A Randomized, Open-Label Study Conducted to Evaluate the Bioequivalence of Pegfilgrastim-cbqv On-Body Injector Versus Prefilled Syringe in Healthy Male Participants.

INTRODUCTION: To help prevent febrile neutropenia, pegfilgrastim-cbqv (UDENYCA®; Coherus BioSciences), a pegfilgrastim (NEULASTA®; Amgen) biosimilar, is administered 24-96 h after myelosuppressive chemotherapy. Delivery of pegfilgrastim-cbqv using an on-body injector (OBI) provides an alternative method of administration, affording options in drug delivery. This study aimed to establish pharmacokinetic (PK) and pharmacodynamic (PD) bioequivalence and assess the safety of pegfilgrastim-cbqv administered using an OBI compared with a prefilled syringe (PFS). METHODS: In this open-label, two-period crossover study, healthy adult male participants (N = 189) were randomly assigned 1:1 to receive pegfilgrastim-cbqv 6 mg subcutaneously using an OBI (n = 92) or a PFS (n = 95) in period 1 and then an injection via the other method in period 2. Primary PK end points were area under the concentration-time curve from time 0 to infinity, area under the concentration-time curve from time 0 to the last quantifiable concentration, and maximum plasma concentration. Secondary PD end points, safety, immunogenicity, and tolerability were also assessed. RESULTS: The 90% confidence intervals (CIs) of the geometric mean ratios for the PK and PD end points fell within the predetermined range (80-125%), indicating PK and PD bioequivalence between pegfilgrastim-cbqv OBI and pegfilgrastim-cbqv PFS. Treatment-emergent adverse events (TEAEs) occurred in 87.8% and 75.8% of participants in the OBI and PFS groups, respectively. Most TEAEs were musculoskeletal effects. The most common OBI-related TEAE was injection site erythema (31.7%), which was mild, transient, and self-limiting. The incidence of treatment-emergent antidrug antibodies (ADAs) was similar between the OBI and PFS. ADAs had no apparent impact on PK, PD, or safety. Neutralizing antibodies were not detected in any participant. CONCLUSIONS: Results of the study showed PK and PD bioequivalence of pegfilgrastim-cbqv administered using OBI compared with PFS. OBI and PFS administration had similar safety, tolerability, and immunogenicity profiles. No unexpected safety signals were identified. Graphical Abstract available for this article.

Febrile neutropenia is when a patient has a fever and a lower-than-normal number of white blood cells. When white blood cell counts are low, patients are more susceptible to opportunistic infections as a result of their weakened immune systems. Severe febrile neutropenia can lead to the stopping or delaying of chemotherapy. The drug pegfilgrastim-cbqv is used 24­96 h after chemotherapy to stimulate the growth of white blood cells. Pegfilgrastim-cbqv is available in a single-dose prefilled syringe and in a prefilled autoinjector. If a patient cannot inject themselves with the drug, they must go to a clinic for the injection. Using an on-body injector applied to the skin that automatically injects the drug at a specific time could eliminate the need to go to the clinic. During this study, healthy adult male participants were given pegfilgrastim-cbqv through an on-body injector or a prefilled syringe to investigate if the movement of the drug into, through, and out of the body (pharmacokinetics) and the physiological action of the drug in the body (pharmacodynamics) were similar between the two injection methods. Side effects were also studied. The researchers found that the pharmacokinetics and pharmacodynamics for pegfilgrastim-cbqv given by on-body-injector or prefilled syringe were similar. The number and types of side effects were also similar. The most common side effect for the on-body injector was mild erythema at the injection site. This side effect resolved by itself. The treatment benefit and safety of pegfilgrastim-cbqv were very similar regardless of how the drug was administered.

Pharmacokinetic and Pharmacodynamic Bioequivalence of Pegfilgrastim-cbqv Delivered via a Prefilled Autoinjector and Prefilled Syringe in Healthy Male Participants.

