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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 6/25/2025 has been entered.
Status of Claims
Receipt of Arguments/Remarks filed on 6/25/2025 is acknowledged. Claims 1, 5, 6, 8, 10, 12, 16, 18, 20, 22, and 24 were amended. New claim 26 was added. Claims 1-26 are pending.
Withdrawn Rejections
The amendment filed 6/25/2025 is sufficient to overcome the rejection of claim 4 under 35 U.S.C. § 112(b).
Drawings
The drawings were objected to by the examiner in the Non-Final Rejection filed
10/23/2024 because the description of the drawings refers to color to differentiate drawing
elements and these elements are unclear in the black and white drawings. It is noted that
applicant submitted replacement drawings in color for Figures 1-8, along with a petition for
acceptance of color drawings on 1/23/2025. However, the petition for color drawings was
dismissed as stated in the petition decision dated 2/14/2025. For this reason, the objection to
the drawings as set forth in the Non-Final Rejection is maintained.
Claim Objections
Claim 1 is objected to because of the following informalities: step (2) of claim 1 reads “determing”. This should be “determining”. Appropriate correction is 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.
Claims 1-26 are 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. The term “likely” in claim 1 is a relative term which renders the claim indefinite. The term “likely” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
Step (2) of claim 1 is directed to determining a compound as “likely possessing cardiotoxicity”. It appears that the determination of “likely” being cardiotoxic is based on detection of specific binding in step (1). However, “likely” is not defined in the specification, and the specification does not indicate what degree or threshold of binding interaction as measured in step 1 is necessary for a compound to be considered likely possessing cardiotoxicity versus likely not possessing cardiotoxicity. As a skilled artisan would not be able to reasonably determine what level of binding interaction differentiates “likely possessing” and “likely not possessing” cardiotoxicity, the metes and bounds of the method of claim 1 are not clear.
Claims 2-26 are included in the rejection because they depend on a rejected claim and do not clarify the issue.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claims 1-26 are rejected under 35 U.S.C. 101 because the claimed invention is directed to a judicial exception, an abstract idea (mental process), without significantly more.
A three-step inquiry has been established to determine subject matter eligibility under 35 U.S.C. 101, in accordance with MPEP § 2106:
Step (1): Is the claim directed to a process, machine, manufacture, or composition of matter?
Step (2A): Is the claim directed to a law of nature, natural phenomenon (product of nature), or an abstract idea?
Prong 1: Does the claim recite a law of nature, natural phenomenon, or an abstract idea?
Prong 2: If the claim recites a judicial exception, does it recite additional elements that integrate the judicial exception into a practical application?
Step (2B): If the recited judicial exception is not integrated into a practical application, does the claim recite additional elements that amount to significantly more than the judicial exception?
Claim 1 is directed to an abstract idea. Step (2) of claim 1 involves “determining the compound as likely possessing cardiotoxicity” after detecting specific binding with Drp1. “Determining” is a mental process, as this step encompasses looking at a result (a measurement of specific binding affinity) and, if there is a binding interaction, deciding that the compound is likely cardiotoxic. This action is performed mentally, and therefore claim 1 recites a judicial exception, abstract idea. Claim 1 does not integrate the judicial exception into a practical application. The additional step in claim 1, detecting specific binding between a compound and Drp1 at the GTPase domain, is recited in high generality and broadly encompasses detecting binding of any compound, with no further application beyond simply detecting. Claim 1 does not include additional elements that are sufficient to amount to significantly more than the judicial exception because the step of detecting binding of a compound and Drp1 at the GTPase domain is routine and conventional in the art (see rejection under 35 U.S.C. 102; Wu et al., pg. 1451 Section 4.1). Instant claim 1 does not add any features beyond performing this specific binding screen, for any compound, which is known in the art, and thus does not constitute significantly more than the judicial exception.
Claims 2-4 are directed to the method of claim 1. Therefore, these claims include the mental process of “determining the compound as likely cardiotoxic” as set forth above. Claims 2-4 specify processes that can be used for detecting specific binding of a compound in step (1) of claim 1, i.e. using molecular docking or physically contacting a Drp1 protein or cell with a compound. However, as set forth above regarding claim 1, the method is recited in high generality, as it broadly recites detection of binding of any compound with Drp1, and does not integrate the claims into a practical application beyond detection. Further, the methods recited in claims 2-4, utilizing molecular docking or physical binding to screen for compounds that have a specific binding interaction with Drp1, are routine and conventional in the art (see rejection under 35 U.S.C. 102 below, Wu Section 4.1, 2.6, and 2.10). As such, claims 2-4 do not constitute significantly more than the judicial exception.
