DETAILED ACTION
Status of the Application
Receipt is acknowledged of Applicants’ Request for Continued Examination (RCE), Amendments and Remarks, filed 4 May 2026, in the matter of Application N° 18/268,786. Said documents have been entered on the record. The Examiner further acknowledges the following:
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicants’ submission filed on 4 May 2026 has been entered.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
No claims have been added or canceled.
Claim 12 has been amended to depend from claim 1 instead of claim 11 and to provide proper antecedent basis to claim 1 for polycationic polyelectrolyte.
No new matter has been added.
Thus, claims 1-10, 12, 20, 21, 25-28, 31, 33, 42, 48, 50-52, 55, 57-60, and 62-67 continue to represent all claims currently under consideration.
Information Disclosure Statement
No new Information Disclosure Statements (IDS) have been filed for consideration.
Maintained Objection/Rejection
The following rejections are maintained from the previous Office Correspondence dated 2 February 2026 since the art that was previously cited continues to read on the amended and previously recited limitations.
Specification - Abstract
Applicant is reminded of the proper content of an abstract of the disclosure.
A patent abstract is a concise statement of the technical disclosure of the patent and should include that which is new in the art to which the invention pertains. The abstract should not refer to purported merits or speculative applications of the invention and should not compare the invention with the prior art.
If the patent is of a basic nature, the entire technical disclosure may be new in the art, and the abstract should be directed to the entire disclosure. If the patent is in the nature of an improvement in an old apparatus, process, product, or composition, the abstract should include the technical disclosure of the improvement. The abstract should also mention by way of example any preferred modifications or alternatives.
Where applicable, the abstract should include the following: (1) if a machine or apparatus, its organization and operation; (2) if an article, its method of making; (3) if a chemical compound, its identity and use; (4) if a mixture, its ingredients; (5) if a process, the steps.
Extensive mechanical and design details of an apparatus should not be included in the abstract. The abstract should be in narrative form and generally limited to a single paragraph within the range of 50 to 150 words in length.
See MPEP § 608.01(b) for guidelines for the preparation of patent abstracts.
Response to Arguments
Applicants’ remarks with regard to the objection to the Abstract request commentary or suggestions for amending the Abstract to be taken into consideration.
The Examiner, in response, has no specific suggestions apart from what is set forth in MPEP §608.01(b). Said objection is therefore maintained.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the Examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicants are advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the Examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-10, 20, 21, 25-28, 31, 33, 42, 48, 50-52, 55, 57-60 and 62-65 are rejected under 35 U.S.C. 103 as being unpatentable over Stewart et al. (WO 2019/084548 A1; ISR/IDS reference), further in view of Rolland et al. (EP 2 353 624 A1).
The instantly claimed composition is directed to an injectable composition comprising:
water;
one or more polycationic polyelectrolytes and anionic counterions;
one or more polyanionic polyelectrolytes and cationic counterions; and
a transient contrast agent
The composition additionally recites having an ionic concentration that is (i) sufficient to prevent association of the polycationic polyelectrolytes and the polyanionic polyelectrolytes in water, and (ii) greater than the concentration of ions in the subject, whereupon introduction of the composition into the subject, a solid is produced in situ, and the transient contrast agent diffuses out of the solid.
Stewart discloses in situ solidifying liquid complex coacervates that contain bioactive agents (i.e., anti-angiogenic, chemotherapeutic, etc.) that solidify in situ in blood vessels. The coacervates are formed of oppositely-charged polyelectrolytes at high ionic strengths that undergo aqueous-aqueous phase inversion to produce a microporous solid that locally releases the bioactive agent with which it has been infused (see e.g., Abstract; claims 1 and 2).
Claim 1 of the reference additionally discloses that “the concentration of the ions in the complex coacervate is greater than the concentration of the ions at the administration site in the subject, thereby teaching the second of the two recited functional limitations. The reference additionally discloses that “[p]olyelectrolytes with opposite net charges in aqueous solution can associate into several higher order morphologies depending on the solution conditions and charge ratios. They can form stable colloidal suspensions of polyelectrolyte complex with net surface charges. Repulsion between like surface charges stabilizes the suspension from further association” (see pg. 11, lines 4-8).
The foregoing is considered to teach the limitations recited by independent claims 1, 9, 10, 57, and 62-64.
The limitations of claims 9 and 10 are considered to carry the same limitations as presented in claim 1, notably since both the polycationic and polyanionic polyelectrolytes are already combined with water. Also, see MPEP §2113.
