Quantification of total dinutuximab concentrations in neuroblastoma patients with liquid chromatography tandem mass spectrometry

Integration of protein L-immobilized epoxy magnetic bead capture with LC-MS/MS for therapeutic monoclonal antibody quantification in serum

In recent years, there has been a growing interest in the thriving monoclonal antibody (mAb) industry due to the wide utilization of mAbs in clinical therapies. Robust and accurate bioanalytical methods are required to enable fast quantification of mAbs in biological matrices, especially in the context of pharmacokinetics (PKs)/pharmacodynamics (PDs) and therapeutic drug monitoring (TDM) studies. In this investigation, we presented a novel immuno-magnetic capture coupled with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method designed for the quantification of immunoglobulin G-kappa-based mAbs in biological fluids. The immunoaffinity absorbent for mAb drug purification was meticulously crafted by immobilizing protein L onto monosize, magnetic poly(glycidyl methacrylate) (m-pGMA) beads, synthesized through dispersion polymerization. The microspheres were acquired with an average size of 1.6 μm, and the optimal binding of mAbs from the aqueous mAb solution was determined to be 45.82 mg g-1. The quantification of mAbs in 10 μL serum samples was achieved through affinity purification using m-pGMA@protein L beads (employing rituximab as an internal standard (IS)), on-bead reduction, and rapid tryptic digestion. Remarkably, the entire process, taking less than 2.5 hours, held significant potential for simplifying pretreatment procedures and minimizing analytical time. Furthermore, the developed method underwent validation in accordance with the European Medicines Agency (EMA) guidelines. The assay demonstrated commendable linearity within the 2-400 μg mL-1 range for both daratumumab and pembrolizumab. Intra- and inter-assay coefficients of variation fell within the range of 0.7% to 13.4%, meeting established acceptance criteria. Other validation parameters also conformed to regulatory standards. Ultimately, the efficacy of the method was substantiated in a pharmacokinetic study following a single-dose intravenous administration to mice, underscoring its applicability and reliability in real-world scenarios.

A robust and validated LC-MS/MS method for the quantification of ramucirumab in rat and human serum using direct enzymatic digestion without immunoassay

A new liquid chromatography tandem mass spectrometry (LC-MS/MS) method was established to quantify the anti-gastric cancer fully human monoclonal antibody (ramucirumab) in rat and human serum. The surrogate peptide (GPSVLPLAPSSK) for ramucirumab was generated by trypsin hydrolysis and quantified using the isotopically labeled peptide GPSVLPLAPSSK[13C6, 15N2]ST containing two more amino acids at the carboxyl end as an internal standard to correct for variations introduced during the enzymatic hydrolysis process and any mass spectrometry changes. Additionally, the oxidation and deamidation of unstable peptides (VVSVLTVLHQDWLNGK and NSLYLQMNSLR) were detected. The quantitative range of the proposed method was 1-1000 μg/mL, and complete methodological validation was performed. The precision, accuracy, matrix effect, sensitivity, stability, selectivity, carryover, and interference of the measurements met the required standards. The validated LC-MS/MS method was applied to pharmacokinetic studies in rats administered ramucirumab at 15 mg/kg intravenously. Overall, a robust, efficient, and cost-effective LC-MS/MS method was successfully developed for quantifying ramucirumab in rat and human serum.

Quantification of emicizumab by mass spectrometry in plasma of people with hemophilia A: A method validation study

Background

Emicizumab is a new treatment option for people with hemophilia A. Emicizumab was approved with a body‐weight‐based dosage regimen, without laboratory monitoring requirements. Guidelines, however, recommend measuring emicizumab concentrations when the presence of antidrug antibodies is suspected. Furthermore, drug monitoring can be useful in clinical decision making, in adherence checking, and for research purposes. Therefore, we developed a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for quantifying emicizumab. We performed a validation study on this LC‐MS/MS method quantifying emicizumab in the plasma of people with hemophilia A.

Methods

Sample preparation for LC‐MS/MS analysis included ammonium sulfate protein precipitation and trypsin digestion. A signature peptide of emicizumab and a matching stable isotope‐labeled internal standard were used to quantify emicizumab by LC‐MS/MS analysis. Validation was performed in accordance with the “Guideline on Bioanalytical Method Validation” of the European Medicines Agency (EMA). The LC‐MS/MS method was cross validated against a modified and calibrated (r² Diagnostics) one‐stage clotting assay (OSA).

Conclusions

The LC‐MS/MS method demonstrated linearity over a wide range of emicizumab concentrations, far exceeding the concentrations observed in people with hemophilia A. Precision and accuracy were excellent, and all other validation parameters were also within the acceptance EMA criteria. Cross validation showed that the LC‐MS/MS method and the OSA‐based method can be used interchangeably for drug monitoring of emicizumab without the application of a correction factor.