Claim 5 is directed to the method of claim 1, and therefore includes the mental process step as discussed above. Claim 5 recites an additional step of contacting a Drp1-expressing cell with a compound and assessing Drp1 protein activation. However, this additional step is claimed in high generality and does not integrate the method into a practical application, as it is a broad method of contacting any compound with a cell and does not recite any specific application associated with performing the technique. Further, contacting Drp1-expressing cells with a compound to assess protein activation is routine and conventional in the art (see rejection under 35 U.S.C. 102 below, Wu Section 2.8). As such, claim 5 does not constitute significantly more than the judicial exception.
Claims 6-26 all depend from claim 5, and thus incorporate the mental process step as recited above. Claims 6, 8, 10, 12-14, 16, 18, 20, and 22 all recite additional limitations to step (3) of claim 5, which set forth various assays that can be performed upon contacting the cell with a compound, such as measuring GTPase activity; Drp1 polymerization, localization, and expression; mitochondrial morphology and redox potential; expression of electron transport chain genes; or sarcomere morphology. Claims 7, 9, 11, 15, 17, 19, 21, and 23 recite that the results of these various cellular assays indicate cardiotoxicity. Claims 24-26 recite cell types that can be used in the assays. These additional limitations are recited in high generality and do not integrate the method into a practical application. Additionally, all of the recited assays are routine and conventional in the prior art and are known to be associated with cytotoxicity and cardiotoxicity (see rejections under 35 U.S.C. 102 for claims 6-7, 12, 14-17, and 26; or under 35 U.S.C. 103 for claims 8-11, 13, and 18-25). As such, claims 6-26 do not constitute significantly more than the judicial exception.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-7, 12, 14-17, and 26 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu et al., The FASEB Journal 34:1447-1464 (published November 2, 2019).
Regarding claim 1, Wu teaches the detection of specific binding between a compound and Drp1 at its GTPase domain (Wu Fig. 1; pg. 1458 “Discussion” col. 2, para. 2). Wu teaches that 17 compounds are selected from the screen based on high and specific binding affinity to Drp1 (Wu pg. 1452 Section 4.1). Therefore, Wu anticipates step (1) of claim 1.
The broadest reasonable interpretation of claim 1 step (2), “determining the compound as likely possessing cardiotoxicity”, encompasses a mental process of deciding whether a compound might be cardiotoxic based on a binding interaction. However, not all compounds with specific binding affinity at the Drp1 GTPase domain will necessarily be cardiotoxic, so the method as claimed encompasses screening compounds that could be cardiotoxic or not cardiotoxic. The instant specification page 14-15 states that if a compound specifically binds to Drp1, it is preliminarily deemed to likely be cytotoxic, which must then be confirmed using further testing. Therefore, the compounds screened by Wu, which have a specific binding interaction at the Drp1 GTPase domain, can be considered to be “likely cardiotoxic” before conducting follow-up experiments to confirm whether this is the case.
Further, Wu teaches that Drp1 activation results in mitochondrial dysfunction and cytotoxicity which causes cardiovascular diseases, i.e. cardiotoxicity (Wu pg. 1448 “Introduction” para. 2). Wu teaches screening for inhibitors of Drp1 activity that are nontoxic, however, a skilled artisan would recognize that in a screening process, compounds that activate Drp1 and cause cardiotoxicity can also be identified. Wu teaches that of the 17 compounds with strong specific binding identified in the screen, many of the compounds cause increased mitochondrial fragmentation compared to the control, indicating an activation of Drp1, which is associated with cardiotoxicity (Wu Fig. 2A). Therefore, Wu teaches that compounds with specific binding at Drp1 can activate Drp1 and cause mitochondrial fragmentation, or can inhibit Drp1 function leading to decreased fragmentation, as is the case for compounds 12 and 13, which Wu chooses to follow up on. Therefore, Wu anticipates the claimed method of detecting specific binding and determining “likely” cardiotoxicity.
