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 .
Claim status
Claims 1-20 filed on July 13, 2023 are pending and will be examined on the merits.
Priority
The instant application claims benefit of a provisional application, Application No. 63389240 (filed 14 July, 2022). The effective filing date of instant claims 1-20 is 14 July, 2022.
Information Disclosure Statement
The information disclosure statement filed on July 13, 2023 comply with the provisions of 37 CFR 1.97, 1.98 and MPEP § 609. Accordingly, each information disclosure statement is being considered by the examiner.
Drawings
The drawings are objected to because:
The structure diagrams in Fig. 3A are vague and hardly readable, especially the DSPE-PEG (2000) and the DSPE-PEG(200)-ABY bioconjugate; the annotation of the 3rd structure was partially blocked although readable.
The micelle and diagrams for DSPE-PEG(2000) and DSPE-PEG(2000)-ABY in Fig. 4A are vague and hardly readable.
The structure diagrams in Fig. 5B for “DSPE-PEG(2000)-Mal”, the “DSPE-PEG(2000)-Affibody micelles”, and the “Unilamellar liposome (DPPC)” are vague and hardly readable.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
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.
Claim 12 is 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.
As stated in MPEP2173.05e, a claim is indefinite when it contains words or phrases whose meaning is unclear. In re Packard, 751 F.3d 1307, 1314, 110 USPQ2d 1785, 1789 (Fed. Cir. 2014). The lack of clarity could arise where a claim refers to "said lever" or "the lever," where the claim contains no earlier recitation or limitation of a lever and where it would be unclear as to what element the limitation was making reference. Similarly, if two different levers are recited earlier in the claim, the recitation of "said lever" in the same or subsequent claim would be unclear where it is uncertain which of the two levers was intended.
Claim 12 recites “the method of claim 11, wherein “the phospholipid” is 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC)”, while claim 11 recites phospholipid twice: “the phospholipid-ligand conjugate of claim 1”, and “a) a phospholipid liposome”. It would be unclear as to which phospholipid claim 12 limits. Therefore, the scope of this claim is indefinite. Based on the specification and the drawings, the phospholipid in claim 12 is interpreted as the phospholipid in the phospholipid liposome in claim 11. Claim 12 is examined accordingly.
Claim Rejections - 35 USC § 102
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 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.
Claims 1-2 are rejected under 35 U.S.C. 102 (a)(1) as being anticipated by Cheng et al. "Enhanced siRNA delivery into cells by exploiting the synergy between targeting ligands and cell-penetrating peptides." Biomaterials 32.26 (2011): 6194-6203.
Cheng et al teach a dual targeted nanoparticle that is modified by folate and penetratin via pegylated phospholipid linker (DSPE-PEG) for active cancer cell targeting (Abstract, page 1, page 2, paragraph 2; Figure 2, page 16). The nanoparticle comprises DSPE-PEG (2000)-folate and DSPE-PEG(2000)-penetratin as illustrated in Figure 2. Penetratin (ANTP) is a well-studied cell-penetrating peptides (CPPs) that has been demonstrated to increase cell membrane translocation.
Cheng et al recite, “DSPE-PEG-ANTP was synthesized by coupling DSPE-PEG-maleimide to the C-terminal cysteine of ANTP, bearing a peptide sequence of (RQIKIWFQNRRMKWKKGGC) (page 3, paragraph 3). ANTP (2.1 μmol) was dissolved in DMF, and added to HEPES-EDTA buffer (100mM HEPES, 10mM EDTA, pH 7.5) containing TCEP (50 mM). After reduction of ANTP for one hour, maleimide-PEG-DSPE (30.9 mg) was added and the reaction mixture was incubated overnight at room temperature.
This method of producing phospholipid-ligand bioconjugation meets the limitations in claims 1 and 2. Therefore, a person with ordinary skills in the art would anticipate the method described in claims 1 and 2 based on the teaching of Cheng et al.
