Immunogenicity of golimumab and its clinical relevance in patients with rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis.

OBJECTIVE: Golimumab immunogenicity was extensively studied during clinical development. As anti-drug antibody (ADA) detection with the standard bridging EIA (original-EIA) can yield false-negative results or underestimate ADA incidence and titres due to drug interference, a more sensitive assay was needed to determine clinical impact. METHODS: A highly sensitive drug-tolerant EIA (DT-EIA) was developed and cross-validated against the original-EIA. Samples from phase-3 subcutaneous golimumab rheumatological trials (GO-FORWARD-rheumatoid arthritis, GO-REVEAL-psoriatic arthritis, GO-RAISE-ankylosing spondylitis) were then retested. Associations between ADAs and golimumab pharmacokinetics, efficacy and safety were assessed. RESULTS: The DT-EIA was more sensitive than the original-EIA and capable of detecting ADAs amid golimumab concentrations far exceeding those in immunogenicity test samples. Consequently, an 8-fold increase in the incidence of ADAs was observed with the DT-EIA (31.7%) vs original-EIA (4.1%) in the studies. Most ADA-positive patients identified by the DT-EIA had lower antibody titres, while most with higher titres were previously identified as ADA-positive by the original-EIA. With the DT-EIA, ADA-positive patients generally had lower trough serum golimumab concentrations than ADA-negative patients; however, ADA impact on serum golimumab concentrations was more notable at higher ADA titres (⩾100). No impact of ADAs on clinical efficacy or injection-site reactions was evident. CONCLUSION: ADA incidence was expectedly higher using the DT-EIA vs original-EIA; newly detected ADAs were characterized mostly by low titres, with no impact on clinical efficacy or injection-site reactions, consistent with previously observed original-EIA results. Golimumab immunogenicity with the DT-EIA is consistent with existing knowledge regarding the clinical relevance of ADAs detected with the original-EIA in patients with rheumatological disorders. TRIAL REGISTRATION: NCT00264550, NCT00265096, NCT00265083.

Pharmacokinetics and immunogenicity investigation of a human anti-interleukin-17 monoclonal antibody in non-naïve cynomolgus monkeys.

The pharmacokinetics (PK) of biologic therapeutics, especially monoclonal antibodies (mAbs), in monkeys generally presents the most relevant predictive PK information for humans. However, human mAbs, xenogeneic proteins to monkeys, are likely to be immunogenic. Monkeys previously treated with a human mAb (non-naïve) may have developed antidrug antibodies (ADAs) that cross-react with another test mAb in subsequent studies. Unlike PK studies for small-molecule therapeutics, in which animals may be reused, naïve monkeys have been used almost exclusively for preclinical PK studies of biologic therapeutics to avoid potential pre-existing immunologic cross-reactivity issues. The propensity and extent of pre-existing ADAs have not been systematically investigated to date. In this study, the PK and immunogenicity of mAb A, a human anti-human interkeukin-17 mAb, were investigated in a colony of 31 cynomolgus monkeys previously exposed to other human mAbs against different targets. We screened the monkeys for pre-existing antibodies to mAb A prior to the PK study and showed that 44% of the monkeys had pre-existing cross-reactive antibodies to mAb A, which could affect the PK characterization of the antibody. In the subcolony of monkeys without measurable pre-existing ADAs, PK and immunogenicity of mAb A were successfully characterized. The impact of ADAs on mAb A PK was also demonstrated in the monkeys with pre-existing ADAs. Here we report the results and propose a pragmatic approach for the use of non-naïve monkeys when conducting PK studies of biologic therapeutics.

The challenge of indication extrapolation for infliximab biosimilars.

A biosimilar is intended to be highly similar to a reference biologic such that any differences in quality attributes (i.e., molecular characteristics) do not affect safety or efficacy. Achieving this benchmark for biologics, especially large glycoproteins such as monoclonal antibodies, is challenging given their complex structure and manufacturing. Regulatory guidance on biosimilars issued by the U.S. Food and Drug Administration, Health Canada and European Medicines Agency indicates that, in addition to a demonstration of a high degree of similarity in quality attributes, a reduced number of nonclinical and clinical comparative studies can be sufficient for approval. Following a tiered approach, clinical studies are required to address concerns about possible clinically significant differences that remain after laboratory and nonclinical evaluations. Consequently, a critical question arises: can clinical studies that satisfy concerns regarding safety and efficacy in one condition support "indication extrapolation" to other conditions? This question will be addressed by reviewing the case of a biosimilar to infliximab that was approved recently in South Korea, Europe, and Canada for multiple indications through extrapolation. The principles discussed should also apply to biosimilars of other monoclonal antibodies that are approved to treat multiple distinct conditions.

