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 .
Priority
The present application was filed on 05/11/2022. Acknowledgment is made of the present application as a proper National Stage (371) entry of PCT/EP2020/084366, filed on 12/03/2020, which claims benefit of the foreign Application No. United Kingdom 1917630.4, filed on 12/03/2019.
Claim status
Claims 6, 8, 17-18, 20-23, and 30 are withdrawn. Claims 2, 12-13 and 19 are canceled.
Claims 1, 3-5, 7, 9-11, 14-16, 24-29 and 31-34 are examined herein.
Objections/Rejection status
The rejections of claims 1, 3-5, 7, 9-11, 14-16, 24-29 and 31-34 under 35 USC 103 are updated in view of the amendment of the claim and Applicant’s arguments filed on 06/10/2026.
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.
Claim(s) 1, 3-5, 7, 10-11, 14-15, 24-29 and 31-34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lofas (WO2011/093782, PTO-892 dated 08/27/2025) in view of GE Healthcare (Biacore Sensor Surface Handbook, 2007, PTO-892 dated 08/27/2025), Karlsson (US20170242001), Wang et al. (Non-Size-Based Membrane Chromatographic Separation and Analysis of Monoclonal Antibody Aggregates, Anal. Chem. 2006, 78, 6863-6867, IDS 08/12/2025) and Reeve et al. (US20090192048).
Regarding claims 1 and 24-26, Lofas teaches a method of determining aggregates in a fluid containing the macromolecule, comprising the steps of: contacting a sample of the fluid with a sensing surface of an interaction analysis sensor, wherein the sensing surface is capable of specific binding interaction with the macromolecule; determining at least one kinetic parameter for the interaction of the fluid sample with the sensing surface; comparing the determined kinetic parameter or parameters with that or those determined for at least one fluid sample having a known fraction or fractions of aggregates of the macromolecule; and determining therefrom the fraction of macromolecule in the sample that is in the form of aggregate or aggregates. See Abstract.
Lofas particularly discloses that the sensor surface has a binding partner (i.e., a ligand) to the macromolecule immobilized thereon (see page 2 par.3). The binding partner used in the method is protein A (see par.49), and the macromolecule is a protein, e.g., antibody (see par.6-7). Lofas teaches that the interaction analysis sensor is a mass-sensing biosensor based on surface plasmon resonance (SPR) evanescent wave sensing (see page 3 lines 15-16, see page 4 par.7 and page 5 par.1). Lofas further teaches that the sensor includes the flow-through cell-based Biacore® systems (GE Healthcare Bio-Sciences AB, Uppsala, Sweden) (see page 5 par.2).
However, Lofas does not teach the ligand comprising a hydrophobic group. Lofas does not teach that the log P value of the hydrophobic group should be greater than 0.
GE Healthcare teaches Biacore® systems exploiting the phenomenon of surface plasmon resonance (SPR) to monitor the interaction between molecules in real time. See page 7 section 1.1. GE Healthcare offers a wide selection of different sensor surfaces to fill the varied application requirements for SPR technology (see page 15 section 2.2). In particular, GE Healthcare discloses a sensor chip L1 that has a surface matrix of carboxymethyl dextran attached to lipophilic residues for detecting hydrophobic ligands (see page 18 section Sensor Chip L1).
Karlsson provides an example of a mass-sensing biosensor based on surface plasmon resonance evanescent wave sensing (see pars.60-61 and 70-75) from Biacore® system. Karlsson teaches an analytical system for studying molecular interactions (see Abstract). The analytical system is a mass-sensing biosensor based on surface plasmon resonance evanescent wave sensing (see pars.60 and 75). The sensor surface contains immobilized partners for the analyte, which are ligands comprising functional groups capable of interaction with a target compound, e.g., a hydrophobic group (see pars.11, 16 and 52).
Wang states that protein A does not distinguish between the antibody and its aggregates since the technique depends on the binding of protein A ligand to the Fc domain on the antibody molecules. However, the dimers and higher order aggregates of monoclonal antibodies are reported to have unaffected Fc domains, so the distinguishing is not effective. (See page 6863 col.2 par.2)
Wang provides a hydrophobic interaction membrane chromatography-based technique for rapid, non-size-based separation and analysis of the aggregate content in monoclonal antibody sample. The technique is based on the fact that monoclonal antibody aggregates are more hydrophobic than the monomer form, so the antibody and its aggregated form can be separated apart. See Abstract.
