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 .
Response to Amendment
The amendments filed 09 June, 2026, have been entered. Claims 1 and 4 are amended. Claims 10-11 and 18 are cancelled. Claims 1-9, 12-17, and 19-21 are pending and have been fully considered.
The amendment to claim 1 introduces the language “free of any additional anticoagulant or antimicrobial additives”. As indicated in earlier stages of prosecution with respect to a similar limitation in a previous version of claim 1 (see claim interpretation and 35 U.S.C. 112(b) rejections set forth in the non-final action mailed 03 June, 2025), the stated claim language raises the question of what level of anticoagulant or antimicrobial activity an additive must possess in order to define an “additional anticoagulant or antimicrobial additive”. For example, some chemical compounds may not ordinarily be used as an antimicrobial additive, but may nonetheless exhibit at least some microbe killing or inhibiting affect against certain pathogens at high concentrations. The originally filed specification at [0034] and [0035] sets forth definition for “anticoagulant activity” and “antimicrobial activity”, but does not establish at what level of such activity a component defines an “anticoagulant or antimicrobial activity”.
Following the interview with attorney Brian Jackson on 22 May, 2026 (summary mailed 28 May, 2026), the examiner finds that the claim language is not indefinite, and that the limitation substantially excludes any additional component from the claimed composition which is recognized in the art as having any level of antimicrobial or anticoagulant activity (even if the activity is relatively weak or only at certain concentrations). Also, it is found that the language of the limitation is fairly supported by the originally filed specification (e.g., see [0014], [0034]-[0035], [0044]).
Common examples of compounds with known antimicrobial activity include ethanol, isopropanol, quaternary ammonium compounds, peroxide compounds, hypochlorite compounds, hypochlorous acid, and antibiotics (e.g., penicillin). Common examples of compounds with anticoagulant activity include heparin and derivatives thereof. However, these exemplary compounds are not exhaustive of all additives excluded from the claimed composition, as any additional component which has been shown to have at least some antimicrobial or anticoagulant effect is understood to be excluded from the claimed composition.
Response to Arguments
The applicant’s arguments filed 09 June, 2026, with respect to the previously set forth rejections under 35 U.S.C. 103 have been fully considered. As acknowledged by the applicant, the only distinguishing feature between the composition of claim 1 and the composition disclosed by Mahmoodian (US 2019/0091379) is the concentration of the citrate salt (response filed 09 June, 2026, at page 5, 4th paragraph). The examiner agrees that the claimed range of “about 15.5% to about 16.5% of citrate salt” and the range of “about 3.8% w/v to about 4.2% w/v” disclosed by Mahmoodian do not overlap or approach, and thus Mahmoodian alone does not provide sufficient support for modifying the composition to include citrate salt at a concentration within the claimed range.
The applicant further argues that Ash (EP 1107807 B1) does not provide sufficient support for modifying Mahmoodian to achieve a citrate solution within the claimed range (response at page 5, final paragraph, through page 6, line 2), alleging that: the citrate concentration range disclosed by Ash (1.5-50%) is overly broad; Ash does not provide test data from within the claimed range; the examples of Ash includes other antimicrobials and anticoagulants, contrary to the limitations of the claim; and Ash teaches toward higher concentrations of citrate salt (47%), not the claimed range of about 15.5%-16.5%.
In view of MPEP 2144.05, the examiner finds that the applicant’s arguments are at least partially persuasive because the range of Ash (1.5-50%) is quite broad relative to the claimed range (MPEP 2144.05(II.)(D.)), and there is reasonable doubt as to whether the test results of Ash would necessarily guide a person of ordinary skill in the art toward the claimed range (MPEP 2144.05(II.)(B.)). Also, Ash generally runs counter to the claim language excluding additional antimicrobial or anticoagulant additives.
Accordingly, the previously set froth rejections under 35 U.S.C. 103 are withdrawn.
