DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
1. Claims 2-6, 10, 12, 13, 15, 17, and 20 have been cancelled. Claims 7, 16, 21, and 23 have been amended.
Claims 1, 7-9, 11, 14, 16, 18, 19, and 21-23 are pending and under examination.
2. The objections to claims 7, 16, 21, and 23 are withdraw in response to the amendments filed on 12/24/2025.
Claim Rejections - 35 USC § 103
3. 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.
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negated by the manner in which the invention was made.
4. Claims 1, 8, 9, 11, 14, 16, 18, 19, 21, and 22 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tzeng et al. (Int. J. Nanomed., 2011, 6: 3309-3322), in view of all Furuhata et al. (Bioconjugate Chem,. 2006, 17: 935-942), Mather et al. (Progr. Polym. Sci., 2006, 31: 487-531), and Akinc et al. (Bioconjugate Chem., 2003, 14: 979-988).
Tzeng et al. teach the acrylate-terminated PBAE B4S5 obtained via the Michael addition of the amine 5-amino-1-pentanol (S5) to the acrylate groups of 1,4-butanediol diacrylate (B4). B4S5 has the formula:
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116
288
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i.e., L3 is -CH2-(CH2)2-CH2-, R4 is
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91
96
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and R3 is –(CH2)5OH (claims 1 and 11). Tzeng et al. teach end-capping B4S5 via the Michael addition of 2-methylpentane-1,5-diamine (S4) to the terminal acrylate groups of B4S4 to obtain PBAE B4S5E4 (454), useful for polynucleotide delivery; 454 encapsulates the polynucleotide (such as DNA and siRNA) to form nanoparticles; encapsulation takes place by mixing 454 and the polynucleotide (claims 16, 18, 19, 21, and 22) (see p. 3310, Fig. 1; paragraph bridging p. 3310 and 3311; p. 3311, column 1, second full paragraph; p. 3314, Fig. 6; p. 3316, column 1; p. 3319, column 1, first paragraph).
454 has the structure:
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94
480
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i.e., Ry is -NH-CH2-CH(CH3)-(CH2)2-NH2) (claims 1, 8, and 14)
Tzeng et al. do not teach capping with an oligopeptide (claims 1 and 8). However, capping with an oligopeptide is suggested by the prior art. For example, Furuhata et al. teach that the conjugation of R4 (a cell penetrating peptide) to delivery vehicles enhances cellular uptake of into cells (see Abstract; p. 938, Fig. 4). Mather et al. teach that using the thiol group on cysteine (Cys) over amine offers advantages: selectivity, as Michael addition is selective to thiol over amine; increased addition by when Cys is adjacent to arginine groups (see p. 519; p. 523, paragraph bridging columns 1 and 2). Based on these teachings, one of skill in the art would have found obvious to modify R4 with Cys to obtain Cys-R4 and further use at least one Cys-R4 for capping with the reasonable expectation that doing so would result in a PBAE capable of enhanced transfection. By doing so, one of skill in the art would have obtained a first PBAE set forth by formula I where R1 and R2 are R4 a linked to L1 and L2 via a thioether bond, except that R1 and R2 are Cys-R4 and not Cys-R3 (claims 1 and 11). However, as per MPEP § 716.02, [a]ny differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In this case, there is no evidence of record showing that R3 offers any advantage over R4.
With respect to “n” being 5-10,000 (claim 1) or 5-20 (claim 9), Akinc et al. teach that molecular weight is a factor impacting transfection efficiency (see Abstract; p. 979, column 2). One of skill in the art would have found obvious to use routine experimentation and vary the molecular weight (i.e., “n”) with the reasonable expectation that doing so would identify the range mediating optimal transfection. Routine optimization is not considered inventive and no evidence has been presented that the selection the claimed ranges was other than routine or that the results should be considered unexpected in any way as compared to the closest prior art (see MPEP 2144.05 II).
Thus, the claimed invention was prima facie obvious at the time it was made.
5. Claims 1, 7-9, 11, 14, 16, 18, 19, 21, and 22 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tzeng et al. taken with all Furuhata et al., Mather et al., and Akinc et al., in further view of Lo et al. (Biomaterials, 2008, 29: 2408-2414).
Claim 7 recites the limitation of a second polymer where R1 and R2 comprise “histidine in addition to said cysteine”. This recitation is reasonable interpreted as meaning modifying the Cys-oligopeptide by further incorporating histidine.
The teachings of Tzeng et al., Furuhata et al., Mather et al., and Akinc et al. are applied as above for claims 1, 8, 9, 11, 14, 16, 18, 19, 21, and 22. Tzeng et al., Furuhata et al., Mather et al., and Akinc et al. do not teach modifying Cys-H4 by incorporating histidine (claim 7). Lo et al. teach that incorporating histidine into cell penetrating peptides enhances transfection efficiency by disrupting endosomal membranes and promoting endosomal escape (see Abstract). One of skill in the art would have found obvious to also obtain a second PBAE where Cys-R4 further comprises a histidine with the reasonable expectation that doing so would improve transfection efficiency. Furthermore, one of skill in the art would have found obvious to combine the first and the second PBAEs to achieve the predictable result of obtaining a composition suitable for transfection. MPEP 2144.06 [R-6] I states:
“It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980)
Thus, the claimed invention was prima facie obvious at the time it was made.
6. Claims 1, 8, 9, 11, 14, 16, 18, 19, and 21-23 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tzeng et al. taken with all Furuhata et al., Mather et al., and Akinc et al., in further view of Green et al. (PGPUB 2010/0196492).
The teachings of Tzeng et al., Furuhata et al., Mather et al., and Akinc et al. are applied as above for claims 1, 8, 9, 11, 14, 16, 18, 19, 21, and 22. Tzeng et al., Furuhata et al., Mather et al., and Akinc et al. do not teach spray drying, double emulsion, or phase inversion (claim 23). Green et al. teach spray drying, double emulsion, and phase inversion for obtaining PBAEs particles (see Abstract; [0011]; [0013]; [0047]; [0050]; [0102]). Using spray drying, double emulsion, or phase inversion would have been obvious to one of skill in the art to achieve the predictable result of obtaining PBAE nanoparticles.
Thus, the claimed invention was prima facie obvious at the time it was made.
Response to Arguments
7. The argument of unpredictability is not found persuasive because it is just an argument not supported by any evidence.
As evidenced by Furuhata, the exact mechanism for endocytosis does not need to be known for R4-mediated transfection to occur. While Furuhata teaches nanoliposomes, apart from arguments, the applicant did not provide any evidence indicating lack of reasonable expectation of success in extrapolating Furuhata’s teachings to nanoparticles other than nanoliposomes, such as PBAE nanoparticles. Arguments do not replace evidence where evidence is necessary.
For these reasons, the argument that Mather and Akinc do not improve the substantial uncertainties resulting from the combined teachings of Tzeng and Furuhata is not found persuasive. The applicant did not establish any uncertainty regarding the combined teachings of Tzeng and Furuhata
Furthermore, the rejection does not state replacing R4 with R3. The rejection states there is no evidence of record showing that R3 offers any advantage over R4. Using R3 instead of R4 is not significant if it does not produce a novel feature.
The argument that Lo and Green do not cure the defects of Tzeng, Furuhata, Mather, and Akinc is not found persuasive because there is no defect to be cured in the combined teachings of Tzeng, Furuhata, Mather, and Akinc.
Conclusion
8. THIS ACTION IS MADE FINAL. 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.
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/ILEANA POPA/Primary Examiner, Art Unit 1633