Prosecution Insights
Last updated: April 19, 2026
Application No. 18/241,669

METHODS OF DETERMINING PROTEIN REDUCTION SUSCEPTABILITY

Non-Final OA §103§112§DP
Filed
Sep 01, 2023
Examiner
MOORE, JOHN DAVID
Art Unit
1638
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Sanofi
OA Round
1 (Non-Final)
74%
Grant Probability
Favorable
1-2
OA Rounds
3y 8m
To Grant
88%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
31 granted / 42 resolved
+13.8% vs TC avg
Moderate +14% lift
Without
With
+14.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
28 currently pending
Career history
70
Total Applications
across all art units

Statute-Specific Performance

§101
5.3%
-34.7% vs TC avg
§103
30.6%
-9.4% vs TC avg
§102
15.1%
-24.9% vs TC avg
§112
30.8%
-9.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 42 resolved cases

Office Action

§103 §112 §DP
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 Claims Claims 1-6, 8-12, 14-19, 21-22, and 57 are pending. Priority Claims 1-6, 8-12, 14-19, 21-22, and 57 have priority to PRO 63/497,629 filed on April 21, 2023, and to PRO 63/406,994 filed on September 15, 2022. Information Disclosure Statement The information disclosure statement(s) (IDS) submitted on October 11, 2023, and on January 12, 2024, and on April 10, 2025, were filed before the mailing of the First Office Action on March 14, 2026. The Non-Patent Literature is in compliance with the provisions of 37 CFR 1.97 and are being considered by the examiner. Drawings The drawings are objected to because: Fig. 1 – Not legible. Fig. 3 (Specifically the “MOCK CHO” graph) – not legible. Fig. 4A – Not legible. Fig. 4B – Not legible. Fig. 5 (Specifically “Non Reducing SDS” graph) – Not legible. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. Double Patenting A rejection based on double patenting of the “same invention” type finds its support in the language of 35 U.S.C. 101 which states that “whoever invents or discovers any new and useful process... may obtain a patent therefor...” (Emphasis added). Thus, the term “same invention,” in this context, means an invention drawn to identical subject matter. See Miller v. Eagle Mfg. Co., 151 U.S. 186 (1894); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Ockert, 245 F.2d 467, 114 USPQ 330 (CCPA 1957). A statutory type (35 U.S.C. 101) double patenting rejection can be overcome by canceling or amending the claims that are directed to the same invention so they are no longer coextensive in scope. The filing of a terminal disclaimer cannot overcome a double patenting rejection based upon 35 U.S.C. 101. Applicant is advised that should claim 1 be found allowable, claim 57 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). Claim 57 is merely a reorganized version of claim 1 with the all of the same elements found in claim 1. Thus, despite a difference in wording, the claims have substantially the same scope. 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 17 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. Regarding claim 17, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 17 recites the broad recitation “less than 50 microliters”, and the claim also recites “less than 10 microliters, or 0 microliters” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. Claim Rejections - 35 USC § 103 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 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1-6, 8-12, 14-18, 21-22, and 57 are rejected under 35 U.S.C. §103 as being unpatentable over Rudyk and Eaton (Hereinafter Rudyk) [Biochemical methods for monitoring protein thiol redox states in biological systems, Redox Biol, 2014], in view of Gurzeler et al. [Production of human translation-competent lysates using dual centrifugation, RNA Biology, 2021], in view of Ren et al. [Antibody disulfide bond reduction and recovery during biopharmaceutical process development – a review, Biotechnology and Bioengineering, 2021], in view of Handlogten et al. [Online control of cell culture redox potential prevents antibody interchain disulfide bond reduction, Biotechnology and Bioengineering, 2020], in view of Hardter et al. [Minimizing oxidation of freeze-dried monoclonal antibodies in polymeric vials using a smart packaging approach, Pharmaceutics, 2021], in view of Hutterer et al. [Monoclonal antibody disulfide reduction during manufacturing, Mabs, 2013]. For claim 1 where a method of determining the reduction susceptibility of a protein, Rudyk discloses “determining” the reduction of protein thiols in biological samples, including cell lysate, using thiol-reactive labeling reagents and then comparing redox states under different redox environments [Introduction ¶ 1]. For part (a) of claim 1, Rudyk discloses general knowledge pertaining to comparative redox assay design. Rudyk teaches methods for assessing protein thiol redox status in biological samples, including cell lysates, and explain that these lysates contain endogenous reducing components that are capable of influencing the protein reduction state [Introduction ¶ 3]. Additionally, it would have been prima facie obvious to a person of ordinary skill in the art prior to the claimed invention to provide a first and second cell culture that are identical except that one contains a cell lysate in order to conduct comparative analysis of protein reduction under various conditions. It is merely creating a test group and a control group. For part (b) of claim 1, Rudyk further discloses the use of multiple redox assays with varying reducing agent concentrations in order to generate gradients of redox potential [2. Monitoring reduced protein thiol status ¶ 1]. For part (c) of claim 1, Rudyk teaches performing thiol labeling assays under controlled redox conditions [2. Monitoring reduced produced thiol status ¶ 1]. Furthermore, while Rudyk does not explicitly teach specifically the use of a air-tight container having an interior volume of about 1 mL to about 3 mL with a headspace of less than 100 microliters, it would have been obvious to a person of ordinary skill in the art to incubate the samples in an air-sealed container having a small interior volume and limited headspace given that controlling headspace to limit oxygen is a known design consideration in redox chemistry. Additionally, selecting small vial volumes for bench-scale assays would be considered routine laboratory practice and reducing headspace in order to minimize oxygen is a known method for reducing oxidative interference that leads to improved redox conditions. For part (d) of claim 1 where the level of protein reduction and/or redox potential is determined, Rudyk directly teaches maleimide labeling of reduced thiols [2. Monitoring reduced protein thiol status ¶ 3], iodoacetate labeling [Id.], Ellman’s reagent [2. Monitoring reduced produced thiol status ¶ 1], and then comparing the measurements across samples [5. Monitoring protein S-nitrosation ¶ 2]. For part (e) for claim 1 where determining reduction susceptibility based on measured reduction/redox potential, Rudyk teaches comparative redox analysis [5. Monitoring protein S-nitrosation ¶ 2] by evaluating how protein thiols respond to different redox environments that infers susceptibility from such data which is an inherent analytical step. For claim 2 where the cell lysate was obtained through homogenization of cells, Gurzeler et al., discussing methods for producing human cell lysates via mechanical disruption methods, teaches preparation of functional lysates by physically disrupting cells to release intracellular components, including homogenization, by means of dual centrifugation [Introduction ¶ 4]. For claim 3 where the cell lysate was centrifuged to remove cellular debris, Gurzeler et al. discloses the use of centrifugation for the purpose of removing cellular debris [Results & Discussion ¶ 2]. For claim 4 where the second cell culture fluid is obtained by removing essentially all of the cells from the cell culture medium, while not explicit, Gurzeler in figure 1B shows cells being removed and placed in a vial for dual centrifugation that leads to a supernatant and pellet, i.e. nuclei and unlysed cells. Additionally, removing cells from a culture medium, either by centrifugation or filtration, represent known methods for preparing a lysate-free control fluid and represent known and routine steps in cell culture processing that are a predictable means for generating the non-lysate sample, i.e. control sample. Here, it is prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems and methods of Rudyk where methods for evaluating reduction/redox states in proteins for comparative analysis were discussed with the additional teachings of Gurzeler et al. that discloses methods for obtaining lysates using dual centrifugation. Because of this, there is a reasonable expectation of success that a person of ordinary skill in the art would recognize the teachings of Rudyk and Gurzeler to develop a system for determining or observing any reduction susceptibility of proteins where the samples included a test group and a control group where the samples were compared for analysis. For claim 5 where the protein is a recombinant protein, Ren et al. discussing disulfide bond reduction in monoclonal antibodies, teaches monoclonal antibodies, i.e. recombinant proteins, undergo disulfide bond reduction during biopharmaceutical proves development [Abstract]. Furthermore, Ren et al. stresses the importance of monitoring and analyzing disulfide bond reduction [5 Analytical methods for disulfide bond reduction monitoring and analysis ¶ 1]. For claim 6 where the recombinant protein is an antibody, Ren et al. discloses methods of monitoring disulfide bond reduction in monoclonal antibodies [Figure 2, 3 Impact of disulfide reduction on downstream processing, 4 root cause analysis for disulfide bond reduction ¶ 1]. For claim 8 where the level of protein reduction is determined by assessing the oxidation stated of disulfide bonds, Ren et al. teaches that mAb disulfide bond reduction is essentially an