Large molecule specific assay operation: recommendation for best practices and harmonization from the global bioanalysis consortium harmonization team

Pharmacokinetic Profiles of a Proposed Biosimilar Ustekinumab (BFI-751): Results From a Randomized Phase 1 Trial

BioFactura has developed a proposed biosimilar candidate (BFI-751) to ustekinumab reference product. Results are reported for the first-in-human trial designed to compare the pharmacokinetic profiles, safety, and immunogenicity of BFI-751 and ustekinumab reference products from the European Union and United States as well as similarity of the EU and US reference products. This was a multicenter, randomized, double blind, 3-parallel-group study (trial ID: NCT04843631). Healthy subjects were randomized to receive a single subcutaneous dose of 45 mg of BFI-751, EU ustekinumab, or US ustekinumab. The pharmacokinetic parameters were area under the concentration-time curve (AUC) from time zero to infinity, AUC from time zero to the last quantifiable concentration, and maximum concentration. Safety, tolerability, and immunogenicity data were also reported. Pairwise comparisons among the 3 treatments all met the standard bioequivalence criteria that the 90% confidence interval of the geometric mean ratios of AUC from time zero to infinity, AUC from time zero to the last quantifiable concentration, and maximum concentration are completely within the acceptance interval of 80%-125%. There were no marked differences in the safety and tolerability profiles for subjects receiving BFI-751 as compared to EU or US ustekinumab. Treatment-emergent adverse events were mild to moderate for all treatment groups.

Magnetic bead extraction with acid dissociation immunoassay for the determination of serum CD80-Fc fusion protein

Background: To detect concentrations of subtherapeutic doses of the CD80-Fc fusion protein FPT155 in serum in Phase I studies, a highly sensitive assay was developed. Materials & methods: FPT155 was purified from human serum using magnetic beads coupled to cytotoxic T-lymphocyte-associated antigen-4. After washing away the serum components, FTP155 was released by acid dissociation and neutralization. The eluted drug was quantified in an ELISA using cytotoxic T-lymphocyte-associated antigen-4 as a capture reagent and biotinylated anti-human Fc for detection. The assay was validated with a calibration range of 5-40 ng/ml and a dilutional integrity of up to 100,000 ng/ml. Conclusion: A highly sensitive assay to determine serum concentrations of FPT155 using readily available reagents was developed. The results were in conformity with theoretical calculations.

Technical note: Validation of an in-house bovine serum enzyme immunoassay for progesterone measurement

Measuring circulating progesterone (P4) of dairy cows is a key component of many research studies dealing with basic and applied reproduction physiology. The gold standard in dairy cows for the measurement of P4 in serum is radioimmunoassay (RIA), but it generates radioactive waste and requires licensed facilities. The purpose of this study was to develop and validate an in-house competitive enzyme immunoassay (EIA) to measure the P4 concentration in serum of dairy cattle. The secondary objective was to validate a commercial EIA. In the present study, a competitive EIA was developed using commercially available antibodies and conjugates. Ninety-six well microtiter plates were coated with the secondary antibody and incubated overnight. Following a washing step, the wells were blocked using the primary antibody. Serum samples were prepared by first extracting P4 using petroleum ether, then diluted in working conjugate solution. Samples were pipetted into the coated and blocked plates, then the matching HRP conjugate label (P4-3-HRP, East Coast Bio, North Berwick, ME) was added. The plates were incubated for 2 h, then washed. The substrate solution was added, and the plate was incubated up to 1 h at room temperature in the dark until a blue color had developed. A stop solution was added, and the optical density measured on a microplate reader was set at 450 nm. The binding proportion was calculated by a visible spectrum absorbance reader, and the amount of P4 was calculated using a log-logit regression line. The commercial EIA was executed as suggested by the manufacturer. The validation of the in-house EIA was done by calculating the inter- and intraassay coefficients of variation (CV) and evaluating the parallelism of diluted samples. The results from the in-house and commercial EIA were also compared with the ones from the RIA graphically (scatterplots and Bland-Altman plots) and statistically, using the Spearman correlation coefficient (r) and the Cohen's kappa statistics using a threshold of 1.0 ng/mL (κ). For the in-house EIA, the intraassay CV were all <10%, but the interassay for samples with small and large P4 concentration had CV of 12.5 and 11.0%, respectively. The correlations between the results from the EIA and the RIA were strong (in-house: r = 0.90; commercial: r = 0.83). At small concentrations (<1.0 ng/mL), however, the correlation with the gold standard was weak (in-house: r = 0.27; commercial: r = 0.14). This was likely due to the lack of accuracy at small concentrations, also shown by the absence of parallelism in samples ≤0.4 ng/mL. In conclusion, results from both the in-house and commercial EIA strongly correlated with the gold standard, but less so at smaller concentrations. The in-house EIA offers good accuracy to measure P4 in samples with a concentration >0.4 ng/mL, and a perfect agreement with RIA using a threshold of 1.0 ng/mL.