INTRODUCTION: Pegfilgrastim-cbqv (UDENYCA®; Coherus BioSciences, Redwood City, CA, USA) is a pegfilgrastim (Neulasta®; Amgen, Thousand Oaks, CA, USA) biosimilar approved for administration by prefilled syringe (PFS). The recently approved pegfilgrastim-cbqv prefilled autoinjector (AI) was developed as another method of self-administration and to aid in-office use, providing flexibility in drug delivery. The objectives of the study were to assess the pharmacokinetics (PK) and pharmacodynamics (PD) to determine bioequivalence of the prefilled AI and the PFS for administration of pegfilgrastim-cbqv and to assess the safety profile of the prefilled AI. METHODS: During this open-label, two-period crossover study, healthy adult males (N = 155) were randomly assigned (1:1 ratio) to receive a subcutaneous injection of pegfilgrastim-cbqv using a prefilled AI (n = 76) or a PFS (n = 79) in period 1. During period 2, participants received an injection using the other method. Primary PK and secondary PD parameters were calculated to assess the bioequivalence of the treatment as administered by the two delivery methods. Safety and immunogenicity were also assessed. RESULTS: The 90% CIs of the geometric mean ratios for the PK and PD parameters were within the required range (80-125%), demonstrating bioequivalence between the pegfilgrastim-cbqv prefilled AI and PFS. Treatment-emergent adverse events (TEAEs) were reported by 75% and 74.1% of participants in the prefilled AI and PFS groups, respectively. The most common TEAEs in both treatment groups were myalgia, bone pain, and headache. AI-device-related TEAEs were injection site pain (1.4%) and injection site bruising (0.7%). The incidence of antidrug antibodies and neutralizing antibodies was low and was similar in both treatment sequences. CONCLUSIONS: The bioequivalence of pegfilgrastim-cbqv administered using a prefilled AI and a PFS was established. The safety, including immunogenicity profiles, of pegfilgrastim-cbqv administered using the prefilled AI and the PFS were similar, with no new safety findings.

Pegfilgrastim-cbqv is used 24­96 h after chemotherapy to prevent febrile neutropenia. This is when a patient has a fever and a lower-than-normal number of white blood cells. Pegfilgrastim-cbqv is also used to treat someone who has a fever and a low number of white blood cells after high radiation exposure (hematopoietic acute radiation syndrome). Pegfilgrastim-cbqv is given as an injection by hand. The syringe is already filled with the drug. The US Food and Drug Administration also approved a prefilled autoinjector as another way to give the drug. The autoinjector is a spring-loaded system that delivers pegfilgrastim-cbqv in less than 10 s. A shield covers the needle before and after the drug is given. The autoinjector is safe and effective for patients to give pegfilgrastim-cbqv to themselves and for health care staff to use in-office. This study looked at whether the way in which pegfilgrastim-cbqv moves through the body (pharmacokinetics) and its effects on the body (pharmacodynamics) were similar in healthy adult males when using a prefilled autoinjector and a prefilled syringe. Side effects were also assessed. The two administration methods had very similar pharmacokinetic and pharmacodynamic results for pegfilgrastim-cbqv. The side effects for both groups were also similar. The most common side effects were muscle aches and pains, bone pain, and headaches. Giving pegfilgrastim-cbqv with the prefilled autoinjector was very similar to giving it with the prefilled syringe and the pharmacokinetics, pharmacodynamics, and safety were similar.

Neutralizing Antibody Validation Testing and Reporting Harmonization.

Evolving immunogenicity assay performance expectations and a lack of harmonized neutralizing antibody validation testing and reporting tools have resulted in significant time spent by health authorities and sponsors on resolving filing queries. A team of experts within the American Association of Pharmaceutical Scientists' Therapeutic Product Immunogenicity Community across industry and the Food and Drug Administration addressed challenges unique to cell-based and non-cell-based neutralizing antibody assays. Harmonization of validation expectations and data reporting will facilitate filings to health authorities and are described in this manuscript. This team provides validation testing and reporting strategies and tools for the following assessments: (1) format selection; (2) cut point; (3) assay acceptance criteria; (4) control precision; (5) sensitivity including positive control selection and performance tracking; (6) negative control selection; (7) selectivity/specificity including matrix interference, hemolysis, lipemia, bilirubin, concomitant medications, and structurally similar analytes; (8) drug tolerance; (9) target tolerance; (10) sample stability; and (11) assay robustness.

