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

Equivalence trial of proposed denosumab biosimilar GP2411 and reference denosumab in postmenopausal osteoporosis: the ROSALIA study

Denosumab is a monoclonal antibody used to reduce risk of fractures in osteoporosis. ROSALIA was a multicenter, double-blind, randomized, integrated phase I/phase III study comparing the efficacy, pharmacokinetics (PK), pharmacodynamics (PD), immunogenicity, and safety of proposed biosimilar denosumab GP2411 with reference denosumab (REF-DMAb) (Prolia®; Amgen). Postmenopausal women with osteoporosis were randomized 1:1 to 2 60-mg doses of GP2411 or REF-DMAb, one at study start and one at week 26. At week 52, the REF-DMAb group was re-randomized 1:1 to a third dose of REF-DMAb or switch to GP2411. The primary efficacy endpoint was percentage change from baseline (%CfB) in LS-BMD at week 52. Secondary efficacy endpoints were %CfB in LS-BMD, FN-BMD, and TH-BMD at weeks 26 and 78 (and week 52 for FN-BMD and TH-BMD). Primary PK and PD endpoints were the area under the serum concentration-time curve extrapolated to infinity and maximum drug serum concentration at week 26, and the area under the effect-time curve of the %CfB in serum CTX at week 26. Secondary PK and PD endpoints included drug serum concentrations and %CfB in serum CTX and P1NP during the study period. Similar efficacy was demonstrated at week 52, with 95% CIs of the difference in %CfB in LS-BMD between treatment groups fully contained within prespecified equivalence margins. Similarity in PK and PD was demonstrated at week 26. Immunogenicity was similar between groups and was not impacted by treatment switch. The rate of new vertebral fractures was comparable. Treatment-emergent adverse events were comparable between groups (63.6% [GP2411/GP2411]; 76.0% [REF-DMAb/REF-DMAb]; 76.6% [REF-DMAb/GP2411]). In conclusion, ROSALIA showed similar efficacy, PK and PD, and comparable safety and immunogenicity of GP2411 to REF-DMAb in postmenopausal osteoporosis.

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.

Investigation of Immunogenicity Assessment of Biosimilar Monoclonal Antibodies in the United States

Immunogenicity is critical for biologics. However, reference biologics labeling documents do not necessarily mention immunogenicity impact, rendering the development of biosimilars more challenging. We aimed to investigate the comparative assessment of immunogenicity profiles between biosimilars and their respective reference biologics in the review reports of the biosimilar monoclonal antibody applications approved by the Center for Drug Evaluation and Research (CDER), US Food and Drug Administration (FDA) as of March 13, 2022, covering 22 applications approved between April 5, 2016, and December 17, 2021. The maximum differences in anti-drug antibody (ADA) and neutralizing antibody (NAb) incidences between biosimilars and reference products mostly fell within ± 15% (-13.6% to 12%) and ± 20% (-17.4% to 17.1%, except extreme values of -23.4% and 66.7%), respectively. In comparison with antineoplastic agents, more immunosuppressants had ADA-positive (11/11, 100.0% vs. 8/10, 80.0%)/NAb-positive (11/11, 100.0% vs. 3/10, 30.0%) subjects, and the distribution of the aforementioned incidence differences was wider. The investigated biosimilars with available data for analysis demonstrated a high degree of consistency with their reference products in terms of the impact on pharmacokinetic parameters. No increase in immunogenicity was found in available switching studies. Most (16/22, 72.7%) biosimilars were issued post-marketing requirements that were not directly related to immunogenicity concerns. The FDA considered the totality of evidence assessing clinical consequences of immunogenicity differences, if any. Additional information on titers and subgroup analysis may be warranted to elucidate the critical attributes of immunogenicity impact and to aid in forming cost-effective strategies for biosimilar development.

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.

