DETAILED ACTION
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 .
Election/Restrictions
Applicant’s election of Group I and species of 131I as a radiotherapeutic agent in the reply filed on April 20, 2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
In a telephone call with Charles P. Landrum on April 29, 2026, an election of the species of phospholipid as a liposome species election requirement was made.
Claim Rejections - 35 USC § 112 Indefiniteness
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 4 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.
Claim 4 recites the limitation " the imaging agent." There is insufficient antecedent basis for this limitation in the claim as independent claim 1 only refers to “a diagnostic agent.” It is suggested that claim 4 be amended to “the diagnostic agent” to obviate this rejection.
Clarification and/or amendment is required.
Claim Rejections - 35 USC § 102
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 1-5, 7, and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Barnett et al. (US 2011 0104052; cited on IDS filed October 24, 2023).
Regarding claim 1, 4, 5, 7, and 8, Barnett discloses a method of producing a therapeutic polymer matrix comprising nanoparticles loaded with one or more bioactive agents comprising polymerizing a matrix comprising polymers and nanoparticles; and incubating the nanoparticles and the polymer matrix after polymerization with one or more bioactive agents for a time sufficient to load the nanoparticle and polymer matrix with the agent (claim 13), which reads on a method for post-manufacture loading. Barnett discloses that the polymer matrix can form a microsphere (¶ 26) and the polymer can be a hydrogel (¶ 17), which reads on hydrogel microsphere. Barnett discloses that the bioactive agents can be diagnostic and/or therapeutic agents (claim 2). Barnett discloses that the nanoparticles can be liposomes and that the polymer matrix can contain a plurality of liposomes (¶ 44). Barnett discloses that the agent can be loaded into the liposome using a transmembrane potential produced by creating a concentration gradient such as a pH gradient across the liposome membranes (¶¶ 70-71; ¶ 268). Barnett discloses that creating a transmembrane potential across the liposome membranes is oriented to retain the agent in the liposomes (¶ 328). Barnett discloses that the diagnostic and/or therapeutic agents can be radioactive isotopes such as technetium-99 m (99mTC), iodine-131 (131I), and Rhenium-188 (188Re) (¶¶ 17-18; ¶ 24). Barnett discloses that radioactive isotopes such as 99mTC and 188Re can be complexed with a loading agent such as BMEDA (N,N-bis(2-mercapatoethly)-N',N'-diethylethylenediamine) and the complex can be loaded into the gradient liposomes (¶¶ 347-348).
Regarding claims 2 and 3, Barnett discloses that the polymer of the hydrogel microsphere can be polysaccharide or alginate (¶ 279).
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 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. Applicant is 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 1-5, 7, and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Xiong et al. (US 2014 0127287; cited on IDS filed October 24, 2023) in view of Barnett et al. (US 2011 0104052; cited on IDS filed October 24, 2023).
Regarding claims 1 and 5, Xiong discloses a method for preparing a drug delivery system comprising mixing a hydrogel precursor with a liposome to form a hydrogel precursor-liposome suspension, treating the hydrogel precursor-liposome suspension to polymerize the hydrogel precursor encapsulated by the liposome to form a lipogel (liposome-encapsulated hydrogels), and incubating the lipogel with at least one active agent (claim 10). Xiong discloses that the lipogels can be spherical (¶ 85) and their size can vary depending on the encapsulated active agent (¶ 38). Xiong discloses that a pH gradient can be utilized for remote loading of liposomes (¶ 89). Xiong discloses that the active agent can be a drug or pharmaceutical agent such as doxorubicin (claim 19; ¶ 44), which reads on chemotherapeutic agent of instant claim 5.
Xiong does not disclose a microsphere containing a plurality of liposomes (instant claim 1), an alginate microsphere (instant claims 2 and 3), radioisotopes such as 99mTC or 131I (instant claims 4 and 7), and loading agent such as BMEDA (instant claim 8).
As discussed above, Barnett discloses a method of producing a therapeutic polymer matrix comprising nanoparticles loaded with one or more bioactive agents comprising polymerizing a matrix comprising polymers and nanoparticles; and incubating the nanoparticles and the polymer matrix after polymerization with one or more bioactive agents for a time sufficient to load the nanoparticle and polymer matrix with the agent (claim 13). Barnett discloses that the polymer matrix can form a microsphere (¶ 26) and the polymer matrix can contain a plurality of liposomes (¶ 44). Barnett discloses that the bioactive agents can be a diagnostic and/or therapeutic agent (claim 2) such as 99mTC and 131I (claim 2; ¶¶ 17-18) and 99mTC can be complexed with BMEDA (¶¶ 347-348).
It would have been obvious to a person of ordinary skill in the art before the effective
filing date of the claimed invention to modify the drug delivery system of Xiong by using alginate as a hydrogel, utilizing 99mTC or 131I as an active agent, and employing BMEDA as a loading agent in order to form an alginate microsphere comprising a plurality of liposomes and a radioisotope complexed with BMEDA. A person of ordinary skill in the art would have been motivated to make these modifications and reasonably would have expected success because Barnett teaches that alginate can be used for a hydrogel microsphere comprising a plurality of liposomes, radioisotopes such as 99mTC or 131I can be used as a diagnostic or therapeutic agent, and BMEDA can chelate the radioisotope such as 99mTC and can be used for liposome labeling. Further, a person of ordinary skill in the art would have been motivated to utilize alginate as a biocompatible and biodegradable hydrogel for medical use, to utilize 99mTC or 131I to expand the diagnostic and radiotherapeutic applications of the drug delivery system, and to utilize BMEDA as a loading agent to improve remote loading efficiency, entrapment stability, and pharmacokinetics. Accordingly, applying the teachings of Barnett to the drug delivery system of Xiong constitutes no more than the predictable use of prior art elements according to their established functions, thus rendering claims obvious.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JONG HWAN BAEK whose telephone number is (571)272-0670. The examiner can normally be reached Mon - Thu, 9 am - 3 pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Michael G Hartley can be reached at 571-272-0616. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JONG HWAN BAEK/Examiner, Art Unit 1618
/Michael G. Hartley/Supervisory Patent Examiner, Art Unit 1618
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