Bioanalytics at Mabion supporting Clinical Trials with Precise Data

• Bioanalytical science plays a critical role in the development and clinical evaluation of biologic therapeutics, providing quantitative data that enable researchers and regulators to assess drug exposure, pharmacological activity, and immunogenicity.  
• Pharmacokinetic studies evaluate how the body processes therapeutic molecules through ADME, while pharmacodynamic analyses measure biological responses to treatment. Immunogenicity testing focuses on detecting anti-drug antibodies, which may alter drug clearance, reduce therapeutic efficacy, or lead to adverse reactions. 
• Mabion’s bioanalytical services extend beyond internal product development to include support for external partners and contract research organizations. These services encompass assay development, method validation, clinical sample analysis, and preparation of bioanalytical panels required for clinical trials. 

Integrated Role of Bioanalytics in Biologics Development 

Pharmacokinetic (PK), pharmacodynamic (PD), and immunogenicity analyses together form the foundation of clinical bioanalysis. Analytical laboratories supporting clinical development programs employ a variety of analytical platforms to measure drug exposure and biological activity. Ligand-binding assays (LBAs) remain the most commonly used technologies for quantifying biologic therapeutics due to their high sensitivity and specificity. Enzyme-linked immunosorbent assays (ELISA), and microfluidic immunoassay systems are frequently used for this purpose. These methods rely on antibodies or antigen-binding reagents to detect therapeutic proteins in biological samples and can achieve detection limits in the picogram-to-nanogram range, supporting therapeutic protein production. 

Advances in analytical instrumentation have significantly improved the throughput and precision of bioanalytical workflows. Automated immunoassay platforms, microfluidic analytical systems, and high-resolution mass spectrometry enable rapid processing of large sample volumes generated in clinical trials.^1,2 In parallel, flow cytometry platforms are widely used to measure cellular pharmacodynamic biomarkers, including immune cell populations or receptor expression levels. The integration of these technologies allows researchers to generate multidimensional datasets that link drug exposure with biological effects and clinical outcomes.^3,4 

In addition to analytical technologies, PK/PD modeling enables the integration of drug concentration data with biomarker responses to predict optimal dosing strategies and therapeutic windows. These modeling approaches are particularly valuable for biologic therapeutics, whose PK may exhibit nonlinear characteristics due to target binding or immune-mediated clearance mechanisms. 

Bioanalytical Method Development and Assay Optimization 

Bioanalytical methods must be capable of accurately measuring drug concentrations, and immune responses within complex biological matrices. Because therapeutic proteins often circulate at low concentrations and may interact with endogenous molecules, assay design requires careful optimization to ensure adequate sensitivity, specificity, and reproducibility. 

Method development typically begins with selection of the appropriate analytical platform based on the physicochemical properties of the therapeutic molecule and the intended clinical application. Ligand-binding assays are frequently used for quantifying biologics due to their high specificity for protein targets. These assays involve capture reagents that bind to the therapeutic molecule and detection reagents that produce a measurable signal proportional to the analyte concentration.⁵ 

Another critical aspect of method development involves evaluating drug tolerance in immunogenicity assays. In clinical samples containing high concentrations of therapeutic proteins, anti-drug antibodies may be masked by circulating drug molecules. Assays must therefore be designed to detect antibodies even in the presence of drug concentrations representative of clinical dosing conditions.⁶ 

Bioanalytical method validation ensures that analytical assays meet regulatory requirements for clinical use. Key validation parameters include accuracy, precision, selectivity, sensitivity, and stability. According to regulatory guidance, bioanalytical assays must demonstrate reproducibility within predefined acceptance criteria, typically within ±15% accuracy and precision for most concentrations.⁷ 

Validated bioanalytical methods must be implemented within standardized laboratory workflows that include rigorous quality control procedures. Analytical laboratories typically operate under GMP, GLP and GCP frameworks, ensuring traceability and reproducibility of analytical data generated during clinical trials and throughout GMP Biologics Manufacturing. 

Pharmacokinetic Assessments in Clinical Trials 

Pharmacokinetic studies evaluate how a therapeutic drug interacts with the human body over time. These studies examine the processes of absorption, distribution, metabolism, and excretion – collectively referred to as ADME – which determine how long a drug remains in circulation and at what concentrations it reaches target tissues.⁸ 

In clinical trials involving biotherapeutics, PK analyses are typically performed using ligand-binding assays capable of quantifying drug concentrations in serum or plasma samples.^9,10 These assays generate concentration-time profiles that enable calculation of key PK parameters, including maximum concentration (C_max), time to maximum concentration (T_max), area under the concentration-time curve (AUC), clearance (CL), and elimination half-life (t_½). These parameters collectively describe the systemic exposure of the therapeutic molecule and provide insights into its pharmacological behavior.¹¹ 

