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 .
Status of the Claims
Claims 5 and 8 were pending. Claims 1 and 4 remain withdrawn.
Claims 5 and 8 are amended.
Claims 5 and 8 are examined herein.
Withdrawn Rejections
The rejection of claims 5 and 8 under 35 U.S.C. 112(b) is withdrawn in view of claim 5 amendments.
The rejection of claims 5 and 8 under 35 U.S.C. 103 is withdrawn in view of claim 5 amendments. However, upon further consideration, a new ground(s) of rejection is made in view of Guleria et al.
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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
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 5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Ye et al. (Theranostics. 2011; 1:102-26) in view of Hermanson (Chapter 10, Editor(s): Greg T. Hermanson, Bioconjugate Techniques (Third Edition), Academic Press, 2013, Pages 395-463), Song et al. (Cancer Biother Radiopharm. 2017 Oct;32(8):288-296), Lu et al. (CN105203772A), and Guleria et al. (J Radioanal Nucl Chem (2016) 309:923–930).
Regarding claim 5, Ye teaches integrin targeting for tumor optical imaging (Title). The reference teaches methods for preparing integrin αvβ3 targeting probes using fluorescent dye-RGD peptide conjugates, their multivalent analogs, and conjugates (Abstract). Fig. 2 provides a schematic representation of an integrin-specific labeling agent, comprising a fluorescent probe, a linker, and a target-specific peptide. Specifically, Ye teaches fluorescently labeled c(RGDfK) peptide using Cy5.5 fluorescent dye (pg. 107, col. 2, par. 2 and Fig. 3, structure with X:H).
Regarding the conjugation step, Ye teaches “[c]onjugation chemistry used is related to the functionalities of the ligand, fluorophore, and the resulting conjugate structures. Different fluorophores containing amino, carboxylic acid, and its active N-hydroxysuccinimide (NHS) ester groups can be frequently used in the ligand conjugation” (pg. 105, col. 2, last par. and pg. 106, col. 1, par. 1).
Additionally, Ye teaches that “[d]imerization or multimerization of the cyclic RGD peptide provided a viable approach to improve the binding affinity and in vivo imaging” (pg. 107, col. 2, last par.). Specifically, the reference teaches E-[c(RGDfK)]2 dimeric RGD peptide and “all the peptides had stronger binding than the monomeric counterpart in integrin αvβ3-positive U87MG xenograft models” (pg. 108, col. 1, par. 1).
Regarding the FITC-derivative of claim 5, Ye teaches that fluorescein-type fluorophores can be used for labeling integrin probes (pg. 103, col. 2, par. 3).
Ye does not specifically teach fluorescein isothiocyanate used for conjugation; the conjugating the NH2-cyclic RGD peptide precursor to the fluorescent material comprises conjugating the NH2-D-[c(RGDfK)]2 through thiourea linkage to the FITC in
phosphate buffered solution (PBS) with stirring for 1 hour at room temperature, and the FITC-D-[c(RGDfK)]2 is purified to at least 95% purity.
Regarding claim 5, Hermanson teaches fluorescent probes for bioconjugation reactions (Chapter title). Specifically, Hermanson teaches that “FITC is one of the most popular fluorescent probes ever created” (pg. 399, col. 1, par. 1).
Additionally, Hermanson teaches that a conjugation reaction between an amine-containing molecule and FITC results in a formation of a thiourea linker (pg. 399, Fig. 10.5). As such, Hermanson teaches conjugating the NH2-D-[c(RGDfK)]2 through tiourea linkage to the FITC. Formation of this linkage is inherent to a conjugation reaction between an amine-containing molecule and FITC.
Ye and Hermanson do not specifically teach aspartic acid residue (D) linker; the conjugating the NH2-cyclic RGD peptide precursor to the fluorescent material comprises conjugating the NH2-D-[c(RGDfK)]2 in phosphate buffered solution (PBS) with stirring for 1 hour at room temperature, and the FITC-D-[c(RGDfK)]2 is purified to at least 95% purity.