However, a new grounds of rejection is set forth below, which combines the teachings of Mahmoodian with the teachings of Weijmer et al. (“Superior antimicrobial activity of trisodium citrate over heparin for catheter locking”, Nephrology Dialysis Transplantation, 2002, Vol. 17, pp. 2189-2195). Particularly, the new grounds of rejection finds that Weijmer discloses an evaluation of the antimicrobial performance of a citrate salt solution having a citrate salt concentration (15%) within the claimed range, wherein the evaluation demonstrates that the 15% solution is suitable for inhibiting the growth of five tested species of microorganisms (see Figs. 1, 15% trisodium citrate results). Weijmer further found that a lower concentration (7.5%) of a citrate salt solution provided a weaker antimicrobial effect relative to the 15% solution (see Figs. 1 and 3, 7.5% trisodium citrate). Additionally, Weijmer acknowledges that clinical application of the test results should be implemented carefully (page 2194, left column, second paragraph), especially in view of a fatality that occurred when a high concentration trisodium citrate solution was injected into an unstable patient with existing electrolyte disturbances (page 2194, last four lines of left column, through first three liens of right column; also see citation no. 25 on page 2195).
Therefore, although Weijmer indicates that a 30% citrate salt solution demonstrated the most potent antimicrobial effect (page 2194, right column, second paragraph), a person of ordinary skill in the art may reasonably be guided by the combined teachings of Mahmoodian and Weijmer to arrive at a catheter lock solution having a citrate salt concentration within the claimed range for the benefit of achieving at least a microbial inhibiting effect (see performance of 15% TSC in Fig. 1 of Weijmer) without significantly increasing the risk of patient death in clinical use (consider Weijmer at page 2194, last four lines of left column, through first three liens of right column; also see citation no. 25 on page 2195).
The new grounds of rejection—presented below—are necessitated by the changes in scope associated with the amendments to the claims.
Claim Interpretation
The instant specification defines the following term appearing in the claims as follows:
- “about” refers to a difference of ±10% of a value (instant specification at [0040]).
Consequently, the range of “about 15.5% w/v to about 16.5% w/v” recited in claim 1 (line 2) encompasses a range of 13.95% w/v to 18.15% w/v; all ranges recited with the term “about” are similarly broadened by the term.
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.
Claims 1-9, 12-17, and 19-21 are rejected under 35 U.S.C. 103 as being unpatentable over Mahmoodian et al. (US 2019/0091379 A1) in view of Weijmer et al. (“Superior antimicrobial activity of trisodium citrate over heparin for catheter locking”, Nephrology Dialysis Transplantation, 2002, Vol. 17, pp. 2189-2195; Weijmer was previously cited with the action mailed 25 November, 2025).
Regarding instant claim 1, claim 1 of Mahmoodian reads as follows:
1. A catheter lock solution comprising: about 3.8% w/v to about 4.2% w/v of a citrate salt; water for injection; and, optionally, an acid, wherein a pH of the catheter lock solution is between about 6.4 and about 7.5, and wherein the catheter lock solution is free of any additional components having anticoagulant or antimicrobial activity.
It is thus evident that claim 1 of Mahmoodian is nearly identical to the instant claim 1, Mahmoodian clearly teaching all of an antimicrobial catheter lock solution comprising: a citrate salt; water for injection; and, optionally, an acid, wherein a pH of the catheter lock solution is between about 6.4 and 7.5, wherein the catheter lock solution is free of any additional anticoagulant or antimicrobial additives.
The composition of claim 1 of Mahmoodian differs from the instant claim only with respect to the recited concentration of the citrate salt; Mahmoodian recites a range of about 3.8% w/v to about 4.2% w/v, whereas the instant claim recites a range of about 15.5% w/v to about 16.5% w/v (effectively 13.95% w/v to 18.15% w/v, see claim interpretation section above). Generally, Mahmoodian recognized the usefulness of a citrate salt solution as a catheter lock solution because trisodium citrate can prevent clotting in catheter lumens and catheter tips ([0036], [0045]) and provides other advantages over conventional heparin solutions including improved shelf life and reduced cost ([0037]). Also, although Mahmoodian teaches solutions having a citrate salt concentration of 3.8% w/v to 4.2% w/v (Tables 6-7, [0067]), Mahmoodian but does not discredit or discourage trying solutions of different concentrations.
