DETAILED ACTION
Applicant’s amendment to the claims in the Response filed on 04/23/2026, adding newly presented limitations, is acknowledged.
The objection to the Specification is withdrawn in view of the Substitute Specification filed on 04/23/2026.
The objection to the claims is withdrawn in view of Applicant’s amendment to the claims in the Response filed on 04/23/2026.
The rejection of record under 35 U.S.C. § 112(b) is withdrawn in view of Applicant’s amendment to the claims in the Response filed on 04/23/2026. A new ground of rejection under 35 U.S.C. § 112(b) is set forth below, which was necessitated by Applicant’s amendment to the claims in the Response filed on 04/23/2026.
The rejections of record under 35 U.S.C. §§ 102 and 103 are withdrawn in view of Applicant’s amendment to the claims in the Response filed on 04/23/2026. A new ground of rejection under 35 U.S.C. § 103 is set forth below, which was necessitated by Applicant’s amendment to the claims in the Response filed on 04/23/2026.
Claim Rejections - 35 USC § 112
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 16-19 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.
Claim 16, as amended, recites a “method for expressing an exogenous RNA and/or an
exogenous protein in cells, comprising: introducing a single-stranded DNA comprising a nucleic acid sequence encoding the exogenous RNA and/or exogenous protein into the cells, wherein a value of a mass ratio of the single-stranded DNA to the transfection reagent in the composition is 100 to 0.1.”
There is insufficient antecedent for the recitation of “the transfection reagent in the composition.” Moreover, claim 16 broadly requires “introducing a single-stranded DNA” into the cells, which does not appear limited to transfection, yet the claim, as amended, now recites “the transfection reagent.” It is unclear what means for introducing the single-stranded DNA into the cells are encompassed by claim 16.
The claim also recites “single-stranded DNA,” but does not recite any “composition,” so it is unclear what constitutes “the composition” and how it relates to the single-stranded DNA.
The dependent claims do not add additional clarity and, therefore, are also indefinite. For purposes of compact prosecution and applying prior art, claim 16 was narrowly interpreted herein to require introducing single-stranded DNA into cells by transfecting the cells with a composition comprising the single-stranded DNA and a transfection reagent, wherein a value of a mass ratio of the single-stranded DNA to the transfection reagent in the composition is 100 to 0.1.
It is noted that any interpretation of the claims set forth above does not relieve Applicant of the responsibility of responding to this rejection. If the actual interpretation of the claims is different than that posited by the Examiner, additional rejections and art may be readily applied in a subsequent final Office action.
Claim Rejections - 35 USC § 103
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 16-19 are rejected under 35 U.S.C. 103 as obvious over Wolff et al. (WO 00/74635, IDS-FOR, hereinafter “Wolff”) in view of Wang et al. (Molecules, 23(2564):1-15 (2018), hereinafter “Wang”).
Regarding claim 16, Wolff teaches a method for expressing an exogenous protein in cells, comprising introducing a single-stranded DNA (ssDNA) comprising a nucleic acid sequence encoding the exogenous protein (Abstract; page 19, lines 10-30).
Regarding claim 17, Wolff teaches that the cells are tumor (cancer) cells (page 1, lines 19-20; page 27, lines 6-8).
Regarding claim 18, Wolff teaches that the cells are 3T3 mouse embryonic fibroblast cells (page 39, Example 12).
Regarding claim 19, Wolff teaches that the cells are HeLa cells (page 42, E) Transfection of HeLa cells).
Wolff teaches introducing the ssDNA into the cells by transfection using various commercially available transfection reagents (TR) such as LIPOFECTAMINE (page 5, lines 10-26; page 12, lines 10-30).
Wolff does not teach a value of a mass ratio of the single-stranded DNA to the TR in the composition is 100 to 0.1. However, Wang teaches screening of commonly used commercial transfection reagents towards efficient transfection of single-stranded oligonucleotides (SSO) (Abstract). Wang teaches that transfection efficiency depends upon the cell line selected, the TR selected, the ratio of TR to SSO, and the toxicity of a specific TR to a specific cell line (FIGS. 1-15).
As such, it would have been a matter of routine experimentation using standard laboratory techniques available at the time of filing to determine the optimal TR and TR to ssDNA ratio for a given cell line in the method taught by Wolff to maximize transfection efficiency while minimizing cytotoxicity with a reasonable expectation of success. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Accordingly, the claimed invention was prima facie obvious to one of ordinary skill in the art at the time of filing especially in the absence of evidence to the contrary.
