Ex vivo comparative immunogenicity assessment (EVCIA) to determine relative immunogenicity in chronic plaque psoriasis in participants receiving Humira® or undergoing repeated switches between Humira® and AVT02.

Immunogenicity against biologic medicines is ubiquitous, and it is traditionally measured by the final humoral response. However, the onset of a sustained immunogenic response begins at the cellular level with activation of T cells and maturation of naïve B cells into plasma cells. Ex vivo comparative immunogenicity assessment (EVCIA) of cellular immunogenicity in participants with moderate-to-severe chronic plaque psoriasis in the AVT02-GL-302 study, who received either reference product (RP) alone (non-switching arm) or switched between RP and AVT02 (switching arm) after 1:1 randomization at week 12. Peripheral blood mononuclear cells (PBMCs) were collected and cryopreserved from 28 participants at: baseline (before treatment) (week 1); pre-randomization (week 12); and week 16 and week 28 in both switching and non-switching arms. PBMCs were thawed and re-exposed to either medium alone (negative control), RP, AVT02, keyhole limpet hemocyanin (KLH) (positive control), RP+KLH, or AVT02+KLH. Samples from 10 participants (predetermined average cell viability of 75% across all timepoints) from each arm were analyzed for cytokine release after 24 hours and for Th-cell proliferation, 6 days post-seeding. Until week 28, cytokine release and Th-cell proliferation was similar at all time points in both switching and non-switching arms. Overall cellular immune response was elevated post-KLH re-exposure at all timepoints. The comparable ex vivo cellular immunogenicity between switching and non-switching arms complements the confirmation of interchangeability in the main study. Given the sensitivity of novel EVCIA, detecting cellular immunogenicity could be a potential outcome in predicting the immunogenicity of biologic medicines.

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.

Assessing the Interchangeability of AVT02 and Humira® in Participants with Moderate­to­Severe 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 (AUCtau, W26-28) and 108.1% (98.3-117.9%) for maximum concentration over the dosing interval from weeks 26-28 (Cmax, W26-28). The 90% CIs for the switching versus non-switching arithmetic means ratio for primary endpoints AUCtau, W26-28 and Cmax, 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.

A randomized, double-blind, 3-arm, parallel study assessing the pharmacokinetics, safety, tolerability and immunogenicity of AVT04, an ustekinumab candidate biosimilar, in healthy adults.

BACKGROUND: This study assessed pharmacokinetic (PK) similarity, safety, and immunogenicity of AVT04, a candidate biosimilar, compared with reference product (RP) ustekinumab (EU-approved and US-licensed Stelara®). METHODS: Healthy subjects (N = 298) were randomized 1:1:1 to receive one 45 mg dose of AVT04, EU-RP, or US-RP. The primary PK parameters were Cmax and AUC0-inf. PK similarity was demonstrated if the 90% confidence intervals (CI) for the ratio of geometric means were all contained within the prespecified margins of 80% and 125%. Additional PK parameters, including AUC0-t, were also assessed. Safety and immunogenicity were also assessed until Day 92. RESULTS: After pre-specified protein content normalization, the 90% CI for the ratio of geometric means for primary PK parameters were all contained within the pre-specified bioequivalence margins of 80% and 125%, supporting demonstration of PK similarity between AVT04 and both EU- and US-RP. Secondary PK parameters supported the analysis. Safety and immunogenicity profiles were comparable across all three treatment arms, although the study was not powered to detect small differences in these parameters. CONCLUSION: Results supported a demonstration of PK similarity between candidate biosimilar AVT04, US-RP and EU-RP. Similar safety and immunogenicity were also shown.Clinical trial registration: www.clinicaltrials.gov identifier is NCT04744363.

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.

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.

Missing data imputation using utility-based regression and sampling approaches.