Nonetheless, Mahmoodian alone does not fairly teach the catheter lock solution comprising about 15.5% w/v to about 16.5% w/v of a citrate salt.
However, in the analogous art of antimicrobial catheter locking compositions (superior antimicrobial activity of trisodium citrate over heparin for catheter locking—title), Weijmer discusses how trisodium citrate salt solutions have been used in place of heparin solutions as catheter lock solutions to prevent the contamination of catheter lumens, with citrate salt solutions advantageously having both an anticoagulation property and an antimicrobial property without the risk of inducing side effects associated with heparin (page 2190, left column , paragraph beginning at third line). Weijmer further discloses an evaluation of the antimicrobial properties of four concentrations of trisodium citrate (TSC) solutions against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans (page 2189, “Method” paragraph of Abstract; further details of experiment disclosed at page 2190, “Subjects and methods” section), relevant results of which are displayed in Figs. 1 and 3 below.
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The results of Weijmer include a result for a 15% trisodium citrate solution, said solution having a citrate salt concentration laying within the claimed range of about 15.5% w/v to about 16.5% w/v (effectively 13.95% w/v to 18.15% w/v due to term “about”). Fig. 1 shows the 15% trisodium citrate solution reducing the population of Staphylococcus epidermidis (triangle), Staphylococcus aureus (closed circle, dashed line), and Escherichia coli (open square, solid line), and at least preventing a full log increase in colony forming units of Pseudomonas aeruginosa (closed square, dashed line) and Candida albicans (open circle, solid line) over a 24 hour period. Fig. 3 indicates that the 15% trisodium citrate solution also achieved at least a modest zone of inhibition for 4 of the 5 test microorganisms (P. aeruginosa is the only test microorganism for which the zone of inhibition is 0 for the 15% trisodium citrate solution in Fig. 3). A lower concentration of trisodium citrate (7.5%) was not sufficient to inhibit the growth of Pseudomonas aeruginosa after 24 hours (Fig. 1, trisodium citrate 7.5% result shows multiple log increase in colony forming units per milliliter for P. aeruginosa after 24 hours), and only achieved a measurable zone of inhibition for two of the five test organisms (Fig. 3 shows 7.5% trisodium citrate solution only achieving zone of inhibition for S. aureus and S. epidermidis). These results are indicative of a fair antimicrobial effect within [or approaching] the claimed citrate salt range, and demonstrate that the antimicrobial effect is weakened at lower concentrations. Therefore, the above evidence of Weijmer would at least motivate a person of ordinary skill in the art to try increasing the concentration of citrate salt in the catheter lock solution of Mahmoodian for the benefit of improving the inhibition of microbial growth (i.e., the antimicrobial effect) achieved by the solution.
It is further acknowledged that the results of Weijmer show improved antimicrobial results when the citrate salt concentration is increased above the claimed range (Fig. 1 shows the 30% trisodium citrate solution achieving grater decreases in the microbial populations, and Fig. 3 shows the 30% trisodium citate solution achieving a zone of inhibition for all five microorganisms; Weijmer further concludes that the TSC 30% was the most potent antimicrobial locking solution—page 2194, right column, paragraph beginning line 4). However, for most of the tested microorganisms, the results between the 15% and 30% citrate solutions differ only modestly with respect to magnitude and not in kind, with the 15% solution at least being capable of inhibiting the proliferation (i.e., greater than a 1 log increase in CFU/mL) of all five tested microorganisms (Fig. 1). Furthermore, Weijmer indicates that excessively high amounts of trisodium citrate in locking catheters can be dangerous (“concern has risen of using TSC for locking catheters after a fatal incident [25]. In this particular case, however, a large amount of TSC was injected in a previously unstable patient with severe electrolyte disturbances. It is clear that the use of these solution should be restricted to authorized and skilled health professionals”—page 2194, last 4 lines of left column, and first 3 lines of right column), and Weijmer cautions direct application of in vitro results without confirmation by further clinical trials (page 2194, left column, second paragraph). From the above teachings of Weijmer, a person of ordinary skill in the art would be reasonably guided to select a trisodium citrate concentration which is at least capable of inhibiting the growth of microorganisms but which does not pose a serious health risk to patients.
