Prosecution Insights
Last updated: April 19, 2026
Application No. 18/555,439

"Good" buffer-based cationic lipids

Final Rejection §112§DP
Filed
Oct 13, 2023
Examiner
SHOMER, ISAAC
Art Unit
1612
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Translate Bio, Inc.
OA Round
2 (Final)
63%
Grant Probability
Moderate
3-4
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

§112 §DP
DETAILED ACTION Applicants’ arguments, filed 6 February 2026, have been fully considered. Rejections and/or objections not reiterated from previous office actions are hereby withdrawn. The following rejections and/or objections are either reiterated or newly applied. They constitute the complete set presently being applied to the instant application. Claim Interpretation The examiner has provided the following annotated structure of claim 1, with annotation by the examiner. PNG media_image1.png 335 581 media_image1.png Greyscale The above-indicated nitrogen atoms are amine nitrogen atoms, and not amide, carbamate, or urethane nitrogen atoms. This is because the subscripts “a” and “b” must e at least 1. In view of this, the above-indicated nitrogen atoms are not next to a carbonyl carbon and are not amide, carbamate, or urethane nitrogen atoms. The examiner notes that amines are significantly different from amides, carbamate, or urethanes because amines can be protonated at physiological pH or pH values slightly below physiological pH. In contrast, amides, carbamates, or urethanes generally cannot be protonated in aqueous solution. This is because the carbonyl bond withdraws electrons from the electron lone pair on the nitrogen atom by resonance from the amide/carbamate/urethane nitrogen atom. This prevents said nitrogen atom in an amide/carbamate/urethane from engaging in a covalent bond with a hydrogen ion using the lone electron pair on the nitrogen atom. In contrast, in an amine, there is no functional group withdrawing the electron lone pair by resonance; this frees the electron lone pair to engage in covalent bonding with a hydrogen ion and form a protonated amine (i.e. substituted ammonium ion). This distinction is relevant because ionizable cationic lipids are useful for forming lipid nanoparticles to deliver nucleic acids. Were all of the above-indicated nitrogen atoms to be amides/carbamates/urethanes and therefore incapable of protonation, the resultant lipid would not have been an ionizable cationic lipid and would not have been expected to have formed a lipid nanoparticle capable of delivering a nucleic acid. Claim 38 recites the phrase “encapsulation percentage.” This phrase is disclosed in the specification, e.g. as of page 51, paragraph 0154. However, this phrase does not appear to define the term “encapsulation percentage.” For the purposes of examination under prior art, the examiner takes the position that an encapsulation percentage of at least 70% means that at least 70% of the total weight of the lipid nanoparticle is mRNA. The examiner further notes here that the presence of multiple numerical ranges in the alternative does not appear to be a cause for indefiniteness. The mere fact that a compound (or in this case composition) may be embraced by more than one member of a Markush group recited in the claim does not necessarily render the scope of the claim unclear. For example, the Markush group, "selected from the group consisting of amino, halogen, nitro, chloro and alkyl" should be acceptable even though "halogen" is generic to "chloro." See MPEP 2173.05(h)(I), last paragraph in section. Similarly, a claim reciting the broad range “at least 70%” and the narrower range “at least 95%” appears to be acceptable even though “at least 70%” is generic to “at least 95%.” The examiner also notes that the subject matter descried in MPEP 2173.05(c) does not appear to be applicable here because claim 38 recites ranges that are clearly presented in the alternative, and does not recite preferences or examples. Regarding new claims 50-51, the examiner notes that the instant application as filed does not disclose the term “immunogen” but does disclose the term “antigen” as of at least page 3, paragraph [013] of the instant specification. For the purposes of examination under prior art, the examiner understands the terms “immunogen” and “antigen” to have the same meaning. Additionally, although the specification does not clearly disclose that the antigen is a protein, the skilled artisan would have understood the disclosed antigen to have been a protein because mRNA encodes proteins. Note