Assessment of real-life patient handling experience of AVT02 administered subcutaneously via autoinjector in patients with moderate to severe active rheumatoid arthritis: an open-label, single-arm clinical trial, then an extension phase of AVT02 administered with a prefilled syringe

BACKGROUND

This study investigated the ability of patients, naïve to adalimumab treatment and self-injection with an autoinjector (AI), to successfully self-administer AVT02, an adalimumab biosimilar, using a custom, ergonomic AI (Alvotech hf., Reykjavik, Iceland).

RESEARCH DESIGN AND METHODS

This was a single-arm, open-label study, consisting of an 8-week active period and 48-week extension phase. Patients with moderate to severe rheumatoid arthritis (RA) self-administered 40 mg AVT02 subcutaneously via AI in the active period, followed by prefilled syringe in the extension phase. The primary endpoint was the percentage of successful self-injections up to Week 8. Usability and robustness of the AI were evaluated in the active period; safety, efficacy, pharmacokinetic and immunogenicity data were assessed throughout the study.

RESULTS

The AI success rate was 100%. No handling events were noted up to Week 8. Both Ctrough measurements and immunogenicity profile were in line with expectations from previous studies, with no unexpected safety signals.

CONCLUSIONS

This study demonstrated that AVT02-AI can be successfully and reliably used for repeated self-injections of AVT02 by moderate to severe RA patients, despite no previous experience of adalimumab self-administration. The extension phase provides long-term efficacy and safety data for AVT02 in RA.

STUDY IDENTIFIER

NCT04224194.

Randomized, double-blind, multicenter study to evaluate efficacy, safety, tolerability, and immunogenicity between AVT04 and the reference product ustekinumab in patients with moderate-to-severe chronic plaque psoriasis

BACKGROUND

This study compared efficacy, safety, tolerability, pharmacokinetics (PK), and immunogenicity between AVT04 and reference product (RP) ustekinumab (Stelara®) in patients with moderate-to-severe chronic plaque psoriasis (PsO).

PATIENTS AND METHODS

This multicenter, double-blind, 52-week study randomized patients in 1:2 ratio to AVT04 or RP. At week 16, responsive patients (≥50% improvement in psoriasis area and severity index (PASI)) previously on AVT04 continued on AVT04, while those on RP were re-randomized 1:1 to switch to AVT04 or stay on RP. The primary endpoint was a percent improvement in PASI from baseline to week 12. Therapeutic equivalence was demonstrated if the confidence interval (CI) for the adjusted difference in means was contained within the equivalence margins; ±10% (90%CI).

RESULTS

Of the 581 patients initially randomized (AVT04:RP, 194:387), 575 completed week 16 and 544 completed end of study visit. The percent PASI improvement for AVT04 vs RP was 87.3% vs 86.8% (CI: -2.14%, 3.01%); study met its primary endpoint. Efficacy, safety and PK profiles were comparable across treatment arms throughout the entire study duration, and the incidence of antibodies to ustekinumab had no clinically meaningful impact.

CONCLUSION

This study demonstrates the therapeutic equivalence between AVT04 and RP in patients with moderate-to-severe chronic PsO, with similar safety and tolerability.

TRIAL REGISTRATION

NCT04930042; EudraCT Number: 2020-004,493-22.

A multicenter, randomized, open-label, 2-arm parallel study to compare the pharmacokinetics, safety and tolerability of AVT02 administered subcutaneously via prefilled syringe or autoinjector in healthy adults

BACKGROUND

AVT02 is an adalimumab biosimilar, with bioequivalence previously established along with clinical similarity. This study assessed the pharmacokinetic (PK) similarity of a single dose of 100 mg/mL AVT02 administered via prefilled syringe (PFS) or autoinjector (AI).

RESEARCH DESIGN AND METHODS

In this open-label, 2-arm, parallel-group study, healthy adults were randomized 1:1 to receive one 40 mg (100 mg/mL) dose of AVT02 subcutaneously via PFS (N = 102) or AI (N = 105). Primary PK parameters (Cmax, AUC0-t and AUC0-inf) were evaluated up to Day 64 of the study. Secondary PK parameters, safety, tolerability and immunogenicity were also assessed.