2019 White Paper On Recent Issues in Bioanalysis: FDA BMV Guidance, ICH M10 BMV Guideline and Regulatory Inputs (Part 2 - Recommendations on 2018 FDA BMV Guidance, 2019 ICH M10 BMV Draft Guideline and Regulatory Agencies' Input on Bioanalysis, Biomarkers and Immunogenicity)

The 2019 13^th Workshop on Recent Issues in Bioanalysis (WRIB) took place in New Orleans, LA on 1-5 April 2019 with an attendance of over 1000 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers, immunogenicity and gene therapy. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LCMS, hybrid LBA/LCMS, LBA cell-based/flow cytometry assays and qPCR approaches. This 2019 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2019 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on the 2018 FDA BMV guidance, 2019 ICH M10 BMV draft guideline and regulatory agencies' input on bioanalysis, biomarkers, immunogenicity and gene therapy. Part 1 (Innovation in small molecules and oligonucleotides and mass spectrometry method development strategies for large molecules bioanalysis) and Part 3 (New insights in biomarker assay validation, current and effective strategies for critical reagent management, flow cytometry validation in drug discovery and development and CLSI H62, interpretation of the 2019 FDA immunogenicity guidance and gene therapy bioanalytical challenges) are published in volume 10 of Bioanalysis, issues 22 and 24 (2019), respectively.

Current practices and future outlook on the integration of biomarkers in the drug development process

Over the last decade, there has been broad incorporation of translational biomarkers into the early drug development process to predict safety concerns, measure target engagement and monitor disease progression. One goal of translational biomarkers is to create a cycle whereby preclinical readouts influence candidate selection and subsequent clinical data are fed back into research to facilitate better decision making. Successes have been limited and not as broad in scope as desired. Collaborations between industry and regulators have increased the number of qualified biomarkers; but the process is lengthy and expensive. A high level overview of translational biomarkers as well as a discussion of some of the successes and failures encountered in development is discussed here.

Parallelism experiments to evaluate matrix effects, selectivity and sensitivity in ligand-binding assay method development: pros and cons

Parallelism is an essential experiment characterizing relative accuracy for a ligand-binding assay (LBA). By assessing the effects of dilution on the quantitation of endogenous analyte(s) in matrix, selectivity, matrix effects, minimum required dilution, endogenous levels of healthy and diseased populations and the LLOQ are assessed in a single experiment. This review compares and discusses all available approaches that can be used to assess key assay parameters for pharmacokinetic and biomarker LBAs, as well as the advantages and disadvantages of each approach. This review also summarizes a systematic approach that can apply to guide endogenous LBA method development and optimization with a suggested way to interpret parallelism data.

Bypassing nonparallelism of a monoclonal antibody ligand-binding assay by employment of alternative assay formats

Determination of concentration-time profiles in cynomolgus monkeys of a therapeutic monoclonal antibody against a soluble target revealed a substantial discrepancy between a generic anti-human IgG capture/detection and target bridging assay with the target bridging assay leading to dose- and time-dependent underquantification of drug concentrations, lack of parallelism and subsequently different pharmacokinetic parameters. In contrast, plasma levels derived from a target capture and an anti-idiotypic antibody bridging assay were in close concordance with the generic assay and demonstrated parallelism with high precision across several dilutions. The results provide a practical attempt to overcome nonparallelism by employing alternative assay formats utilizing tailored assay reagent combinations in order to obtain unbiased pharmacokinetic data.

Recommendations for Use and Fit-for-Purpose Validation of Biomarker Multiplex Ligand Binding Assays in Drug Development

Multiplex ligand binding assays (LBAs) are increasingly being used to support many stages of drug development. The complexity of multiplex assays creates many unique challenges in comparison to single-plexed assays leading to various adjustments for validation and potentially during sample analysis to accommodate all of the analytes being measured. This often requires a compromise in decision making with respect to choosing final assay conditions and acceptance criteria of some key assay parameters, depending on the intended use of the assay. The critical parameters that are impacted due to the added challenges associated with multiplexing include the minimum required dilution (MRD), quality control samples that span the range of all analytes being measured, quantitative ranges which can be compromised for certain targets, achieving parallelism for all analytes of interest, cross-talk across assays, freeze-thaw stability across analytes, among many others. Thus, these challenges also increase the complexity of validating the performance of the assay for its intended use. This paper describes the challenges encountered with multiplex LBAs, discusses the underlying causes, and provides solutions to help overcome these challenges. Finally, we provide recommendations on how to perform a fit-for-purpose-based validation, emphasizing issues that are unique to multiplex kit assays.

