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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/21/2026 has been entered.
Priority
The present application was filed on 11/02/2020. Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. UNITED KINGDOM 1808529 filed on 05/24/2018.
Claim status
Claims 3-5, 7, 10, 13 and 16 are canceled. Claims 1, 9, 17 and 19 are amended. Claims 1, 2, 6, 8-9, 11-12, 14-15 and 17-19 are pending and examine herein.
Rejections/Objections status
The objection of claim 9 is withdrawn in view of the amendment of the claims filed on 02/21/26.
The rejection of claims 1, 2, 6, 8-9, 11-12, 14-15 and 17-19 under 35 USC 103 is updated in view of the amendment of the claims filed on 02/21/26.
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.
Claims 1-2, 6, 8-9, 11-12, 14-15, 17 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Barnidge et al. (Using Mass Spectrometry to Monitor Monoclonal Immunoglobulins in Patients with a Monoclonal Gammopathy, Proteome Res. 2014, 13, 1419−1427) in view of Hortin and Remaley (Mass Determination of Major Plasma Proteins by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry, Clinical Proteomics, vol.2, 2006, PTO-892 dated 09/26/2023), and Iles et al. (GB 2530521, PTO-892 dated 09/12/2023).
For claims 1 and 19, Barnidge teaches a method for detecting and optionally quantifying intact monoclonal immunoglobulins in a serum sample (see Abstract, page 1420 col.1 Serum section).
The method comprises the following steps:
providing a sample of blood, serum or plasma containing or suspected of containing a monoclonal immunoglobulin from a subject (see Abstract, page 1419 col.1, and page 1420 col.1 Serum section: teaching that the serum sample contains monoclonal immunoglobulin M-protein consisting of the intact immunoglobulin in combination);
diluting the blood, serum or plasma sample with water or an aqueous buffer to form a diluted blood, serum or plasma sample, wherein the blood, serum or plasma sample is treated with a reducing agent during or after dilution, to separate the light chain and the heavy chain of the monoclonal immunoglobulins (see Abstract and page 1420 col.1 Serum section: teaching that serum sample is diluted with PBS, then serum sample is reduced using DTT to separate light chains from heavy chains);
ionizing the diluted and reduced blood, serum or plasma sample (see page 1420 col.2 ESI-Q-TOF MS section: teaching that Spectra were collected on an ABSciex TripleTOF 5600
quadrupole time-of-flight mass spectrometer in ESI positive mode with a Turbo V dual-ion
source with an automated calibrant delivery system);
subjecting the ionized sample to mass spectrometry to detect and optionally quantify intact monoclonal immunoglobulin (see page 1420 col.1 par. 2: teaching the application of a mass spectrometry-based platform routinely used by pharma in mAb quality control, micro LC-ESI-Q-TOF MS, for the rapid detection, quantification, and isotyping of monoclonal immunoglobulins from patients; see more on page 1420 col.2 ESI-Q-TOF MS section; see Data Analysis section).
Barnidge also teaches that the mass spectrometer can determine the molecular mass of the M-protein light chain and heavy chain with high precision and accuracy, creating an individualized M-protein biomarker value that can be used to monitor clonal plasma cells over long periods of time (see page 1425 Conclusions par.1). Therefore, the teaching of Barnidge encompasses the subject matter of claim 19.
Barnidge does not teach that the blood, serum or plasma sample is not purified by immunopurification or removal of other non-immunoglobulin proteins prior to subjecting the sample to mass spectrometry.
Iles teaches a rapid screening method for testing a biomarker of cancer in bodily fluids by using direct MALDI – ToF or ESI mass spectral analysis which means that the MS analysis may be carried out directly on a post extraction or following dilution sample, for example in distilled deionized water, or other suitable diluent (see page 4 pars.3 and 7). Iles also emphasizes that the method meets the need of simple sampling, rapid and affordable testing for a routine clinical service (see page 4 par.2).