Regarding claim 2, Wu teaches simulating binding between the compound and the GTPase domain by molecular docking (Wu Fig. 1; Results page 1448-1449, Section 4.1 “In silico chemical screen for Drp1 GTPase inhibitors”). Wu teaches an in silico chemical screen to simulate binding between the Drp1 GTPase domain and a library of over 4000 compounds. (Wu Fig. 1).
Regarding claim 3, Wu teaches contacting the Drp1 protein with the compound, using an immunoprecipitation technique in which the binding and effects of compounds are tested using isolated Drp1 protein (Wu Materials and Methods page 1449, Section 2.6 “Immunoprecipitation of Drp1”).
Regarding claim 4, Wu teaches contacting a cell expressing the Drp1 protein with the compound, using a cell transfection assay to introduce a Drp1 plasmid to A549 cells for further testing by contacting the cell with compounds of interest (Materials and Methods page 1450, Section 2.10 “Cell Transfection”).
Regarding claim 5, Wu teaches contacting a Drp-1 expressing cell with a compound and assessing Drp1 protein activation, for example by measuring GTPase activity (Fig. 5; Results section 4.5 “Drpitor1 and Drpitor1a are selective Drp1 GTPase inhibitors”; Materials and Methods page 1449 section 2.8 “GTPase assay”). “Assessing Drp1 protein activation” can include a measurement of both increased or decreased Drp1 activity compared to a control. Therefore, the method of claim 5 is anticipated by Wu.
Regarding claims 6-7, Wu teaches measuring GTPase activity of the Drp1 protein in the presence and absence of a compound (Fig. 5; Results section 4.5 “Drpitor1 and Drpitor1a are selective Drp1 GTPase inhibitors”; Materials and Methods page 1449 section 2.8 “GTPase assay”). Wu teaches that an increase in Drp1 GTPase activity correlates with increased mitochondrial fission and cytotoxicity, causing cardiotoxicity, i.e. cardiac IR injury (Wu Abstract; pg. 1448 “Introduction” para. 2; pg. 1455 “Discussion” para. 1-3; pg. 1455 Section 4.8).
Regarding claims 12 and 14-15, Wu teaches measuring Drp1 expression level in the presence and absence of a compound, comprising measuring Drp1 protein level (Wu Supplemental Fig. 2A; pg. 1454 “Results” section 4.5 para. 1). Wu teaches that an increase in Drp1 expression level in response to a compound correlates with mitochondrial toxicity and cardiac disease (Wu pg. 1448 “Introduction” para. 2; pg. 1455 “Discussion” para. 1-3).
Regarding claims 16-17, Wu teaches monitoring mitochondrial morphology in the presence of a compound (Wu pg. 1456 Fig. 4; pg. 1453-1454 Section 4.4). Wu teaches the measurement of mitochondrial fragmentation count as well as mitochondrial filamentation and fragmentation in response to treatment with compounds (Wu Fig. 4). Wu teaches that increased mitochondrial fragmentation indicates cytotoxicity and cardiotoxicity (Wu pg. 1448 “Introduction” para. 1-2; pg. 1455 “Discussion” para. 1-2).
Regarding claim 26, Wu teaches the expression of Drp1 in non-cardiomyocyte cells, A549 and MCF7 (Wu pg. 1448 Section 2.3). Wu teaches that Drp1 activation leads to mitochondrial dysfunction, which causes cardiac IR injury (Wu pg. 1458 para. 1). Wu teaches screening compounds using non-cardiomyocyte cells, and based on changes to mitochondrial dysfunction in these cells, assesses the effect of the compounds on cardiac function in an ex vivo model. Thus, a skilled artisan would recognize that studies of Drp1 protein activity and associated changes to mitochondrial function, even in a non-cardiomyocyte cell, are applicable to determining cardiotoxicity.
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.
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 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al.,
as applied to claims 1-7, 12, 14-17, and 26 above, in view of Ganesan et al., Molecular biology of the cell, 30(3):302-311.
Wu teaches the method according to claim 5, as set forth above. Wu does not teach polymerization of Drp1 as set forth in claims 8-9.
Ganesan teaches that cyclin C binds to the Drp1 GTPase domain and increases GTPase activity, resulting in mitochondrial dysfunction and fission (Ganesan pg. 303 "Cyclin C binds directly to the Drp1 GTPase domain through its C-terminal cyclin box"; pg. 306 "Cyclin C increases Drp1 GTPase activity by enhancing GTP affinity").
