DETAILED ACTION
The amendment and RCE filed on 09/08/2025 has been entered and fully considered. Claim 99 is canceled. Claims 83, 85-96 and 100-105 are pending, of which claims 100-105 are amended.
Response to Amendment
In response to amendment, the examiner establishes 112(b) rejection and modifies rejection over the prior art established in the previous 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 .
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.
Claim 90 and 102 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 claim recites a cholesterol ester structure in which the terminal carbon is depicted as having C(R₄)₃ (i.e., three substituents), while the corresponding structural depiction and chemical understanding of cholesterol esters suggests a terminal carbon bearing two methyl substituents (isopropyl group).
As a result, it is unclear whether the claim intends:
a carbon substituted with two methyl groups, or
a carbon substituted with three substituents (i.e., tertiary carbon with three R₄ groups).
This distinction is not merely stylistic, but materially affects the scope of the claim because:
a carbon bearing two methyl groups corresponds to the known cholesterol side chain structure, whereas
a carbon bearing three substituents (C(R₄)₃) would define a different chemical structure.
Thus, the claim language introduces uncertainty as to the exact chemical structure being claimed.
Even if the specification includes a similar structure, the claims must independently set forth the metes and bounds of the invention.
A discrepancy or ambiguity in the claim cannot be cured by reference to the specification where:
multiple interpretations remain possible, or
the claim language itself is unclear
Accordingly, the objection is maintained.
Applicant is required to amend the claim to clearly specify:
the number and identity of substituents on the terminal carbon, and
to ensure the structural formula is internally consistent and unambiguous.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 83, 85-96 and 100-105 is/are rejected under 35 U.S.C. 103 as being unpatentable over Watkins (WO 2016/019140, IDS) in view of Warren (European Journal of Soil Science, 2018, IDS).
Regarding claim 83, Watkins discloses a universal lipid quantitative standard (ULQS) comprising a plurality of isotopically labeled lipid standards (par [0007]), wherein the plurality of isotopically labeled lipid standards includes at least one lipid species from one or more lipid classes selected from the group consisting of: a phospholipid class, a lysophospholipid class, a cholesterol ester class, a triacylglycerol class, a diacylglycerol class, a ceramide class, and a sphingomyelin class (par [0037][00105]).
Walkins teaches that “a method is provided for synthesizing one or more mixtures of lipid molecules representative of the composition of lipid molecular species present in one or more corresponding lipid classes in a sample of interest” (par [0007]). Claim 40 of Walkins further teaches that “composition for use as an internal standard comprising one or more mixtures of lipid molecules representative of the composition of lipid molecular species present in one or more corresponding lipid classes in a sample of interest, each mixture of lipid molecules comprising: a lipid backbone having an isotopically-labeled fatty acid at a first position on the lipid backbone, wherein the lipid backbone is for a lipid class having at least two acyl groups; and a mixture of at least two different fatty acids present at a separate position on the lipid backbone, wherein the mixture of fatty acids is representative of the fatty acids that occur in the corresponding lipid class in the sample of interest, and wherein each of the fatty acids in the mixture is present at a ratio representative of the ratio of occurrence of the fatty acid in the lipid molecular species present in the corresponding lipid class in the sample of interest.”. Here, Walkins teaches that the number of isotopically labeled lipid standards are the number of the potential corresponding lipid classes in a sample of interest.
Watkins teaches that lipid standards should be selected to represent the diversity of lipid molecular species across lipid classes, and that mixtures of lipid standards are constructed to reflect lipid composition in samples (claim 40).
Thus, Watkins establishes that:
the selection and number of lipid species is driven by achieving representative coverage of lipid diversity.
Warren teaches that LC-MS lipid analysis uses:
“a deuterium-labelled lipid mixture (Splash Lipidomix Mass Spec Standard, Avanti Polar Lipids, Alabaster, AB, USA) that contained lipid species from each of the major lipid classes” (page 792, par 7)
This teaching demonstrates that:
lipid standards are implemented as predefined mixtures,
comprising multiple lipid species across classes, and
selected to enable quantitative LC-MS analysis.
The prior art establishes that:
increasing the number of lipid standards improves coverage of lipid diversity, while
limiting the number reduces experimental complexity and cost
Thus, the number of lipid species in the mixture directly affects performance, and is therefore a result-effective variable.
Warren demonstrates that practitioners select finite sets of lipid species for practical implementation, confirming that the number of standards is chosen based on desired analytical performance.
Accordingly, selecting a specific number of lipid species per class would have been a matter of routine optimization to balance coverage and practicality.
