 and R2 Both C8 alkyl As such, the compound of Furaya reads on the claimed chemical structure. The examiner notes that Furaya refers to the above compound as a surfactant rather than a lipid. Nevertheless, the compound of Furaya is the same as that required by the instant claims and therefore reads on the claimed requirements. When the structure recited in the reference is substantially identical to that of the claims, the claimed properties or functions are presumed to be inherent. See MPEP 2112.01(I), also see MPEP 2112.01(II). As to claim 25, Furaya teaches -O(C=O)O- as both L1 and L2; see the explanation above. As to claim 26, Furaya teaches -O(C=O)O- as both L1 and L2; see the explanation above. As to claim 27, the compound of Furaya would appear to read on the claimed compound wherein n=1 and R3 and R6 are both hydrogen. As to claim 28, the compound of Furaya would appear to read on the claimed compound wherein n=1, R3 and R6 are both hydrogen, and y and z are both 2. As to claim 30, the compound of Furaya would appear to read on the requirements of claim 30 wherein both the value of “a” with respect to R1 and the value of “a” with respect to R2 are both 8, and all values of R7a and R7b with respect to both R1 and R2 are hydrogen. As to claim 31, a case wherein all values of R7a and R7b are hydrogen reads on the additional requirements of this claim. The examiner additionally notes that Furaya appears to teach the benefits of using a carbonates in the structure of the surfactant as of paragraph 0007, which is reproduced below from the top of page 16 of the translation. PNG media_image8.png 116 1122 media_image8.png Greyscale As such, Furaya teaches the benefits of using carbonates in the chemical structure. Claim Rejections - 35 USC § 103 – Obviousness 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) 24-38 and 41-43 is/are rejected under 35 U.S.C. 103 as being unpatentable over Benenato et al. (WO 2021/055835 A1). Benenato et al. (hereafter referred to as Benenato) is drawn to carbonate containing lipid compounds, as of Benenato, title and abstract. Benenato teaches various compounds including compound 22 on page 16, which is reproduced below with annotation by the examiner clarifying how each feature of this compound reads on the claimed invention. See the anticipation rejection above over Benenato by itself. PNG media_image4.png 125 406 media_image4.png Greyscale As to claim 24, purely en arguendo and in regard to this ground of rejection only, the examiner will proceed with the understanding that Benenato teaches all of the claimed requirements, but not in the same embodiment. As such, while the prior art teaches all of the claimed components, the prior art is not anticipatory insofar as these components must be selected from various lists/locations in the prior art reference. It would have been prima facie obvious; however, to have selected the recited components from various lists/locations in the prior art reference and to have combined them together. This is because such a modification would have represented nothing more than the predictable use of prior art components according to their established functions. Combining separate prior art components (from a single prior art reference) according to known methods to yield predictable results is prima facie obvious. See MPEP 2143, Exemplary Rationale A. As to claim 25, both L1 and L2 are-O(C=O)O- in structure #22 of Benenato. As to claim 26, both L1 and L2 are-O(C=O)O- in structure #22 of Benenato. As to claim 27, the above-reproduced structure of Benenato would appear to read on the claimed invention wherein R3 is hydroxyl, R6 is hydrogen and n is 2. As to claim 28, the above-reproduced structure of Benenato would appear to read on the claimed invention wherein R3 is hydroxyl, R6 is hydrogen, n is 2, y is 6 and z is 6. As to claim 29, this claim is rejected for essentially the same reason that claim 28 is rejected. As to claim 30, in the case of R1, this reads on the claim in the manner that “a” is 9 and all values of R7a and R7b are hydrogen. In the case of R2, this reads on the claimed requirements such that “a” is 9, all but one value of R7a and R7b are hydrogen; however, a single R7b group attached to the carbon atom closest to the carbonate oxygen is a C8 hydrocarbyl group. See the section above entitled “Claim Interpretation” for more detailed explanation as to how claim 30 is being interpreted. As to claim 31, there are multiple occurrences of R7a and R7b as hydrogen. See the explanation above. As to claim 32, there is a single occurrence of R7b as C8 hydrocarbyl. See the explanation above regarding why claim 30 is rejected. As to claim 33, the structure of compound 22 of Benenato reads on this moiety as R2, which is recited by claim 34. PNG media_image5.png 86 270 media_image5.png Greyscale As to claim 34, the chemical structure of Benenato appears to differ from the following claimed structure PNG media_image1.png 94 572 media_image1.png Greyscale only by the length of various carbon chains; specifically, those between the carbonate groups and the central tertiary amine nitrogen atom. While this appears to render claim 34 not to be anticipated by Benenato, it does not appear to be sufficient to overcome the applied prima facie case of obviousness. A prima facie case of