Regarding the linker structure, Ye teaches examples of very different linkers connecting integrin-targeting peptides to their fluorescent labels. For example, a 5-carbon atom NHS ester linker (Fig. 1); linkers based on mercapto-mercapto, maleimide-mercapto, and azido-alkyne reactions (pg. 106, col. 1, par. 1), where linkers formed by each reaction have different lengths and molecular properties; polyethylene glycol linker and simple oligopeptide sequence such as Gly-Gly-Gly (pg. 106, col. 2, par. 1); dimeric peptides E-[c(RGDfK)]2 and E-[G-G-G-c(RGDfK)]2 with either glutamic acid residue or glutamic acid residue-G-G-G linkers (pg. 108, col. 1, par. 1); E-PEG4 linker (pg. 109, col. 1, par. 1), and a huge RAFT linker in a Cy5-labeled RAFT-c(-RGDfK-)4 probe (pg. 109, col. 1, par. 2 and Fig. 5).
Given such diversity of the linkers used to conjugate RGD-peptides to their labels one having ordinary skill in the art would have concluded that the exact structure of the linker is either non-critical or dependents on a specific application.
Regarding claim 5, Song teaches a radiotracer 99mTc-IDA-D-[c(RGDfK)]2 for single-photon emission tomography (Abstract), which contains an aspartic acid residue (D) as a linker between the radiotracer and the integrin-specific peptide.
Additionally, Song teaches that the radiotracer 99mTc-IDA-D-[c(RGDfK)]2 was purified by semipreparative high-performance liquid chromatography and radiochemical purity of 95% was mandatory (pg. 290, col. 1, par. 1). Purity levels of 95% and at least 95% are the same.
Ye, Hermanson, and Song do not specifically teach the conjugating the NH2-cyclic RGD peptide precursor to the fluorescent material comprises conjugating the NH2-D-[c(RGDfK)]2 in phosphate buffered solution (PBS) with stirring for 1 hour at room temperature.
Regarding claim 5, Lu teaches labeling of D-dimer antibody with FITC (pg. 1 - Description). Specifically, Lu teaches that D-dimer antibody and fluorescein FITC were diluted with PBS solution ([0028]), mixed with glycine, and then mixed at 30°C for 1 hour at room temperature ([0029]). As such, Lu teaches conjugating FITC in PBS, for 1 hour, at almost room temperature, and with stirring. In the art of chemical reactions stirring is equivalent to mixing, because both stirring and mixing achieve the same result of keeping reaction homogenous.
Regarding the incubation temperature: room temperature is generally recognized as 200C or 293K; 300C corresponds to 303K. Since rates of chemical reactions depend on temperature expressed in Kelvins, the difference between 300C and 200C is only 3% in Kelvins (100% x (303K – 293K)/303K). The 3% difference in the incubation temperature is very small for most practical applications, including the FITC conjugation reaction; therefore, one having ordinary skill in the art would find it obvious to perform FITC conjugation reaction at either temperature with reasonable expectation of success.
Regarding the limitation of chemical purity (as in “at least 95% chemical purity”), Song teaches that “A quality control check with pH, endotoxin testing, analytic HPLC, and residual solvent measurement by gas chromatography was performed before human injection; a radiochemical purity of 95% was mandatory” (pg. 290, col. 1, par. 1). The quality control check performed by Song did not include any radiochemical assays; therefore, in the absence of other radiochemical isotopes radiochemical purity reported by Song is chemical purity.