The biomarker of cancer can be a paraprotein such as a Bence Jones protein (BJP) i.e. kappa or lambda free light chains, or fragments thereof (see page 6 par.2). The sample obtained from the patient is a bodily fluid sample, which comprises blood and serum (see page 6 par.3). In serum, FLC kappa exists predominantly as a monomer with a molecular weight of 22.5 kDa and FLC lambda as a dimer with a molecular weight of 45 kDa (see page 6 par.2). Also, the sample can be a neat sample or can be diluted with buffer or diluent (see page 6 par.4). While mass spectrometry is common for qualitative mass spectra, the qualitative mass spectra can be converted into a quantitative value (see page 8 par.1). Thus, the method can optionally quantify the biomarker, e.g., free light chains.
The teaching of Iles encompasses the method of detecting and optionally quantifying the free light chain in the blood, serum or plasma sample, wherein the sample is not purified by immunopurification or removal of other non-immunoglobulin proteins prior to subjecting the sample to mass spectrometry.
Hortin and Remaley teaches that a method of simple “dilute and shoot” approach for MALDI-TOF/MS analysis of serum or plasma may be of greatest value in identifying qualitative changes of proteins (see Discussion page 113). While sample preparation is a key step in the analysis of complex specimens by MALDITOF/MS, variables of protein concentration or salt concentration or specimen fractionation may strongly influence the observed spectra. Moreover, these preparation steps involve significant time, expense, and potential losses of selected components. Therefore, direct analysis of serum provides a very simple approach that might be applicable for routine in the clinical laboratory and that would avoid modification or selective losses of components during preparation. See page 104.
Hortin and Remaley also teaches that MALDI-TOF/MS directly in diluted serum may be useful in analyzing plasma proteins particularly those with a mass <30,000 or mass to charge m/z <30,000 because there is better sensitivity, resolution, and less interference from the most abundant components in serum, e.g., albumin (see Abstract and page 112 col.1 par.3col.2 par.2). Hortin and Remaley teaches the mass spectrometry analysis is primarily qualitative but it can be applied to quantitate the relative amounts of different proteins (see page 113 col.1 par.1).
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 detecting or quantifying intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin taught by Barnidge by using mass spectrometry-based method without sample purification or enrichment as taught by Iles, and Hortin and Remaley. The modification provides a very simple approach that can be applicable for routine in the clinical laboratory and that would avoid modification or selective losses of components during preparation, e.g., purification step (see Iles page 4 par.2, see Hortin and Remaley page 104).
One having an ordinary skill in the art would have had a reasonable expectation of success in combining Barnidge, Iles, and Hortin and Remaley because they are directed to the method of detecting and quantifying a protein in blood or plasma or serum sample using mass spectrometry. While Iles teaches that mass spectrometry is used to characterize free light or heavy chains in the bodily fluid (e.g., serum) without using an enrichment or purification step, the method of Iles would be able to detect intact monoclonal immunoglobulin because the detection of intact monoclonal immunoglobulin is also based on the detection of the separated light chain from the intact monoclonal immunoglobulin as taught by Barnidge.
Moreover, Hortin and Remaley teaches that the “dilute and shoot” mass spectrometry is useful in analyzing plasma proteins particularly those with a mass <30,000 or mass to charge m/z <30,000 (see Abstract and page 112 col.1 par.3col.2 par.2), so the method can be used for analyzing light chains of a monoclonal antibody because the mass to charge of kappa light chain is around 22.5 kDa as taught by Iles (see page 6 par.2).
Since Barnidge teaches that the purification step is processed before the reduction step, and the reduction sample is mixed with MS matrix prior to being injected to MS system, it would be obvious to expect the successfulness of the combination of reduction step and a “dilute and shoot” workflow in detecting or quantifying an intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin because there is no step between reduction step and “shoot” MS step as taught by Barnidge, e.g., the reduced sample does not need to be purified before MS step.
For claim 2, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge does not teach that the blood, serum or plasma sample is at least partially dried and is rehydrated with the water or aqueous buffer.
Iles teaches that the blood sample may be a dried blood spot (see page 6 lines 20). Iles also teaches the sample is diluted in diluent before being analyzed (see page 6 lines 22-28).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the modified method of Barnidge on detecting the intact monoclonal immunoglobulin in a dried blood sample as taught by Iles for the benefit of convenient sample storage. One having an ordinary skill in the art would have had a reasonable expectation of success in combining Barnidge, Iles, and Hortin and Remaley because the reasons discussed in claim 1 above.