Claim Rejections - 35 USC § 103
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 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 3-4, 8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011) as applied to claims 1-2 above, and further Natarajan et al. "Characterization of site-specific ScFv PEGylation for tumor-targeting pharmaceuticals.” Bioconjugate chemistry 16.1 (2005): 113-121.
Claims 1 and 2 and the teaching of Cheng et al regarding these claims are discussed above.
Cheng et al do not teach the ligand to be an affibody, an antibody, a VHH antibody, a single chain variable fragment, or a diabody.
However, Natarajan et al teach a method of “using site-specific conjugation of small tumor binding proteins and poly (ethylene glycol) (PEG) scaffolds to provide modular multivalent, homo- or heterofunctional cancer-targeting molecules having preferred molecular size, valence, and functionality” (Abstract, page 113) wherein the small tumor binding proteins can be scFvs. Natarajan et al teach that scFvs can be “recombinantly produced in a vector that adds an unpaired cysteine (c) near the scFv carboxyterminus (scFv-c), thus providing a specific site for thiol conjugation”. Natarajan et al teach the production of PEG-scFvs (Figure 1, page 2) using several PEG-Mal molecules (Table 1, page 2) and 4 scFvs specific for Muc1, which presents unique epitope on many epithelial cancers (page 2, column 2, paragraph 2).
Since both Cheng et al and Natarajan et al use the same Michael addition reaction of maleimide-thiol click chemistry to conjugate a peptide with free C-terminal cysteine to PEG-Mal containing molecule, it would have been obvious to utilize a phospholipid molecule like DSPE-PEG(2000)-Mal taught by Cheng et al to create a DSPE-PEG(2000)-scFv molecule using the method taught by Natarajan et al.
Regarding claims 8 and 10 which are drawn to the ratio of phospholipid to C-terminal modified cysteine ligand and the reaction pH, respectively, Natarajan et al recite that “The PEG to scFv molar ratio for conjugation reactions was initially studied with scFv-c as D5-c for PEG-(Mal)2 (2 kDa) at 2, 5,10, 20, and 50-fold molar excess of PEG”, where D5 is one of the 4 anti-Muc1 scFvs (page 115, column 2, paragraph 5), and “the reaction was carried out in 0.1M sodium phosphate buffer, pH 7.0”. (page 115, column 1, paragraph 2)
Based on the teachings of Cheng et al and Natarajan et al, it would have been obvious for a person with ordinary skills in the art to produce a phospholipid-scFv bioconjugate by contacting a phospholipid polymer with a maleimide-containing functional group with an scFv bearing a C-terminal cysteine, at 20:1 molar ratio and at a neutral pH of 7.0.
Claims 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011) and in view of Natarajan et al as applied to claims 1 and 4 above, and further in view of Abou-Elkacem et al. "Affibody proteins specific for b7-h3 (cd276)” (US20210340257A1, published 2021).
Claims 1 and 4 and the teaching of Cheng et al (2011) and Natarajan et al (2005) regarding these claims are discussed above.
Cheng et al or Natarajan et al do not teach the surface protein to be B7-H3.
However, Abou-Elkacem et al recite “B7-H3 has been validated as a biomarker, which can be used as an ultrasound molecular imaging target differentially expressed on the neovasculature of human breast tumor compared to benign lesions and normal breast
tissue (page 34, example 1, paragraph [0175]. Microbubbles (MBs), typically used for contrast-enhanced ultrasound, can be functionalized with high-affinity binding ligands against molecular targets, such as B7-H3, on tumor vasculature to enable highly specific detection of cancer.” Abou-Elkacem et al disclose B3-H7 affibody sequences including AC12 (Fig. 1) with SEQ ID No:3 which showed 100% identity with SEQ ID NO: 5 in instant claim 6:
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Abou-Elkacem et al further teach that these B7H3 affibodies are used to generate targeted microbubbles that successfully produced tumor specific imaging in mouse breast cancer models in vivo (Fig 2-7, page 3-4, paragraphs [0021-0034]).