oxidation-reduction, i.e. redox, reaction that involves redox enzyme [4 Root cause analysis for disulfide bond reduction ¶ 1]. For claim 9 where the redox potential is determined by measuring one or more listed, Ren et al. teaches that glutathione, thioredoxin, and nicotinamide adenine dinucleotide phosphate (NADPH) are known enzyme systems that contribute to disulfide bond reduction [4 Root cause analysis for disulfide bond reduction ¶ 1]. For claim 10 where the redox potential is determined by using a redox potential probe, Handlogten et al. discussing online control of cell culture redox potential, discloses the use of monitoring cell culture redox potential via an online redox probe [Abstract]. For claim 11 where the level or protein reduction is determined by the amount of intact and/or reduced protein after incubating with each set of samples, Ren et al. discloses monitoring structural integrity and redox-induced changes in recombinant proteins [6.31 Inhibit enzyme expression in the cells ¶ 1]. For claim 12 where the amount of intact and/or reduced protein is determined using a native SDS-PAGE gel, Ren et al. further discloses the use of SDS-PAGE, i.e. a size-based method, for detecting and quantifying protein modifications, including disulfide bond reductions [5 Analytical methods for disulfide bond reduction monitoring and analysis ¶ 2]. For claim 14 where the protein reduction is determined and the results are graphed, Ren et al. discloses monitoring intact and reduced antibody species [8.2 identifying disulfide bond reduction risks using machine learning algorithms ¶ 1]. Furthermore, graphical representation of reduction versus process conditions or redox state is routine analytical steps in bioprocessing. For claim 15 wherein the air-sealed container is an air-sealed glass vial, Hardter et al., discussing minimizing oxidation of freeze-dried monoclonal antibodies, teaches that oxidation is an important degradation pathway for monoclonal antibodies, and that continuous migration of oxygen into drug product containers should be avoided overall [Abstract]. Hardter et al. further teaches that glass vials are known for their ability to maintain low levels of headspace oxygen [3.2 Effect of the Absorber on the oxygen levels in the headspaces of the lyophilizates ¶ 2]. Given this, there is a reasonable expectation of success that a person of ordinary skill in the art would recognize that glass vials provide a unique advantage in maintaining low headspace oxygen levels compared to polymer vials given that polymers are known to be more permeable to gases in general. Because of this, it is prima facie obvious to a person of ordinary skill prior to the filing of the claimed invention to modify the systems of Rudyk discussing biochemical methods for monitoring protein thiol redox and Ren et al. where antibody disulfide bond reduction in biopharmaceutical process development was discussed with the additional teachings of Hardter et al. that disclosed that glass vials have a lower oxygen permeability and therefore are able to maintain a lower oxygen headspace. This would lead a person of ordinary skill in the art to understand that the use of glass vials, especially for small batch testing, would be more beneficial given the oxygen level in the headspace could be more easily controlled given glass is less permeable to gases when compared to polymer vials. For claim 16 where the air-sealed container has an interior volume of about 2 mL to about 2.5 mL, Hutterer et al. discloses the use of small scale model systems for replicating and monitoring antibody reduction behavior [Small scale model ¶ 1]. Additionally, the use of small-scale models are routinely employed for reduction studies. Therefore, the use of 2 mL to 2.5 mL glass vials would have been obvious to a person of ordinary skill given small-scale redox environments are well-understood to differ from large-scale systems due to oxygen exposure and process conditions. For claim 17 where the air-sealed container has less than 50 microliters or less of headspace, although Hutterer et al. or Ren et al. disclose headspace limitations of less than 50 microliters, headspace in small-scale protein assays directly effect oxidative exposure of proteins. Meaning, the less air in the vial, the lower the oxygen available to drive disulfide reduction. Therefore, selecting headspace volumes would be considered routine optimization on well-known biochemical principles. Furthermore, Hutterer et al. and Rudyk both discuss minimizing headspace to control oxidative interference despite not listing specific headspace volumes. For claim 18 where the protein is incubated with each sample set of samples for about 0.5 to 4 hours prior to step (c), Hutterer et al. teaches that samples were taken at 0, 0.5, 1, 2, 4, 8 and 24 hours where the samples were placed in a 3L bioreactor, where the resulting slurry was sparged with nitrogen to simulate an anaerobic environment [Small scale model ¶ 1]. Although not specifically disclosing incubation