A generic sample preparation method for the multiplex analysis of seven therapeutic monoclonal antibodies in human plasma or serum with liquid chromatography-tandem mass spectrometry

Due to the increasing number of therapeutic monoclonal antibodies (mAbs) used in the clinic, there is an increasing need for robust analytical methods to quantify total mAb concentrations in human plasma for clinical studies and therapeutic drug monitoring. We developed an easy, rapid, and robust sample preparation method for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The method was validated for infliximab (IFX), rituximab (RTX), cetuximab (CTX), dupilumab (DPL), dinutuximab (DNX), vedolizumab (VDZ), and emicizumab (EMZ). Saturated ammonium sulfate (AS) was used to precipitate immunoglobulins in human plasma. After centrifugation, supernatant containing albumin was decanted, and the precipitated immunoglobulin fraction was re-dissolved in buffer containing 6M guanidine. This fraction was then completely denatured, reduced, alkylated, and trypsin digested. Finally, signature peptides from the seven mAbs were simultaneously quantified on LC-MS/MS together with their internal standards stable isotopically labeled peptide counterparts. The linear dynamic ranges (1 - 512 mg/L) of IFX, CTX, RTX, and EMZ showed excellent (R2 > 0.999) linearity and those of DPL, DNX, and VDZ showed good (R2 > 0.995) linearity. The method was validated in accordance with the EMA guidelines. EDTA plasma, sodium citrate plasma, heparin plasma, and serum yielded similar results. Prepared samples were stable at room temperature (20°C) and at 5°C for 3 days, and showed no decline in concentration for all tested mAbs. This described method, which has the advantage of an easy, rapid, and robust pre-analytical sample preparation, can be used as a template to quantify other mAbs in human plasma or serum.

Dinutuximab in adult-onset chemotherapy refractory high-risk neuroblastoma

INTRODUCTION

Neuroblastoma is the most common extracranial solid tumor in pediatrics but is considerably uncommon in adults, with approximately 1 case per 10 million diagnosed per year and is associated with poor prognosis. There are no standard treatment protocols for adult-onset neuroblastomas and there are only a few published case reports on neuroblastoma in adults.

CASE REPORT

We report our treatment experience in a 41-year-old female diagnosed with high-risk, poorly differentiated neuroblastoma.

MANAGEMENT AND OUTCOME

Our patient received two cycles of dinutuximab adapted from the Children's Oncology Group ANBL1221 protocol. The patient experienced pain, neuropathy, pruritus, and infusion reactions which were managed with supportive care. Due to the lack of tumor regression, dinutuximab was omitted from future treatments. Currently, the patient is asymptomatic from her disease and remains off of all therapy and pain medication.

DISCUSSION

While dinutuximab has produced promising outcomes in pediatric patients, it is not without potentially severe adverse effects. Serious reactions of capillary leak syndrome, infusion reactions, pain, and neuropathy have been reported. Clinicians must be cognizant of the treatment-related toxicities associated with dinutuximab therapy, ranging from pain, neuropathy, pruritus, and infusion reactions as explored in this patient case.

Immunomodulatory potential of anti-idiotypic antibodies for the treatment of autoimmune diseases

The immune system is a complex network of specialized cells and organs that recognises and reacts against foreign pathogens while remaining unresponsive to host tissues. This ability to self-tolerate is known as immunological tolerance. Autoimmune disease occurs when the immune system fails to differentiate between self and non-self antigens and releases autoantibodies to attack our own cells. Anti-idiotypic (anti-ID) antibodies are important in maintaining a balanced idiotypic regulatory network by neutralising and inhibiting the secretion of autoantibodies. Recently, anti-ID antibodies have been advanced as an alternative form of immunotherapy as they can specifically target autoantibodies, cause less toxicity and side effects, and could provide long-lasting immunity. This review article discusses the immunomodulatory potential of anti-ID antibodies for the treatment of autoimmune diseases.

The immune system protects the body against infections and diseases, such as by producing antibodies. Usually, these antibodies only attack pathogens, leaving healthy cells unharmed. However, autoimmune disease may develop when the immune system mistakenly recognises part of the body as foreign and produces antibodies to attack them. Antibodies that attack our own cells are called autoantibodies. Anti-idiotypic antibodies could be utilized to stop autoantibodies from attacking self cells with minimal side effects and long-lasting immunity. This review discusses anti-idiotypic antibodies usage as an alternative form of immunotherapy to inhibit autoantibodies in autoimmune disease.

Bottom-up sample preparation for the LC-MS/MS quantification of anti-cancer monoclonal antibodies in bio matrices

Therapeutic monoclonal antibodies (mAbs) are rapidly taking over the treatment of many malignancies, and an astonishing number of mAbs is in development. This causes a high demand for quantification of mAbs in biomatrices both for measuring therapeutic mAb concentrations and to support pharmacokinetics and pharmacodynamics studies. Conventionally, ligand-binding assays are used for these purposes, but LC-MS is gaining popularity. Although intact (top-down) and subunit (middle-down) mAb quantification is reported, signature peptide (bottom-up) quantification is currently most advantageous. This review provides an overview of the reported bottom-up mAb quantification methods in biomatrices as well as general recommendations regarding signature peptide and internal standard selection, reagent use and optimization of digestion in bottom-up quantification methods.