Based on the teaching of Cheng et al, Natarajan et al and Abou- Elkacem et al, it would be obvious for an ordinary artisan to modify a B3H7 affibody, such as AC12, with a C-terminal cysteine and produce a DSPE-PEG(2000)-AC12 bioconjugate, which meets the limitation of claims 5 and 6.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011), in view of Wöll et al. "Pentaglycine lipid derivates–rp-HPLC analytics for bioorthogonal anchor molecules in targeted, multiple-composite liposomal drug delivery systems." International journal of pharmaceutics 547.1-2 (2018): 602-610.
Claim 7 is drawn to a pentaglycine bridge preceding the C terminal cysteine residue in the ligand of claim 1.
Claim 1 and the teaching of Cheng et al (2011) regarding claim 1 are discussed above.
Cheng et al do not teach a pentaglycine bridge.
However, Wöll et al (2018) teach two differently PEGylated pentaglycine modified liposomal formulations with the following advantages: 1) Pentaglycine modified lipid is suitable for site specific biorthogonal conjugation of targeting ligands; 2) pentaglycine modified lipids exhibit favorable stability properties; 3) pentaglycine modified lipids can be detected and analyzed with accuracy and precision using the (reversed phase) rp-HPLC based analytical method.
Wöll et al (2018) recites, “Glycine modified lipids (Fig. 1) are based on two myristyl alcohols ether linked to an amino-propandiol moiety being coupled to the δ-carboxy-group of an iso-glutamine by an amide linkage. The pentaglycine motif is either directly (here called DMA-G5) C-terminally linked to the α-standing amino function of the iso-glutamine, or spaced via a 2000 Da monodisperse polyethylene linker (DMA-PEG-G5).” (page 603, column 1, paragraph 4). Both DMA-PEG-G5 and DMA-G5 are stable when sample temperature was reduced to 4oC, with recovery rates of 97-100% (page 606, column 2, paragraph 2; page 7, Table 6). The pentaglycine bridge allows site specific conjugation of a ligand (such as an VHH) using sortase-A technology, yielding a homogenous product profile, which is highly desired for quality controls and regulatory authorities (page 608, column 2, paragraph 1). A mix of Sortase-A, LPTEG-modified VHH and pentaglycine modified liposomes was incubated for 4 h to allow VHH coupling, which showed favorable physical properties before and after VHH coupling (page 608, column 2, paragraph 1, Table 8).
Wöll et al (2018) developed a versatile rp-HPLC based analytical method that allows quantification of these two pentaglycine modified lipids simultaneously with other lipid excipients with good analytical performance, ensuring analyzability of various bilayer combinations, which is important in formulation screens for targeted drug delivery.
Due to the above advantages of pentaglycine modified lipids, a person with ordinary skills in the art would be motivated to utilize a pentaglycine bridge in the phospholipid-ligand bioconjugate in instant claim 1 to provide liposomal formulation stability and analytical advantage taught by Wöll et al (2018). Since a C terminal cysteine is required for conjugation to a maleimide containing phospholipid, it is convenient to include a pentaglycine bridge preceding the C-terminal cysteine into the construct expressing the recombinant ligand, once the modified ligand is conjugated to maleimide containing phospholipid, the resultant phospholipid bioconjugate will contain a pentaglycine bridge between the ligand and the phospholipid.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011), in view of Mozafari. "Nanoliposomes: preparation and analysis." Liposomes: Methods and protocols, volume 1: Pharmaceutical nanocarriers. Totowa, NJ: Humana press, 2009. 29-50 and Khorasani et al. "Nanoliposome technology for the food and nutraceutical industries." Trends in Food Science & Technology 79 (2018): 106-115, and in further view of Martínez-Jothar et al. "Insights into maleimide-thiol conjugation chemistry: Conditions for efficient surface functionalization of nanoparticles for receptor targeting." Journal of controlled release 282 (2018): 101-109.
Claim 9 is drawn to a preparation step of the phospholipid in claim 1 by heating the phospholipid to greater than 50 oC for at least 3 hours and reducing the temperature of the phospholipid to room temperature for at least 1 hour prior to the contacting step.