The limitations of independent claim 65 and dependent claim 67 are considered to be disclosed by the foregoing as well as by the disclosure that “when the in situ solidifying liquid complex coacervate is introduced into a vessel in the subject, a solid is produced from the liquid complex coacervate. Further, in this aspect, the adhesive solid creates an artificial embolus within the vessel. Still further in this aspect, the artificial embolus selectively reduces or inhibits blood flow to the target tissue” (see pg. 10, line 25 to pg. 11, line 2). Target tissues disclosed as having their blood flow reduced or inhibited include aneurysms, a varicose vein, an arteriovenous (vascular) malformation, an open or bleeding wound, and a tumor (see e.g., pg. 37, lines 21-27; claim 46).
Claims 29 and 30 disclose that the coacervate will further comprise a contrast agent or visualization agent, such as an iodinated compound. The reference further defines the contrasting agent as being present in amounts of up to 30% (w/w) (or up to 300 mg/mL) (see pg. 20, lines 2-3).
The iodinated compound is further defined as being, for example, iodixanol, iohexol, diatrizoic acid, and ioxaglate (see pg. 20, lines 7-12).
The foregoing is considered to teach the limitations recited by instant claims 2, 3, and 5.
Where Stewart is admittedly deficient is with regard to using an iodinated oil as the organic iodine contrasting agent, as set forth in claim 4.
Rolland is considered to remedy this deficiency. Like Stewart, Rolland is directed to a biocompatible, chemically inert, radio-opaque, long-term degradable, non-adhesive gelatine-based gel material suitable for occluding body passageways in a mammal patient (claim 1).
The Examiner notes that polymeric material used by Stewart is distinct from that used by Rolland. However, the end result is the same; namely the production of an injectable liquid material that solidifies in situ and delivers one or more active agents in vivo alongside a transient contrasting agent (see e.g., claims 1-5, 13, and 14). Rolland discloses in claim 4 that the contrasting agent is chosen from an iodinated oil.
MPEP §2144.06(II) states that “[i]n order to rely on equivalence as a rationale supporting an obviousness rejection, the equivalency must be recognized in the prior art, and cannot be based on Applicants’ disclosure or the mere fact that the components at issue are functional or mechanical equivalents.”
In the instant case, the Examiner has presented a clear showing that the iodinated oil of Rolland and the iodinated compounds of Stewart both, independently operate as iodine-based contrasting agents that are released from compositions that are injected into the body and solidified in situ.
The Examiner thus submits that a person of ordinary skill in the art, before the effective filing date of the claimed invention, would have reasonably expected success at producing the instant composition by modifying the iodinated contrasting compound used by Stewart with the iodinated oil used by Rolland.
The limitations of claim 6 recite that 100% of the contrast agent diffuses out of the solid or gel in a range of from about 5 minutes to 30 days. The Examiner acknowledges that while the reference discloses the diffusion/release for the different bioactive agents in terms of days (see e.g., claim 45), a time range is not expressly disclosed for the contrast/visualization agent.
Despite this perceived deficiency, the Examiner submits that such an agent would also possess a similar diffusion rate, particularly given that it is also disclosed as being a visualization agent (i.e., used to track the progress of the active being delivered). Thus, the Examiner submits that the reference teaches and suggests claim 6.
Furthermore, the Examiner submits that the claim also recites the above rejected compositional and structural limitations of claim 1. Pursuant to MPEP §2112.01(I), “[w]here the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.”
The Examiner again submits that the foregoing property is met in view of the release rate of the other co-formulated agents.
The limitations recited by claims 7 and 8 define the counterions as comprising sodium and chloride (i.e., monovalent ions). The ion concentration is also recited as ranging from 1.5-20 times greater than the ion concentration in the subject (see e.g., claims 1 and 18).
The latter limitation of claim 8 is taught above. The disclosed salt that produces ions is further defined as comprising a monovalent salt is further defined as being for example, sodium chloride (see e.g., pg. 16, lines 5-8), such as sodium chloride at a concentration of 1.2 M (see pg. 17, lines 2-3).
The polycationic salt limitations presented in instant claims 20, 21, and 25-28 are disclosed by claims 1 and 2 of the reference (see also pg. 13, lines 1-9).
The polyanionic salt limitations presented in instant claims 31, 33, 42, 48, and 50-52 are disclosed by claim 10 of the reference (i.e., sodium hexametaphosphate).