For claim 6, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1, wherein the diluted blood, serum or plasma sample is mixed with a matrix, prior to being ionized (see Barnidge page 1420 Serum section: teaches that sample is mixed with formic acid prior to injection to ESI-Q-TOF MS).
For claim 8, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1, wherein the light chain is kappa or lambda light chain (see Barnidge Fig.1 and page 1422 col.1 par.2: teaches the detection of kappa light chain).
For claim 9, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge does not teach the mass spectrometry is matrix assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry.
Iles teaches that a variety of mass spectrometry techniques can carry out direct mass spectral analysis, e.g., MALDI – ToF or ESI mass spectral analysis (see page 4 par.7). Hortin and Remaley supports for the use of MALDITOF/MS in a “dilute and shoot” analysis of serum or plasma (see Abstract).
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 detecting or quantifying intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin taught by Barnidge by using mass spectrometry-based method without sample purification or enrichment as taught by Iles, and Hortin and Remaley. See discussion in claim 1 above.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the MALDITOF/MS for the ESI-Q-TOF MS in the modified method of Barnidge as an obvious matter to try, namely choosing from a finite list of suitable, art recognized/known methods for direct mass spectral analysis for detecting or quantifying intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin because the MALDITOF/MS and the ESI-Q-TOF MS are functionally equivalent as taught by Iles.
For claim 11, Barnidge, Iles, and Hortin and Remaley teach the method in claim 6. Barnidge does not teach that the matrix is a MALDI matrix.
Iles teaches that a variety of mass spectrometry techniques can carry out direct mass spectral analysis, e.g., MALDI – ToF or ESI mass spectral analysis (see page 4 par.7). Iles teaches that the sample is mixed with a matrix prior to being ionized (see page 4 par.4). Hortin and Remaley supports for the use of MALDITOF/MS in a “dilute and shoot” analysis of serum or plasma (see Abstract). Hortin and Remaley teaches that the sample is mixed with a MALDI matrix prior to being ionized (see page 111-112 Discussion par.1).
Since it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the MALDITOF/MS for the ESI-Q-TOF MS in the method of Barnidge for direct mass spectral analysis for detecting or quantifying intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin as discussed in claim 9 above, it would have been obvious to use the MALDI matrix to mix with the sample before ionization as taught by Hortin and Remaley for the successfulness of the analysis.
For claim 12, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge teaches that the sample is from a subject who has, or who is suspected as having a proliferative disease associated with plasma producing cells (see page 1419 col.1 par.1 and page 1420 col.1 pars.2-3: teaching that the serum sample is collected from subjects having plasma cell proliferative disorders, e.g., multiple myeloma).
For claim 14, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge does not teach that the blood, serum or plasma sample is diluted by between 1:50 and 1:5000 prior to being detected by mass spectrometry.
Barnidge teaches that the sample is diluted 10-fold (see page 1420 Serum section). Also, Iles teaches the sample is preferably diluted to 1/1000; or ranging from 1/5 to 1/2500 (see page 6 lines 24-27). Hortin and Remaley teaches that a protein could be analyzed directly in serum with appropriate dilution (see Abstract, page 107 col.1 par.2: teaching that sample is diluted 5 fold with aqueous diluent before further threefold dilution with matrix to obtain any detectable spectra; see page 111 col.1 par.1 teaching that there was an optimal dilution for analysis of most components other than albumin that was about a 10- or 20-fold dilution with ammonium acetate prior to further dilution with matrix).
While Barnidge, Iles, Hortin and Remaley do not teach the same sample dilution prior to mass spectrometry analysis as recited in claim 14, they do suggest varying dilutions of sample before mass spectrometry analysis. Particularly, the appropriate dilution of the sample should be investigated extensively if one uses the MS method for profiling the relative amounts of target protein (see Hortin and Remaley page 113 col.1).