Plasma neurofilament heavy chain levels and disease progression in amyotrophic lateral sclerosis: insights from a longitudinal study

OBJECTIVE

To investigate the role of longitudinal plasma neurofilament heavy chain protein (NfH) levels as an indicator of clinical progression and survival in amyotrophic lateral sclerosis (ALS).

METHODS

A cross-sectional study involving 136 clinically heterogeneous patients with ALS and 104 healthy and neurological controls was extended to include a prospective analysis of 74 of these ALS cases, with samplings at approximately 3-month intervals in a follow-up period of up to 3 years. We analysed the correlation between longitudinal NfH-phosphoform levels and disease progression. Temporal patterns of NfH changes were evaluated using multilevel linear regression.

RESULTS

Baseline plasma NfH levels were higher than controls only in patients with ALS with short disease duration to baseline sampling. Compared with controls, fast-progressing patients with ALS, particularly those with a short diagnostic latency and disease duration, had higher plasma NfH levels at an early stage and lower levels closer to end-stage disease. Lower NfH levels between visits were associated with rapid functional deterioration. We also detected antibodies against NfH, NfH aggregates and NfH cleavage products.

CONCLUSIONS

Disease progression in ALS involves defined trajectories of plasma NfH levels, reflecting speed of neurological decline and survival. Intervisit plasma NfH changes are also indicative of disease progression. This study confirms that longitudinal measurements of NfH plasma levels are more informative than cross-sectional studies, where the time of sampling may represent a bias in the interpretation of the results. Autoantibodies against NfH aggregates and NfH cleavage products may explain the variable expression of plasma NfH with disease progression.

TRAIL REGISTRATION NUMBER

NIHRID6160.

Serial measurements of phosphorylated neurofilament-heavy in the serum of subjects with amyotrophic lateral sclerosis

There is a need for a blood biomarker of disease activity in ALS. This marker needs to measure the loss of motor neurones. Phosphorylated neurofilament heavy chain (pNfH) in the serum is a biomarker of axonal injury. Previous studies have found that levels of pNfH are elevated in ALS. We have performed a serial study of pNfH levels in 98 subjects from our ALS clinic. There was significant elevation of levels of pNfH in subjects with ALS compared to controls, although there was considerable variability. In studies of individuals who had two or more serial samples, we found that the levels of pNfH increased over time in the early stage of disease. Levels were low in subjects with long survival. The rate of rise of pNfH was inversely correlated with survival. We suggest that the initial level of pNfH is a marker of disease severity and that changes in pNfH levels are markers of disease progression.

Calculations for Adjusting Endogenous Biomarker Levels During Analytical Recovery Assessments for Ligand-Binding Assay Bioanalytical Method Validation

It is often necessary to adjust for detectable endogenous biomarker levels in spiked validation samples (VS) and in selectivity determinations during bioanalytical method validation for ligand-binding assays (LBA) with a matrix like normal human serum (NHS). Described herein are case studies of biomarker analyses using multiplex LBA which highlight the challenges associated with such adjustments when calculating percent analytical recovery (%AR). The LBA test methods were the Meso Scale Discovery V-PLEX® proinflammatory and cytokine panels with NHS as test matrix. The NHS matrix blank exhibited varied endogenous content of the 20 individual cytokines before spiking, ranging from undetectable to readily quantifiable. Addition and subtraction methods for adjusting endogenous cytokine levels in %AR calculations are both used in the bioanalytical field. The two methods were compared in %AR calculations following spiking and analysis of VS for cytokines having detectable endogenous levels in NHS. Calculations for %AR obtained by subtracting quantifiable endogenous biomarker concentrations from the respective total analytical VS values yielded reproducible and credible conclusions. The addition method, in contrast, yielded %AR conclusions that were frequently unreliable and discordant with values obtained with the subtraction adjustment method. It is shown that subtraction of assay signal attributable to matrix is a feasible alternative when endogenous biomarkers levels are below the limit of quantitation, but above the limit of detection. These analyses confirm that the subtraction method is preferable over that using addition to adjust for detectable endogenous biomarker levels when calculating %AR for biomarker LBA.

European Bioanalysis Forum: recommendation on dealing with hemolyzed and hyperlipidemic matrices

Recent guidelines on bioanalytical method validation have recommended to investigate matrix effects in special matrices such as hemolytic and hyperlipidemic plasma. However, these guidelines were not clear on how to implement these recommendations. The European Bioanalysis Forum has discussed this topic in depth and has asked for feedback from member companies. Those discussions have resulted in more specific guidance on how to define hemolytic and hyperlipidemic plasma, how to validate bioanalytical methods for these matrices and how to deal with hemolytic and hyperlipidemic study samples. These recommendations are presented in this manuscript.