A risk-based bioanalytical strategy for the assessment of antibody immune responses against biological drugs.

Bioanalytical assessments of anti-drug antibodies (ADAs) provide an understanding of the immunogenicity of biological drug molecules. The potential to induce ADAs after treatment with biologics is a safety issue that has become an important consideration in the development of biologics and a critical aspect of regulatory filings. US and European regulatory agencies are recommending that sponsors study immunogenicity using a risk-based approach, encouraging sponsors to formulate and implement their own risk management plans and to conduct discussions with the agencies when necessary. It follows from this that the greater the safety risks of ADAs, the more diligently one should clarify the immunogenicity of the product. Here we propose a general strategy to broadly assign immunogenicity risk levels to biological drug products, and present risk level-based 'fit-for-purpose' bioanalytical schemes for the investigations of treatment-related ADAs in clinical and nonclinical studies.

Immunogenicity of biologically-derived therapeutics: assessment and interpretation of nonclinical safety studies.

An evaluation of potential antibody formation to biologic therapeutics during the course of nonclinical safety studies and its impact on the toxicity profile is expected under current regulatory guidance and is accepted standard practice. However, approaches for incorporating this information in the interpretation of nonclinical safety studies are not clearly established. Described here are the immunological basis of anti-drug antibody formation to biopharmaceuticals (immunogenicity) in laboratory animals, and approaches for generating and interpreting immunogenicity data from nonclinical safety studies of biotechnology-derived therapeutics to support their progression to clinical evaluation. We subscribe that immunogenicity testing strategies should be adapted to the specific needs of each therapeutic development program, and data generated from such analyses should be integrated with available clinical and anatomic pathology, pharmacokinetic, and pharmacodynamic data to properly interpret nonclinical studies.

Current challenges in assessing immunogenicity.

Biography Gopi Shankar is a Vice President at Janssen BioTherapeutics, the biotechnology discovery and development unit of Janssen Research & Development, LLC (one of the Pharmaceutical Companies of Johnson & Johnson). His department of approximately 150 scientists is responsible for characterizing biophysical and pharmacological parameters of biologic molecules for discovery and for developing preclinical projects through first-in-human trials by determining pharmacokinetics, toxicokinetics, target pharmacodynamics, starting dose and projected efficacious dose recommendations. The department also provides analytical and bioanalytical results for Janssen's clinical trials of biologics. Throughout his entire career, Dr Shankar has focused on the development of innovative solutions to scientific hurdles, developed consensus and harmonized scientific practices. A renowned expert in the field of immunogenicity and a Fellow of the American Association of Pharmaceutical Scientists (AAPS), Dr Shankar has led or contributed to several highly impactful scientific advances in immunogenicity; his research, consensus-building efforts and best-practice publications have transformed the thinking and tactical processes related to clinical immunogenicity.

A generic method for the detection of polyethylene glycol specific IgG and IgM antibodies in human serum.