RESULTS

The 90% CIs for the ratio of geometric least squares means were contained within the pre-specified 80-125% equivalence margins for the primary PK parameters, demonstrating bioequivalence of AVT02 when administered by PFS or AI. The incidence of treatment-emergent adverse events was comparable between the two groups, with a low frequency of injection site reactions observed. Immunogenicity profiles were also similar between the two groups.

CONCLUSION

Bioequivalence was demonstrated for a single dose of AVT02 administered via PFS or AI. These results will help to increase availability of devices for patients, enabling treatment choice and flexibility.

Assessing the Interchangeability of AVT02 and Humira® in Participants with Moderate‑to‑Severe Chronic Plaque Psoriasis: Pharmacokinetics, Efficacy, Safety, and Immunogenicity Results from a Multicenter, Double-Blind, Randomized, Parallel-Group Study

BACKGROUND

The US Food and Drug Administration (FDA) interchangeability guidelines state that the primary endpoint in a switching study should assess the impact of switching between the proposed interchangeable product and the reference product on clinical pharmacokinetics (PK) and pharmacodynamics (if available), as these assessments are generally sensitive to changes in immunogenicity and/or exposure that may arise due to switching. In addition, interchangeability designation requires no clinically meaningful difference in safety and efficacy of switching between the biosimilar and reference, compared with when using the reference product alone.

OBJECTIVES

 The aim of this study was to investigate the PK, immunogenicity, efficacy, and safety in participants undergoing repeated switches between Humira^® and AVT02 as part of a global interchangeable development program.

METHODS

This multicenter, randomized, double-blind, parallel-group study in patients with moderate-to-severe plaque psoriasis comprises three parts: lead-in period (weeks 1-12), switching module (weeks 12-28), and the optional extension phase (weeks 28-52). Following the lead-in period during which all participants received the reference product (80 mg in week 1, followed by 40 mg every other week), participants with a clinical response of ≥ 75% improvement in the Psoriasis Area and Severity Index (PASI75) were randomized 1:1 to receive AVT02 alternating with the reference product (switching arm) or reference product only (non-switching arm). At week 28, participants who were PASI50 responders could opt to take part in an open-label extension phase receiving AVT02 up to week 50, with an end of study visit at week 52. PK, safety, immunogenicity, and efficacy were evaluated at various timepoints throughout the study for both switching and non-switching arms.

RESULTS

In total, 550 participants were randomized to switching (277) and non-switching arms (273). The switching versus non-switching arithmetic least square means ratio [90% confidence intervals (CIs)] was 101.7% (91.4-112.0%) for the area under the concentration-time curve over the dosing interval from weeks 26-28 (AUC_{tau, W26-28}) and 108.1% (98.3-117.9%) for maximum concentration over the dosing interval from weeks 26-28 (C_{max, W26-28}). The 90% CIs for the switching versus non-switching arithmetic means ratio for primary endpoints AUC_{tau, W26-28} and C_{max, W26-28} were within the prespecified limits of 80-125%, demonstrating comparable PK profiles between groups. In addition, the PASI, Dermatology Life Quality Index, and static Physician's Global Assessment efficacy scores were highly similar for both treatment groups. There were no clinically meaningful differences between the immunogenicity and safety assessments of repeated switching between AVT02 and the reference product, versus the reference product alone.

CONCLUSIONS

This study demonstrated that the risk, in terms of safety or diminished efficacy of switching between the biosimilar and the reference product, is not greater than the risk of using the reference product alone, as required by the FDA for interchangeability designation. Beyond the scope of interchangeability, a consistent long-term safety and immunogenicity profile, with no impact on the trough levels up to 52 weeks, was established.