Regarding GL-HEPES-E3-E12-DS-4-E10 The examiner notes that the term “GL-HEPES-E3-E12-DS-4-E10” is understood to refer to a lipid with the following structure, as of the instant specification on page 136, paragraph 0297, reproduced below. PNG media_image2.png 362 498 media_image2.png Greyscale This is relevant in the rejections set forth below on the grounds of non-statutory double patenting in which the term “GL-HEPES-E3-E12-DS-4-E10” is recited in various conflicting and copending claims. Claim Objections – Multiple Dependent Claim Claim 48 is objected to under 37 CFR 1.75(c) as being in improper form because a multiple dependent claim should refer to other claims in the alternative only. See MPEP § 608.01(n). Accordingly, the claim has not been further treated on the merits. Claim Rejections - 35 USC § 112(d) – Failure to Limit Parent Claim The following is a quotation of 35 U.S.C. 112(d): (d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph: Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. Claims 44-45 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claims 44-45 appear to recite subject matter that is broader than the subject matter of claims 1 and 26 upon which claims 44-45 depend. This is because the claim limitation permitting that alkyl groups in claims 1 and 26 be substituted appears to be outside the scope of claims 1 and 26, which excluded such substitutions. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements. Withdrawn Obviousness Rejection Due to AIA Exception 35 U.S.C. 102(b)(2)(C) The instant claims were previously rejected as obvious over Karmakar et al. (WO 2022/066916 A1). In response, applicant has presented the following response, as of page 70 of applicant’s response on 6 February 2026, reproduced below. PNG media_image3.png 304 642 media_image3.png Greyscale The above-reproduced text is understood to be sufficient to invoke an exception under AIA 35 U.S.C. 102(b)(2)(C) regarding the above-applied prior art. See MPEP 2154.02(c). As such, the previously applied prior art rejection has been withdrawn by the examiner. Relevant Art – No Rejection Kim Reference: As relevant prior art, the examiner cites Kim et al. (Sciences Advances, Vol. 7, 2021, pages 1-12 and 11 supplemental pages). Kim et al. (hereafter referred to as Kim) teaches ionizable lipids for targeting different cell types in the liver, as of Kim, page 1, title and abstract. One lipid taught by Kim has the following structure, as of Kim, second supplemental page, figure S1, reproduced below. PNG media_image4.png 554 968 media_image4.png Greyscale The above-reproduced chemical structure differs from the claimed chemical structure because it fails to teach the required functional groups A1 and Z1. There would have been no motivation for the skilled artisan to have modified the above chemical structure to have included these functional groups. Karve ‘427 and ‘611 References: The examiner notes Karve et al. (WO 2020/219427 A1) and Karve et al. (WO 2020/257611 A1). Karve ‘427 teaches a chemical structure on page 46, paragraph 0181, that appears to have essentially the same deficiency as the structure of Kim. Karve ‘611 teaches a chemical structure as of page 45, paragraph 0190, that has essentially the same deficiency as that of Kim. Heartlein Reference: Also as relevant prior art, the examiner cites Heartlein (WO 2022/006527 A1), which was effectively filed earlier than the effective filing date of the instant application. Heartlein is drawn to compositions for administration of mRNA, as of Heartlein, title and abstract. The compositions administered by Heartlein may include one of various ionizable cationic lipids. One ionizable cationic lipid taught by Heartlein is the following, as of Heartlein, page 49, structure reproduced below with annotation by the examiner. PNG media_image5.png 194 604 media_image5.png Greyscale As such, the structure of Heartlein includes a carbonyl group not present in the instantly claimed chemical structure. This renders the compound of Heartlein to be an amide where the claims require an amine at the indicated location. There would have been no motivation for the skilled artisan to have modified Heartlein to have achieved the claimed chemical structure. Heartlein also teaches the following chemical structure, as of page 42, paragraph 0174, reproduced below. PNG media_image6.png 174 406 media_image6.png Greyscale This structure differs from the claimed subject matter because it lacks the required functional groups A1 and Z1. This is the same reason