DETAILED ACTION
Applicant’s amendment submitted 4/27/2026 is acknowledged. Claim 16 is currently amended. Claims 1-15, 17, and 22 are canceled. Claim 23 remains withdrawn pursuant to 37 CFR 1.142(b) as being drawn to a non-elected invention. Claims 16, 18-21, and 23 are pending in the instant application.
Claims 16 and 18-21 are the subject of this office 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 .
Priority
The instant application is a U.S. National Phase of PCT/EP2020/078559, filed on 10/12/2020, and claims foreign priority to EP19202465.1, filed 10/10/2019.
Response to Amendment
Applicant’s amendment to claim 16 overcomes each objection previously set forth in the Non-Final Rejection mailed on 2/11/2026.
Claim Rejections - 35 USC § 102
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 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.
Maintained Rejection: Claims 16 and 18-21 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lux et al. (ACS Appl. Mater. Interfaces, 2017, Vol. 9, pp.37587-37596; of record).
Regarding claim 16, Lux teaches perfluorobutane-filled microbubbles conjugated with thrombin-sensitive activatable cell-penetrating peptides (ACPPs) that detect acute thrombosis with ultrasound imaging (see Abstract, see paragraph bridging pp.37588-89, p.37592, paragraph bridging left and right columns, right column, 1st paragraph, and Figs. 2-4 and 6). Lux teaches the microbubble shell is made of distearoylglycerophosphocholine (DSPC), disteroylglycerophosphoethanolamine-maleimide(polyethelene glycol)-5000 (DSPE-PEG(5000)-mal), reading on a microbubble made of phospholipids with surfactants (see p.37592, paragraph bridging left and right columns, and Fig. 3A). Lux further teaches the microbubble is conjugated to activatable cell-penetrating peptide that is cleavable by the serine protease thrombin, reading on a peptide substrate for an enzyme of interest (see p.37592, left column, 1st-5th paragraphs, right column, 1st paragraph, and Figs. 1, 4, and S4A). Paragraph [0047] of the originally-filed specification provides evidence that substrates (e.g. peptides) may be covalently bond to the material of the shell using maleimide as crosslinking agents. ACPP comprises two terminal amino ends that crosslinks to the shell of the microbubble (see p.37592, left column, 1st paragraph, and Fig. S4A). Thus, the ACPPs conjugated to maleimide microbubbles are covalently crosslinked, reading on wherein the peptide substrate for an enzyme of interest is a crosslinking element bound by covalent bonds to the microbubble shell. Lux further teaches ACPP is cleaved by thrombin between the arginine and serine amino acids (see p.37588, left column, last paragraph, p.37592, left column, 1st and 5th paragraph, and Figs. 2, 3A, 4A, and S3A-B). Cleavage of ACPP conjugated to the maleimide microbubbles would eliminate cross linkages, thus reading on wherein cleavage of the peptide substrate by the enzyme of interest eliminates cross linkages. Lux incubated the ACPP conjugated maleimide microbubbles in vitro with thrombin and ultrasound imaged the interaction, demonstrating a shift in ultrasound intensity post incubation and cleavage of ACPP, reading on wherein the microbubble alters its interaction with ultrasound waves in response to elimination of cross linkages and wherein the altered interaction is an observable alteration in resonance frequency of the microbubble or attenuation due to a persistent change of mechanical properties of a shell of the microbubble (see p.37593, paragraph bridging left and right columns, and Fig. S8).
Regarding claim 18, Lux teaches the ACPP-MBs can be used to diagnose acute deep vein thrombosis, which is known to have a thrombin-rich environment, reading on for use in a method of diagnosis in vivo of a disease associated with or caused by an altered activity of the enzyme of interest (see p.37587, passage bridging left and right columns).
Regarding claim 19, Lux demonstrates the ACPP-MBs are suitable as an ultrasound contrast agent showing thrombin activity (see p.37593, paragraph bridging left and right columns, and Fig. S8).
Regarding claim 20, Lux teaches the ACPP-MBs have a mean diameter of 2.1 μM, which is within the claimed range of 0.5 – 4 μM (see p.37592, right column, 1st paragraph, and Fig. S4C).