Detection of anti-drug antibodies is a critical step in the development of large molecule biopharmaceuticals. In the case of multicomponent/multifunctional molecules, such as fusion proteins and protein conjugates such as covalent polyethylene glycol (PEG)~protein conjugates, it is useful to further characterize anti-drug antibody (ADA) binding to key domains of the drug. The detection of anti-PEG antibodies poses special challenges that if overlooked can result in underreporting antibody responses. Here we describe the development and characterization of a novel ELISA to detect anti-PEG antibodies that provides a more complete interpretation of anti-PEG than other published methods. Being specific to the PEG moiety alone, this method is intended to detect anti-PEG antibodies independent of the protein to which PEG is conjugated. Based upon early indications that our assay could detect anti-PEG antibodies at a surprisingly high frequency in the general population, our emphasis throughout method development and validation was to ensure that non-specific signals and unintended interactions were not falsely contributing to detection of anti-PEG antibodies. Techniques, including orthogonal methods used to ensure that this ELISA detected antibodies specific to PEG included competition, immunodepletion, immunoprecipitation/western blot and an Octet kinetic binding analysis. The validated ELISA can detect 100 ng/mL of an anti-PEG IgG positive control and 800 ng/mL of an anti-PEG IgM positive control in the presence of 7.5 µg/mL of the PEGylated therapeutic (MW 64 kDa). The intra-assay percent co-efficient of variation (CV) and inter-assay CV of the low positive control samples in the screening method were 4.1 to 7.2% and 16.7 to 17.7%, respectively. Additional assay performance parameters that were validated are also described. When the validated assay was applied to a population of 200 healthy blood donors with no known exposure to biopharmaceutical PEG conjugates it indicated a pre-existing anti-PEG antibody prevalence of 97.5%. We suggest this surprising result is a consequence of exposure to PEG additives in everyday products, such as cosmetics, processed foods and over-the-counter (OTC) pharmaceuticals.

Analysis of regulatory guidance on antidrug antibody testing for therapeutic protein products.

Therapeutic proteins have the potential to induce unwanted immune responses. The potential impact of immunogenicity on pharmacokinetics, pharmacodynamics, safety and efficacy are well established. Here, we analyze key aspects of current US FDA and EMA guidelines on the development and validation of antidrug antibody assays. Although FDA and EMA guidance documents are in harmony on most points, EMA allows greater leeway for scientific judgement, while FDA recommends specific approaches that may not be appropriate in some situations. Many white papers suggest approaches different from the guidance documents, however, these can conflict with each other and are themselves only scientifically valid in certain situations. Here, we indicate when alternatives to guidance may be needed and what those approaches might be.

Immunogenicity of Golimumab and its Clinical Relevance in Patients With Ulcerative Colitis.

BACKGROUND: Antidrug antibody (ADA) detection with standard bridging enzyme immunoassays (EIA) can yield false-negative results or underestimate titers through drug interference. A more sensitive assay was needed to determine clinical impact of antigolimumab antibodies. METHODS: A high-sensitivity, drug-tolerant EIA (DT-EIA) was developed and cross-validated against the original EIA, and samples from induction/maintenance studies in golimumab-treated patients with ulcerative colitis were analyzed for ADAs using both methods. Immunogenicity results were compared, and pharmacokinetic, efficacy, and safety associations were evaluated. RESULTS: An 8-fold increase in ADA-positive patients (21.8% DT-EIA vs 2.8% EIA) reflected DT-EIA improved sensitivity and drug tolerance. Most newly detected ADA-positive patients (using DT-EIA) had low antibody titers, whereas most with high antibody titers were ADA-positive with original EIA. With DT-EIA, week 44 median trough serum golimumab concentrations among ADA-positive patients were approximately half vs ADA-negative (0.51 vs 0.85 µg/mL [50 mg q4w]; 0.85 vs 1.60 µg/mL [100 mg q4w]). Antidrug antibody impact on golimumab concentrations was more notable at titers ≥1:100. During induction, ADAs had no notable impact on efficacy. During maintenance, proportions of patients maintaining clinical response through week 54 were lower using DT-EIA: 38.1% ADA-positive and 52.8% ADA-negative. Antidrug antibody status had no impact on injection-site reaction incidence. CONCLUSIONS: A more sensitive DT-EIA identified higher proportions of ADA-positive patients. A trend of decreasing drug concentrations with increasing ADA titers was observed. Pharmacokinetic impact was better elucidated with DT-EIA. Although development of ADA did not preclude efficacy, a trend toward decreased efficacy in ADA-positive vs ADA-negative patients was observed during maintenance treatment. Antidrug antibody status did not impact safety.

Recommendations on risk-based strategies for detection and characterization of antibodies against biotechnology products.