It is known in the art that phospholipid ingredients undergo a phase transition, or gel to liquid crystalline transition, at phase transition temperature (Tc), at which the lipidic bilayer loses much of its ordered packing while its fluidity increases (Mozafari 2009, page 33, paragraph 1). It is recommended that liposome preparation be carried out at temperatures well above Tc of the vesicles. For instance, in the case of vesicles containing dipalmitoyl phosphatidylcholine (DPPC, Tc = 41°C), it has been suggested that the liposome preparation procedure be carried out at 10°C higher than the Tc at 51°C (18, 19). This is in order to make sure that all the phospholipids are dissolved in the suspension medium homogenously and have sufficient flexibility to align themselves in the structure of lipid vesicles.
Mozafari (2009) teaches an improved heating method that is economical and capable of manufacturing nanoliposomes, with superior monodispersity and storage stability using a simple protocol and one vessel. This method is summarized by Khorasani et al (2018) comprising three steps (page 110, column 2, paragraph 1):
1. Adding nanoliposomal ingredients to a preheated (40–60 °C) mixture of the active agent and a polyol such as glycerol, propylene glycol or sorbitol in a heat-resistant vessel.
2. Heating the mixture at 40–60 °C while stirring (e.g. 1000 rpm) on a hotplate stirrer under an inert atmosphere.
3. Following manufacture of the nanoliposomes, the product must be kept at temperatures above phase transition temperature (Tc) of the phospholipid ingredients under an inert atmosphere to allow the vesicles to anneal and stabilize. Subsequently, temperature of the nanoliposomal formulation needs to be gradually brought down to an ambient temperature before storage (Fig. 3).
Martínez-Jothar et al (2018) teach that the maleimide-thiol click reaction is frequently applied in functionalization protocols because of the high reactivity of maleimide under mild conditions (i.e. room temperature and aqueous buffers) (pag 102, column 1, paragraph 2). Martínez-Jothar et al (2018) recite a method of functionalization of maleimide-PEG PLGA nanoparticles (NPs) with a Her2 nanobody, 11A4, which is C-terminal cysteine modified (page 102, column 2, paragraph 1) and the optimal reaction efficiency was achieved after 2h incubation at room temperature (page 1, Abstract, page 103, column 2, paragraph 3).
Based on the teachings of Mozafari, Khorasani et al and Martínez-Jothar et al discussed above, it is within the abilities of an ordinary artisan to choose a temperature of above 50oC which falls within the range of 40-60 oC taught by Mozafari to heat the phospholipids for at least 3hrs to ensure a homogeneous liquid-crystalline phase and to cool the maleimide containing phospholipid to room temperature for 1hr to ensure sufficient liposomal annealing and stabilization and subsequent optimal maleimide-thiol click reaction with a ligand containing a C terminal cysteine residue taught by Martínez-Jothar et al. As such, one of ordinary skills in the art would have arrived at the instantly claimed heating and cooling limitations in claim 9 through no more than routine experimentation. Generally, differences in temperature or incubation time will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such temperature or length of incubation time is critical. "[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).
Claims 11-18 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011) and in view of Natarajan et al (2005) as applied to claim 1, and further in view of Abou-Saleh et al. "Horizon: Microfluidic platform for the production of therapeutic microbubbles and nanobubbles." Review of Scientific Instruments 92.7 (2021).
Claim 11 is drawn to a method of producing a target microbubble, the method comprising contacting a micelle comprising the phospholipid-ligand conjugate of claim 1 with: a) a phospholipid liposome; and b) an inert gas.