Wang demonstrates that the hydrophobic surface is capable of increased binding interaction with aggregated antibody compared to non-aggregated antibody (see page 6865 col.2 par.1: teaching that the antibody aggregates were more hydrophobic than the antibody itself, and an attempt was made to fractionate Campath-9 from its aggregates using HIMC; page 6865 col.2 par.2 and page 6866 col.1 par.1 and Fig.2-3: demonstrating that monomer forms go off the membrane first, and dimer and higher aggregates come after).
Reeve teaches a method of producing a multimeric capture agent for binding a ligand (see Abstract), wherein the capture agent comprises at least first and second monomer units (see par.8). The monomer unit can be any suitable type of molecule, e.g., amino acids (see par.28). The amino acid may provide a hydrophobic moiety for ligand binding (see par.46). The hydrophobic amino acids are selected from the group consisting of leucine, isoleucine, valine, norvaline, methionine, tyrosine, tryptophan and phenylalanine. More preferably, the hydrophobic amino acid is phenylalanine (see par.84).
Since the hydrophobic group can consist of leucine, isoleucine, valine, norvaline, methionine, tyrosine, tryptophan and phenylalanine (see Reeve par.84), therefore it appears to have a log P value>0 as discloses in the instant specification (par.65-69: the term “hydrophobic group” as used herein is defined as a group of molecules which has a log P value>0, e.g., comprise the side chain of an amino acid selected from the group consisting of alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, and tyrosine, or a hydrophobic derivative of said side chain, preferably the side chain of an amino acid selected from the group consisting of phenylalanine, tryptophan, and tyrosine).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the binding partner on the surface of the sensor of Lofas, with the ligand comprising a hydrophobic functional group to determine aggregates in a fluid containing the macromolecule, because the ligand comprising a hydrophobic functional group is functionally equivalent to the binding partner of Lofas in terms of binding to aggregates in the sample (Karlsson teaches that hydrophobic group containing ligands, which are immobilized on the SPR surface, are used for detecting interactions between molecules in a sample and the ligands; Wang teaches that an interaction of a hydrophobic surface and the aggregates of a protein is greater than that with the monomer of the protein).
One having an ordinary skill in the art would have been motivated to use the ligand having a hydrophobic functional group on the sensor surface because it is capable of increased binding interaction with aggregated molecules, as taught by Wang. Moreover, the replacement will improve the method of detecting aggregates of Lofas because the binding ligand of Lofas (protein A) is not efficient in distinguishing between the antibody and its aggregates (Wang page 6863 col.2 par.2). As such, it would be obvious to use the ligand comprising the hydrophobic amino acid residue for ligand binding as taught by Reeve, wherein the hydrophobic amino acids comprise valine, leucine, tyrosine, tryptophan, phenylalanine, isoleucine, methionine. Accordingly, the hydrophobic group has a log P value >0 as discussed above.
One having an ordinary skill in the art would have had a reasonable expectation of success in substituting the ligand with hydrophobic groups for the binding ligand in Lofas, because GE Healthcare supports the use of a sensor chip that has a binding ligand comprising hydrophobic groups on its surface, for detecting hydrophobic analytes (see GE Healthcare page 18).
Regarding claims 3-5 and 27-29, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claim 1. Lofas does not teach the hydrophobic group comprising the side chain of an amino acid selected from the group consisting of phenylalanine, tryptophan, and tyrosine as in claims 3-5 and 27-29.
Lofas in view of GE Healthcare, Karlsson, and Wang teaches that the sensor chip having an immobilized ligand comprising hydrophobic or lipophilic groups on the surface can be used to determine aggregated molecule (see discussion in claim 1 above).
Reeve teaches a ligand comprising hydrophobic groups that can be immobilized on a surface to capture a target analyte (see Reeve at least in Abstract, pars.8, 28, 46 and 84). See discussion in claim 1 above. The ligand comprises a side chain of an amino acid selected from the group consisting of leucine, isoleucine, valine, methionine, tyrosine, tryptophan and phenylalanine (see Reeve pars.44-46, 84).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the binding partner on the surface of the sensor of Lofas, with the ligand comprising hydrophobic functional groups capable of interaction with a target compound to determine aggregated macromolecules in a sample, because the reasons discussed above in claim 1. Therefore, it would have been obvious to use the ligand comprising the hydrophobic amino acid residues, e.g., tyrosine, tryptophan, phenylalanine as taught by Reeve.