Phase I clinical trials represent the first stage in which investigational drugs are administered to human subjects. The primary objective of these trials is to evaluate safety and tolerability while characterizing PK profiles across a range of doses. Phase I studies frequently involve dose-escalation designs in which small cohorts of participants receive increasing doses of the investigational product under close clinical monitoring.¹² 

Data collected during Phase I trials are used to establish dose-exposure relationships that guide subsequent clinical development. Researchers analyze how drug concentrations change in response to different dosing levels and determine whether the observed exposure falls within a safe and therapeutically effective range. These studies may also reveal nonlinear PK associated with target-mediated drug disposition, a phenomenon frequently observed for monoclonal antibodies that bind to high-affinity cellular receptors. 

In addition to dose escalation studies, Phase I trials may include investigations of drug distribution and elimination pathways. These analyses help identify potential accumulation of the therapeutic molecule in specific tissues and determine the duration of pharmacological activity. Such information is crucial for designing dosing schedules in later clinical trial phases.¹³ 

PK analyses also play a key role in evaluating interindividual variability in drug exposure. Differences in age, body weight, disease state, or concomitant medications may influence drug clearance and distribution. Population pharmacokinetics modeling is often used to assess these factors and determine whether dose adjustments are necessary for specific patient populations.¹⁴ 

Pharmacodynamic Biological Response Monitoring 

While pharmacokinetics describes how the body affects a drug, pharmacodynamics examines how the drug affects the body. PD analyses measure biological responses resulting from drug exposure and provide critical information regarding mechanism of action, therapeutic efficacy, and potential adverse effects. In clinical trials, PD studies often involve measurement of biomarkers that reflect activation or inhibition of specific molecular pathways targeted by the therapeutic agent. 

Pharmacodynamic biomarkers may include circulating proteins, cytokines, metabolites, or cellular markers that change in response to drug treatment. For biologic therapeutics such as monoclonal antibodies, PD markers frequently involve immune cell populations or receptor expression levels. Flow cytometry and multiplex immunoassays are commonly used to quantify these biomarkers in clinical samples.¹⁵ 

In early-phase clinical trials, PD analyses help determine the optimal biological dose and maximum tolerated dose of an investigational drug. Phase I trials often evaluate PD responses alongside PK data to identify dose levels that produce measurable biological effects without causing unacceptable toxicity. By correlating drug exposure with pharmacodynamic outcomes, researchers can establish exposure-response relationships that guide dose selection for subsequent clinical phases. 

Phase II clinical trials further evaluate pharmacodynamic responses in larger patient populations to confirm preliminary evidence of therapeutic efficacy. In these trials, PD biomarkers may serve as surrogate endpoints that predict clinical outcomes. For example, reductions in disease-associated biomarkers or modulation of immune cell populations may indicate successful target engagement by the therapeutic molecule.¹⁶ 

Pharmacodynamic monitoring also plays a critical role in identifying potential adverse events associated with drug treatment. Changes in biomarker levels may signal immune activation, cytokine release, or other biological processes that could lead to toxicity. Continuous monitoring of PD responses during clinical trials allows investigators to detect these signals early and implement appropriate safety measures. 

By integrating pharmacokinetic and pharmacodynamic data, researchers can construct PK-PD models that describe the relationship between drug exposure and biological response. These models provide valuable insights into the mechanisms underlying therapeutic efficacy and help predict clinical outcomes across different patient populations.¹⁸ 

Immunogenicity Testing and ADA Detection 

Immunogenicity is a major concern in the development of biologic therapeutics because therapeutic proteins may trigger immune responses in treated patients. These immune responses often involve the production of anti-drug antibodies (ADAs), which can bind to the therapeutic molecule and interfere with its pharmacological activity. ADAs may be neutralizing or non-neutralizing, affecting pharmacokinetics by altering drug clearance or distribution. 

The detection and characterization of ADAs are therefore essential components of clinical trial bioanalysis. Immunogenicity testing typically follows a tiered approach consisting of screening assays, confirmatory assays, and antibody titration assays. Screening assays identify samples containing potential ADAs, while confirmatory assays verify the specificity of the detected antibodies. Positive samples may then undergo titration assays to determine antibody levels.¹⁹ 

Neutralizing antibody assays are often conducted as an additional step in immunogenicity assessment. These assays evaluate whether detected antibodies inhibit the biological activity of the therapeutic molecule. Cell-based bioassays are commonly used for this purpose because they measure functional inhibition of drug-target interactions.²⁰ 

Immunogenicity monitoring is particularly important in clinical trials involving repeated dosing of biologic therapeutics. The formation of ADAs may lead to accelerated drug clearance, reducing systemic drug exposure and potentially diminishing therapeutic efficacy. In some cases, immune responses may also cause hypersensitivity reactions or other adverse events. 