Biosimilar Pegfilgrastim-cbqv Demonstrated Similar Immunogenicity to Pegfilgrastim in Healthy Subjects Across Three Randomized Clinical Studies.

INTRODUCTION: Biologic therapeutics can trigger immune responses in patients. As part of the totality of evidence that is required for regulatory approval of biosimilars, immunogenicity similarity must be assessed in the clinical programs. Pegfilgrastim-cbqv (UDENYCA®) is a pegfilgrastim biosimilar approved in the USA and European Union. This article demonstrates the similar immunogenicity of pegfilgrastim-cbqv compared with its reference product, pegfilgrastim (Neulasta®). METHODS: The immunogenicity of pegfilgrastim-cbqv was assessed in three clinical studies in healthy subjects (one specifically designed to evaluate immunogenicity similarity and two studies to assess pharmacokinetics and pharmacodynamics bioequivalence) using a tiered approach, in which plasma samples were tested for the presence of antidrug antibodies (ADAs) as well as ADA binding-specificity, titer and neutralizing activity. To assess the clinical impact of ADAs, pharmacokinetics, pharmacodynamics and safety profiles were compared between ADA-positive and -negative subjects. RESULTS: These studies demonstrated similar immunogenicity of pegfilgrastim-cbqv and pegfilgrastim. The small differences in ADA incidence between treatment groups observed in the immunogenicity study were driven by non-neutralizing, low-titer, polyethylene glycol (PEG)-reactive ADAs, which are commonly present in healthy subjects. No treatment-emergent neutralizing antibodies (NAbs) were detected in either treatment group, and there was no apparent impact of ADAs on pharmacokinetics, pharmacodynamics or safety. CONCLUSION: Pegfilgrastim-cbqv has similar immunogenicity to pegfilgrastim. The presented immunogenicity, pharmacokinetics, pharmacodynamics and safety data support the overall demonstration of no clinically meaningful differences between pegfilgrastim-cbqv and pegfilgrastim. CLINICAL TRIAL REGISTRATION: NCT02418104 (CHS-1701-04, April 2015), NCT02650973 (CHS-1701-05, February 2016) and NCT02385851 (CHS-1701-03, March 2015).

Pharmacokinetic and Pharmacodynamic Equivalence of Pegfilgrastim-cbqv and Pegfilgrastim in Healthy Subjects.

INTRODUCTION: Pegfilgrastim-cbqv was developed as a biosimilar of pegfilgrastim, a pegylated form of recombinant human granulocyte colony-stimulating factor approved for decreasing febrile neutropenia-associated infection in patients receiving myelosuppressive drugs. This multicenter, randomized, single-blind, partial-reference-replicated, three-sequence crossover study assessed pharmacokinetic and pharmacodynamic bioequivalence of pegfilgrastim-cbqv and pegfilgrastim in healthy subjects. METHODS: One hundred twenty-two subjects were randomized to one of three treatment sequences; each included one dose of pegfilgrastim-cbqv and two doses of pegfilgrastim separated by ≥ 28 days. The primary pharmacokinetic end points were area under the curve (AUC) from 0 to infinity (AUC0-∞) and maximum concentration (Cmax). The primary pharmacodynamic end points were maximum absolute neutrophil count (ANCmax) and ANC AUC from time 0 to the last measurable observation (ANC AUC0-last). Pharmacokinetic and pharmacodynamic bioequivalences were demonstrated if the 90% CI for the geometric mean ratio (GMR) of pegfilgrastim-cbqv to pegfilgrastim was within 80-125% for the primary end points. RESULTS: Pharmacokinetic bioequivalence criteria were met for Cmax (GMR 105.0; 90% CI 95.5-115.4) and AUC0-∞ (GMR 97.5; 90% CI 88.6-107.2). Pharmacodynamic bioequivalence criteria were met for ANCmax (GMR 99.6; 90% CI 96.2-103.2) and ANC AUC0-last (GMR 96.7; 90% CI 92.2-101.4). Adverse events occurred in 76.0%, 76.6%, and 73.1% of subjects for pegfilgrastim-cbqv, first pegfilgrastim, and second pegfilgrastim dosing periods across treatment sequences, respectively. Investigators found no drug-related serious adverse events. CONCLUSION: This study established pharmacokinetic and pharmacodynamic bioequivalence of pegfilgrastim-cbqv to pegfilgrastim. The treatments displayed similar safety profiles, including immunogenicity, with no unexpected safety findings. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov, NCT02650973, February 2016.