CLINICAL TRIAL REGISTRATION

NCT04453137; date of registration: 1 July 2020.

Candidate Bevacizumab Biosimilar CT-P16 versus European Union Reference Bevacizumab in Patients with Metastatic or Recurrent Non-Small Cell Lung Cancer: A Randomized Controlled Trial

BACKGROUND

CT-P16 is a candidate bevacizumab biosimilar.

OBJECTIVE

This double-blind, multicenter, parallel-group, phase III study aimed to establish equivalent efficacy between CT-P16 and European Union-approved reference bevacizumab (EU-bevacizumab) in patients with metastatic or recurrent non-squamous non-small cell lung cancer (nsNSCLC).

PATIENTS AND METHODS

Patients with stage IV or recurrent nsNSCLC were randomized (1:1) to receive CT-P16 or EU-bevacizumab (15 mg/kg every 3 weeks; ≤ 6 cycles) with paclitaxel (200 mg/m²) and carboplatin (area under the curve 6.0; both for 4-6 cycles), as induction therapy. Patients with controlled disease after induction therapy continued with CT-P16 or EU-bevacizumab maintenance therapy. The primary endpoint was objective response rate (ORR) during the induction period. Time-to-event analyses, pharmacokinetics, safety, and immunogenicity were also evaluated. Results obtained after 1 year of follow-up are presented.

RESULTS

Overall, 689 patients were randomized (CT-P16, N = 342; EU-bevacizumab, N = 347). ORR was 42.40% (95% confidence interval [CI] 37.16-47.64) and 42.07% (95% CI 36.88-47.27) for CT-P16 and EU-bevacizumab, respectively. The risk difference (0.40 [95% CI - 7.02 to 7.83]) and risk ratio (1.0136 [90% CI 0.8767-1.1719]) for ORR fell within predefined equivalence margins (- 12.5 to + 12.5%, and 0.7368 to 1.3572, respectively), demonstrating equivalence between CT-P16 and EU-bevacizumab. Median response duration, time to progression, progression-free survival, and overall survival were comparable between treatment groups. Safety profiles were similar: 96.2% (CT-P16) and 93.0% (EU-bevacizumab) of patients experienced treatment-emergent adverse events. Pharmacokinetics and immunogenicity were comparable between groups.

CONCLUSIONS

Equivalent efficacy and similar pharmacokinetics, safety, and immunogenicity support bioequivalence of CT-P16 and EU-bevacizumab in patients with nsNSCLC.

TRIAL REGISTRATION NUMBER

NCT03676192.

Immunogenicity of LY2963016 insulin glargine and Lantus® insulin glargine in Chinese patients with type 1 or type 2 diabetes mellitus

AIMS

To evaluate the immunogenicity of LY2963016 insulin glargine (LY IGlar) versus originator insulin glargine (IGlar [Lantus®]) in Chinese patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

ABES and ABET were prospective, randomized, active control, open-label, phase III studies, which enrolled Chinese patients with T1DM (N = 272) and T2DM (N = 536), respectively. Using data from these trials, immunogenicity of LY IGlar and IGlar was evaluated by comparing the proportion of patients with detectable anti-insulin glargine antibodies and the median antibody levels (percent binding) between the treatment groups. The incidence of anti-insulin antibodies and treatment-emergent antibody response (TEAR) were compared using Fisher's exact test or Pearson's chi-squared test. Levels of anti-insulin antibodies were compared using the Wilcoxon rank-sum test. We also evaluated the relationship between antibody formation or TEAR and clinical outcomes using analysis of covariance, negative binomial regression, or partial correlations.

RESULTS

There were no significant treatment differences in the incidence of detectable anti-insulin antibodies, median antibody levels or TEAR, overall or at Week 24 with last observation carried forward, and median antibody levels were low (<5%) after 24 weeks of treatment, in patients with T1DM or T2DM. Levels of anti-insulin antibodies and development of TEAR were not associated with efficacy (glycated haemoglobin, insulin dose [U/kg/d] and hypoglycaemia) or safety outcomes.