Data are often missing not at random (MNAR) in scientific experiments. We treat the MNAR problem as an imbalanced learning task. Standard predictive error measures of regression (e.g., mean squared error) are not suitable for imbalanced learning problems, such as in clinical trials where extreme values tend to be MNAR. We investigate hybrid imbalanced learning approaches that combine utility-based regression (UBR) with synthetic minority oversampling technique for regression (SMOTER) in cross-sectional trial settings. UBR optimizes the product of the conditional probability density (estimated by quantile regression forests) and a utility function which takes the relevance of the target variable value and the prediction error into account. SMOTER oversamples the relevant rare cases. Simulations show that the proposed method provides plausible predictions and reduces the bias for realistic missing data scenarios when compared with standard approaches like random forests and multiple imputation (systematic bias is observed in those methods, i.e., a tendency to underestimate the mean and standard deviation given the presence of MNAR in the area of high values of the target variable). The proposed method is implemented in a real dataset from an antidepressant clinical trial, and similar pattern of the systematic bias from commonly used methods is observed in the real data compare to the proposed method. Therefore, we encourage the integration of utility-based learning strategies for handling of missing data in the analysis of clinical trials.

Joint analysis of PK and immunogenicity outcomes using factorization model - a powerful approach for PK similarity study.

Biological products, whether they are innovator products or biosimilars, can incite an immunogenic response ensuing in the development of anti-drug antibodies (ADA). The presence of ADA's often affects the drug clearance, resulting in an increase in the variability of pharmacokinetic (PK) analysis and challenges in the design and analysis of PK similarity studies. Immunogenic response is a complex process which may be manifested by product and non-product-related factors. Potential imbalances in non-product-related factors between treatment groups may lead to differences in antibodies formation and thus in PK outcome. The current standard statistical approaches dismiss any associations between immunogenicity and PK outcomes. However, we consider PK and immunogenicity as the two correlated outcomes of the study treatment. In this research, we propose a factorization model for the simultaneous analysis of PK parameters (normal variable after taking log-transformation) and immunogenic response subgroup (binary variable). The central principle of the factorization model is to describe the likelihood function as the product of the marginal distribution of one outcome and the conditional distribution of the second outcome given the previous one. Factorization model captures the additional information contained in the correlation between the outcomes, it is more efficient than models that ignore potential dependencies between the outcomes. In our context, factorization model accounts for variability in PK data by considering the influence of immunogenicity. Based on our simulation studies, the factorization model provides more accurate and efficient estimates of the treatment effect in the PK data by taking into account the impact of immunogenicity. These findings are supported by two PK similarity clinical studies with a highly immunogenic biologic.

Missing data imputation in clinical trials using recurrent neural network facilitated by clustering and oversampling.

In clinical practice, the composition of missing data may be complex, for example, a mixture of missing at random (MAR) and missing not at random (MNAR) assumptions. Many methods under the assumption of MAR are available. Under the assumption of MNAR, likelihood-based methods require specification of the joint distribution of the data, and the missingness mechanism has been introduced as sensitivity analysis. These classic models heavily rely on the underlying assumption, and, in many realistic scenarios, they can produce unreliable estimates. In this paper, we develop a machine learning based missing data prediction framework with the aim of handling more realistic missing data scenarios. We use an imbalanced learning technique (i.e., oversampling of minority class) to handle the MNAR data. To implement oversampling in longitudinal continuous variable, we first perform clustering via k$k$ -mean trajectories. And use the recurrent neural network (RNN) to model the longitudinal data. Further, we apply bootstrap aggregating to improve the accuracy of prediction and also to consider the uncertainty of a single prediction. We evaluate the proposed method using simulated data. The prediction result is evaluated at the individual patient level and the overall population level. We demonstrate the powerful predictive capability of RNN for longitudinal data and its flexibility for nonlinear modeling. Overall, the proposed method provides an accurate individual prediction for both MAR and MNAR data and reduce the bias of missing data in treatment effect estimation when compared to standard methods and classic models. Finally, we implement the proposed method in a real dataset from an antidepressant clinical trial. In summary, this paper offers an opportunity to encourage the integration of machine learning strategies for handling of missing data in the analysis of randomized clinical trials.

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 Cmax, AUC0-t, and AUC0-inf. Bioequivalence was demonstrated if the 90% confidence intervals (CI) for the ratio of geometric means for the primary pharmacokinetic (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.