*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 .
Applicant's response dated June 3, 2026 is acknowledged.
Priority
This application is a 371 of PCT/GB2021/051247 filed on 05/21/2021, and claims
foreign priority in GB2007701.2 filed on 05/22/2020.
Claim Status
Claims 1-3, 5, 7, 8, 10, and 13-25 are pending. Claims 1 and 10 were amended. Claims 4, 6, 9, 11, and 12 were canceled. Claims 15, 16, 20, 23, and 24 are withdrawn. Claims 1-3, 5, 7, 8, 10, 13, 14, 17-19, 21, 22, and 25 are examined.
Withdrawn Claim Rejections -35 USC§ 102
Rejections of claims 1-3, 5, 7, 8, 19, 21, 22, and 25 as being anticipated by Chouifra (Biointerphases, Volume 12, Number 2, pages 1-13, Published June 14, 2017) are withdrawn because claim 1 was amended by limiting m to 3-12, which is outside the scope of the prior art.
Claim Objections
Claims 13, 14, and 17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The closest prior art of record is Xu and its teachings are described below. Xu does not teach the limitations of claims 13, 14, and 17 and it would not have been obvious to modify Xu in order to arrive to the limitations of claims 13, 14, and 17.
Maintained Claim Rejections - 35 USC§ 103
Modified as Necessitated by Amendment
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.
Claims 1-3, 5, 7, 8, 10, 18, 19, 21, 22, and 25 are rejected under 35 U.S.C. 103 as being
unpatentable over Xu (US 2016/0340460 Al Published November 24, 2016 - of record in IDS
11/21/2022).
The claims encompass a branched polymer according to Formula I.
The teachings of Xu are related to sulfonated polyphosphazene copolymers (Abstract).
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(paragraph 0012), wherein Rl is -OCH3 or -F; R2 is Na or H; n is the number of phosphazene residue units, i.e. the length of a
polyphosphazene chain; x is the number of styrene residue units, and ranges from 0 to 100; y is
the number of p-( 4-sulfonato butoxy) styrene residue units, and ranges from 0 to 100; m is the
number of combination units of styrene residues and p-(4-sulfonato butoxy) styrene residues,
and ranges from 0 to 100; r indicates that the copolymer of styrene residue and p-(4-sulfonato
butoxy) styrene residue is a random copolymer (paragraph 0013). An example of a polymer
includes poly(4-fluoro phenoxy)(4-methyl phenoxy)phosphazene-graft-poly{(styrene )x-co-[4-(
4-sulfonato butoxy)styrene]y} (F-PSx-PSBOSy) (paragraph 0019) and more specifically FPSBOS26 and M-PSBQS40 (paragraph 0026). Example 2 teaches a method of making poly[(4-
fluoro phenoxy)( 4-methyl phenoxy )phosphazene-graft-poly {(styrene )x -co-[ 4-( 4-sulfonato
butoxy)styrene]y} (F-PSx-PSBOSy) and provides Table l with molecular weights and graft
lengths (paragraphs 0042 and 0043).
Xu does not state the number of repeating units without the graft and the number of
repeating units with the graft in F-PSBOS26. Table 1 provides molecular weights of graft
copolymers. It would have been prima facie obvious to a person skilled in the art to have formed
F-PSBOS26 having a number average molecular weight of l.13xl05 and weight average
molecular weight of l.94xl05 with a reasonable expectation of success because Table 1 teaches
said combination of molecular weights for a graft copolymer F-PAS26. Xu teaches that the units without the graft are present in the amount of (0.5-0.9)n and the units with the graft are present in the amount of (0.l-0.5)n where n is the length of the polymer chain. In poly[(4-fluoro phenoxy)(4-methyl phenoxy)phosphazene-graft-[4-(4-sulfonatobutoxy )styrene ]26} (F-PSBO S26 ), the molecular weight of the residue without the graft is 282 g/mole and the molecular weight of the residue with the graft is 7536 g/mole. The molecular weight of the grafted residue was calculated based on the sodium salt of the sulfonate. It would have been obvious to vary the number of repeating units with the graft and without the graft in order to form a copolymer that meets the parameters set forth by Xu. A graft copolymer having a number average molecular weight of 113,000 Da would contain at most 14 repeating units of grafted residue because 15 repeating units is equal to the entire polymer weight. Therefore, the remaining molecular weight would be repeating units without the graft. Fourteen units is equal to 105,504 Da (14*7536 Da). The difference between the total weight of the copolymer and the total weight of the 14 grafted units is 7496 Da (l 13,000-105,504), therefore there would have been 26 residues without a graft
(7496/282). A graft copolymer having 14 grafted and 26 ungrafted residues has a total of 40
residues and the ratio of the grafted to ungrafted is 0.35 :0.65. A graft copolymer having 12
grafted (90,432 Da) and 80 ungrafted (22,560 Da) repeating units has a ratio of grafted to
ungrafted of 0.13 :0.87. The values fall in the ranges of ratios of grafted to ungrafted residues
taught by Xu. The above calculation was done as an example of how the number of repeating
units without the graft and with the graft would be calculated.