In view of:
Watkins teaching representative multi-species lipid mixtures, and
Warren teaching implementation of such mixtures as predefined, multi-class lipid standard panels used in LC-MS,
it would have been obvious to a person of ordinary skill in the art to select a specific number of lipid species per class to achieve a desired balance between analytical coverage and experimental complexity.
Regarding claim 100, Watkins discloses a universal lipid quantitative standard (ULQS) comprising a plurality of isotopically labeled lipid standards (par [0007]).
Walkins teaches that “a method is provided for synthesizing one or more mixtures of lipid molecules representative of the composition of lipid molecular species present in one or more corresponding lipid classes in a sample of interest” (par [0007]). Claim 40 of Walkins further teaches that “composition for use as an internal standard comprising one or more mixtures of lipid molecules representative of the composition of lipid molecular species present in one or more corresponding lipid classes in a sample of interest, each mixture of lipid molecules comprising: a lipid backbone having an isotopically-labeled fatty acid at a first position on the lipid backbone, wherein the lipid backbone is for a lipid class having at least two acyl groups; and a mixture of at least two different fatty acids present at a separate position on the lipid backbone, wherein the mixture of fatty acids is representative of the fatty acids that occur in the corresponding lipid class in the sample of interest, and wherein each of the fatty acids in the mixture is present at a ratio representative of the ratio of occurrence of the fatty acid in the lipid molecular species present in the corresponding lipid class in the sample of interest.”. Here, Walkins teaches that the number of isotopically labeled lipid standards are the number of the potential corresponding lipid classes in a sample of interest.
Watkins teaches that lipid standards should be selected to represent the diversity of lipid molecular species across lipid classes, and that mixtures of lipid standards are constructed to reflect lipid composition in samples (claim 40).
Thus, Watkins establishes that:
the selection and number of lipid species is driven by achieving representative coverage of lipid diversity.
Warren teaches that LC-MS lipid analysis uses:
“a deuterium-labelled lipid mixture (Splash Lipidomix Mass Spec Standard, Avanti Polar Lipids, Alabaster, AB, USA) that contained lipid species from each of the major lipid classes” (page 792, par 7)
This teaching demonstrates that:
lipid standards are implemented as predefined mixtures,
comprising multiple lipid species across classes, and
selected to enable quantitative LC-MS analysis.
The prior art establishes that:
increasing the number of lipid standards improves coverage of lipid diversity, while
limiting the number reduces experimental complexity and cost
Thus, the number of lipid species in the mixture directly affects performance, and is therefore a result-effective variable.
Warren demonstrates that practitioners select finite sets of lipid species for practical implementation, confirming that:
the number of standards is chosen based on desired analytical performance.
Accordingly, selecting a specific number of lipid species per class would have been a matter of routine optimization to balance coverage and practicality.
In view of:
Watkins teaching representative multi-species lipid mixtures, and
Warren teaching implementation of such mixtures as predefined, multi-class lipid standard panels used in LC-MS,
it would have been obvious to a person of ordinary skill in the art to select a specific number of lipid species per class to achieve a desired balance between analytical coverage and experimental complexity.
Regarding claim 85, Watkins discloses that wherein the phospholipid species, the lysophospholipid species, the cholesterol ester species, the triacylglycerol species, the diacylglycerol species, the ceramide species, and the sphingomyelin species lipid species for each lipid class are selected (par [0037][00105]).
“to correct for ionization efficiency, extraction efficiency, and differential fragmentation efficiency in a mass spectrometry analysis”, a stable isotope-labeled analog of the analyte is typically used as an internal standard; this means a molecule with the same chemical structure as the analyte but with a different isotopic mass (like deuterium substitution) that allows the mass spectrometer to distinguish between the analyte and the internal standard while still behaving similarly throughout the analytical process.
Besides, the phrase “to correct for at least one of the following: ionization efficiency, extraction efficiency, and differential fragmentation efficiency of the lipid species in a sample” merely describes an intended result and does not further limit the structure of the ULQS, therefore caried no weight in the patentability determination.
Regarding claim 86, Watkins discloses that wherein the phospholipid includes one or more phospholipid species selected from the group consisting of: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG), and phosphatidylinositol (Pl) (par [00105]).
Regarding claim 87, Watkins discloses that wherein the phospholipid species are represented by the general formula I, except the location of the deuterium substitution (Fig. 2, par [0057]):
wherein:
R1 is -(CH2)n-N(CH3)3, -(CH2)n-NH3, -(CH2)n-C(H)(NH3)-C(O)-O-, -(CH2)n-CH(OH)-CH(OH),
inositol, and H;
n is 1 to 6;
R2 is a C3 to C30 saturated or unsaturated acyl chain;
R3 is a C3 to C30 saturated or unsaturated acyl chain; and
R4 is independently H.