It would have been obvious to one having an ordinary skill in the art to discover the optimum workable ranges of sample dilutions by normal optimization procedure taught by Hortin and Remaley (see page 110). One having ordinary skill in the art would have a reasonable expectation of success in arriving at the claimed area through routine optimization because the prior arts specifically disclose varying sample dilutions for the purpose of obtaining an accurate measurement.
For claim 15, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge teaches that a patient is tested for the presence of the intact M-protein in serum to provide a clinical support for a plasma cell proliferative disorder (see page 1419 col.1 par.1, and page 1420 col.1 par.2). Therefore, the modified method of Barnidge can be used for diagnosing or prognosing a proliferative disease associated with plasma producing cells.
For claim 17, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1, wherein step (iii) of the method comprises detecting and optionally quantifying the light chain of the intact monoclonal immunoglobulin (see Barnidge Abstract, and page 1419 col.2 par.2 page 1420 col.1 par.1: teaches that the light chain portion of the M-protein is detected using the mass spectral analysis).
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Barnidge in view of Iles, and Hortin and Remaley, as applied to claim 1 above, and further in view of Murray (US20170023584).
For claim 18, Barnidge, Iles, and Hortin and Remaley teach the method in claim 1. Barnidge does not teach that the light chain is detected and optionally quantified within a mass to charge window of 7,000 to 25,000.
Iles teaches that immunoglobulin Kappa produces peaks in the range about 25000 m/z to 28000 m/z (see page 7 last paragraph).
Murray teaches a method for detecting and optionally quantifying intact monoclonal immunoglobulins in a sample (see at least Abstract, par.17, and par.123-125). Murray teaches that MALDI-TOF MS identifies proteins and peptides as mass charge (m/z) spectral peaks (see par.101). The m/z regions of the kappa or lambda light chain isotype can range from 23,000-23,200 m/z or 11,500-11,600 m/z (see par.93).
Iles and Murray teaches that the mass to charge for analyzing the light chain is varied (23,000-23,200 m/z or 11,500-11,600 m/z, or 25000 m/z to 28000 m/z), implying that the mass charge range for analyzing the light chain varies depending on each analyte.
Since the prior arts teach that the mass to charge window can be different from analyte to analyte, absent unexpected results, it would have been obvious to one of ordinary skill to discover the optimum or workable mass to charge window for analyzing the light chain in the MALDI-TOF mass spectrometry. One having ordinary skills in the art would have a reasonable expectation of arriving at the claimed area because it is the result of the detecting or quantitating light chain using MALDI-TOF mass spectrometry as taught by Iles and Murray.
Response to Arguments
Applicant's arguments filed 02/21/2026 have been fully considered but are not persuasive.
Applicant argued, in the Remarks sections 1-4, that the combined references Murray, Kim and Iles would not suggest to one skilled in the art that intact monoclonal immunoglobulins could be detected or quantified by mass spectrometry with a reduction step during or after sample dilution and without being "purified by immunopurification or removal of other non-immunoglobulin proteins prior to detecting" and as recited in the amended claims. Applicant argued that Murray and Iles do not teach a reduction step and do not suggest that reduction can be successfully integrated into a “dilute and shoot” workflow.
This argument is moot because the claims are taught by newly cited references Barnidge, Iles, and Hortin and Remaley as discussed above.
Barnidge teaches the mass spectrometry method of detecting and quantifying an intact monoclonal immunoglobulin and a light chain portion of the intact monoclonal immunoglobulin in serum sample. The method comprises the reduction step and purification step. Also, Barnidge teaches the purification step occurs before the reduction step, and the sample after reduction is mixed with the matrix of mass spectrometry and then injected into a mass spectrometry system to be analyzed. See Abstract page 1420 Serum section.
Iles teaches the mass spectrometry method of detecting and quantifying free light chains in serum samples. The method does not comprise the reduction step or purification step, which makes it simple, rapid and affordable for a routine clinical service. See pages 4, 6 , 7 and 8.
Hortin and Remaley teaches that direct analysis of serum provides a very simple approach that might be applicable for routine in the clinical laboratory and that would avoid modification or selective losses of components during preparation. See page 104.