The claimed branched polymer is obvious over Xu's graft copolymer having 12-14 grafts
of poly-[ 4-( 4-sulfonatobutoxy )styrene ]26 because
-the polymer backbone corresponds to the polyvalent core structure,
-[4-(4-sulfonatobutoxy)styrene] corresponds to the X residue having a sulfonate substituent,
-Y is absent,
-any moiety that terminates poly-[ 4-( 4-sulfonatobutoxy )styrene ]26 corresponds to Z, a person skilled in the art would have understood that once the polymerization reaction is complete the formed polymer is complete and has an end group,
-the number of grafts corresponds to m, which is obvious because it overlaps 12-14,
-the number of repeating [ 4-( 4-sulfonatobutoxy )styrene] residues corresponds to n, which
is obvious because it encompasses 26, and
-q is 0.
Claims 2, 3, and 5 are obvious over 4-(4-sulfonatobutoxy)styrene because it is
encompassed by formula II when R3 and R2 are both hydrogen atoms, and RI is aryl (phenyl in
claim 3) substituted with sulfonate and C4alkoxy.
Claim 7 is obvious because the claimed ranges encompass 26, which is the number of 4-
(4-sulfonatobutoxy)styrene repeating units.
Regarding claim 8, the polymer of 4-(4-sulfonatobutoxy)styrene has a hydrogen atom on the last repeating unit, which reads on a capping group.
Regarding claims 10 and 18, it would have been obvious to have varied the number of residues of 4-( 4-sulfonatobutoxy)styrene within the graft up to 100 with a reasonable expectation of success because Xu teaches that the number of said units ranges from 0 to 100. A residue grafted with 91 4-(4-sulfonatobutoxy)styrene would have a molecular weight of 25,671 Da ((279*91)+282). A grafted copolymer of molecular weight 113,000 Da having 4 grafted residues would have 36 residues without grafts. Four grafted residues would have a molecular weight of 102,684 Da. The difference between the total weight of the graft copolymer and the total weight of the grafted units corresponds to the total molecular weight of the residues without grafts (113,000-102,684 = 10,316). Dividing 10,316 by molecular weight of a residue without a graft (282 Da) provides the number of repeating units without a graft (10,316/282), which is 36. The ratio of grafted units to units without a graft is 0.1:0.9 which falls in the range required by Xu. Xu requires (0.5-0.9)n units that are not grafted and (0.1-0.5)n grafted units. The claimed range of n is obvious because it encompasses 91. Xu's graft does not contain a monomer Y therefore q is 0. Xu's graft copolymer contains four grafted repeating units which meets the limitation mis 4. It is noted that Xu teaches a genus of graft copolymers where the numbers of repeating units in the copolymer and the graft vary over a range of values, and it would have been obvious to have formed Xu's graft copolymer by varying those ranges and Xu's genus of graft copolymers would have overlapped with the claimed genus of copolymers. Regarding claim 10, the claim is obvious because Xu' s polymer does not contain a monomer Y, which meets the limitation where q is 0. The range of m is obvious because the range of 4 to 10 encompasses 4. Xu's graft copolymer as shown above contains an embodiment having 4 repeating units grafted with 4-(4-sulfonatobutoxy )styrene26.
Regarding claim 19, Xu's method of making the graft copolymer results in a composition
comprising said graft copolymer, which meets the claimed limitation of a composition.
Regarding claims 21 and 25, it would have been obvious to have formed a membrane
from the graft copolymer as described above because Xu teaches forming a membrane through
film forming by solution casting method (paragraph 0021), a membrane reads on a device and
because it has the same chemical composition as claimed, it could have been used as a device for
sterilization or viral disinfection, absent evidence to the contrary. The membrane is made
through solution casting, and the skilled artisan would have understood that a container was used
to form the film and the container reads on a means for dispensing the composition. The formed
film could have been dispensed from the container after formation. A membrane formed form
the graft copolymers reads on a material comprising the graft copolymer.