Regarding claim 8, Ganesan teaches measuring oligomerization of the Drp1 protein with itself in the presence of cyclin C (Fig. 3C; page 305 "Cyclin C increases Drp1 oligomerization").
Regarding claim 9, Ganesan teaches that binding of cyclin C leads to an increase in oligomerization, accompanied by mitochondrial fragmentation and increased Drp1 GTPase activity (Ganesan pg. 304 "Cyclin box-2 is sufficient..."; pg. 306 "Cyclin C increases Drp1 GTPase activity by enhancing GTP affinity").
It would have been obvious to a skilled artisan, before the effective filing date, to
combine the teachings of Wu and Ganesan and incorporate a measurement of Drp1 polymerization for assessing cardiotoxicity. Both Wu and Ganesan teach detecting binding to the Drp1 GTPase domain, and that activation of Drp1 leads to mitochondrial dysfunction, which is implicated in a variety of diseases including cardiac conditions. Thus, it would be obvious that a measurement of Drp1 oligomerization, as taught by Ganesan to be associated with binding to Drp1 and mitochondrial fragmentation, could be used as an indicator of cardiotoxicity.
A person of ordinary skill in the art would have been motivated to combine these
teachings because Ganesan teaches that the binding of cyclin C, which results in oligomerization of Drp1, leads to Drp1 activation and mitochondrial fragmentation, and measuring oligomerization of Drp1 would provide another method of assessing cardiotoxicity based on mitochondrial dysfunction, which would be considered advantageous to use in addition to the assays taught by Wu.
A skilled artisan would have a reasonable expectation of success in combining the
teachings of these references and incorporating an assay to measure Drp1 polymerization as an indicator of cardiotoxicity, given Ganesan’s teachings that Drp1 oligomerization is enhanced by binding at the Drp1 GTPase domain leading to mitochondrial dysfunction, to achieve the predictable outcome of increased Drp1 polymerization corresponding to cardiotoxicity.
Claims 10-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al.,
as applied to claims 1-7, 12, 14-17, and 26 above, in view of Nomura et al., Redox Biology; 13:407-17.
Wu teaches the method of claim 5 as set forth above. Wu does not teach localization of Drp1 in the mitochondria as set forth in claims 10-11, or measuring mRNA level of Drp1 as set forth in claim 13.
Nomura teaches that Drp1 is activated in response to 3'-azido-3'-deoxythymidine (AZT) in H9c2 cells, which are used as a model for cardiomyopathy (Nomura pg. 407 Abstract). Nomura further teaches that this disruption to mitochondrial function indicates that AZT is cardiotoxic (Nomura pg. 408 col. 1; pg. 411-412 Section 3.5, Fig. 6B).
Regarding claim 10, Nomura teaches measuring localization of the Drp1 protein in the mitochondria with and without AZT (Nomura pg. 409 section 2.9, pg. 413 Fig. 6E).
Regarding claim 11, Nomura teaches that increased Drp1 localization in the mitochondria is indicative of disruption to mitochondrial dynamics, which indicates cardiotoxicity (Nomura pg. 412 para. 1).
Regarding claims 12-13, Nomura teaches measuring mRNA expression of Drp1 in the presence and absence of AZT (Nomura pg. 412 Fig. 5).
It would have been obvious to a skilled artisan, before the effective filing date, to
combine the teachings of Wu and Nomura, incorporating an assay to assess localization of Drp1 in the mitochondria and measure Drp1 mRNA expression in the method of Wu. Both Wu and Nomura are directed to assessing Drp1-mediated mitochondrial dynamics. It would have been obvious to a skilled artisan that the method taught by Nomura to measure mitochondrial localization could be used in conjunction with the methods of Wu, which teaches assaying other mitochondrial features such as fragmentation. The method of measuring mRNA expression taught by Nomura is a well-known technique for assaying gene expression. It would have been obvious that this method could be used in addition to the method taught by Wu, which measures Drp1 activity using protein levels.