Response to Arguments
Applicant’s arguments filed 04/23/2026 have been fully considered but they are not persuasive. Applicant’s arguments are discussed to the extent they apply to the current grounds of rejection set forth above.
On pages 6-7 of the Response, Applicant urges that Wolf “cautions that ‘the presence of a large excess of polycations may be toxic to cells and tissues.’” However, as discussed above, Wang teaches that the toxicity of a particular polycation transfection regent (TR) is heavily dependent on the specific cell line selected. As such, the selection and amount of TR for a given cell line would have been a matter of routine optimization well within the ability of a PHOSITA to maximize transfection efficiency.
On page 7 of the Response, Applicant urges that “claim 16 is non-obvious in view of the unexpected results demonstrated in the present application.” Applicant suggests that “transfection efficiency of ssDNA under amended claim 16 is significantly higher than that of double-stranded plasmid DNA (see Example 4), and the method exhibits substantially reduced cytotoxicity (see Example 5). The same results are demonstrated for linear ssDNA (see Example 6).” Applicant further urges “the present application demonstrates a surprising synergistic effect:
when ssDNA is combined with the transfection reagent at the claimed mass ratio, the larger proportion of transfection reagent simultaneously reduces the cytotoxicity that would otherwise be expected from high reagent concentrations, while also improving ssDNA transfection efficiency.”
Applicant’s data and results in the Specification were fully considered but are problematic for several reasons. First, Applicant’s data is limited to LIPOFECTAMINE 2000, while the instant claims appear to contemplate any “transfection reagent,” so the instant claims are not commensurate in scope with alleged unexpected results.
Second, the ratio of nucleic acid (NA) to transfection regent (TR) is generally expressed as µg NA to µl of TR (see e.g., Wang, FIG. 2). In contrast, the Examples in the Specification appear to utilize LIPOFECTAMINE 2000 (L2000) in terms of weight, i.e., μg of L2000 to ng of DNA. Example 3 utilizes 1.5 µg (1500 ng) of L2000 with 460 ng of ssDNA (3.3x), which does not appear inconsistent with the prior art. Dalby1 evidences that L2000 is supplied as a 1 mg/ml solution, so 1.5 µg of L2000 would correspond to 1.5 µl of L2000. This would provide a ratio of 1.5 µl of L2000 to 0.46 μg of ssDNA, i.e., 3.26:1, which is consistent with the prior art. Example 4 appears to utilize, e.g., 0.5 µg (0.5 µl), 1.0 µg (1.0 µl), or 2.0 µg (2.0 µl) of L2000 with 0.460 μg of ssDNA corresponding to approximately 1:1, 2.17:1, or 4.35:1, respectively. At best, Applicant appeared to be use volumes of L2000 that were consistent with the prior art2 with lower amounts of ssDNA.
Third, even if the ratios were as high as claimed, as discussed above, Wang teaches that transfection efficiency depends upon the cell line selected, the TR selected, the ratio of TR to ssDNA, and the toxicity of a specific TR to a specific cell line. As such, it would have been a matter of routine experimentation using standard laboratory techniques available at the time of filing to determine the optimal TR and TR to ssDNA ratio for a given cell line for use in the method taught by Wolff to maximize transfection efficiency with a reasonable expectation of success.
Fourth, GenScript3 evidences that ssDNA is less toxic to cells than dsDNA, so Applicant’s results are not unexpected, but, rather, consistent with the prior art, i.e., the PHOSITA would have known and reasonable expected that transfection with ssDNA instead of dsDNA would result in reduced the cytotoxicity.
As such, the Specification does not evidence any unexpected results, and the rejections of record are maintained for the reasons set forth above.
Conclusion
NO CLAIMS ARE 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 THOMAS J VISONE whose telephone number is (571)270-0684. The examiner can normally be reached Monday-Thursday, 8:30 AM to 6:30 PM.
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, Yvonne Eyler can be reached at (571) 272-1200. 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.
/THOMAS J. VISONE/ Supervisory Patent Examiner, Art Unit 1672
1 Dalby et al., Methods, 33:95-103 (2004), § 2.3 Amount of DNA and DNA:Lipofectamine 2000 ratio
2 See Dalby, § 2.3 Amount of DNA and DNA:Lipofectamine 2000 ratio
3https://www.genscript.com/gsfiles/techfiles/ssDNA_case_study_screen_reading_version03272019%2epdf?1080252417, March 27, 2019, accessed September 3, 2026, FIG. 3; p. 5, Conclusions.