Therefore, it would be obvious to a person having ordinary skill in the art to modify the catheter lock solution of Mahmoodian such that the citrate salt concentration is increased to about 15%, as seen in Weijmer, for the benefit of increasing the antimicrobial effect of the solution (Figs. 1 and 3 of Weijmer show a 15% trisodium citrate solution having an improved antimicrobial effect over a 7.5% trisodium citrate solution) while minimizing the risk of endangering a patient to unsafe levels of trisodium citrate (Weijmer at page 2194, last 4 lines of left column, and first 3 lines of right column, indicates that the accidental injection of a large amounts of sodium citrate resulted in a patient death).
With respect to further prosecution, it is noted that presently, the 15% citrate salt solution of modified Mahmoodian lays within the effectively claimed range (13.95%-18.15%). If the term “about” was removed from claim 1, the 15% solution of modified Mahmoodian would not lay directly in the claimed range, but the 15% value would be sufficiently close to the claimed range to maintain a finding of obviousness absent persuasive evidence of significance, i.e., a showing of a meaningful difference in quality between the claimed and prior art compositions; see In re Becket, 88 F.2d 684 (CCPA 1937) as cited in MPEP 2144.05(I.)&(III.)(A.). Also, the constraint of improved antimicrobial effect at higher citrate salt concentrations in a catheter lock solution against the constraint of increased risk of patient fatalities at high citrate salt concentrations (which are evident from Weijmer, as discussed above) provides a framework which would otherwise guide a person of ordinary skill in the art to arrive—by routine experimentation and optimization—at a citrate salt concentration which achieves a desired antimicrobial effect and a desired patient risk level; see MPEP 2144.05(II.). Therefore, adjustments to the claimed concentration level alone are not expected to be sufficient to overcome a finding of obviousness absent persuasive evidence of criticality.
Regarding claim 2, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches the citrate salt is a sodium citrate salt (claim 2 of Mahmoodian).
Regarding claim 3, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches the citrate salt is trisodium citrate (claim 3 of Mahmoodian).
Regarding claim 4, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches the catheter lock solution comprises an acid (claim 4 of Mahmoodian).
Regarding claim 5, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 4. Mahmoodian further teaches the acid is a diluted acid (claim 5 of Mahmoodian).
Regarding claim 6, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 5. Mahmoodian further teaches the diluted acid is diluted hydrochloric acid (claim 6 of Mahmoodian).
Regarding claim 7, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 6. Mahmoodian further teaches the catheter lock solution comprises the acid in an amount between about 0.1% and about 0.7% v/v (claim 7 of Mahmoodian).
Regarding claim 8, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches the citrate salt comprises trisodium citrate di-hydrate (claim 8 of Mahmoodian).
Regarding claim 9, Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches the catheter lock solution comprises trisodium citrate, water-for-injection, and about 0.7% v/v of 10% HCl (claim 9 of Mahmoodian). As modified in view of Weijmer with respect to claim 1, the concentration of citrate salt (trisodium citrate) in the modified solution of Mahmoodian is about 16% (Weijmer teaches 15% solution, which lays within the effectively claimed range of 14.4%-17.6%; see rejection of claim 1 above).
Regarding claim 12, the claim is a method for making the solution of claim 1. Mahmoodian teaches a method of making the solution consisting of steps of dissolving a citrate salt in water-for-injection (WFI) and, optionally, adding an acid until the pH of the catheter lock solution is between about 6.4 and about 7.5 (claim 12 of Mahmoodian). The method of Mahmoodian yields an approximately 4% citrate salt solution, whereas the instant method requires an approximately 16% citrate salt solution to correspond with instant claim 1. However, it would be obvious to a person having ordinary skill in the art to modify the method of Mahmoodian in view of Weijmer such that the formed catheter lock solution has a citrate salt concentration within the claimed range (15.5%-16.5% w/v) for the reasons discussed with respect to claim 1 above.