In a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
1. Mass Shift
The purpose of isotopic labeling in MALDI-MS is often to introduce a mass difference between the labeled and unlabeled compound for unambiguous identification or quantification.
As long as the isotope is incorporated into the molecule and does not get lost during ionization, its position typically does not affect the mass shift observed.
2. Ionization Efficiency
The position of the isotope can sometimes influence ionization efficiency due to subtle changes in the molecule's chemical properties. For example:
2H (deuterium) at exchangeable sites (e.g., hydroxyl or amine hydrogens) can undergo back-exchange with the solvent or matrix, potentially reducing the observed labeling.
3. Calibration and Quantification
In MALDI-MS quantitative analysis, isotopically labeled compounds are often used as internal standards. The label should be placed in a non-exchangeable position to ensure that the labeled standard behaves identically to the analyte during ionization and detection.
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Indeed, in the instant claim 93, the deuterium substitution is on the backbone of sphingolipid.
Regarding claim 88, Watkins discloses that wherein the lysophospholipid includes one or more selected from the group consisting of: lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylsphoserine (LPS), lysophosphatidylglycerol (LPG), and lysophosphatidylinositol (LPI) (par [00105]).
Regarding claim 89 and 101, Watkins discloses that wherein the lysophospholipid species are represented by the general formula II, except the location of the deuterium substitution:
wherein:
R1 is -(CH2)n-N(CH3)3, -(CH2)n-NH3, -(CH2)n-C(H)(NH3)-C(O)-O-, -(CH2)n-CH(OH)-CH(OH), inositol, and H;
n is 1 to 6;
R2 is a C2 to C24 saturated or unsaturated acyl chain; and
R4 is independently H.
As has been discussed regarding claim 87 above, in a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Regarding claim 89, Watkins discloses that wherein the lysophospholipid species are represented by the general formula II, except the location of the deuterium substitution:
wherein:
R1 is -(CH2)n-N(CH3)3, -(CH2)n-NH3, -(CH2)n-C(H)(NH3)-C(O)-O-, -(CH2)n-CH(OH)-CH(OH), inositol, and H;
n is 1 to 6;
R2 is a C2 to C24 saturated or unsaturated acyl chain; and
R4 is independently H.
As has been discussed regarding claim 87 above, in a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Regarding claim 90 and 102, Watkins discloses that wherein the cholesterol ester species are represented by the general formula III, or a pharmaceutically acceptable salt thereof (Fig. 9, par [00144][0051]):
wherein:
R2 is a C9 to C29 saturated or unsaturated acyl chain; and
R4 is independently H or an isotope of H, provided that at least one of R4 is an isotope of H.
Regarding claim 91 and 103, Watkins discloses that wherein the triacylglycerol class includes one or more triacylglycerol species, and wherein the triacylglycerol species are represented by the general formula IV, except the location of the deuterium substitution (Fig. 7, par [0062]):
R2 is a C3 to C30 saturated or unsaturated acyl chain;
R3 are each independently a C3 to C25 saturated or unsaturated acyl chain; and
R4 is independently H.
As has been discussed regarding claim 87 above, in a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Regarding claim 92 and 104, Watkins discloses that wherein the diacylglycerol class includes one or more diacylglycerol species, wherein the diacylglycerol species are represented by the general formula V, except the location of the deuterium substitution:
wherein:
R2 is a C3 to C30 saturated or unsaturated acyl chain;
R3 is a C3 to C25 saturated or unsaturated acyl chain; and
R4 is independently H.
As has been discussed regarding claim 87 above, in a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Regarding claim 93 and 105, Watkins discloses that wherein the ceramide class includes one or more ceramide species, wherein the ceramide species are represented by the general formula VI, or a pharmaceutically acceptable salt thereof (with an isotopically-labeled sphingolipid backbone) (par [0051]):
wherein:
R2 is a C10 to C30 saturated or unsaturated acyl chain; and
R4 is independently H or an isotope of H, provided that at least one of R4 is an isotope of H.
Regarding claim 94, Watkins discloses that wherein the sphingomyelin class includes one or more sphingomyelin species, wherein the sphingomyelin species are represented by the general formula VII, except the location of the deuterium substitution (par [0051]).
As has been discussed regarding claim 87 above, in a MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrum, where the compound does not fragment, the location of isotopic labeling generally matters less compared to techniques where fragmentation occurs. However, there are still important considerations:
Since the difference of the location of deuterium substitution between Watkins and the instant claim does not affect the above considerations, the difference is merely a design of choices.