The appropriate evaluation of the immunogenicity of biopharmaceuticals is of major importance for their successful development and licensure. Antibodies elicited by these products in many cases cause no detectable clinical effects in humans. However, antibodies to some therapeutic proteins have been shown to cause a variety of clinical consequences ranging from relatively mild to serious adverse events. In addition, antibodies can affect drug efficacy. In non-clinical studies, anti-drug antibodies (ADA) can complicate interpretation of the toxicity, pharmacokinetic (PK) and pharmacodynamic (PD) data. Therefore, it is important to develop testing strategies that provide valid assessments of antibody responses in both non-clinical and clinical studies. This document provides recommendations for antibody testing strategies stemming from the experience of contributing authors. The recommendations are intended to foster a more unified approach to antibody testing across the biopharmaceutical industry. The strategies proposed are also expected to contribute to better understanding of antibody responses and to further advance immunogenicity evaluation.

Recommendations for the validation of immunoassays used for detection of host antibodies against biotechnology products.

Most biological drug products elicit some level of anti-drug antibody (ADA) response. This antibody response can, in some cases, lead to potentially serious side effects and/or loss of efficacy. In humans, ADA often causes no detectable clinical effects, but in the instances of some therapeutic proteins these antibodies have been shown to cause a variety of clinical consequences ranging from relatively mild to serious adverse events. In nonclinical (preclinical) studies, ADA can affect drug exposure, complicating the interpretation of the toxicity, pharmacokinetic (PK) and pharmacodynamic (PD) data. Therefore, the immunogenicity of therapeutic proteins is a concern for clinicians, manufacturers and regulatory agencies. In order to assess the immunogenic potential of biological drug molecules, and be able to correlate laboratory results with clinical events, it is important to develop reliable laboratory test methods that provide valid assessments of antibody responses in both nonclinical and clinical studies. For this, method validation is considered important, and is a necessary bioanalytical component of drug marketing authorization applications. Existing regulatory guidance documents dealing with the validation of methods address immunoassays in a limited manner, and in particular lack information on the validation of immunogenicity methods. Hence this article provides scientific recommendations for the validation of ADA immunoassays. Unique validation performance characteristics are addressed in addition to those provided in existing regulatory documents pertaining to bioanalyses. The authors recommend experimental and statistical approaches for the validation of immunoassay performance characteristics; these recommendations should be considered as examples of best practice and are intended to foster a more unified approach to antibody testing across the biopharmaceutical industry.

Pharmacokinetics and safety of golimumab, a fully human anti-TNF-alpha monoclonal antibody, in subjects with rheumatoid arthritis.

Golimumab is a fully human antitumor necrosis factor alpha (TNF-alpha) monoclonal antibody that is being developed for intravenous and subcutaneous administration. To assess the pharmacokinetics and safety of the intravenous formulation of golimumab, 36 adult subjects with rheumatoid arthritis were randomly assigned to receive a single infusion of placebo or golimumab (0.1, 0.3, 1, 3, 6, or 10 mg/kg). Serum concentrations of golimumab were determined using a validated enzyme-linked immunosorbent assay method. In addition to the noncompartmental analysis and compartmental modeling, a population pharmacokinetics analysis using NONMEM was also conducted. Both the maximum serum concentration and the area under the serum concentrationtime curve appeared to increase in a dose-proportional manner. The median half-life ranged from 7 to 20 days. A 2-compartment population pharmacokinetic model adequately described the pharmacokinetics of golimumab. The following pharmacokinetic parameters (typical value [% coefficient of variation]) were estimated from the population pharmacokinetic model: clearance (CL: 0.40 [10.1%] L/d), volume of distribution in the central compartment (V(c): 3.07 [6.4%] L), intercompartmental clearance (Q: 0.42 [15.5%] L/d), and volume of distribution in the peripheral compartment (V(p): 3.68 [11.8%] L). Interindividual variability of the pharmacokinetic parameters was quantified for CL (44.3%), V(c) (25.5%), Q (44.6%), and V(p) (44.6%). Residual variability was estimated to be 15.0%. Body weight was found to be an important covariate on V(c). Golimumab was generally well tolerated. The pharmacokinetics of golimumab appeared to be linear over the dose range evaluated in this study.

Implementing a tiered approach to bioanalytical method validation for large-molecule ligand-binding assay methods in pharmacokinetic assessments.