A person of ordinary skill in the art would have been motivated to combine these
teachings because it is known that certain drug treatments, for example antiretroviral therapies,
can have the negative effect of cardiomyopathy due to mitochondrial dysfunction and it is important to screen for potential cardiotoxicity of drugs to prevent adverse effects in patients
(Nomura pg. 407-408 para. 2; pg. 415 col. 2). The method of assaying Drp1 localization provides another assessment of cardiotoxicity which would be considered beneficial to add to the methods of Wu.
A skilled artisan would have a reasonable expectation of success in combining the
teachings of these references to achieve the predictable outcome of measuring an increase in Drp1 localization to the mitochondria associated with cardiotoxicity of a compound, as Nomura teaches that localization to the mitochondria indicates Drp1-mediated mitochondrial dysfunction, which causes cardiotoxicity.
Claims 18-21 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al.,
as applied to claims 1-7, 12, 14-17, and 26 above, and further in view of Manczak et al., Human molecular genetics, 28(2):177-199, (ePub Sep. 19, 2018), as evidenced by Alberts et al., Molecular Biology of the Cell, 4th edition, Electron Transport Chains and Their Proton Pumps (2002).
Wu teaches the method of claim 5, as set forth above. Wu does not teach measuring redox potential of mitochondria within the cell in the presence and absence of the compound as set forth in claims 18-19, or measuring mRNA or protein level of the genes set forth in claims 20-21.
Regarding claim 18, Manczak teaches measuring enzymatic activity of electron transport chain (ETC) complexes I, Ill, and IV in response to Mdivi-1 treatment of cells, by measuring oxidation of NADH to NAO+ (page 186 "ETC Enzymatic activities in N2a cells treated with Mdivi-1"; Fig. 7). It is known in the art that redox potential is a measurement of the tendency to transfer electrons, and electron transfer occurs via the electron transport chain. Further, redox potential increases as electrons move along the electron transport chain. This is described in Alberts et al. (Fig. 14-26; "The Redox Potential Is a Measure of Electron Affinities"). Thus, the activity of the ETC complexes correlates with the cellular redox potential, with an increase in the activity of ETC complexes corresponding to increased redox potential, and vice versa.
Regarding claim 19, Manczak teaches increased activity of complex I and II in cells treated with a lower concentration of Mdivi-1, and decreased activity of these complexes in cells treated with a higher concentration of Mdivi-1 (page 186 "ETC Enzymatic activities in N2a cells treated with Mdivi-1"; Fig. 7). Manczak teaches that a reduction in complex I activity in the presence of a high concentration of Mdivi-1, which correlates with a reduction in redox potential, is indicative of toxicity (page 186 "ETC Enzymatic activities in N2a cells treated with Mdivi-1").
Regarding claim 20, Manczak teaches measuring the mRNA level of numerous ETC genes including ND1, ND5, and ATP6 in response to Mdivi-1 treatment of cells (Table 1; page 179 "Mitochondrial ETC Genes").
Regarding claim 21, Manczak teaches that decrease in the mRNA level of
ETC genes in the presence of the higher concentrations of Mdivi-1 indicates toxicity of the
compound (Table 1, page 179 "Mitochondrial ETC Genes"; page 181 "Mitochondrial ETC
genes").
It would have been obvious to a skilled artisan, before the effective filing date, to
combine the teachings of Wu with the teachings of Manczak and Alberts to measure redox potential as an assessment of Drp1 protein activation. Similar to the teachings of Wu, Manczak teaches that mitochondrial dysfunction is associated with negative health outcomes, and activation of Drp1 leads to increased mitochondrial fission (Manczak pg. 178 col. 2). Manczak teaches that ETC activity is an important aspect of Drp1-dependent mitochondrial function (Manczak pg. 186 col. 2, pg. 187 col. 1). It would have been obvious to a skilled artisan that redox potential, which is based on ETC activity, or measuring the expression of ETC genes, could be combined with the method as taught by Wu.
A person of ordinary skill in the art would have been motivated to incorporate the
teachings of Manczak with the teachings of Wu, because ETC activity/redox potential is an important consideration in developing therapeutics (Manczak pg. 195 "Summary and Conclusions"). Assaying ETC activity and redox potential in response to a compound would provide another method of assessing cardiotoxicity, which would be considered an improvement to the method of Wu.