Regarding claim 95-96, Since the difference of the location of deuterium substitution between Watkins and the instant claims do not affect the above considerations, the difference is merely a design of choices.
Response to Arguments
Applicant's arguments filed 09/08/2025 have been fully considered but they are not persuasive.
The argument to the objection of claim 90 and 102 is considered but is moot in view of new ground of rejection.
The arguments to the 103 rejections are considered but are not persuasive.
Applicant argues that the Examiner has not provided evidence that optimizing the number of lipid species included in the standards would have been a matter of routine experimentation and that the claimed specific combinations are not predictable.
This argument is not persuasive.
1. Watkins teaches the design principle of representative mixtures
Watkins teaches that lipid standards should be selected to represent the diversity of lipid molecular species across lipid classes, and that mixtures of lipid standards are constructed to reflect lipid composition in samples (claim 40).
Thus, Watkins establishes that:
the selection and number of lipid species is driven by achieving representative coverage of lipid diversity.
2. Warren (2018) provides explicit evidence of finite, predefined lipid standard panels
Warren teaches that LC-MS lipid analysis uses:
“a deuterium-labelled lipid mixture (Splash Lipidomix Mass Spec Standard, Avanti Polar Lipids, Alabaster, AB, USA) that contained lipid species from each of the major lipid classes” (page 792, par 7)
This teaching demonstrates that:
lipid standards are implemented as predefined mixtures,
comprising multiple lipid species across classes, and
selected to enable quantitative LC-MS analysis.
Importantly, this is not a conceptual suggestion, but an actual working implementation of a multi-class lipid standard panel.
3. The number of lipid species is a result-effective variable
The prior art establishes that:
increasing the number of lipid standards improves coverage of lipid diversity, while
limiting the number reduces experimental complexity and cost
Thus, the number of lipid species in the mixture directly affects performance, and is therefore a result-effective variable.
Warren demonstrates that practitioners select finite sets of lipid species for practical implementation, confirming that:
the number of standards is chosen based on desired analytical performance.
Accordingly, selecting a specific number of lipid species per class would have been:
a matter of routine optimization to balance coverage and practicality.
4. Applicant’s “no evidence” argument is contradicted by Warren
Applicant asserts that the Examiner has provided no evidence supporting routine optimization.
However, Warren provides direct evidence that:
multi-class lipid standard mixtures are implemented as finite, structured panels, and
such panels are used in quantitative LC-MS workflows.
Thus, the record contains clear evidence that:
the claimed type of composition (multi-class mixtures with selected numbers of lipid species) was already practiced in the art.
5. No criticality or unexpected results
Applicant has not shown that the claimed specific numbers:
are critical, or
produce unexpected results
Absent such evidence, the claimed numerical selections represent:
routine design choices within known approaches
6. Conclusion
In view of:
Watkins teaching representative multi-species lipid mixtures, and
Warren teaching implementation of such mixtures as predefined, multi-class lipid standard panels used in LC-MS,
it would have been obvious to a person of ordinary skill in the art to select a specific number of lipid species per class to achieve a desired balance between analytical coverage and experimental complexity.
Accordingly, the rejection under 35 U.S.C. §103 is maintained.
Applicant asserts that the Examiner has not provided evidence that routine experimentation would achieve the claimed combinations.
However:
Watkins provides the design framework (representative mixtures) (claim 40)
Warren provides empirical evidence of finite, multi-class standard panels used in practice (page 792, par 7)
Thus, the record contains clear evidence that:
the claimed type of composition (multi-class, multi-species lipid standard mixtures with defined sizes) was already implemented in the art.
Applicant has not demonstrated that:
the specific recited numbers of lipid species per class are critical, or
that they produce unexpected results relative to other selections
Absent such evidence, the claimed numerical selections represent:
design choices within a known range of options
In view of:
Watkins teaching representative multi-species lipid mixtures (claim 40), and
Warren teaching practical implementation of such mixtures as finite panels of isotopically labeled lipid standards across classes (page 792, par 7),
it would have been obvious to a person of ordinary skill in the art to select a specific number of lipid species per class to achieve the desired balance between analytical coverage and experimental complexity.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to XIAOYUN R XU, Ph. D. whose telephone number is (571)270-5560. The examiner can normally be reached M-F 8am-5pm.
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, Lyle Alexander can be reached on 571-272-1254. 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.
/XIAOYUN R XU, Ph.D./ Primary Examiner, Art Unit 1797
Prosecution Insights