One having an ordinary skill in the art would have had a reasonable expectation of success in using the ligand taught by Reeve because Lofas is generic to a sensor chip that has a binding partner to the analyte immobilized thereon (see Lofas page 2 par.3) and Reeve provides a specific binding partner comprising the hydrophobic amino acid residue, which can be used to detect aggregated molecules as taught by Wang.
Regarding claim 7, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claim 1. Lofas teaches a step of comparing the determined kinetic parameter or parameters with that or those determined for at least one fluid sample having a known fraction or fractions of aggregates of the macromolecule, and determining therefrom the fraction of macromolecule in the sample that is in the form of aggregate or aggregates (see abstract).
Regarding claims 10 and 31, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claims 1 and 24. Lofas teaches that the macromolecule may be determined by the method is typically a protein or polypeptide, particularly a therapeutic protein or polypeptide, such as an antibody, but may also be, for example, a nucleic acid (see page 3, par.3).
Regarding claims 11 and 32, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claims 1 and 24. Lofas teaches the sensor include the flow-through cell-based Biacore® systems (GE Healthcare Bio-Sciences AB, Uppsala, Sweden) (see page 5 par.2). GE Healthcare teaches that the sensor chip comprises a ligand immobilized on the sensor surface which the ligand comprises common functional groups such as amino group (see page 16 section 2.2.1) or carboxyl group (see page 18 section 2.2.4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the method of Lofas for determining of aggregates comprising one or more macromolecules in a sample because the method of Lofas uses the biosensor of GE Healthcare having a ligand which comprises common functional groups such as amino group or carboxyl group so that the ligand can interact with the analyte of interest as taught by GE Healthcare (see GE Healthcare page 7, section 1.2).
One having an ordinary skill in the art would have had a reasonable expectation of success in combining Lofas and GE Healthcare because Lofas is directed to the method of determining aggregates of a macromolecule using the sensor chip from GE Healthcare.
Regarding claims 14-15, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claim 1. Lofas teaches the method can describe the progress of the molecular interaction in real time with Biacore system including an association phase part and a dissociation phase part (see page 5 par.3-4). The method also comprises calculating the association rate and dissociation rate (see page 7 par.2).
Regarding claims 33-34, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claim 24. Lofas teaches that the interaction analysis sensor is preferably a biosensor, especially a mass-sensing biosensor (see page 3 lines 15-16), or surface plasmon resonance (SPR) sensors (see page 5 par.1).
Claim(s) 9 and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve, as applied in claim 1 above, and further in view of Pol et al. (Evaluation of calibration-free concentration analysis provided by Biacore™ systems, Analytical Biochemistry 510 (2016) 88-97, PTO-892 dated 08/27/2025).
Regarding claims 9 and 16, Lofas in view of GE Healthcare, Karlsson, Wang, and Reeve teaches the method of claim 1. Lofas teaches that the method using the sensor, e.g., Biacore of GE Healthcare can determine mass detection (see page 4 last paragraph). GE Healthcare provides that the sensor chip and system can determine the molecular weight of the aggregate(s) (see page 68 section 6.1.4/2). Lofas does not teach step c (ii) comprising a diffusion coefficient determination for the aggregates.
However, Pol teaches Surface Plasmon Resonance biosensors measure the interaction between a molecule in solution and its interaction partner attached to a sensor surface (see Abstract), e.g. Biacore platform with Biacore T200 and Biacore X100 evaluation software (see page 88 col.2 par.2). The software can conduct Calibration Free Concentration Analysis (CFCA) including the diffusion coefficient (see at least page 89 and Table 1; see page 91 section 3.3).
According to Pol, CFCA does not require a standard and makes it possible to determine the active concentration directly. This method requires that binding rates are at least partially limited by transport effects, that the diffusion coefficient of the molecule can be determined and that the Biacore response can be converted into mass. Whereas, traditionally, the active binding concentration measurements provide relative values as a new sample is compared to a standard. However, proteins may be differently expressed or may have undergone post translational modifications that influence binding activity, and for that reason, the relevance of the standard can be questioned, and the absolute active concentration may never be known. See pages 95-96 section 5.