Bioanalytical methods must enable the delivery of data that meet sound, scientifically justified, fit-for-purpose criteria. At early phases of biotherapeutic drug development, suitable criteria of a ligand-binding assay could be met for pharmacokinetic (PK) in-study sample testing without a full validation defined by regulatory guidelines. To ensure fit-for-purpose methods support PK testing through all phases of biotherapeutic development, three tiers of method validation - regulatory, scientific and research validations - are proposed. The three-tiered framework for method validation outlines the differences in the parameters that should be assessed, the acceptance criteria that may be applied, and the documentation necessary at each level. The criteria for selecting the appropriate application of each of these PK method validation workflows are discussed.

Comparisons of Serum Infliximab and Antibodies-to-Infliximab Tests Used in Inflammatory Bowel Disease Clinical Trials of Remicade®.

Monitoring infliximab (IFX) concentrations and antibodies-to-IFX (ATI) titers during inflammatory bowel disease treatment may allow more informed decisions in assessing exposure/response and determining appropriate dosing. To aid in interpreting results from different commercial tests in the context of Janssen's published Remicade® results, the reliability of Janssen's IFX and ATI assays was compared with commercial assays from KU Leuven, Sanquin, Dynacare, and LabCorp. Test results were independently reported to Janssen. All assays were tested for specificity, selectivity, and precision. ATI assays were evaluated for sensitivity, drug interference, and potential interference of tumor necrosis factor-alpha (TNF-α). IFX assays were specific, accurate, and reproducible. Intra-class correlation of Janssen IFX assay results with those from KU Leuven, Sanquin, Dynacare, and LabCorp were 0.960, 0.895, 0.931, and 0.971, respectively. ATI titers >10 interfered with IFX assessment in all IFX assays, whereas TNF-α (≤50 ng/mL) did not interfere with IFX detection in any assay. ATI assays specifically and reproducibly detected ATI. Janssen, Sanquin, and LabCorp ATI methods were more resistant to IFX interference than Dynacare and KU Leuven, which were affected by IFX concentrations at ≥2 µg/mL. TNF-α (<5 ng/mL) did not interfere with ATI detection. Strong agreement was observed between Janssen's IFX and ATI assays and the diagnostic service provider assays. Our study results indicate that all four commercially available assays are suitable for therapeutic drug monitoring of IFX. The substantial agreement reported here between the comparator assays and the Janssen drug-tolerant assay provides support to clinicians in their use of these commercial assays, and for understanding their patients' IFX and ATI results relative to published data from clinical studies of Remicade.

Scientific and regulatory considerations on the immunogenicity of biologics.

Immune responses against non-vaccine biologics can affect their efficacy and safety, resulting in adverse events that could include administration reactions, hypersensitivity, deficiency syndromes and lack of a clinical response in treated patients. With the relatively recent development of numerous biologics, immunogenicity testing has become a key component in the demonstration of clinical safety and efficacy; in fact, it is highly unlikely that regulatory approval would be granted for a biologic without an assessment of its immunogenicity. However, recommendations from regulatory agencies regarding the requirements for when and how to carry out immunogenicity testing are dispersed among numerous guidance documents. To enable the evaluation of the effects of immunogenicity on safety and efficacy, the authors have consolidated recommendations from the regulatory guidelines, and present current approaches and future directions for the assessment of immunogenicity.

Validation of immunoassays used to assess immunogenicity to therapeutic monoclonal antibodies.

Immunogenicity has always been an important consideration in the evaluation of pharmaceutical protein biologics. In this article, method validation parameters relevant to enzyme immunoassays are described for assays applied to the analysis of anti-drug antibodies, with special considerations for immunogenicity to therapeutic monoclonal antibodies. Common strategies for experimental investigation of various validation parameters are proposed. In addition, a novel, yet simple, approach is proposed to categorize the validation effort into two mutually interdependent phases, based on the characterization of validation parameters as "system descriptive" or "system controlled". System descriptive parameters are those that must be characterized but need not have pre-specified acceptance criteria for assay validation. In contrast, system-controlled parameters should be understood early in assay development, and optimized and confirmed using a priori acceptance criteria in validation to assure sufficient control over them during routine bioanalysis. This approach not only streamlines the validation process but also eliminates unnecessary redundancies. This validation method can be achieved with proper scientific rigor and remain within the realm of GLP compliance. The authors hope that other research groups would engage in discussions on validation of anti-drug antibody assays in order to establish a consistent approach across the industry and academia.