Recommendations for the Development and Validation of Immunogenicity Assays in Support of Biosimilar Programs.

For biosimilar drug development programs, it is essential to demonstrate that there are no clinically significant differences between the proposed biosimilar therapeutic (biosimilar) and its reference product (originator). Based on a stepwise comprehensive comparability exercise, the biosimilar must demonstrate similarity to the originator in physicochemical characteristics, biological activity, pharmacokinetics, efficacy, and safety, including immunogenicity. The goal of the immunogenicity assessment is to evaluate potential differences between the proposed biosimilar product and the originator product in the incidence and severity of human immune responses. Establishing that there are no clinically meaningful differences in the immune response between the products is a key element in the demonstration of biosimilarity. An issue of practical, regulatory, and financial importance is to establish whether a two-assay (based on the biosimilar and originator respectively) or a one-assay approach (based on the biosimilar) is optimal for the comparative immunogenicity assessment. This paper recommends the use of a single, biosimilar-based assay for assessing immunogenic similarity in support of biosimilar drug development. The development and validation of an ADA assay used for a biosimilar program should include all the assessments recommended for an innovator program (10-16, 29). In addition, specific parameters also need to be evaluated, to gain confidence that the assay can detect antibodies against both the biosimilar and the originator. Specifically, the biosimilar and the originator should be compared in antigenic equivalence, to assess the ability of the biosimilar and the originator to bind in a similar manner to the positive control(s), as well as in the confirmatory assay and drug tolerance experiments. Practical guidance for the development and validation of anti-drug antibody (ADA) assays to assess immunogenicity of a biosimilar in comparison to the originator, using the one-assay approach, are described herein.

Comparison of cell-based and non-cell-based assay platforms for the detection of clinically relevant anti-drug neutralizing antibodies for immunogenicity assessment of therapeutic proteins.

Anti-drug neutralizing antibodies (NAbs) formed due to unwanted immunogenicity of a therapeutic protein point towards a mature immune response. NAb detection is important in interpreting the therapeutic's efficacy and safety in vivo. In vitro cell-based NAb assays provide a physiological system for NAb detection, however are complex assays. Non-cell-based competitive ligand binding (CLB) approaches are also employed for NAb detection. Instead of cells, CLB assays use soluble receptor and conjugated reagents and are easier to perform, however have reduced physiological relevance. The aim of this study was to compare the performance of CLB assays to established cell-based assays to determine the former's ability to detect clinically relevant NAbs towards therapeutics that (i) acted as an agonist or (ii) acted as antagonists by binding to a target receptor. We performed a head-to-head comparison of the performance of cell-based and CLB NAb assays for erythropoietin (EPO) and two anti-receptor monoclonal antibodies (AMG-X and AMG 317). Clinically relevant NAb-positive samples identified previously by a cell-based assay were assessed in the corresponding CLB format(s). A panel of 12 engineered fully human anti-EPO monoclonal antibodies (MAbs) was tested in both EPO NAb assay formats. Our results showed that the CLB format was (i) capable of detecting human anti-EPO MAbs of differing neutralizing capabilities and affinities and (ii) provided similar results as the cell-based assay for detecting NAbs in patient samples. The cell-based and CLB assays also behaved comparably in detecting NAbs in clinical samples for AMG-X. In the case of anti-AMG 317 NAbs, the CLB format failed to detect NAbs in more than 50% of the tested samples. We conclude that assay sensitivity, drug tolerance and the selected assay matrix played an important role in the inability of AMG 317 CLB assays to detect clinically relevant NAbs.