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 detecting or quantifying intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin taught by Barnidge by using mass spectrometry-based method without sample purification or enrichment as taught by Iles, and Hortin and Remaley. The modification provides a very simple approach that can be applicable for routine in the clinical laboratory and that would avoid modification or selective losses of components during preparation, e.g., purification step (see Iles page 4 par.2, see Hortin and Remaley page 104).
One having an ordinary skill in the art would have a reasonable expectation of success in combining Barnidge, Iles, and Hortin and Remaley because they are directed to the method of detecting and quantifying a protein in blood or plasma or serum samples using mass spectrometry. While Iles teaches that mass spectrometry is used to characterize free light or heavy chains in the bodily fluid (e.g., serum) without using an enrichment or purification step, the method of Iles would be able to detect intact monoclonal immunoglobulin because the detection of intact monoclonal immunoglobulin is also based on the detection of the separated light chain from the intact monoclonal immunoglobulin as taught by Barnidge. Moreover, Hortin and Remaley teaches that the “dilute and shoot” mass spectrometry is useful in analyzing plasma proteins, particularly those with a mass <30,000 or mass to charge m/z <30,000 (see Abstract and page 112 col.1 par.3col.2 par.2), so the method can be used for analyzing light chains of a monoclonal antibody because the mass to charge of kappa light chain is around 22.5 kDa as taught by Iles (see page 6 par.2). Since Barnidge teaches that the purification step occurs before the reduction step, and the reduction sample is mixed with an MS matrix before being injected to MS system, it would be obvious to expect the successfulness of the combination of reduction step and a “dilute and shoot” workflow in detecting or quantifying an intact monoclonal immunoglobulin or a light chain of intact monoclonal immunoglobulin because there is no step between reduction step and “shoot” MS step as taught by Barnidge, e.g., the reduced sample does not need to be purified before MS step.
Regarding section 5.1 of the Remarks, Applicant argues that "Iles describes the hypothetical possibility of detecting Bence Jones proteins, i.e., kappa or lambda free light chains (FLCs ), or fragments thereof in urine (page 6, paragraph 2). Urine, having passed through and been filtered by the kidney, is a much "cleaner" sample than blood, serum, or plasma." Applicant argues that Iles does not provide an example of detecting free light chain immunoglobulin in blood, plasma or serum samples without pre-purification. Iles also does not describe detecting or quantifying intact monoclonal immunoglobulins. This disclosure would not have been sufficient to lead the skilled person to believe that intact monoclonal immunoglobulins could be detected and quantified by mass spectrometry analysis of relatively complex samples, such as blood, serum or plasma, without purification or removal of other non-immunoglobulin proteins.
It is noted that Examiner did not find this teaching of Iles on page 6 paragraph 2. In fact, Iles teaches detecting Bence Jones proteins, i.e., kappa or lambda free light chains (FLCs ), or fragments thereof in a bodily fluid sample comprising cerebrospinal fluid, seminal fluids, vaginal fluids, interstitial fluids, tissue aspirates, saliva, urine, blood and serum. Preferably, the sample is a urine sample or a serum sample. See Iles page 6 paragraph 2-3. Therefore, Iles does teach detecting light chains in a serum which is a complex sample with numerous background components.
While Iles does not provide an example of detecting free light chain immunoglobulin in blood, plasma or serum samples, Iles teaches that the method can analyze the sample from bodily fluids without the need of an additional concentration or isolation step (see Iles page 7 lines 5-6). Iles clearly teaches that the bodily fluids are cerebrospinal fluid, blood and serum (see Iles page 6 lines 13-15). Also, the sample can be a neat sample or can be diluted with buffer or diluent (see Iles page 6 lines 21-28).
Since Iles teaches a method of detecting a light or heavy chain in serum sample without purification or removal of other non-immunoglobulin proteins, the method would be able to detect an intact monoclonal immunoglobulin because the detection of intact monoclonal immunoglobulin is based on the detection of the separated light chain of the intact monoclonal immunoglobulin in the sample.
Conclusion
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.
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, Bao-Thuy L Nguyen can be reached on 571-272-0824. 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.
/CHAU N.B. TRAN/Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677 March 18, 2026