Immune monitoring: it's prudent to adopt current quality regulations.

The United States Food and Drug Administration and its international governmental counterparts provide strict guidelines for product manufacture, quality control and clinical practice, but no regulations exist for immune monitoring. This is not surprising because it is a relatively new field that is increasingly applied in clinical trials of immunotherapy. Immune monitoring is experimental in nature, usually performed in an R&D laboratory, and is typically not integrated into an organization's quality assessment system. With the proliferation of immunotherapy studies and immunogenicity testing, regulatory agencies will progressively increasingly demand that quality regulations be applied to immune monitoring in the future. Here, I highlight the relevance of existing regulations, which, I believe, should be prospectively tied into the development and performance of immune monitoring methods.

The COSTIM bioassay: a novel potency test for dendritic cells.

The utility of dendritic cells (DCs) in experimental immunotherapy has driven significant advances in the manufacture of these cells. They are increasingly prepared in vitro for use in clinical trials of human disease, particularly cancer. Thus, it has become imperative that, in concert with other quality control measures, a potency test be employed for lot (batch)-release testing of DC products, both in preclinical studies and human clinical trials. The mixed lymphocyte reaction (MLR) assay has served as a 'gold standard' for evaluating the functional ability of antigen presenting cells. Alternatively, some researchers also employ immunophenotyping, a test unrelated to cellular function, as a potency-determining test. We have developed a novel method named the 'COSTIM bioassay', which, as we describe in this paper, is suitable for quality control or lot-release testing. In this method T-cells are stimulated with a sub-optimal amount of anti-CD3 antibody, such that they remain unable to proliferate unless a source of co-stimulation (accessory cells, such as DC) is added to the culture. Thus, the COSTIM bioassay is a functional test that selectively measures co-stimulatory activity, or functional potency. This method takes less than 2 days for completion and assures better quality control than the MLR.

Recommendations for the design and optimization of immunoassays used in the detection of host antibodies against biotechnology products.

Most biopharmaceutical therapeutics elicit some level of antibody response against the product. This antibody response can, in some cases, lead to potentially serious side effects and/or loss of efficacy. Therefore, the immunogenicity of therapeutic proteins is a concern for clinicians, manufacturers and regulatory agencies. In order to assess immunogenicity of these molecules, appropriate detection, quantitation and characterization of antibody responses are necessary. Inadequately designed antibody assays have led to the hampering of product development or, during licensure, post-marketing commitments. This document provides scientific recommendations based on the experience of the authors for the development of anti-product antibody immunoassays intended for preclinical or clinical studies. While the main focus of this document is assay design considerations, we provide scientific focus and background to the various assay performance parameters necessary for developing a valid assay. Sections on assay performance parameters, including those that appear in regulatory guidances, are contained in this manuscript.

Interferon-gamma Added During Bacillus Calmette-Guerin Induced Dendritic Cell Maturation Stimulates Potent Th1 Immune Responses.

Dendritic cells (DC) are increasingly prepared in vitro for use in immunotherapy trials. Mature DC express high levels of surface molecules needed for T cell activation and are superior at antigen-presentation than immature DC. Bacillus Calmette-Guerin (BCG) is one of several products known to induce DC maturation, and interferon (IFN)-gamma has been shown to enhance the activity of DC stimulated with certain maturation factors. In this study, we investigated the use of IFN-gamma in combination with the powerful maturation agent, BCG. The treatment of immature DC with IFN-gamma plus BCG led to the upregulation of CD54, CD80, and CD86 in comparison with BCG treatment alone. In MLR or recall immune responses, the addition of IFN-gamma at the time of BCG-treatment did not increase the number of antigen-specific T cells but enhanced the development of IFN-gamma-producing Th1 cells. In primary immune responses, on the other hand, BCG and IFN-gamma co-treated DC stimulated higher proportions of specific T cells as well as IFN-gamma secretion by these T cells. Thus the use of IFN-gamma during BCG-induced DC maturation differentially affects the nature of recall versus naïve antigen-specific T-cell responses. IFN-gamma co-treatment with BCG was found to induce IL-12 and, in some instances, inhibit IL-10 secretion by DC. These findings greatly enhance the potential of BCG-matured dendritic cells for use in cancer immunotherapy.