obviousness may be made when chemical compounds have very close structural similarities and similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." See MPEP 2144.09(I). In this case, both the compounds of Benenato and those of the instantly claimed invention are ionizable cationic lipids usable for the formation of lipid nanoparticles for delivery of nucleic acids. As such, the subject matter of Benenato appears to be sufficiently similar to the claimed subject matter to render the claimed compound prima facie obvious based upon structural similarity. Additionally, compounds which are … homologs (compounds differing regularly by the successive addition of the same chemical group, e.g., by -CH2- groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties. See MPEP 2144.09(II). As to claim 35, Benenato teaches a lipid nanoparticle in the abstract, which reads on the required delivery system. As to claim 36, Benenato teaches mRNA as of pages 81-82, paragraph 00263. As to claim 37, Benenato teaches a mRNA vaccine in at least page 90, paragraphs 00286-00287. As to claim 38, Benenato teaches a cancer vaccine as of page 42, paragraph 00130. As to claim 41, Benenato teaches mRNA as of pages 81-82, paragraph 00263. The mRNA reads on the required bioactive substance. As to claims 42-43, Benenato teaches the following lipid nanoparticle, as of page 85, top paragraph, relevant text reproduced below. PNG media_image6.png 144 598 media_image6.png Greyscale These formulations would appear to read on the claimed structure. Claim(s) 39-40 is/are rejected under 35 U.S.C. 103 as being unpatentable over Benenato et al. (WO 2021/055835 A1) in view of Schoenmaker et al. (International Journal of Pharmaceutics, Vol. 601, 2021, Article 120586, pages 1-13). Benenato is drawn to a lipid nanoparticle for delivery of mRNA comprising a particular lipid. See the rejections above over Benenato by itself. Benenato does not teach a SARS-CoV-2 vaccine. Schoenmaker et al. (hereafter referred to as Schoenmaker) is drawn to commercially available COVID-19 (i.e. SARS-CoV-2) vaccines formed from mRNA and lipids, as of Schoenmaker, page 1, title and abstract. Schoenmaker teaches mRNA for vaccination against SARS-CoV-2, as of Schoenmaker, page 3, figure 1, reproduced below. PNG media_image9.png 454 762 media_image9.png Greyscale Schoenmaker also teaches the use of lipid nanoparticles to deliver said mRNA, and emphasizes the importance of using ionizable cationic lipids, as of Schoenmaker, page 1, title and abstract as well as elsewhere in the document. Schoenmaker differs from the claimed invention because Schoenmaker does not teach an L1 and/or L2 which is -O(C=O)O; in contrast, the L1 and/or L2 taught by Schoenmaker is an ester rather than a carbonate, as of Schoenmaker, page 8, relevant structure reproduced below with annotation by the examiner of the portions of the structures of Schoenmaker that render Schoenmaker different from the claimed structure. PNG media_image10.png 394 988 media_image10.png Greyscale It would have been prima facie obvious for one of ordinary skill in the art to have substituted the ionizable cationic lipid of Benenato in place of that of Schoenmaker in a lipid nanoparticle for delivering mRNA for vaccination against SARS-CoV-2, as taught by Schoenmaker. Schoenmaker is drawn to a lipid nanoparticle comprising an ionizable cationic lipid for delivery of mRNA that acts as a vaccine against SARS-CoV-2. As both Schoenmaker and Benenato teach ionizable cationic lipids for the formation of lipid nanoparticles for delivery of mRNA, the skilled artisan would have been motivated to have substituted the ionizable cationic lipid of Benenato in place of that of Schoenmaker for predictable delivery of an mRNA active agent which can be used for vaccination with a reasonable expectation of success. As to claim 39, the mRNA of Schoenmaker vaccinates against SARS-Cov-2 (i.e. COVID-19), which is a coronavirus, as of Schoenmaker, page 1. As to claim 40, the mRNA of Schoenmaker vaccinates against SARS-Cov-2 (i.e. COVID-19), which is a coronavirus, as of Schoenmaker, page 1. Note Regarding Reference Date: Schoenmaker was published on 9 April 2021. See the bottom of page 1 of Schoenmaker for information regarding the publication date. This is less than a year earlier than the earliest effective filing date of the instant application, which is 7 July 2021. As such, Schoenmaker is prior art under AIA 35 U.S.C. 102(a)(1). Conclusion No claim is allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ISAAC SHOMER whose telephone number is (571)270-7671. The examiner can normally be reached 7:30 AM to 5:00 PM Monday Through Friday. 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, Sahana Kaup can be reached at (571)272-6897. 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. ISAAC . SHOMER Primary Examiner Art Unit 1612 /ISAAC SHOMER/ Primary Examiner, Art Unit 1612
Read full office action

Prosecution Timeline

Jan 03, 2024
Application Filed
Feb 20, 2026
Non-Final Rejection — §102, §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
63%
Grant Probability
94%
With Interview (+31.0%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 1164 resolved cases by this examiner. Grant probability derived from career allow rate.

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