that Kim differs from the claimed invention. Zhang References: The examiner further notes Zhang et al. (WO 2019/226925 A1) and Zhang et al. (WO 2020/097384 A1) – these references appear to be deficient for essentially the same reason that Heartlein is deficient. Chivukula Reference: The examiner further notes Chivukula et al. (WO 2022/264109 A1). Chivukula et al. (hereafter referred to as Chivukula) is drawn to mRNA influenza vaccines comprising lipid nanoparticles, as of Chivukula, title and abstract. The lipids taught by Chivukula, page 15, formula 3 would appear to comprise all of the claimed requirements. Nevertheless, Chivukula was published in 2022, and appears to have been effectively filed as of 18 June 2021. This is not as early as the earliest effective filing date of the instant application, which is 15 April 2021. As such, Chivukula is not prior art under AIA 35 U.S.C. 102(a)(1) and is not prior art under 35 U.S.C. 102(a)(2). Casimiro References: As relevant art, the examiner cites Casimiro et al. (WO 2022/099003 A1). Casimiro et al. (hereafter referred to as Casimiro) teaches lipids that appear to have the same structure as the claimed lipid on page 17. Casimiro was published in 2022, which is after the effective filing date of the instant application. As such, Casimiro is not prior art under AIA 35 U.S.C. 102(a)(1). Regarding the effective filing date of Casimiro and issues relating to 35 U.S.C. 102(a)(2), the examiner notes the following, wherein the front page of the Casimiro reference is reproduced below with annotation by the examiner. PNG media_image7.png 665 904 media_image7.png Greyscale Casimiro claims priority to provisional application 63/110,965, filed on 6 November 2020. Nevertheless, this provisional application fails to support the subject matter in Casimiro that has the same chemical structure as what is required by the instant claims. As such, no rejection over Casimiro is written because the subject matter in Casimiro that is within the claim scope was not effectively filed prior to the effective filing date of the instant application. As such, Casimiro is not prior art under AIA 35 U.S.C. 102(a)(2). This rationale also applies to Casimiro et al. (US 2022/0142923 A1). Karve ‘085 Reference: As relevant prior art, the examiner cites Karve et al. (WO 2020/227085 A1). Karve ‘085 is drawn to a dithioester cationic lipid for delivery of mRNA, as of Karve ‘085, title and abstract. Karve ‘085 teaches the following chemical structure, as of page 2, paragraph 007, which is reproduced below with annotation by the examiner regarding the differences between the structure of Karve ‘085 and the claimed invention. PNG media_image8.png 261 448 media_image8.png Greyscale The examiner notes that in Karve ‘085, the thioester groups are oriented such that the carbonyl carbon faces the interior ring, and the sulfur atom faces the exterior amine and long carbon chains. This contrasts with the claimed invention, where the sulfur atom faces the interior ring and the carbonyl carbon faces the exterior amines and long carbon chains. Hope Reference: As relevant prior art, the examiner cites Hope et al. (WO 2011/075656 A1), which was cited on the information disclosure statement (IDS) submitted on 6 February 2026. Hope et al. (hereafter referred to as Hope) teaches various cationic lipids for delivery of nucleic acids, as of Hope, title and abstract. Hope teaches the following lipid in one embodiment, as of Hope, page 30, relevant chemical structure reproduced below. PNG media_image9.png 520 612 media_image9.png Greyscale The above-reproduced lipid differs from the claimed compound at least because (a) the above-reproduced lipid has five nitrogen atoms, whereas the claimed lipid has four nitrogen atoms. Also (b) the above-reproduced lipid has quaternary ammonium groups, whereas the claimed lipid has tertiary amines. Non-Statutory Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-53 of U.S. Patent No. 11,771,653. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-45 of U.S. Patent No. 12,239,735. Although the claims at issue are not identical, they are not patentably distinct from each other because of the following reasons: The instant claims are drawn to a compound with a particular chemical structure. This lipid can be used to form a lipid nanoparticle comprising mRNA, e.g. in claims 30-32, 37, and 38, as well as treating or preventing a disease using the delivered mRNA, as of claim 42. The conflicting claims of both patents are drawn to a lipid nanoparticle comprising the cationic lipid GL-HEPES-E3-E12-DS-4-E10. The examiner understands GL-HEPES-E3-E12-DS-4-E10 to have the following chemical structure. PNG media_image2.png 362 498 media_image2.png Greyscale See the section above entitled “Note Regarding GL-HEPES-E3-E12-DS-4-E10.” The conflicting claims differ from the instant claims because the conflicting claims recite specific percentages of PEG lipid, cholesterol and helper lipid, as of conflicting claim 1. This is not required by instant claim 1, and instant claim 32 recites additional lipids, albeit at broader ranges. Nevertheless, the subject matter of the conflicting claims is within the scope of the instant claims, thereby effectively anticipating the subject matter of the instant claims. This results in a prima facie case of anticipatory-type non-statutory double patenting. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-5, 8, 11-12, 17, 20-21, 23-26, 28, 30, 32-35, and 38 of copending Application No. 18/052,600 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because of the following reasons. The instant claims are drawn to a compound with a particular chemical structure. This lipid can be used to form a lipid nanoparticle comprising mRNA, e.g. in claims 30-32, 37, and 38, as well as treating or preventing a disease using the delivered mRNA, as of claim 42. Copending claim 26 of the ‘600 application recites a mRNA vaccine comprising GL-HEPES-E3-E12-DS-4-E10 in a lipid nanoparticle. The examiner understands this lipid to have the chemical structure indicated in the above section of the office action entitled “Note Regarding GL-HEPES-E3-E12-DS-4-E10.” The copending claims differ from the instant claims because the copending claims recite a specific type of mRNA. This is not required by the instant claims, which recite mRNA generally as of instant claim 36. Nevertheless, the subject matter of the copending claims is within the scope of the instant claims, thereby effectively anticipating the subject matter of the instant claims. This results in a prima facie case of anticipatory-type non-statutory double patenting. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-68 of U.S. Patent No. 12,502,424. Although the claims at issue are not identical, they are not patentably distinct from each other because of the following reasons: The instant claims are drawn to a compound with a particular chemical structure. This lipid can be used to form a lipid nanoparticle comprising mRNA, e.g. in claims 30-32, 37, and 38, as well as treating or preventing a disease using the delivered mRNA, as of claim 42. Conflicting claim 46 recites a mRNA vaccine comprising GL-HEPES-E3-E12-DS-4-E10 in a lipid nanoparticle. The examiner understands this lipid to have the chemical structure indicated in the above section of the office action entitled “Note Regarding GL-HEPES-E3-E12-DS-4-E10.” The conflicting claims differ from the instant claims because the conflicting claims recite a specific type of mRNA. This is not required by the instant claims, which recite mRNA generally as of instant claim 36. Nevertheless, the subject matter of the conflicting claims is within the scope of the instant claims, thereby effectively anticipating the subject matter of the instant claims. This results in a prima facie case of anticipatory-type non-statutory double patenting. This is not a new ground of rejection because this rejection was previously presented as a provisional non-statutory double patenting rejection over the claims of US application serial number 18/654,557. The ‘557 application has issued into US Patent 12,502,424. As such, this rejection is the same rejection as previously presented over the ‘557 application. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-23 of copending Application No. 18/856,198 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because of the following reasons. The instant claims are drawn to a compound with a particular chemical structure. This lipid can be used to form a lipid nanoparticle comprising mRNA, e.g. in claims 30-32, 37, and 38, as well as treating or preventing a disease using the delivered mRNA, as of claim 42. Copending claim 1 recites a compound with the following structure, which is reproduced below with annotation by the examiner. PNG media_image10.png 216 627 media_image10.png Greyscale The structure of the compound of the copending claim appears to be essentially the same as that required by the instant claims with the exception of the portions pointed out in boxes drawn by the