Moreover, Pol provides that by examining experimental conditions including immobilization levels and temperature for a range of analytes, and by using global analysis of several sample dilutions, conditions that gave the most robust results were identified (see Abstract). Pol notes that CFCA, e.g., diffusion coefficient value, may be temperature-dependent (see page 91 section 3.3; see page 94-95 section 4.2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Lofas, determining a diffusion coefficient for the aggregates at different temperatures, because Pol teaches that the active concentration of an aggregate can be directly determined without the use of standard, and the Biacore platform can convert the diffusion coefficient into mass. Since the CFCA, e.g., diffusion coefficient value, may be temperature-dependent, experiments should be done at varied temperatures to get the accuracy, precision and robustness of CFCA (see section 4.3 page 94-95; page 96 col.2 par.4).
One having an ordinary skill in the art would have had a reasonable expectation of success in combining Lofas and Pol because Lofas uses a Biacore system and chip to determine aggregates of a macromolecule monomer in a fluid. Pol further teaches the Biacore platform can do CFCA including the diffusion coefficient at different temperatures to achieve the accuracy, precision and robustness of CFCA.
Response to Arguments
Applicant's arguments filed 06/10/2026 have been fully considered but they are not persuasive.
Applicant argues that GE Healthcare, Karlsson, and Wang do not provide any motivation for or explanation as to how to modify the method of Lofas to arrive at that of Applicant's claims.
This argument is not persuasive. Lofas teaches a method of determining aggregates of an antibody in a fluid by protein A immobilized on the SPR sensor surface as a binding ligand. Karlsson teaches that hydrophobic group-containing ligands, which are immobilized on the SPR surface, have already been used for detecting interactions between molecules in a sample and the ligands. Wang states that protein A is not efficient in distinguishing between the antibody and its aggregates. Wang uses the hydrophobic surface to separate the monomer from aggregates of antibodies based on the fact that an interaction of a hydrophobic surface and the aggregates of a protein is greater than that with the monomer of the protein. One having an ordinary skill in the art would have been motivated to use the ligand having a hydrophobic functional group on the sensor surface because it is capable of increased binding interaction with aggregated molecules, as taught by Wang. Moreover, the replacement will improve the method of detecting aggregates of Lofas because the binding ligand of Lofas (protein A) is not efficient in distinguishing between the antibody and its aggregates (Wang page 6863 col.2 par.2). One having an ordinary skill in the art would have had a reasonable expectation of success in substituting the ligand with hydrophobic groups for the binding ligand in Lofas, because GE Healthcare supports the use of a sensor chip that has a binding ligand comprising hydrophobic groups on its surface, for detecting hydrophobic analytes (see GE Healthcare page 18).
Applicant argues that the method of Reeve is unrelated to the technical field of the present invention. One of ordinary skill in the art would not have had any motivation to apply the teaching of Reeve in seeking an alternative method for measurement of aggregates as described in Applicant's specification and as recited in Applicant's claims.
This argument is not persuasive. While Reeve does not teach the same technical field of the present invention, Examiner relies on Reeve to make a capture reagent with hydrophobic groups that can be used for binding a ligand. The hydrophobic groups comprise valine, leucine, tyrosine, tryptophan, phenylalanine, isoleucine, methionine etc. It is up to the user preference to apply the capture reagent to a specific use.
Applicant argues that Pol does not supplement the aforementioned deficiencies of Lofas, GE Healthcare, Karlsson, Wang, and/or Reeve, at least because Pol measures aggregation using the relationship of active concentration to total concentration of the macromolecule. The teachings of Pol are therefore related to different aggregation principles than those recited in Applicant's claims.
This argument is not persuasive. Lofas teaches that at least one parameter related to aggregate(s) of the macromolecule(s) is determined based on the interaction between a macromolecule and its ligand partner attached to an SPR sensor surface. Pol teaches that Surface Plasmon Resonance biosensors measure the interaction between a molecule in solution and its interaction partner attached to a sensor surface. Therefore, the methods of Lofas and Pol are analogous in determining at least one parameter related to the interaction between a molecule in solution and its interaction partner attached to a sensor surface. The parameters related to the molecule are mass or binding rates. Pol teaches that the diffusion coefficient of the molecule needs to be determined, so that the sensor system can covert the diffusion coefficient of the molecule into mass. Since Pol can determine at least one parameter related to the molecule bound to its partner attached to the sensor surface, the method of Pol is relevant to the method of Lofas.
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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHAU N.B. TRAN whose telephone number is (571)272-3663. The examiner can normally be reached Mon-Fri 8:30-6:30 CT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Bao-Thuy L Nguyen can be reached at 571-272-0824. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CHAU N.B. TRAN/Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677 October 12, 2026
