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 .
This Office action is in response to the amendment filed 6/19/2026. Claims 1-22 and 36 are cancelled; claims 23, 25, 28 and 31-32 are amended. Accordingly, claims 23-35 and 37 are currently pending in the application.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Objections
Claim 23 is objected to because of the following informalities: Claim 23 recites “the crosslinked poly(allylamine) polymer is of formula (I)”. However, structure of formula I lacks clarity and is not legible. Applicant is advised to present an image that is clear and legible. For examination purposes, Examiner refers to the image in preliminary amendment filed 6/10/2024. Appropriate correction and/or clarification are required.
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 32 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 32 recites the limitation "the poly(allylamine) polymer" in line 2. There is insufficient antecedent basis for this limitation in the claim. For Examination purposes, it is interpreted as a poly(allylamine) polymer that is used to make crosslinked poly(allylamine) polymer (see paragraph 00127 of specification) of claim 23.
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.
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 23-24, 26-35 and 37are rejected under 35 U.S.C. 103 as being unpatentable over Klaerner et al (US 2019/0134076 A1) in view of Buurman et al (WO 2013/087237 A1).
Regarding claims 23 and 29-31, Klaerner et al disclose pharmaceutical compositions (abstract). See embodiment 836, wherein a polymer is formed from allylamine hydrochloride (i.e., reads on the residue of allylamine in present claim 23) and diallylpropyldiamine (see Table C and reads on residue of N.N’-diallyl-1,3-diamino propane in present claim 23). To dry preformed amine polymer beads is added 1,2-dichloroethane (i.e., reads on the residue of 1,2-dicholorethane in present claim 23) and reaction mixture held at 700C. The beads were purified until the pH of solution was 7 (paragraphs 0872-0873). Exemplary crosslinking agents include 1,2-dichloroethane (paragraph 0175). Hence, the polymer formed in embodiment 836 is implicitly a crosslinked poly(allylamine) polymer. The composition is within a sealed package (i.e., reads on packaged pharmaceutical product in present claim 23). The head space may be filled with an inert gas such as nitrogen (i.e., reads on inert environment in present claim 23). In one embodiment, the container includes one or more oxygen scavenging layers (paragraph 0268) which reads on an oxygen scavenger in present claim 23.
Klaerner et al are silent with respect to total number of sp2 allyl carbon atoms in the crosslinked poly(allylamine) polymer; and allylamine content increase when tested with Heated Stability Assay.
However, regarding total number of sp2 allyl carbon atoms in the crosslinked poly(allylamine) polymer, Buurman et al in the same field of endeavor teach a process of separation of crosslinked polyallylamine from allylamine and to a process of determination of the content of allylamine in the crosslinked polyallylamine (abstract). To comply with requirements of pharmaceutical quality, it must be essentially free from residual allylamine which is a seriously toxic compound (page 2, lines 9-10). The process involves treating, under agitation, the crosslinked polyallylamine with an aqueous buffer solution. The process provides a crosslinked polyallylamine with a residual allylamine of less than 5 ppm (page 3, lines 14-25) which is equivalent to 0.0005% of allylamine (i.e., overlaps with the total number of carbon atoms present in the crosslinked poly(allylamine) as sp2 allyl carbons, since number of sp2 carbon atoms are dependent on the amount of unreacted allyl amine in the crosslinked poly(allylamine)). Therefore, in light of the teachings in Buurman et al, it would have been obvious to one skilled in art prior to the filing of present application, to purify the crosslinked poly(allylamine), of Klaerner et al, based on the teachings in Buurman et al, to obtain a crosslinked poly(allylamine) having total number of carbon atoms of sp2 allyl carbons in overlapping ranges (such as less than 1.0% as in present claims 23, less than 0.9% as in present claim 29 and less than 0.8% as in present claim 30), and optimize to any desired level including more than 0.3% but less than 1.0% as in present claim 31, for above mentioned advantages. Since PTO cannot conduct experiments, the burden of proof is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding, allylamine content increase when tested with Heated Stability Assay, given that free residual amine can be reduced to a content as low as less than 5 ppm based on the teachings in Buurman and there is no indication in Klaerner et al, that the crosslinked polymer decomposes under heating to generate free allyl amine contributing to an increase in sp2 allyl carbons, one skilled in in art prior to the filing of present application would have a reasonable basis to expect the allylamine content of the crosslinked poly(allylamine) polymer to increase by less than 1.5 ppm/day allylamine when tested with the Heated Stability Assay, absent evidence to the contrary. Since PTO cannot conduct experiments, the burden of proof is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding claim 24, Klaerner et al teach that composition is within a sealed package. In one embodiment, the container includes one or more oxygen scavenging layers (paragraph 0268).
Regarding claims 26-28, Klaerner et al teach that composition is within a sealed package. The head space may be filled with an inert gas such as nitrogen. In one embodiment, the container includes one or more oxygen scavenging layers (paragraph 0268).