Quantification of T Cell Binding Polyclonal Rabbit Anti-thymocyte Globulin in Human Plasma with Liquid Chromatography Tandem-Mass Spectrometry

The addition of rabbit anti-human thymocyte globulin (ATG) to the conditioning regimen prior to allogeneic hematopoietic cell transplantation has significantly reduced the risk of graft-versus-host disease (GvHD) and graft failure. However, ATG has a small therapeutic window. Overexposure of ATG post-HCT hampers T cell immune reconstitution and has been associated with increased relapse rates and viral reactivations, whereas underexposure has been associated with an increased incidence of GvHD, both of which lead to increased mortality. Therapeutic drug monitoring of T cell binding ATG plasma levels provides a means to optimize dosing for patients at high risk for graft failure to ensure timely T cell immune reconstitution and subsequently increase survival chances. This manuscript describes the first liquid chromatography tandem-mass spectrometry (LC-MS/MS) method to quantify the pharmacologically active fraction of polyclonal ATG in plasma. This was achieved through immunoaffinity purification of active ATG from plasma with Jurkat T cells. After the binding and washing, samples were eluted, denatured, and trypsin-digested. Signature peptides originating from the IgG constant chain were measured with LC-MS/MS. Critical method parameters were optimized, and the method was successfully validated following European Medicines Agency (EMA) guidelines. The method covered the therapeutic range of ATG and was validated at a lower limit of quantification (LLOQ) of 1 AU/mL with an overall CV and bias of 11.8% and - 2.5%, respectively. In conclusion, we developed a LC-MS/MS-based method to quantify active polyclonal rabbit ATG in human plasma. We suggest that this novel assay can be used to monitor and optimize dosing of ATG in clinical practice.

Six-step workflow for the quantification of therapeutic monoclonal antibodies in biological matrices with liquid chromatography mass spectrometry - A tutorial

The promising pipeline of therapeutic monoclonal antibodies (mAbs) demands robust bioanalytical methods with swift development times for pharmacokinetic studies. Over the past decades ligand binding assays were the methods of choice for absolute quantification. However, the production of the required anti-idiotypic antibodies and ligands limits high-throughput method development for sensitive, accurate, and reproducible quantification of therapeutic mAbs. In recent years, high-resolution liquid chromatography tandem mass-spectrometry (LC-MS) systems have enabled absolute quantification of therapeutic mAbs with short method development times. These systems have additional benefits, such as a large linear dynamic range, a high specificity and the option of multiplexing. Here, we briefly discuss the current strategies for the quantification of therapeutic mAbs in biological matrices using LC-MS analysis based on top-down and middle-down quantitative proteomics. Then, we present the widely used bottom-up method in a six-step workflow, which can be used as guidance for quantitative LC-MS/MS method development of mAbs. Finally, strengths and weaknesses of the bottom-up method, which currently provides the most benefits, are discussed in detail.

Quantification of neutralizing anti-drug antibodies and their neutralizing capacity using competitive displacement and tandem mass spectrometry: Infliximab as proof of principle

Background

The development of anti-drug antibodies (ADA) in patients treated with therapeutic proteins can result in treatment failure. The clinically most relevant fraction of these antibodies are the neutralizing anti-drug antibodies (NAb) that block the pharmacological function of the drug. Consequently, the detection of NAb in plasma is a better predictor of loss of therapeutic response than increased levels of total anti-drug antibodies (ADA) test. Traditional assays to detect ADA and NAb have limited specificity, sensitivity and linear dynamic range.

Method

Here, we demonstrate for the first time the potential of a LC-MS/MS method to measure the concentration of NAb against therapeutic proteins in plasma as exemplified with infliximab (IFX). We designed a competitive screening assay in which the presence of NAb in patients plasma prevents the binding of stable isotopically labeled (SIL) mAb infliximab to TNF-α ligand fixed on a 96-well plate.

Results

After washing, eluting and digesting, the signal intensity of SIL IFX-derived signature peptides was inversely and strongly correlated with NAb concentration in the sample: R² ​= ​0.999. Evaluation data showed that the assay has a high specificity (100%) and a high sensitivity (94%) to predict NAb presence. Cross-validation against total ADA measured by a reference laboratory using radio immunoassay assay (RIA) for ADA provided a good correlation (r² ​= ​0.79).

Conclusion

We developed for the first time a robust and fast screening method on the basis of LC-MS/MS to determine the presence of NAb and its neutralizing capacity in plasma. The analyses of NAb can be combined with therapeutic mAb quantification. Furthermore, the quantification of the neutralizing capacity expressed as mAb mass equivalents opens the door to new personalized dosing strategies in patients with NAb.

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A novel method to quantify neutralizing antibodies and their neutralizing capacity is presented.

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Neutralizing antibodies to infliximab have been determined with liquid chromatography tandem-mass spectrometry.

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Signal of SIL infliximab showed a strong correlation (r² ​= ​0.999) to the concentration neutralizing antibodies in plasma.

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Method was highly specific (100%) and selective (94%) and was well correlated with radioimmunoassay (r² ​= ​0.79).