Abou-Saleh (2021) et al teach a microfluidic platform, Horizon, for the production of therapeutic microbubbles. The microfluidics (MF) design consists of an FF (flow focused) design with a central inlet channel for the gas and two opposing inlet channels for introduction of the liquid phase, a narrow orifice and a single outlet. In the microspray (MS) chip design (Fig. 3), the depth of the exit channel undergoes a sudden expansion (by 25 μm), giving a total exit channel depth of 50 μm [Fig. 3(b)]. This expansion causes a rapid pressure drop, which results in the MBs being produced in the MS regime (page 5, column 2, paragraph 3). Using similar design, this microfluidic platform (the Horizon instrument) is also capable of producing MBs with an attached drug payload, or therapeutic microbubbles (thMBs) (page 6, column 2, paragraph 4). Specifically, biotinylated liposomes were incubated with NeutrAvidin for 15 min prior to being added to a lipid solution containing a portion of biotinylated lipids (prepared for the MB production) and incubated for a further 15 min. Then, the whole mix is introduced into the Horizon for MF production of thMBs with liposomes as depicted in the schematic shown in Figs. 8(a) and 8(b).
Regarding claims 12 and 13 which are drawn to the phospholipid liposome being DPPC and the inert gas being perfluorobutane gas, respectively, and claim 14 and 15 which are drawn to the mole percentages of the phospholipid bioconjugate and the phospholipid in the targeted microbubble in claim 11, Abou-Saleh et al (2021) teach the lipid composition for MS-MB formulation to be DPPC+DSPEPEG2000, mixed at the molar ratio of 95:5 mol.% (page 5, column 2 paragraph 2); and the MS-MBs can be made using C4F10 (perfluorobutane), SF6, and O2 with no significant changes in concentration (page 5, column 2, paragraph 5).
Regarding claims 16 and 17 which are drawn to the sizes of the phospholipid liposome and the targeted microbubble, in claim 11, respectively. Abou-Saleh et al (2021) teach that the lipid formulation of DPPC and DSPE-PEG2000 contained small liposomes of ~90nm (page 7, column 1, paragraph 1, supplemental figure 2). And the diameter of the therapeutic microbubbles (thMB) generated by the Horizon instrument is in the range of 2-4mm (Fi. 9(b))
Therefore, it would have been obvious for a person with ordinary skills in the art to generate micelle of DSPE-PEG[2000]-bioconjugate as discussed above, and mix it with DPPC liposome prepared with a size of ~90nm, with the lipid molar ratio of DSPE-PEG-bioconjugate:DPPC=5:95 as taught by Abou-Saleh et al (2021) in a Horizon instrument to produce targeted microbubbles with diameter around 2-4 mm and a perfluorobutane gas core, which meet the limitations in claims 11-18.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011), in view of Natarajan et al (2005) and Abou-Saleh et al (2021) as applied to claim 11, and further in view of Grubbs et al “Targeting microbubbles”, US patent No: US10,149,906 B2, published Dec. 11, 2018.
Grubbs et al teach that “solutions of microbubbles may be prepared by combining the bubble forming material with a solvent and then applying energy to induce bubble formation. In some embodiments, such energy is applied in the form of mechanical (vibrational) energy by shaking or otherwise mixing the solution.” (page 13, column 12, line 30-35). Such agitation or shaking can be achieved by a Vilmix shaker or an equivalent shaker (page 15, column 17, line 2-4).
Therefore, it would have been obvious to mix a micelle comprising the phospholipid bioconjugate, a phospholipid liposome and an inert gas in a shaker like Vilmix that can provide mechanical agitation to generate a target microbubble.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (2011), in view of Natarajan et al (2005) and Abou-Saleh et al (2021) as applied to claim 11, and further in view of Sun et al. "Ultrasound microbubbles mediated sonosensitizer and antibody co-delivery for highly efficient synergistic therapy on HER2-positive gastric cancer." ACS applied materials & interfaces 14.1 (2021): 452-463 and Zhang et al. "Therapeutic potential of an anti-HER2 single chain antibody–DM1 conjugates for the treatment of HER2-positive cancer." Signal transduction and targeted therapy 2.1 (2017): 17015.
Claim 20 is drawn to the method of producing a target microbubble further comprising contacting the micelle comprising the phospholipid-ligand bioconjugate in claim 11 with a second micelle comprising a phospholipid-therapeutic agent bioconjugate, wherein the therapeutic agent is selected from the group consisting of a chemotherapeutic agent, a toxin, a radioactive isotope, a kinase inhibitor, an immunomodulator, and a hormone blocker.