Regarding the limitation of C-18 reverse phase high-performance liquid chromatography (RP-HPLC), Song teaches 99mTc-IDA-D-[c(RGDfK)]2 was purified by high-performance liquid chromatography using Eclipse XDB-C18 column (pg. 290, col. 1, par. 1). The high-performance liquid chromatography using C18 column of Song meets the limitation of C-18 reverse phase high-performance liquid chromatography of instant invention, because C18 column is a reverse phase column.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the E-[c(RGDfK)]2 probe of Ye with FITC label as taught by Hermanson, as an obvious matter of simple substitution of one known fluorescent label for another to obtain predictable results. Ye is generic with regard to specific fluorescein derivative and Hermanson teaches that “FITC is one of the most popular fluorescent probes ever created” (pg. 399, col. 1, par. 1). Since FITC is a well-known fluorescent probe used in various labeling experiments one would have a reasonable expectation of success.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to substitute glutamic acid residue in E-[c(RGDfK)]2 peptide of Ye (pg. 108, col. 1, par. 1) with aspartic acid residue as taught by Song, as "obvious to try" – choosing from a finite number of identified, predictable solutions (see above for examples of different linkers taught by Ye), with a reasonable expectation of success. A substitution of one dicarboxy amino acid (aspartic acid) for another dicarboxy amino acid (glutamic acid) provides a reasonable expectation of success because both amino acids are present in natural proteins and share similar chemical properties.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to perform the conjugation of D-[c(RGDfK)]2 probe of Ye, Hermanson and Song with FITC label using reaction conditions as taught by Lu, as an obvious matter of using of known technique to improve similar product in the same way. Additionally, it would have been obvious to make the combination because Ye, Hermanson and Song is generic with respect to specific conjugation reaction conditions and one skilled in the art would have been motivated to use the appropriate reaction temperature and duration for Ye, Hermanson and Song.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because the references are similarly drawn to conjugation of amino-containing [c(RGDfK)]2 probe with FITC label, and Lu has demonstrated the reaction conditions that provide acceptable performance.
Ye, Hermanson, Song, and Lu do not specifically teach using a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid and electrospray ionization mass spectrometry (ESI-MS) for detecting a peak at m/z about 1693.3 [M+H]+.
Regarding the limitation of a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid, Guleria teaches preparation and bioevaluation of 99mTc-labeled tetrameric D-[c(RGDfK)]2 complex (Title and Abstract). Specifically, Guleria teaches using a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid for HPLC characterization of the 99mTcN-[E-c(RGDfK)2]2 complex (pg. 925, col. 1, par. 4).
Additionally, Guleria teaches using electrospray ionization (ESI) mass spectra for characterization of dithiocarbamate derivative of E-c(RGDfK)2 (pg. 924, col. 2, par. 2). Guleria does not specifically teach m/z about 1693.3 because the exact m/z value depends on molecular weight of each compound. The exact m/z value is an inherent property of each compound. Molecular weight of FITC-D-[c(RGDfK)]2 is equal to 1693.8, which corresponds to about m/z value of 1693.3 of instant invention.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to purify the FITC-D-[c(RGDfK)]2 probe of Ye, Hermanson, Song, and Lu using a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid as taught by Guleria, as an obvious matter of using of known purification technique to purify similar product in the same way.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because the references of Ye, Hermanson, Song, and Lu and Guleria are similarly drawn to c(RGDfK)-containing probes; and Guleria has demonstrated a successful purification method using acetonitrile/water/0.1 % trifluoroacetic acid solvent mixture.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to characterize the FITC-D-[c(RGDfK)]2 probe of Ye, Hermanson, Song, and Lu using electrospray ionization mass spectrometry (ESI-MS) as taught by Guleria, as an obvious matter of using of known analytical technique to characterize similar product in the same way. Detection of a peak at m/z about 1693.3 [M+H]+ is an inherent property of FITC-D-[c(RGDfK)]2 probe.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because the references of Ye, Hermanson, Song, and Lu and Guleria are similarly drawn to c(RGDfK)-containing probes; and Guleria has demonstrated a successful characterization of c(RGDfK)-containing probes by electrospray ionization mass spectrometry.