Regarding claim 21, Lux teaches the ACPP-MBs have a shell that is made of distearoylglycerophosphocholine (DSPC), disteroylglycerophosphoethanolamine-maleimide(polyethelene glycol)-5000 (DSPE-PEG(5000)-mal), a perfluorobutane gas core, and the shell is covered by the ACPP thrombin substrate, reading on claim 21 (see Abstract, p.37592, left column, 1st paragraph,-right column, 1st paragraph, and Figs. 1, 3A, 4, and S4A).
Thus, Lux anticipates claims 16 and 18-21.
Response to Arguments
Applicant's arguments filed 4/27/2026 have been fully considered but they are not persuasive.
In Applicant’s Remarks, see p.4, last paragraph,-p.7, last paragraph, Applicant argues the rejection of claims 16 and 18-21 over Lux is based on a misrepresentation of the teachings of Lux. Applicant argues the ACPP peptide is conjugated to the microbubble shell at a single point via its C-terminus cysteine to a maleimide group on the shell and does not act as a crosslinker that connects different components of the shell to increase stiffness. Applicant further argues Lux teaches a mechanism of action characterized by a change in surface charge, leading to adhesion of the microbubbles to the negatively charged surfaces of red blood cells within a thrombus or clot. Applicant further argues Lux explicitly discloses that microbubbles do not possess the claimed effect and that no significant change in ultrasound signal is reported. Applicant argues Lux demonstrates that cleavage of ACPP peptide does not cause persistent change in the mechanical or acoustic properties of the individual microbubbles. Applicant further argues the signal enhancement observed by Lux is due to adhesion and accumulation of the activated microbubbles to clot surfaces and not due to changes in the individual microbubbles. This is not found persuasive.
Lux teaches the claimed structural elements of the responsive microbubble of claim 16. Specifically, Lux teaches perfluorobutane-filled microbubbles conjugated with thrombin-sensitive activatable cell-penetrating peptides (ACPPs) that detect acute thrombosis with ultrasound imaging (see Abstract, see paragraph bridging pp.37588-89, p.37592, paragraph bridging left and right columns, right column, 1st paragraph, and Figs. 2-4 and 6). Lux teaches the microbubble shell is made of distearoylglycerophosphocholine (DSPC), disteroylglycerophosphoethanolamine-maleimide(polyethelene glycol)-5000 (DSPE-PEG(5000)-mal), reading on a microbubble made of phospholipids with surfactants (see p.37592, paragraph bridging left and right columns, and Fig. 3A). Lux further teaches the microbubble is conjugated to activatable cell-penetrating peptide that is cleavable by the serine protease thrombin, reading on a peptide substrate for an enzyme of interest (see p.37592, left column, 1st-5th paragraphs, right column, 1st paragraph, and Figs. 1, 4, and S4A). Paragraph [0047] of the originally-filed specification provides evidence that substrates (e.g. peptides) may be covalently bond to the material of the shell using maleimide as crosslinking agents. ACPP comprises two terminal amino ends that crosslinks to the shell of the microbubble (see p.37592, left column, 1st paragraph, and Fig. S4A). Thus, the ACPPs conjugated to maleimide microbubbles are covalently crosslinked, reading on wherein the peptide substrate for an enzyme of interest is a crosslinking element bound by covalent bonds to the microbubble shell. Lux further teaches ACPP is cleaved by thrombin between the arginine and serine amino acids (see p.37588, left column, last paragraph, p.37592, left column, 1st and 5th paragraph, and Figs. 2, 3A, 4A, and S3A-B). Cleavage of ACPP conjugated to the maleimide microbubbles would eliminate cross linkages, thus reading on wherein cleavage of the peptide substrate by the enzyme of interest eliminates cross linkages. Lux incubated the ACPP conjugated maleimide microbubbles in vitro with thrombin and ultrasound imaged the interaction, demonstrating a shift in ultrasound intensity post incubation and cleavage of ACPP, reading on wherein the microbubble alters its interaction with ultrasound waves in response to elimination of cross linkages and wherein the altered interaction is an observable alteration in resonance frequency of the microbubble or attenuation due to a persistent change of mechanical properties of a shell of the microbubble (see p.37593, paragraph bridging left and right columns, and Fig. S8). Thus, Lux teaches an equivalent responsive microbubble comprising the claimed structural features and cleavage functionality resulting in a change in ultrasound signal as recited in claim 16 and does not teach away from the claimed invention.
Conclusion
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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/J.P.S./Examiner, Art Unit 1651
/MELENIE L GORDON/Supervisory Patent Examiner, Art Unit 1651
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