Development of a Novel BAFF Responsive Cell Line Suitable for Detecting Bioactive BAFF and Neutralizing Antibodies against BAFF-Pathway Inhibiting Therapeutics.

BAFF has a critical role in B-cell survival, maturation and function, which makes its pathway a prime therapeutic target for various autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis and Sjögren's syndrome. A cell-based assay that measures the functional activity of BAFF is required for many high throughput purposes, such as lead target screening and BAFF quantification. We report here the development of a sensitive BAFF responsive cell line via stable transfection of the BAFFR-TNFR1 hybrid receptor into monkey kidney epithelial COS-1 cells. The cellular response to BAFF can be detected by measuring the secretion of IL-8. This BAFF bioassay is not only reproducible and sensitive, but also responsive to a wide concentration range of BAFF stimulation in sera from various species. This cell line is useful in the development of sensitive bioassays to measure the levels of bioactive BAFF, inhibition of BAFF and neutralizing antibodies against any BAFF pathway-mediated therapeutic proteins.

Development and optimization of neutralizing antibody assays to monitor clinical immunogenicity.

The development of an unwanted immune response to a protein therapeutic is a constant concern and necessitates careful monitoring of this class of drugs during clinical development. Neutralizing antibodies can have a significant impact on bioavailability, efficacy and safety of a protein therapeutic. Consequently, immunogenicity testing is required prior to obtaining regulatory approval and in some cases even after a product is marketed. Given the importance of this testing, it is critical that sensitive and robust assays are developed for detection of clinically relevant neutralizing antibodies. This review will describe considerations and current best practices for developing assays to detect neutralizing antibodies to protein therapeutics.

Development and characterization of a human antibody reference panel against erythropoietin suitable for the standardization of ESA immunogenicity testing.

Recombinant human erythropoietin (EPO) has been used therapeutically for more than two decades in the treatment of anemia. Although EPO is generally well tolerated, in rare cases, patients have developed anti-EPO antibodies that can negatively impact safety and efficacy. Therefore, the detection of antibodies against EPO is a regulatory requirement during clinical development and post-approval. Although it is a rare phenomenon, antibody-mediated pure red cell aplasia (PRCA) is a serious complication than can result from antibodies that develop and neutralize EPO as well as endogenous erythropoietin. Currently, there are no universally accepted analytical methods to detect the full repertoire of binding and neutralizing anti-EPO antibodies. A number of different methods that differ in terms of antibodies detected and assay sensitivities are used by different manufacturers. There is also a lack of antibody reference reagents, and therefore no consistent basis for detecting and measuring anti-EPO antibodies. Reference reagents, with established ranges, are essential to monitor the safety and efficacy of all erythropoiesis-stimulating agents (ESAs) structurally related to human erythropoietin. This is the first report of the development and characterization of a panel of fully human antibodies against EPO suitable as reference reagents. The characteristics of antibodies within the panel were selected based on the prevalence of non-neutralizing IgG and IgM antibodies in non-PRCA patients and neutralizing IgG antibodies, including IgG1 and IgG4, in antibody-mediated PRCA subjects. The reference panel includes antibodies of high- and low-affinity with binding specificity to neutralizing and non-neutralizing erythropoietin epitopes. The subclass of human antibodies in this reference panel includes an IgG1, IgG2, and IgG4, as well as an IgM isotype. This antibody panel could help select appropriate immunogenicity assays, guide validation, and monitor assay performance. Further, this human anti-ESA antibody panel may help set the limits of each assay platform in terms of the full repertoire of the anti-ESA antibodies, and may facilitate standardization of ESA immunogenicity reporting across assay platforms.