A skilled artisan would have a reasonable expectation of success in combining these
teachings to achieve the predictable outcome of measuring changes to redox potential or ETC gene expression in a Drp1-producing cell in response to a compound, given the demonstrated success of this technique taught by Manczak using Mdivi-1, which binds to Drp1. A skilled artisan could reasonably expect that a compound which induces a reduction in redox potential or decrease in ETC gene expression would be cardiotoxic, given the teachings that reduced redox potential and ND1, ND5, and ATP6 expression are associated with mitochondrial dysfunction and cytotoxicity.
Claims 22-25 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. as applied to claims 1-7, 12, 14-17, and 26 above, and further in view of Toshikatsu et al. Toxicol Appl. Pharmacol.; 15:383:114761.
Wu teaches the method of claim 5 as set forth above. Wu does not teach monitoring morphology of the sarcomere within the Drp1-expressing cell as set forth in claims 22-25.
Regarding claim 22, Toshikatsu teaches a method using cardiomyocytes to evaluate drug-induced cardiotoxicity by monitoring sarcomere morphology (Toshikatsu Fig. 1; pg. 6 section 3.1).
Regarding claim 23, Toshikatsu additionally teaches that increased sarcomere disarray in the presence of the compound indicates cardiotoxicity of the compound (Toshikatsu pg. 7 Fig. 1; Results page 6 section 3.1).
Regarding claim 24, Toshikatsu teaches the use of cardiomyocytes (Toshikatsu pg. 2 section 2.2).
Regarding claim 25, Toshikatsu additionally teaches the use of hiPSC-CMs in
evaluating drug cardiotoxicity. (Toshikatsu pg. 2 section 2.2).
It would have been obvious to a skilled artisan, before the effective filing date, to
combine the teachings of Wu with the teachings of Toshikatsu and monitor sarcomere morphology as part of the method of assessing cardiotoxicity. Like Wu, Toshikatsu also teaches a cell-based assay for screening cardiotoxic effects of drugs. Toshikatsu additionally teaches that abnormal sarcomere structure is indicative of a drug's cardiotoxicity (Toshikatsu pg. 2 col. 1). It would have been obvious to a skilled artisan that the teachings could be combined and that the assay taught by Toshikatsu to measure sarcomere morphology is a useful metric in assessing cardiotoxicity that could be applied to the Drp1-expressing cells of the method taught by Wu.
A person of ordinary skill in the art would have been motivated to combine the teachings
of these references and incorporate the method of monitoring sarcomere morphology taught by
Toshikatsu, because Toshikatsu teaches that monitoring sarcomere morphology can be used as
an alternative method for assessing drug-induced changes to cardiac contractility, which is a
major issue but difficult to accomplish using other methods that typically involve obtaining rodent
hearts, which is time-consuming and costly (Toshikatsu pg. 2 col. 1).
A skilled artisan would have a reasonable expectation of success in making this
combination to achieve the predictable outcome of assessing sarcomere morphology as part of
the cardiotoxicity screen taught by Wu given the demonstrated utility of this technique for assessing cardiotoxicity of numerous cancer drugs taught by Toshikatsu.
Response to Arguments
Applicant's arguments filed 6/25/2025 have been fully considered but they are not persuasive.
Applicant argues that Wu teaches identification of Drp1 inhibitors, which is the opposite of the instant invention that identifies cardiotoxic compounds based on activation of Drp1. Applicant argues that Wu and Ganesan give conflicting indications of whether a compound that binds Drp1 is an activator or an inhibitor. Applicant argues that Nomura provides a connection between Drp1 activation and cardiotoxicity but does not mention specific binding to Drp1. Applicant argues that the combination of these references does not provide adequate motivation to use specific binding to the GTPase domain as an indicator of cardiotoxicity.
The Examiner disagrees with this assertion. As currently amended, claim 1 of the instant invention requires two steps: (1) detecting specific binding between a compound and the Drp1 GTPase domain, and (2) determining the compound as possessing cardiotoxicity. Wu teaches step (1), as the method of Wu uses both molecular docking and contacting of compounds with Drp1 to identify specific binding between a compound and Drp1 at the GTPase domain, as set forth above. While Wu then goes on to assess whether the compounds identified as having a binding interaction with Drp1 at the GTPase domain are inhibitors of Drp1 activity, the method of detecting specific binding is still the same as that set forth in instant claim 1 step (1).