Regarding claim 8 and use of the integrin targeting probe in fluorescence fundus angiography, Ye teaches that Cy5.5-labeled c(RGDfK) peptide was used in the intravenous injection of a tumor model (pg. 107, col. 2, par. 2) making it suitable for fluorescence fundus angiography recited in claim 8. Ye teaches Cy5, Cy5.5, Cy7, Cy7.5 dyes are fluorophores which are particularly useful for in vivo fluorescence imaging, where using near-infrared light instead of visible light can improve the light penetration and minimize the autofluorescence of some endogenous absorbers such as hemoglobin (pg. 103, col. 2, par. 2-3).
Although Ye does not specifically teach the fluorescence fundus angiography using fluorescently-labeled c(RGDfK) peptides, such limitation is drawn to intended use of the method and therefore the prior art only needs to be capable of performing the recited intended use. So long as fluorescently-labeled c(RGDfK) peptides of Ye are capable of in vivo imaging upon intravenous injection, it reads on the claims. Ye teaches the same functional limitations of the integrin targeting probe as recited in the claims, therefore it is considered capable of performing the same intended use.
Response to Arguments
Applicant's arguments filed on November 12, 2025 have been fully considered.
Claims 5 and 8 were rejected under 35 U.S.C. § 103 as being unpatentable over Ye, Hermanson, Song, and Lu. Applicant argues that “the rational for combining the references overlooks contextual incompatibilities and the combined references fail to teach or suggest the above recited features” (pg. 5, par. 4). The above recited features refer to the amended claim 5. The argument is persuasive. The rejection of claims 5 and 8 has been withdrawn. However, claim 5 amendments necessitated a new prior art search and new grounds of rejection have been found in view of newly found prior art reference of Guleria. Therefore, claims 5 and 8 are rejected under 35 U.S.C. § 103 as unpatentable over Ye, Hermanson, Song, Lu, and Guleria, as presented in details above. Newly added limitations are briefly addressed below:
Regarding the limitation of chemical purity (as in “at least 95% chemical purity”), Song teaches that “A quality control check with pH, endotoxin testing, analytic HPLC, and residual solvent measurement by gas chromatography was performed before human injection; a radiochemical purity of 95% was mandatory” (pg. 290, col. 1, par. 1). The quality control check performed by Song did not include any radiochemical assays; therefore, in the absence of other radiochemical isotopes radiochemical purity reported by Song is chemical purity.
Regarding the limitation of C-18 reverse phase high-performance liquid chromatography (RP-HPLC), Song teaches 99mTc-IDA-D-[c(RGDfK)]2 was purified by high-performance liquid chromatography using Eclipse XDB-C18 column (pg. 290, col. 1, par. 1). The high-performance liquid chromatography using C18 column of Song meets the limitation of C-18 reverse phase high-performance liquid chromatography of instant invention, because C18 column is a reverse phase column.
Regarding the limitation of a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid, Guleria teaches preparation and bioevaluation of 99mTc-labeled tetrameric D-[c(RGDfK)]2 complex (Title and Abstract). Specifically, Guleria teaches using a solvent mixture of acetonitrile/water/0.1 % trifluoroacetic acid for HPLC characterization of the 99mTcN-[E-c(RGDfK)2]2 complex (pg. 925, col. 1, par. 4).
Regarding the limitation of electrospray ionization mass spectrometry, Guleria teaches using electrospray ionization (ESI) mass spectra for characterization of dithiocarbamate derivative of E-c(RGDfK)2 (pg. 924, col. 2, par. 2). Guleria does not specifically teach m/z about 1693.3 because the exact m/z value depends on molecular weight of each compound. It is an inherent property of each compound. Molecular weight of FITC-D-[c(RGDfK)]2 is equal to 1693.8, which is about m/z value of 1693.3 of instant invention.