Claim 11 and the teaching of Cheng et al (2011), Natarajan et al (2005) and Abou-Saleh et al (2021) regarding claim 11, are discussed above.
Cheng et al teach a nanoparticle comprising two phospholipid bioconjugates: DSPE-PEG-folate and DSPE-PEG-penetratin loaded with therapeutic siRNA, wherein both bioconjugates are utilized as targeting ligands to efficiently deliver siRNA to tumor cells, instead of therapeutic agents.
However, Sun et al (2021) teach an ultrasound microbubble for simultaneous delivery of a sonosensitizer and therapeutic antibody, Trastuzumab, with SF6 gas core, to achieve targeting combination of sonodynamic therapy (SDT) and antibody therapy of HER2-positive gastric cancer (page 452, Abstract, page 453, column 1, paragraph 2-4, column 2, paragraph 1, Scheme 1). The sonosensitizer, pyropheophorbide, conjugated lipid (pyropheophorbide-lipid) are self-assembling phospholipids where the near-infrared photosensitizer pyropheophorbide a (Pyro) is covalently attached to a phospholipid backbone and can generate single oxygen cytotoxin upon ultrasound triggered activation. The therapeutic antibody Trastuzumab is conjugated to the nanoparticles containing the sonosensitizer (P NPs) with active ester to obtain antibody-coupled nanoparticles containing the sonosensitizer (TP NPs). The trastuzumab conjugated microbubble (TP MB) was then obtained by mechanically shaking of the TP NPs with ethylene glycol and glycerol (page 453, column 2, paragraph 3). Sun et al recite, “When TP-MBs were injected into the body, they can enhance the ultrasound imaging signal to identify the tumor location and size. TP MBs can be specifically disrupted at the tumor tissue under US irradiation and in situ convert into TP NPs (nano-particles), resulting in significant accumulation of TP NPs at the tumor site, attributed to both MBs-mediated cavitation and the active targeting (of the) antibody. When these TP NPs were internalized into tumor cells, sonosensitizer-mediated SDT and antibody mediated therapeutics showed synergistic anticancer activity both in vitro and in vivo, holding great potential in improving the therapeutic efficiency on HER2-positive gastric cancer.” (page 453, column 1 paragraph 4, column 2, paragraph 1).
Sun et al (2021) et al do not teach a Her2 antibody phospholipid conjugate using maleimide or C-terminal cysteine. However, combining the teaching of Cheng et al (2011), Natarajan et al (2005) and Abou-Saleh et al (2021), an ordinary artisan would be able to modify a Her2 specific scFv, such as T-SA1 and T-SA2 (scFv antibodies derived from trastuzumab fused with human serum albumin) developed and characterized by Zhang et al (2017) that shows Her 2 specific cell killing and in vivo anti-tumor effect when conjugated to cytotoxin DM1, with a C-terminal cysteine, and conjugate it to DSPE-PEG[2000]-Mal, as taught by Natarajan et al (2005) and mix it with the sonosensitizer containing pyropheophorbide-lipid, taught by Sun et al (2021) and an inert gas using a microfluidic device such as Horizon, taught by Abou-Saleh et al (2021), to generate a target microbubble with both a Her2 targeting therapeutic antibody and a sonosensitizer that generates potent singlet oxygen toxin upon ultrasound activation.
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.
Instant claims 1-6, 8 and 10 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 4 of U.S. Patent No. 12,274,759 (herein, US’759) in view of Cheng et al (2011) and Natarajan et al (2005).
Claim 4 of US’749 recites B7H3 affibodies including SEQ ID NO. 3 that has 100% identity to SEC ID NO. 5 (sequence alignment shown above) of the instant claim 6, which reads to the B7H3 affibody, AC12.