Regarding claim 32, given that carbon to nitrogen ratio is dependent on the amount of free allylamine in the crosslinked poly(allylamine) polymer and the degree of crosslinking; and hence their ratio in relation to that in the starting poly(allylamine) polymer, it is the Office’s position that it is within the scope of one skilled in art prior to the filing of present application to optimize the degree of crosslinking based on the disclosure in Klearner et al combined with the teachings in Buurman to reduce the amount of free allylamine to a desired level, and obtain the claimed ratio of about 0.9, absent evidence to the contrary.
Regarding claims 33-34, Buurman et al teach that extraction process provides apart from the crosslinked allylamine, an aqueous solution comprising essentially the entire original amount of allylamine in the starting material. This solution may be subjected to a suitable method of determination of the content of allylamine and the amount of allylamine in the original sample may be then easily calculated (page 9, lines 4-8). However, given that the residual amount of allylamine in the crosslinked polyallylamine is as low as less than 5 ppm, one skilled in art prior to the filing of present application would have a reasonable basis to expect the % sp2 allyl carbons to fall in the presently claimed range when measured using the claimed method, absent evidence to the contrary. Since PTO cannot conduct experiments, the burden of proof is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding claim 35, Buurman et al teach a process that provides crosslinked polyallylamine with a content of residual allylamine of less than 5 ppm (page 3, lines 24-25).
Regarding claim 37, Klaerner et al teach a method of treating metabolic acidosis (paragraph 0029).
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Klaerner et al (US 2019/0134076 A1) in view of Buurman et al (WO 2013/087237 A1) and Barshied (US 2006/0076536 A1)
The discussion with respect to Klaerner et al and Buurman et al in paragraph 11 above is incorporated here by reference.
Klaerner et al and Buurman et al are silent with respect to the species of oxygen scavenger.
However, Barshied in the same filed of endeavor teaches pharmaceutical packaging for increasing product shelf life, reducing degradation of pharmaceuticals by reducing oxygen levels present in the pharmaceutical package (abstract). Non-limiting examples of oxygen scavenging elements include Mn and Co(II) (paragraph 0035) which read on the oxygen scavenger in present claim 25. Case law holds that selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945). Therefore, in light of the teachings in Barshied and case law, it would have been obvious to one skilled in art prior to the filing of present application to include oxygen scavenger, of Barshied, in the pharmaceutical package, of Klaerner et al in view of Buurman et al, for above mentioned advantages.
Response to Arguments
It is noted that rejection under 35 U.S.C. 112(b) as set forth in paragraph 5a, of office action mailed 3/20/2026, is withdrawn in view of applicant arguments that are persuasive. In light of the applicant argument, residue of 1,2-dicholoroethane in clam 23 is interpreted by Examiner as a unit generated from crosslinking the residue of allylamine in the poly(allyl)amine polymer with 1,2-dichloroethane to form the crosslinked poly(allylamine) polymer.
The objections, and rejections under 112(d) and 103 as set forth in paragraphs 3, 7 and 12-13, of Office action mailed 3/20/2026, are withdrawn in view of amendments and/or applicant arguments and/or new grounds of rejection set forth in this Office action, necessitated by amendment.
While the grounds of rejection are changed, it was still deemed appropriate to address some of the arguments which would be pertinent to new grounds of rejection in this office action (See paragraph 14 below).
Applicant's arguments, filed 6/19/2026, have been fully considered but they are not persuasive. Specifically, general thrust of Applicant’s argument is that free allylamine is unpolymerized monomer physically trapped in the polymer matrix and is removable by extraction as in Buurman by washing with aqueous buffer. In contrast, the Heated Stability Assay measures the rate at which new allylamine is generated over 72 hours at 600C. This generation arises from degradation of sp2 allyl carbon substituents that are covalently bonded to the polymer backbone as a consequence of incomplete allyl group conversion during polymerization. The two sp2 allyl carbons are different and independent. Klaerner’s standard radical polymerization conditions include no teaching directed to maximizing allyl conversion to maximizing allyl conversion or minimizing pendant sp2 allyl groups.
In response, polymerization process in Klaerner includes heating the polymerization mixture during crosslinking for 16 hours by placing in an oil bath at 700C (paragraph 0873). Heated Stability Assay testing in present invention includes putting the sample in convection oven set at 600C for 72 hours and measuring the free sp2 allyl carbon atoms (see paragraph 0192 of present application published as US 2024/0254267 A1). Given that crosslinking is conducted in Klaerner et al for 16 hours at 700C, and any free allylamine in the crosslinked polymer can be purified to remove the toxic allylamine based on the teachings in Buurman, one skilled in art would have a reasonable basis to expect the crosslinked poly(allylamine) polymer, of Klaerner et al in view of Buurman, to see an increase of allylamine content of the crosslinked poly(allylamine) polymer when tested with Heated Stability Assay of less than 1.5 ppm/day.
Conclusion
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARUNA P REDDY whose telephone number is (571)272-6566. The examiner can normally be reached 8:30 AM to 5:00 PM M-F.
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, Arrie (Lanee) Reuther can be reached at 571-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/KARUNA P REDDY/Primary Examiner, Art Unit 1764
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