Regulatory Relevance of Bioanalytical Data 

The European Medicines Agency and U.S. Food and Drug Administration place strong emphasis on the generation of reliable bioanalytical data in clinical trials involving biologic therapeutics. EMA guidelines for bioanalytical method validation and immunogenicity assessment require that analytical assays used in clinical studies demonstrate adequate sensitivity, specificity, accuracy, and reproducibility. These requirements ensure that drug concentration measurements and immunogenicity assessments are sufficiently robust to support regulatory decision-making.⁷ 

In addition to assay validation requirements, the EMA emphasizes integrated analysis of pharmacokinetic, pharmacodynamic, and immunogenicity data in clinical trial submissions. Sponsors must demonstrate how these datasets collectively support the safety and efficacy of the investigational therapeutic. For biosimilar products, comparative PK and immunogenicity analyses are particularly important for demonstrating similarity to the reference product.²² 

The FDA also emphasizes the importance of a tiered immunogenicity testing strategy consisting of screening, confirmatory, and neutralizing antibody assays. This approach ensures that detected immune responses are accurately characterized and assessed for potential clinical significance.²³ 

Bioanalytics as a Strategic Capability in Mabion’s CDMO Model 

Through the integration of advanced analytical technologies, validated methodologies, and regulatory-compliant workflows, Mabion ensures that clinical development programs are supported by precise, reproducible, and scientifically robust bioanalytical data. As a biologics CDMO, Mabion integrates bioanalytical services into a broader end-to-end development framework, unlike many providers that offer these capabilities as standalone services. 

Mabion also has experience in conducting clinical studies, which allows us to better understand the perspective of our clients. Prior to its transformation into a CDMO, the company worked on the development of a rituximab biosimilar. In its clinical development, MabionCD20 advanced to Phase III. Bioanalytics played a critical role in demonstrating biosimilarity to the reference product (MabThera/Rituxan). The clinical studies were designed to generate comparative data on pharmacokinetics, efficacy, safety, and immunogenicity. They were conducted across 51 clinical sites in Bosnia and Herzegovina, Georgia, Poland, Serbia, and Ukraine. The study confirmed therapeutic equivalence between the biosimilar and the reference product. Also in the case of the indication CD20-positive diffuse large B-cell lymphoma, MADILYM clinical trials have shown a high level of biosimilarity between MabionCD20 and the reference product. 

In addition, MabionCD20 has received orphan drug designation from the FDA in certain indications, including autoimmune hemolytic anemia and membranous nephropathy. These regulatory designations highlight the therapeutic potential of the molecule and support further clinical development activities.^24,25 

Conclusion 

Bioanalytical science is a significant component of modern biologics development. enabling accurate measurement of drug exposure, biological activity, and immune responses during clinical trials. Bioanalytics collectively provide the quantitative framework necessary for evaluating the safety and efficacy of therapeutic proteins. 

Advances in analytical technologies enhanced the precision and efficiency of bioanalytical workflows. These technologies enable researchers to generate robust datasets linking drug concentrations with biological responses and clinical outcomes. 

FAQ

Prepared by:

Jakub Knurek

Marketing Specialist

j.knurek@mabion.eu

Jakub Knurek

Marketing Specialist

Jakub Knurek is a marketing and business development expert specializing in CDMO operations with scientific and biopharmaceutical background. During the COVID-19 pandemic, he contributed to the development of the Novavax protein vaccine. As a side project, he runs his own pharma company.

As the author of numerous articles, he is recognized as an important voice of the younger generation of scientists. He is a member of Mabion’s representation at industry trade shows, including BIO International Convention 2025 in Boston, 2nd Global Biologics India 2025 in Hydrabad, CPHI 2024 in Milan, CPHI 2023 in Barcelona, Life Sciences Baltics 2023 in Vilnius. He actively participates in academic, business and industry discussions, such as the “Building the Future Pharma Workforce” panel at CPHI Milan 2024.

Izabela Kuskowska

Analytical Methods Validation Specialist

i.kuskowska@mabion.eu

Izabela Kuskowska

Analytical Methods Validation Specialist

Izabela has nearly a decade of experience in the biotech industry, starting in Quality Control and developing a strong expertise in method validation. She has worked with both biochemical methods, such as HPLC, and biological assays, including qPCR, ELISA, and cell-based assays. Now, Izabela coordinates the transfer of analytical technologies from external partners to Mabion, ensuring seamless implementation, consistency, and compliance. Her role involves bridging scientific and regulatory aspects to support the successful integration of new analytical methods. Izabela left Mabion in 2026.

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25. Mabion has received ODD status from the FDA for the drug MabionCD20 in the indication of autoimmune hemolytic anemia. 2023.