times between 0.5 and 4 hours, it would have been prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems of Hutterer et al. to incubate the protein with each sample prior to adding the protein to the air-sealed container allowing for measurable interaction between protein and reducing environment. For claim 19 where the reduction susceptibility of the protein is compared with a reference standard, Rudyk does not explicitly disclose comparing the reduction susceptibility of a protein with a reference standard comprising a standard curve of reduction susceptibility of a reference protein. However, it would have been prima facie obvious to a person of ordinary skill in the art at the time the claimed invention was filed to compare the measured reduction susceptibility of the protein to a “reference standard” or “standard curve” in order to interpret the obtained measurement. The use of standard curves and reference standards to analyze experimental data is a well-known and routine practice in biochemical and analytical assays that allows researchers to determine things such as relative activity, susceptibility, or concentration levels and comparing those results to known standards. For claim 21 where the protein is selected based on the reduction susceptibility of the protein, Ren et al. discloses analytical methods to monitor intact versus reduced protein species during process development and notes that these measurements inform selection of stable proteins or antibody candidates for manufacturing [5 Analytical methods for disulfide bond reduction monitoring and analysis ¶ 1and 2]. For claim 22, Rudyk discloses all the steps (a) through (e) as described above. Additionally, for part (f), both Hutterer et al. and Ren et al. discuss modifying cell cultures or manufacturing processes based on observed protein stability and disulfide reduction. Because of this, it would have been prima facie obvious to a person of ordinary skill in the art prior to the filing of the claimed invention to modify the systems of Rudyk and Gurzeler et al. with the additional teachings of both Hutterer et al. and Ren et al. to use reduction susceptibility data from small-scale assays to adjust cell culture conditions, e.g. temperature, agitation, oxygen levels, lysate exposure, to improve protein stability. This represents a predictable application of routine process development in biopharmaceutical manufacturing. For claim 57, where a method of determining the reduction susceptibility of a protein, Rudyk discloses “determining” the reduction of protein thiols in biological samples, including cell lysate, using thiol-reactive labeling reagents and then comparing redox states under different redox environments [Introduction ¶ 1]. For claim 57, Rudyk discloses all the steps (a) through (c) as described above. Note: Claim 57 is merely a reorganized statement of claim 1, therefore the same analysis for the §103 rejection for claim 1 is applied to claim 57. The Supreme court has acknowledged: When a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one. If a person of ordinary skill can implement a predictable varition..103 likely bars its patentability…if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond that person’s skill. A court must ask whether the improvement is more than the predictable use of prior-art elements according to their established functions… …the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results (see KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 U.S. 2007) emphasis added. In KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), the Supreme Court reaffirmed "the conclusion that when a patent 'simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." Id. at 417 (quoting Sakraida v. Ag Pro, Inc., 425 U.S. 273,282 (1976)). The Supreme Court also emphasized a flexible approach to the obviousness question, stating that the analysis under 35 U.S.C. § 103 "need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ." Id. at 418; see also id. at 421 ("A person of ordinary skill is... a person of ordinary creativity, not an automaton."). From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. Conclusion No claims allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN DAVID MOORE whose telephone number is (703)756-1887. The examiner can normally be reached M-F 8-5. 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, Tracy Vivlemore can be reached on 571-272-2914. 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. /JOHN DAVID MOORE/Examiner, Art Unit 1638 /Tracy Vivlemore/ Supervisory Primary Examiner, Art Unit 1638
Read full office action

Prosecution Timeline

Sep 01, 2023
Application Filed
Mar 06, 2026
Non-Final Rejection — §103, §112, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
74%
Grant Probability
88%
With Interview (+14.3%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 42 resolved cases by this examiner. Grant probability derived from career allow rate.

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