CONCLUSIONS

The immunogenicity profiles of LY IGlar and IGlar are similar, with low levels of anti-insulin antibodies observed for both insulins. No association was observed between antibody levels or TEAR status and clinical outcomes.

2021 White Paper on Recent Issues in Bioanalysis: TAb/NAb, Viral Vector CDx, Shedding Assays; CRISPR/Cas9 & CAR-T Immunogenicity; PCR & Vaccine Assay Performance; ADA Assay Comparability & Cut Point Appropriateness (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccine Assays; Immunogenicity of Biotherapeutics and Novel Modalities; Integrated Summary of Immunogenicity Harmonization)

The 15th edition of the Workshop on Recent Issues in Bioanalysis (15th WRIB) was held on 27 September to 1 October 2021. Even with a last-minute move from in-person to virtual, an overwhelmingly high number of nearly 900 professionals representing pharma and biotech companies, contract research organizations (CROs), and multiple regulatory agencies still eagerly convened to actively discuss the most current topics of interest in bioanalysis. The 15th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on biomarker assay development and validation (BAV) (focused on clarifying the confusion created by the increased use of the term "Context of Use - COU"); mass spectrometry of proteins (therapeutic, biomarker and transgene); state-of-the-art cytometry innovation and validation; and, critical reagent and positive control generation were the special features of the 15th edition. This 2021 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 2021 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on TAb/NAb, Viral Vector CDx, Shedding Assays; CRISPR/Cas9 & CAR-T Immunogenicity; PCR & Vaccine Assay Performance; ADA Assay Comparability & Cut Point Appropriateness. Part 1A (Endogenous Compounds, Small Molecules, Complex Methods, Regulated Mass Spec of Large Molecules, Small Molecule, PoC), Part 1B (Regulatory Agencies' Inputs on Bioanalysis, Biomarkers, Immunogenicity, Gene & Cell Therapy and Vaccine) and Part 2 (ISR for Biomarkers, Liquid Biopsies, Spectral Cytometry, Inhalation/Oral & Multispecific Biotherapeutics, Accuracy/LLOQ for Flow Cytometry) are published in volume 14 of Bioanalysis, issues 9 and 10 (2022), respectively.

A randomized, adaptive design, double-blind, 3-arm, parallel study assessing the pharmacokinetics and safety of AVT02, a high-concentration (100 mg/mL) adalimumab biosimilar, in healthy adult subjects (ALVOPAD FIRST)

BACKGROUND

This study (ALVOPAD FIRST) assessed bioequivalence, safety, and immunogenicity of AVT02, an adalimumab biosimilar, compared with reference product adalimumab (EU- and US-approved Humira®).

METHODS

Healthy subjects (N = 392) were randomized 1:1:1 to receive one 40 mg dose of AVT02, EU-reference product, or US-reference product subcutaneously. An interim analysis was planned when ~30 subjects per arm had completed the study, to optimize final sample size. The primary PK parameters were C_max, AUC_0-t, and AUC_0-inf. Bioequivalence was demonstrated if the 90% CI for the ratio of geometric means for the primary PK parameters were all contained within the prespecified margins of 80% and 125%. Safety and immunogenicity were assessed until Day 64.

RESULTS

The 90% CI for the ratio of geometric means for the primary PK parameters, based on Fisher's Combination test analysis, were all contained within the prespecified bioequivalence margins of 80% and 125%, supporting the demonstration of bioequivalence between AVT02 and both EU- and US-reference product. The safety and immunogenicity profiles were comparable across all three treatment arms.

CONCLUSION

PK bioequivalence was supported between AVT02, US-licensed- and EU-approved-reference product adalimumab. Similar safety and immunogenicity were also demonstrated.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT03849313).