examiner. Nevertheless, the examiner notes that the concept of including the indicated ester appears to have been recited by the portion of instant claim 1 reciting and defining R1A and R1B as -W1-X1-Y1. This rejection does not apply to instant claim 29 because the compound recited by instant claim 29 does not include the ester functional groups indicated above in boxes. Claims 1-2, 15-32, 36, 38, 42, 44-47, and 49-58 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 3-8, 20, 25, 27, 31-35, 39-40, and 47-48 of copending Application No. 18/246,263 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because of the following reasons. The instant claims are drawn to a compound with a particular chemical structure. This lipid can be used to form a lipid nanoparticle comprising mRNA, e.g. in claims 30-32, 37, and 38, as well as treating or preventing a disease using the delivered mRNA, as of claim 42. The copending claims are drawn to a compound with the following chemical structure, as of copending claim 1, reproduced below with annotations by the examiner. PNG media_image11.png 236 518 media_image11.png Greyscale The structure of the compound of the copending claims differs from the claimed compound due to having methyl groups at the indicated location where the instantly claimed compound has hydrogens instead of methyl groups at the indicated locations. Nevertheless, a prima facie case of obviousness (or in this case, obviousness-type non-statutory double patenting) 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, there appears to be a close structural similarity between the prior art and the claimed subject matter, and both the prior art compound and the claimed compounds are used as ionizable cationic lipids in lipid nanoparticles for delivery of nucleic acids such as mRNA, as of copending claim 45 which recites delivery of mRNA, which is the same purpose as recited by instant claim 42. Response to Arguments Regarding Double Patenting Rejections In applicant’s response on 6 February 2026 (hereafter referred to as applicant’s response), applicant has provided arguments regarding the previously applied double patenting rejections. These arguments are addressed below. In applicant’s response, page 70, applicant requests that the non-statutory double patenting rejections over US Patent 11,771,653 and 12,239,735 be held in abeyance. As such, these double patenting rejections have been maintained by the examiner. In applicant’s response, page 71, applicant requests that the provisional non-statutory double patenting rejections over applications 18/052,600 and 18/856,198 be held in abeyance. As such, these double patenting rejections have been maintained by the examiner. A provisional non-statutory double patenting rejection was previously presented over US application serial number 18/654,557. Applicant requested that this rejection be held in abeyance as of page 71 of applicant’s response. As such, this rejection has been maintained by the examiner, but has been converted to a non-provisional rejection because US application 18/654,557 has issued as US patent 12,502,424 between the time of mailing of the prior office action and the time of issuance of this office action. Applicant makes arguments regarding the previously applied rejection over US application serial number 18/246,263, as of applicant’s response on pages 73-74. Applicant’s arguments relate to the fact that the copending claims require methyl groups at particular positions on the piperazine ring where the claims require hydrogen atoms at those positions; see the following diagram which was drawn by the examiner and is reproduced from page 24 of the prior office action. PNG media_image11.png 236 518 media_image11.png Greyscale Applicant makes the following argument regarding this issue, as of page 73, relevant text reproduced below. PNG media_image12.png 208 630 media_image12.png Greyscale This is not persuasive. Both the claimed compound and the compound of the copending applications are ionizable cationic lipids usable in lipid nanoparticle delivery vehicles for genetic therapeutic agents. See e.g. instant claims 49-50 and copending claim 40. The skilled artisan would have been aware that both the compounds of the copending claims and of the instant claims would have been ionizable cationic lipids because both compounds comprise amine nitrogen atoms capable of being protonated to have a positive charge, as well as highly lipophilic portions of the molecule. This would have been the case regardless of whether the