Regarding claims 22 and 25, it would have been obvious to have added water to the
reaction mixture from which the grafted copolymer was formed because Xu teaches adding
water to the reaction mixture in order to precipitate the product (paragraph 0037). This
embodiment meets the claimed limitations because water is a pharmaceutically acceptable
excipient and the composition reads on a pharmaceutical composition because it contains the
same components as claimed. A composition comprising the graft copolymer and water reads on
a material comprising the graft copolymer.
Response to Arguments
Applicant’s arguments submitted in the remarks dated June 3, 2026 were fully considered but are not persuasive for the following reasons.
Argument that Xu does not teach the “polyvalent core structure” feature is not persuasive because the polymer backbone meets this limitation. Instant application defines the term "polyvalent core structure" as referring to any moiety having multiple branches, wherein the branches are capable of covalently bonding to the residues of the polymer chains attached thereto. See paragraph 0037. This definition does not structurally distinguish the claimed polyvalent core structure, i.e. any moiety having multiple branches, from Xu’s polymer backbone which is considered a moiety having multiple branches. The claims do not limit the arrangement of the branches on the polyvalent core structure, therefore applicant’s argument regarding random distribution of branches along the polymer backbone in Xu’s grant copolymer is not persuasive.
Applicant’s calculation regarding the variable “m” is not persuasive because it is based on an embodiment of a polymer that is different from the polymer over which the claims are rejected. The claims are rejected over F-PSBOS26 graft polymer, for which a molecular weight and number of grafted and ungrafted repeating units are unknown. Xu requires (0.5-0.9)n units that are not grafted and (0.1-0.5)n grafted units. The examiner relied on one exemplified molecular weight and Xu’s repeating unit requirement to determine the range of grafted and ungrafted repeating units in F-PSBOS26. Molecular weight 113,000 was used for calculation purpose. Any one of the molecular weights listed in Table 1 could have been used.
Applicant’s argument that claim 1 requires the presence of a block of at least 5 sulfated or sulfonated X residues (n is 5-500) on each branch of the claimed branched polymer is not persuasive because the claim does not actually require X and Y repeating units to be arranged in any particular way.
Applicant’s argument that it cannot be said that Xu discloses, expressly or inherently, a branched polymer having a block of at least 5 concurrent p-(-4-sulfonate butoxy)styrene groups on each grafted residue is not persuasive because the claims are rejected over FPSBOS26 which contains grafts, where each graft consists of 26 repeating units of SBOS (4-sulfone butoxy)styrene), which renders the claimed n variable obvious because 26 is encompassed by 5-500 and q is 0.
Applicant’s argument that there is no evidence that Xu’s FPSBOS26 contains 26 concurrent SBOS units is not persuasive because it is clear from the polymer name that there are no other repeating units in the grafts. It would have been reasonable to interpret the chemical name “poly[(4-fluoro phenoxy)(4-methyl phenoxy)phosphazene-graft-[4-(4-sulfonatobutoxy )styrene ]26}” (F-PSBOS26) as written and it is readily apparent to the skilled artisan that the grafted polymer only contains 26 units of -[4-(4-sulfonatobutoxy )styrene ]26.
Applicant’s arguments related to how the instantly claimed branched polymer is formed are not persuasive because the arguments are based on limitations that are not claimed. The limitations that are not claimed include branched polymers were prepared as block polymers, which means that polymers feature a high-density cluster of anionic residues surrounding the core of the branched polymer and virucidal activity of the branched polymer. Although claims are interpreted in light of the specification, it is improper to read limitations from the specification into the claims.
The instantly claimed polymer is structurally indistinguishable form Xu’s polymer and a person skilled in the art would have expected the two polymers to have the same properties when tested under the same conditions. Thus, applicant’s arguments related to healthcare use and anti-viral application of instantly claimed polymer are not persuasive. Additionally, the claims do not recite any intended use of the polymers.
Conclusion
Claims 1-3, 5, 7, 8, 10, 18, 19, 21, 22, and 25 are rejected. Claims 13, 14, and 17 are
objected to.
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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/ALMA PIPIC/
Primary Examiner, Art Unit 1617
Prosecution Insights