Efficacy, Safety and Immunogenicity of AVT02 Versus Originator Adalimumab in Subjects with Moderate to Severe Chronic Plaque Psoriasis: A Multicentre, Double-Blind, Randomised, Parallel Group, Active Control, Phase III Study

Background

AVT02 (adalimumab) is a proposed biosimilar to Humira^®. AVT02 is produced at a 100 mg/mL concentration with a citrate-free formulation.

Objectives

The aim of this study was to compare the efficacy, safety and immunogenicity of AVT02 versus Humira^® in subjects with moderate to severe chronic plaque psoriasis.

Methods

This double-blind, randomised, parallel group, active control study of adult subjects compared (at a 1:1 ratio) AVT02 with originator adalimumab 80 mg subcutaneously in Week 1, then 40 mg every other week. At Week 16, subjects who had received originator adalimumab were re-randomised at a 1:1 ratio to continue receiving originator adalimumab, or to switch to AVT02, every other week until Week 48, with final efficacy endpoint at Week 50. Subjects who initially received AVT02 continued to receive AVT02 from Week 16 to Week 48. The primary endpoint was percentage improvement in Psoriasis Area and Severity Index (PASI) score at Week 16. Secondary efficacy endpoints included percentage improvement in PASI score at additional timepoints, change from baseline in Dermatology Life Quality Index (DLQI) score and number and percentage of subjects achieving static Physician’s Global Assessment (sPGA) responses of ‘clear’ or ‘almost clear’. Additional secondary endpoints included comparison of adverse event profiles, anti-drug antibodies and neutralising antibodies, and serum trough levels of adalimumab at steady state.

Results

A total of 413 subjects were randomised (205 to AVT02 and 208 to originator). The percentage improvement in PASI score at Week 16 was 91.6% for AVT02-treated subjects and 89.6% for originator adalimumab. The 90% confidence intervals for the primary endpoint were within the pre-defined equivalence margin of ±10% (90% CI − 0.76 to 5.29; 95% CI − 1.34 to 5.88), and a comparable pattern for DLQI score (11.4-point and 10.6-point improvement in AVT02-treated and originator adalimumab-treated groups, respectively) and sPGA (90.5% in both groups achieving ‘clear’ or ‘almost clear’) at Week 16 supported the assessment. Efficacy persisted through Week 50 of the study in all treatment groups, including those who switched from originator adalimumab to AVT02, for percent improvement in PASI score, quality-of-life assessment and sPGA. The safety, tolerability and immunogenicity profiles between AVT02 and originator adalimumab were similar at Week 16, and this persisted in the switched and continued groups through Week 50.

Conclusion

Objective and subjective measures of efficacy supported the evaluation of biosimilarity between AVT02 and originator adalimumab at Week 16 and until Week 50, in switched and continued treatment groups. AVT02 was safe and well tolerated, with a safety and immunogenicity profile similar to that observed in originator adalimumab with no clinically meaningful difference between the two.

Clinical Trial Registration

EudraCT: 2017-003367-35; ClinicalTrials.gov: NCT03849404.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00502-w.

Toward comparability of anti-drug antibody assays: is the amount of anti-drug antibody–reagent complexes at cut-point (CP-ARC) the missing piece?

Immunogenicity testing is a mandatory and critical activity during the development of therapeutic proteins. Multiple regulatory guidelines provide clear recommendations on appropriate immunogenicity testing strategies and required bioanalytical assay performances. Unfortunately, it is still generally accepted that a comparison of the immunogenicity of different compounds is not possible due to apparent performance differences of the used bioanalytical methods. In this perspective, we propose the ‘cut-point anti-drug antibody–reagents complex’ (CP-ARC) concept for technical comparability of the bioanalytical methods. The feasibility and implementation in routine assay development is discussed as well as the potential improvement of reporting of bioanalytical immunogenicity data to allow comparison across drugs. Scientific sound comparability of the bioanalytical methods is the first step toward comparability of clinical immunogenicity.