As discussed above, Cheng et al (2011) teach a method of producing phospholipid-ligand bioconjugate using DSPE-PEG-maleimide and a ligand with C-terminal cysteine, whereas Natarajan et al (2005) teach that the ligand to be conjugated to the phospholipid can be a small tumor binding peptide, such as an anti-MUC 1 scFV, and such a phospholipid-scFV bioconjugate can be generated at the 20-fold molar excess of the lipid and a neutral PH.
Therefore, it would have been obvious for an ordinary artisan to take the B7H3 affibody AC12 taught by US’759, modify it with a C terminal cysteine and generate a DSPE-PEG-AC12 using the methods taught by Cheng et al and Natarajan et al, which reads to the limitations in instant claims 1-6.
Instant claims 7 and 9 which are drawn to a pentaglycine bridge preceding the C terminal cysteine and the phospholipid preparation method, respectively, and the teaching of Wöll et al (2018) Mozafari (2009), Khorasani et al (2018 and Martínez-Jothar et al (2018) regarding these claims, are discussed above.
Therefore, it would have been obvious for an ordinary artisan to utilize a B7H3 affibody, such as AC12, modify it with a C terminal cysteine preceding a pentaglycine bridge, prepare the maleimide containing phospholipid as described in claim 9 and produce a phospholipid-B7H3 affibody bioconjugate.
Instant claims 11-19 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 14 of U.S. Patent No. 12,274,759 (herein, US’759) in view of Cheng et al (2011), Natarajan et al (2005) and Abou-Saleh et al (2021), as applied to instant claims 11-18 or Grubbs et al (2018), as applied to instant claim 19.
Claim 14 of US’759 recites a contrast agent comprising a microbubble conjugated to a polypeptide of claim 1 comprising 1-36 residues of a B7H3 affibody, including AC12 (SEQ ID NO. 3).
Instant claim 11-19 and the teachings of Cheng et al (2011), Natarajan et al (2005) and Abou-Saleh et al (2021) and Grubbs et al (2018) regarding these claims, are discussed above.
Regarding instant claims 11-18, it would have been obvious for an ordinary artisan to produce a phosphorlipid-AC12 affibody conjugate as discussed above, and contact it with a phospholipid liposome such as DPPC with a diameter of ~90nm and within the molar ratio range of instant claims 14-15, and an inert gas such as perfluorobutane, in a microfluidics instrument, such as Horizon taught by Abou-Saleh, and produce a B7H3 affibody conjugated microbubble with an expected diameter of 2-4mm.
Regarding instant claim 19, it would have been obvious for an ordinary artisan to take the phospholipid-AC12 affibody bioconjugate and mix it with a phospholipid liposome and an inert gas in a mechanical agitation device, such as Vilmix taught by Grubbs et al (2018) to generate a B7H3 affibody conjugated microbubble.
Instant claim 20 is rejected on the ground of nonstatutory double patenting as being unpatentable over claim 14 of U.S. Patent No. 12,274,759 (herein, US’759) in view of Cheng et al (2011), Natarajan et al (2005), Abou-Saleh et al (2021) and Sun et al (2021).
Instant claim 20 and the teaching of Cheng et al (2011), Natarajan et al (2005), Abou-Saleh et al (2021), Sun et al (2017) regarding this claim, are discussed above.
Claim 14 of US’759 does not recite a target microbubble with a second bioconjugate that is a therapeutic agent.
However, combining the teaching of Cheng et al (2011), Natarajan et al (2005), Abou-Saleh et al (2021) and Sun et al (2021), an ordinary artisan would be able to produce a phospholipid-B7H3 affibody bioconjugate, and mix it with the sonosensitizer containing Pyropheophorbide-lipid, taught by Sun et al (2021) and an inert gas using a microfluidic device such as Horizon, taught by Abou-Saleh et al (2021), to generate a target microbubble with both a B7H3 targeting ligand and a sonosensitizer that generates potent singlet oxygen toxin upon ultrasound activation.
Conclusion
All claims are rejected.
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/HONG REN/
Examiner, Art Unit 1647
/JOANNE HAMA/ Supervisory Patent Examiner, Art Unit 1647