Regarding claim 13, the claim is directed toward a pre-filled syringe comprising a syringe containing the antimicrobial catheter lock solution of claim 1. Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches incorporating the catheter lock solution into a pre-filled syringe (claim 15; [0020], [0037], [0050]-[0051]).
Regarding claim 14, the claim is directed toward a catheter comprising a tube defining a lumen therethrough, wherein at least a portion of the lumen is infused with the antimicrobial catheter lock solution of claim 1. Mahmoodian in view of Weijmer teaches the antimicrobial catheter lock solution of claim 1. Mahmoodian further teaches a catheter comprising a tube defining a lumen therethrough, wherein at least a portion of the lumen is infused with an antimicrobial catheter lock solution (claim 16 of Mahmoodian). Accordingly, it would be obvious to a person having ordinary skill in the art to modify the catheter [of claim 16] of Mahmoodian in view of Weijmer such that the catheter lock solution infused within the catheter is a catheter lock solution consistent with instant claim 1 (i.e., having a citate salt concentration of about 16%) for substantially the reasons discussed with respect to claim 1 above.
Regarding claim 15, the claim is directed toward a method of using the solution of claim 1. Mahmoodian teaches A method of inhibiting coagulation and microbial activity in a catheter comprising:
providing a catheter comprising a tube defining a lumen therethrough; and
infusing, into at least a portion of the lumen of the catheter, an antimicrobial catheter lock solution (claim 17 of Mahmoodian).
The method of Mahmoodian uses an approximately 4% citrate solution, whereas the instant method uses a catheter lock solution according to instant claim 1, which requires an approximately 16% citrate solution. However, it would be obvious to a person having ordinary skill in the the art to modify the method of Mahmoodian in view of Weijmer such that the catheter lock solution has a citrate salt concentration within the claimed range (about 15.5%-16.5% w/v) for the reasons discussed with respect to claim 1 above.
Regarding claim 16, Mahmoodian teaches an antimicrobial catheter lock solution consisting of:
trisodium citrate;
water-for-injection (WFI); and
about 0.0 % v/v to about 0.7% v/v of 10% HCl, wherein the catheter lock solution has a pH of between about 6.4 and about 7.5 (claim 13 of Mahmoodian).
Mahmoodian does not teach the trisodium citrate is at a concentration of about 15.5% w/v to about 16.5% w/v. However, as substantially discussed with respect to claim 1 above, it would be obvious to modify Mahmoodian in view of Weijmer and arrive at a concentration within the claimed range of about 15.5% w/v to about 16.5% w/v (see rejection of claim 1 above).
Regarding claim 17, Mahmoodian teaches an antimicrobial catheter lock solution consisting of: trisodium citrate; water-for-injection (WFI); and about 0.7% v/v of 10% HCl, wherein the catheter lock solution has a pH of about 7 (claim 14). Although Mahmoodian does not teach a trisodium citrate concentration of about 16% (effectively 14.4%-17.6%), it would be obvious to a person having ordinary skill in the art to arrive at such a concentration in view of the teachings of Mahmoodian and Weijmer for the reasons discussed with respect to claim 1 above.
Regarding claim 19, the claim is essentially equivalent to claim 16 except that claim 19 essentially broadens the scope of claim 16 by reciting a sufficient amount of a biocompatible acid such that the pH of the catheter lock solution is between 6.4 and 7.5, whereas claim 16 more narrowly requires a range of 0-0.7% v/v of 10% HCL and a pH between 6.4 and 7.5. Since claim 16 effectively lays within the scope of claim 19, see the rejection of claim 16 above regarding how Mahmoodian in view of Weijmer teaches an antimicrobial catheter lock solution consisting of about 15.5% w/v to about 16.5% w/v of trisodium citrate, water-for-injection, and a sufficient amount of a biocompatible acid such that the pH of the catheter lock solution is between about 6.4 and 7.5.