Applicant argues that “Ye favors NIR dyes for in vivo penetration to avoid FITC's autofluorescence issues; Song's D linker is chelator-bound for radioactivity, not fluorescence; and Lu's protocol includes quenching and heating tailored to antibodies, not peptides. One of ordinary skill in the art would not be motivated to combine the applied references as they are in different fields (e.g., tumor NIR, general chemistry, radiotracers, antibody labeling)” (pg. 5, par. 5). The argument is not persuasive.
In response to applicant's argument that the prior art references are nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case:
Ye teaches integrin targeting for tumor optical imaging (Title). The reference teaches methods for preparing integrin αvβ3 targeting probes using fluorescently labeled c(RGDfK) peptide using Cy5.5 fluorescent dye (pg. 107, col. 2, par. 2 and Fig. 3, structure with X:H). Ye does not specifically teach fluorescein isothiocyanate used for conjugation. Hermanson teaches labeling of biomolecules with fluorescent labels; specifically, that “FITC is one of the most popular fluorescent probes ever created” (pg. 399, col. 1, par. 1). Both Ye and Hermanson teach analogous art of fluorescent labels.
Song teaches another labeled c(RGDfK)-based molecule – a radiotracer 99mTc-IDA-D-[c(RGDfK)]2, which contains an aspartic acid residue (D) as a linker between the label and the integrin-specific peptide. Both Ye and Song teach analogous art of c(RGDfK)-based molecules having different linkers: E- or D-residues. Song's radioactivity tracer was not relied upon in the rejection.
Lu teaches labeling of an antibody with FITC (pg. 1 - Description). Applicant argues that “Lu's protocol includes quenching and heating tailored to antibodies, not peptides” (pg. 5, par. 5), but fails to provide any evidence such tailoring. Lu is teaching FITC labeling of amino groups present in both antibodies and peptides, and having similar reactivities toward FITC. Both Ye and Lu teach analogous art of FITC fluorescent labels.
Applicant argues that “one of ordinary skill would lack a reasonable expectation of success in arriving at this verification, as it resolves FITC reaction inconsistencies not contemplated by the tumor/radio/antibody-focused art” (pg. 5, par. 5). The argument is unclear because Applicant fails to provide evidence for “FITC reaction inconsistencies not contemplated by the tumor/radio/antibody-focused art” and how these inconsistences are solved by instant invention.
Applicant argues that “Song's structure is a radiotracer, not a fluorescent analog, and requires HPLC purification to 95% radiochemical purity (Song, p. 290, col. 1) not chemical purity via the claimed RP-HPLC/MS for a stable fluorescent probe” (pg. 5, last par. – pg. 6, par. 1). The Song's teaching of a radiotracer vs fluorescent tracer of instant invention is immaterial when the purity is concerned - Song teaches that “a radiochemical purity of 95% was mandatory” (pg. 290, col. 1, par. 1). The quality control check performed by Song did not include any radiochemical assays; therefore, in the absence of other radiochemical isotopes radiochemical purity reported by Song is chemical purity. Applicant fails to provide evidence why radiochemical purity of Song is different from chemical purity.
Applicant arguments on pg. 6, par. 2-3 regarding amended limitations of claim 5 (C18, solvent mixture, electrospray, and m/z value) have already been addressed above in Reply #1.
Applicant argues that “Claim 8 depends from claim 5, and recites additional features. The deficiencies of the applied references with respect to claim 5 were discussed above. Claim 8, therefore, distinguishes over the applied references for at least the same reasons as those discussed with respect to claim 5, and/or for the additionally recited features” (pg. 6, par. 5). Presently, claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Ye in view of Hermanson, Song, Lu, and Guleria. Claims 8 fails to recite any additional limitations to overcome this rejection (please see 103 rejection of claim 8 above for details).
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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Alexander Volkov whose telephone number is (571) 272-1899. The examiner can normally be reached M-F 9:00AM-5:00PM (EST).
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/ALEXANDER ALEXANDROVIC VOLKOV/Examiner, Art Unit 1677
/REBECCA M GIERE/Primary Examiner, Art Unit 1677