The limitations of claim 57 are met with the disclosure of an anti-angiogenic or chemotherapeutic agent (see e.g., Abstract). Other of the recited bioactive agents are disclosed by claims 35 and 41.
The limitations of claim 58 recite that the composition of claim 1 has a viscosity ranging from 10-20,000 cps (0.01-20 Pa*s). This is considered to be exemplified by the reference (see pg. 44, line 5 to pg. 45, line 26). Therein, the method forms an embolic coacervate (EC) using a polyguanidinyl copolymer methacrylate copolymer p(GPMA-co-MA) and sodium hexametaphosphate (MP) in combination with sodium chloride. The resulting polymer of PG-MP has a shear viscosity of about 5.0 Pa*s and reported out as low as 1.2 Pa*s.
The limitations of instant claims 59 and 60 are met by the disclosure of claims 18 and 19 of the reference.
Based on the combined teachings of the references, the Examiner submits that a person of ordinary skill in the art would have had a reasonable expectation of success at producing the instantly claimed composition and arriving at the recited method of treatment.
As discussed above, the sole deficiency with the teachings of Stewart is that it does not expressly disclose the inclusion of iodinated oil as one of the organic, iodine-based contrasting agents. Rolland is provided to bridge this gap disclosing injectable delivery compositions comprising a solidifying polymeric blend loaded with both a deliverable active ingredient and iodine contrasting agent (iodinated oil).
Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, and absent a clear showing of evidence to the contrary.
Response to Arguments
Applicants’ arguments with regard to the rejection of claims 1-10, 20, 21, 25-28, 31, 33, 42, 48, 50-52, 55, 57-60, and 62-67 under 35 USC 103(a) as being unpatentable over the combined teachings of Stewart et al. and Rolland et al. have been fully considered, but they are not persuasive.
Much of Applicants’ response is repeated from the previously filed response dated 9 January 2026. Those remarks will not be readdressed here except that they remain unpersuasive for the reasons already made of record.
Applicants newly added remarks take issue with the Examiner’s remarks on pages six and eleven of the previously mailed rejection. Specifically, Applicants address the passage in Stewart, relied upon by the Examiner disclosing that:
“Polyelectrolytes with opposite net charges in aqueous solution can associate into several higher order morphologies depending on the solution conditions and charge ratios. They can form stable colloidal suspensions of polyelectrolyte complex with net surface charges. Repulsion between like surface charges stabilizes the suspension from further association.” (pg. 11, lines 4-8).
Applicants remarks focus on the phrase “higher order morpholog[ies].” Therein, Applicants argue that the teaching of repulsion between like surface charges stabilizes the suspension from further association and when read in the context of the reference means that the suspension is stabilized so that is does not form a higher order morphology material and asserts further that the opposite is taught by Stewart.
The Examiner, in response, acknowledges the remarks, but respectfully maintains that they are not persuasive since the composition disclosed by the reference (e.g., claim 1), continues to read on the composition as instantly recited. It is noted that the cited passage states that association into higher order morphologies is conditional upon solution conditions and charge ratios, the latter parameter of which is recited by instant claims 59 and 60, and those claims are of record as being met by claims 18 and 19 of the reference.
The second of the two conditions is addressed in the rejection above as having been met by claim 1 of the reference whereby the composition has an ion concentration that is greater than the concentration of ions in the subject. Owing to the disclosure of the practiced composition with respect to the scope of the claimed composition, the Examiner respectfully submits that the recited ion concentration is met by Stewart. As such, the recited property that said concentration is ”sufficient to prevent association of the polycationic polyelectrolytes and the polyanionic polyelectrolytes in water. See MPEP §2112.01(I).
Applicants’ arguments, for the above reasons, are found unpersuasive. Said rejection is therefore maintained.
All claims under consideration remain rejected; no claims are allowed.
Conclusion
All claims are drawn to the same invention claimed in the application prior to the entry of the submission under 37 CFR 1.114 and could have been finally rejected on the grounds and art of record in the next Office action if they had been entered in the application prior to entry under 37 CFR 1.114. Accordingly, THIS ACTION IS MADE FINAL even though it is a first action after the filing of a request for continued examination and the submission under 37 CFR 1.114. See MPEP § 706.07(b). 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 extension fee 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.
Correspondence
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to Jeffrey T. Palenik whose telephone number is (571) 270-1966. The Examiner can normally be reached on 9:30 am - 7:00 pm; M-F (EST).
If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Robert A. Wax can be reached on (571) 272-0623. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Jeffrey T. Palenik/
Primary Examiner, Art Unit 1615
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