Regarding claim 20, Mahmoodian in view of Weijmer teaches the antimicrobial lock solution of claim 19, and Mahmoodian further teaches the biocompatible acid is HCl (claim 13 of Mahmoodian requires 0.0-0.7% v/v of 10% HCl in the catheter lock solution and a pH between 6.4 and 7.5).
Regarding claim 21, the claim corresponds to instant claim 13 except that it requires the pre-filled syringe contain the antimicrobial catheter lock solution of instant claim 19 instead of the solution of instant claim 1. Accordingly, see the rejections of claims 1, 13, and 19 above, regarding how Mahmoodian teaches a pre-filled syringe comprising a catheter lock solution (claim 15 of Mahmoodian), how Mahmoodian teaches a lock solution substantially identical to the lock solution of instant claim 19 (claim 13 of Mahmoodian) apart from the citrate salt concentration, how it would be obvious to modify Mahmoodian in view of Weijmer to arrive at a concentration value within the claimed range (see rejection of instant claim 1), and how it would be obvious to provide the modified solution within the pre-filled syringe (see rejection of instant claim 13).
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.
Claims 1-9, 12-17, and 19-21 are rejected on the grounds of nonstatutory double patenting as being unpatentable over claims 1-10 of U.S. Patent No. 11,045,589 B2 in view of Weijmer et al. (Nephrology Dialysis Transplantation, 2002, Vol. 17, pp. 2189-2195).
The cited reference patent—US 11,045,589—corresponds to the patent issued for the Mahmoodian et al. pre-grant publication, US 2019/0091379 A1, relied upon in the rejections under 35 U.S.C. 103 above. Although the claims of the issued patent have been amended from the claims of the pre-grant publication, the claims of the patent still disclose the core subject matter of a catheter lock solution comprising or consisting of a citrate salt (trisodium citrate), water for injection, and 0.1% to 0.7% v/v of 10% HCL (claims 1 and 7 of the reference patent), as well as a method of making the solution (claim 6), a method of using the solution (claim 10), a syringe containing the solution (claim 8), and a catheter comprising a tube defining a lumen that is infused with the solution (claim 7).
Thus, the only distinguishing feature between the instant claims and the claims of the reference patent is the concentration of citrate salt included in the solution. The reference patent includes the citrate salt at a concentration of about 4%, whereas the instant claims are directed toward a citrate salt concentration of about 16%. However, as discussed in the rejection of claim 1 under 35 U.S.C. 103 above, it would be obvious for a person having ordinary skill in the art to modify the solution of the reference patent in view of Weijmer such that the citrate salt concentration is about 16% for the reasons discussed with respect to claim 1 above. Therefore, for substantially the same reasons set forth in the rejections of claims 1-9, 12-17, and 19-21 under 35 U.S.C. 103 above, claims 1-9, 12-17, and 19-21 of the instant application are obvious over claims 1-10 of the reference patent (US 11,045,589) in view of Weijmer.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Associated Press (“FDA Issues Warning on Product Used to Clear Dialysis Machines”, April 14, 2000, published by the Washington Post), which was first cited in the action mailed 25 November, 2025, describes an incident wherein a patient was killed by the accidental injection of 46.7% sodium citrate solution due to the loss of blood calcium. This is the same incident referenced by Weijmer (page 2194, last four lines of left column through first three lines of right column; and page 2195, citation 25). The incident demonstrates that excessively highly sodium citrate solutions were known to come with the risk of inducing hypocalcemia in patients, which can be fatal.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRADY C PILSBURY whose telephone number is (571)272-8054. The examiner can normally be reached M-Th 7:30a-5:00p.
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/BRADY C PILSBURY/Examiner, Art Unit 1799
/JENNIFER WECKER/Primary Examiner, Art Unit 1797
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