Implementation of design of experiments (DOE) in the development and validation of a cell-based bioassay for the detection of anti-drug neutralizing antibodies in human serum.

The administration of biological therapeutics can potentially elicit the development of neutralizing antibodies (NAbs) to the therapeutic drug in patients, which could have a significant impact on drug efficacy and safety. A rigorous in vitro cell-based assay for the detection of NAbs is critical for the assessment of the immunogenicity profile of the therapeutic drug. Conatumumab is a fully human monoclonal agonist antibody directed against the extracellular domain of human TRAIL receptor 2 (TR-2). It is being investigated as a cancer treatment because it is able to induce apoptosis in sensitive tumor cells. This report demonstrates how statistically designed experiments could be employed effectively in different stages of a NAb bioassay life cycle in order to characterize, optimize and stabilize the assay with added benefit of resource efficiency. By combining the approach of design of experiments (DOE) with subject matter expertise and experience, we were able to understand thoroughly how assay parameters affect the performance of the assay individually and interactively, identify the key assay parameters, define assay operating ranges and finally achieve a robust and sensitive cell-based assay for the detection of NAbs to Conatumumab. With the goal of developing a cell-based bioassay that is highly optimized for sensitivity, specificity, precision, and robustness, we performed 2 DOE experiments for assay optimization and 1 DOE experiment to validate assay robustness. We evaluated key operating parameters of the assay such as cell number, percentage of serum matrix, concentration of the therapeutic drug, concentration of the cross-linker, length of various incubation steps, cell age, interval between cell subculture and bioassay time, and detection equipment.

Strategy to confirm the presence of anti-erythropoietin neutralizing antibodies in human serum.

Functional cell-based assays are the preferred method to test for the presence of anti-rHuEPO neutralizing antibodies (NAbs). However, due to the unpredictable nature of test serum matrix effects on cell-based assays, confirmatory assays are essential for verifying NAb positive results observed during the course of sample testing. The cell-based assay used for the detection of NAbs described by Wei et al. [1] used 32D-EPOR cells, a murine myeloid cell line transfected with the human EPO receptor (EPOR). The 32D-EPOR cell line responded to either rHuEPO or murine interleukin 3 (mIL-3) with proliferation. NAbs were expected to only inhibit rHuEPO-induced cell proliferation and not mIL-3 induced proliferation. Due to reliance on proliferation, the results from this cell-based assay can be confounded by the presence of non-antibody inhibitory serum factors. This paper describes a strategy for confirming that the inhibition of rHuEPO-induced proliferation in a cell-based assay is only attributable to NAbs. The strategy of antibody depletion uses a resin mixture composed of Protein G Sepharose and Protein L Sepharose (Protein G/L resin) to significantly reduce the concentration of immunoglobulins of IgG, IgM and IgA isotypes from human serum prior to testing in the cell-based assay. If the reduction in immunoglobulins in a serum sample corresponds to a reduction in inhibition of EPO-induced proliferation, it would infer that EPO neutralizing activity is antibody-mediated and not due to non-antibody inhibitory serum factors.

An ultra-HTS process for the identification of small molecule modulators of orphan G-protein-coupled receptors.

G-protein-coupled receptors (GPCRs) are the most successful target proteins for drug discovery research to date. More than 150 orphan GPCRs of potential therapeutic interest have been identified for which no activating ligands or biological functions are known. One of the greatest challenges in the pharmaceutical industry is to link these orphan GPCRs with human diseases. Highly automated parallel approaches that integrate ultra-high throughput and focused screening can be used to identify small molecule modulators of orphan GPCRs. These small molecules can then be employed as pharmacological tools to explore the function of orphan receptors in models of human disease. In this review, we describe methods that utilize powerful ultra-high-throughput screening technologies to identify surrogate ligands of orphan GPCRs.