above-indicated functional group is a hydrogen atom or a methyl group. As such, contrary to applicant’s arguments, there would have been a reasonable expectation that the relevant functional properties would have been preserved due to the similarity in chemical structure between the compounds recited by the copending claims and those recited by the instant claims. Applicant then cites Takeda Chem. Indus., Ltd. v. Alphapharm Pty., Ltd., 492 F.3d 1350, 83 USPQ2d 1169 (Fed. Cir. 2007) on page 73 of applicant’s response. In view of this, the examiner searched the MPEP for this case, and notes that it is discussed extensively as of MPEP 2143(I)(E) Example 4. It is the examiner’s position that the fact pattern in the cited case differs from that in the instant case for multiple reasons. First, according to the MPEP summary of the cited case, one of the relevant issues is that the prior art found certain disadvantageous properties associated with the lead compound. No such disadvantageous properties were identified in the instantly applied rejection. Additionally, the chemical structures in the cited case were for use as antidiabetic drugs. In contrast, the chemical structures in the instant application and the copending applications are for ionizable cationic lipids for nucleic acid delivery. This difference is particularly relevant because in the case of ionizable cationic lipids, the skilled artisan would have understood that the relevant structural features needed to achieve functionality are a protonatable nitrogen atom covalently bound to a lipophilic moiety. This would have rendered a compound to be an ionizable cationic lipid and would have rendered such compound useful for forming a nanoparticle capable of delivering a nucleic acid. In contrast, there would have been no similarly well-understood chemical structure feature that would have rendered a compound to have been an antidiabetic treatment in the cited case. As such, there would have been greater predictability that minor changes to the chemical structure would have conserved activity in the instant case as compared with the cited case due to the greater predictability of ionizable cationic lipids as compared with antidiabetic treatments. Relevant Patent – No Double Patenting As a relevant patent, the examiner cites US Patent 12,263,213. As an initial matter, the ‘213 patent was published and effectively filed later than the effective filing date of the instant application. As such, this reference is not prior art. The claims of this patent recite the lipid GL-HEPES-E3-E12-DS-4-E10, which is understood to be within the scope of claim 1. Nevertheless, no double patenting rejection over the ‘213 patent has been written because: There appears to be no common inventors between the ‘213 patent and the instant application; and The ‘213 patent does not appear to be commonly assigned with the instant application because the ‘213 patent is assigned to Sanofi whereas the instant application is assigned to Translate Bio. The examiner takes the position that this rationale also applies to copending applications reciting a lipid appearing to be within the scope of what is recited by claim 1 but which have no common inventors with the instant application and are assigned to Sanofi rather than Translate Bio. Conclusion No claim is allowed. 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. 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

Oct 13, 2023
Application Filed
Nov 04, 2025
Non-Final Rejection — §112, §DP
Feb 06, 2026
Response Filed
Mar 04, 2026
Final Rejection — §112, §DP (current)

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LEVERAGING LIPID-PROTEIN INTERACTIONS TO ENGINEER SPATIAL ORGANIZATION IN CELL-FREE SYSTEMS
2y 5m to grant Granted Mar 31, 2026
Patent 12582118
ANTIMICROBIAL COATING MATERIAL FOR SURFACE COATING
2y 5m to grant Granted Mar 24, 2026
Patent 12576029
NONCOMPETITIVE RECEPTOR-TARGETED VACCINE DELIVERY TO PLASMACYTOID DENDRITIC CELLS
2y 5m to grant Granted Mar 17, 2026
Patent 12576160
BISPECIFIC NANOPARTICLE SYSTEMS FOR TARGETING CANCER CELLS
2y 5m to grant Granted Mar 17, 2026
Patent 12576058
METHODS FOR DECREASING INJURIES ASSOCIATED WITH INTRAOPERATIVE HYPOTENSION
2y 5m to grant Granted Mar 17, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
63%
Grant Probability
94%
With Interview (+31.0%)
2y 11m
Median Time to Grant
Moderate
PTA Risk
Based on 1164 resolved cases by this examiner. Grant probability derived from career allow rate.

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