The second step of the instant method “determining the compound as likely possessing cardiotoxicity”, encompasses a mental process of deciding whether a compound might be cardiotoxic based on a specific binding interaction. Therefore, as discussed above, the compounds identified as having a specific binding interaction could be determined to be cardiotoxic or not cardiotoxic. Therefore, prior art teaching detecting specific binding, as taught by Wu, reads on claim 1, as any of the compounds screened in this assay could be considered as “likely” cardiotoxic before further screening to determine if they are indeed cardiotoxic.
The instant specification, page 15, states that “a compound that is preliminarily identified as possibly toxic may be subject to further testing and investigation, for example, in cell-based assays, by detecting its potential cytotoxic effects on one or more types of cells (e.g., cardiomyocytes) as manifested in cell death, loss of viability or functions, etc. Similarly, compounds preliminarily identified as probably non-toxic can also be further tested and verified in various cell-based assays or even animal models as truly possessing no detectable cytotoxicity”. This suggests that, while a compound with specific binding to Drp1 could be cytotoxic/cardiotoxic, further testing is required to determine this, and it is possible that a compound which binds Drp1 at the GTPase domain might be considered “likely” cardiotoxic, but in later tests be revealed as non-cardiotoxic.
Furthermore, it is noted that Fig. 2A of Wu et al. teaches that many compounds which bind to Drp1 at the GTPase domain do not inhibit Drp1 activity (Wu pg. 1453). Applicant argues that the teachings of Wu indicate that a compound which binds Drp1 is likely an inhibitor, not an activator. However, of the 17 compounds selected by Wu as having specific binding to Drp1, 12 compounds cause an increase in mitochondrial fragmentation when contacted with a Drp1-expressing cell (Wu pg. 1453 Fig. 2A). Wu chooses compound 12, referred to as Drpitor1, for further investigation, as Wu is interested in studying inhibitors. However, a skilled artisan, upon looking at the data presented by Wu, would reasonably expect that a compound which exhibits specific binding at the Drp1 GTPase domain is likely to activate Drp1 activity, as the majority of the compounds screened by Wu increase mitochondrial fragmentation.
Applicant further argues that the use of a non-cardiomyocyte cell to express Drp1 is non-obvious because cardiomyocyte cells would be the logical choice for confirming cardiotoxicity of a compound.
Wu teaches expressing Drp1 in a non-cardiomyocyte cell and assaying many indicators of mitochondrial dysfunction such as fragmentation and apoptosis, as set forth above. Wu teaches that Drp1 activation leads to mitochondrial dysfunction, which causes cardiac IR injury (Wu pg. 1458 para. 1). Wu teaches screening compounds using non-cardiomyocyte cells, and based on changes to mitochondrial dysfunction in these cells, assesses the effect of the compounds on cardiac function in an ex vivo model. These teachings indicate that Drp1 activity in a non-cardiomyocyte cell are still relevant for assessing cardiotoxicity, as Wu uses non-cardiomyocyte cells as a first step in screening for compounds which can be used to treat cardiac conditions. While Wu is using a Drp1 inhibitor which causes reduced mitochondrial dysfunction and GTPase activity, it is obvious that a compound which has the opposite effect and increases mitochondrial dysfunction, could also be assayed in the same manner. Therefore, while a cardiomyocyte cell is a logical choice for assessing cardiotoxic effects of a compound, the hallmarks of cardiotoxicity caused by Drp1 activation center around changes to mitochondrial dynamics, which can be assessed in non-cardiomyocyte cell types as shown by Wu.
Therefore, in light of amendments to the claims, new grounds of rejection of claims 1-7, 12, 14-17, and 26 are made under 35 U.S.C. § 102 in view of Wu et al. as set forth above. New grounds of rejection are made under 35 U.S.C. § 103 of claims 8-9 over Wu in view of Ganesan; claims 10-13 over Wu in view of Nomura; claims 18-21 over Wu in view of Manczak and Alberts; and claims 22-25 over Wu in view of Toshikatsu as set forth above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to EMILY F EIX whose telephone number is (571)270-0808. The examiner can normally be reached M-F 8am-5pm ET.
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, Sharmila Landau can be reached at (571)272-0614. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/EMILY F EIX/Examiner, Art Unit 1653
/SHARMILA G LANDAU/Supervisory Patent Examiner, Art Unit 1653