Pharmacokinetics, Safety, and Tolerability of Tezepelumab (AMG 157) in Healthy and Atopic Dermatitis Adult Subjects

A first-in-human, single and multiple dose study of lunsekimig, a novel anti-TSLP/anti-IL-13 NANOBODY® compound, in healthy volunteers

Lunsekimig is a novel, bispecific NANOBODY® molecule that inhibits both thymic stromal lymphopoietin (TSLP) and interleukin (IL)-13, two key mediators of asthma pathophysiology. In this first-in-human study, we evaluated the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of lunsekimig in healthy adult participants. Participants received single ascending doses (SAD) of lunsekimig (10-400 mg intravenous [IV] or 400 mg subcutaneous [SC]) (SAD part) or multiple ascending doses (MAD part) of lunsekimig (100 or 200 mg, every 2 weeks [Q2W] for three SC doses), or placebo. Overall, 48 participants were randomized 3:1 in the SAD part and 4:1 in the MAD part for lunsekimig or placebo. The primary endpoint was safety and tolerability. The secondary endpoints included PK, antidrug antibodies (ADAs) and total target measurement. Lunsekimig was well tolerated and common treatment-emergent adverse events were COVID-19, nasopharyngitis, injection site reactions, and headache. Lunsekimig showed dose-proportional increases in exposure and linear elimination. Mean t1/2z of lunsekimig was around 10 days across all IV and SC doses of the SAD and MAD parts of the study. Increases in the serum concentration of total TSLP and IL-13 for lunsekimig versus placebo indicated target engagement. ADA of low titers were detected in four (11.1%) participants who received lunsekimig in the SAD, and seven (43.8%) in the MAD. In conclusion, lunsekimig was well tolerated in healthy participants with a linear PK profile up to single 400 mg IV and SC dose and multiple doses of 100 and 200 mg SC Q2W, with low immunogenicity.

Population Pharmacokinetic Modeling and Exposure-Efficacy and Body Weight-Response Analyses for Tezepelumab in Patients With Severe, Uncontrolled Asthma

Tezepelumab is a human monoclonal antibody that blocks the activity of thymic stromal lymphopoietin. This analysis assessed the suitability of a fixed-dose regimen of tezepelumab 210 mg every 4 weeks (Q4W) in adults and adolescents with severe, uncontrolled asthma. A population pharmacokinetic model was developed using data from 1368 patients with asthma or healthy participants enrolled in 8 clinical studies (phases 1-3). Tezepelumab exposure-efficacy relationships were analyzed in the phase 3 NAVIGATOR study (NCT03347279), using asthma exacerbation rates over 52 weeks and changes in pre-bronchodilator forced expiratory volume in 1 s at week 52. Tezepelumab pharmacokinetics were well characterized by a 2-compartment linear disposition model with first-order absorption and elimination following subcutaneous and intravenous administration at 2.1-420 and 210-700 mg, respectively. There were no clinically relevant effects on tezepelumab pharmacokinetics from age (≥12 years), sex, race/ethnicity, renal or hepatic function, disease severity (inhaled corticosteroid dose level), concomitant asthma medication use, smoking history, or anti-drug antibodies. Body weight was the most influential covariate on tezepelumab exposure, but no meaningful differences in efficacy or safety were observed across body weight quartiles in patients with asthma who received tezepelumab 210 mg subcutaneously Q4W. There was no apparent relationship between tezepelumab exposure and efficacy at this dose regimen, suggesting that it is on the plateau of the exposure-response curve of tezepelumab. In conclusion, a fixed-dose regimen of tezepelumab 210 mg subcutaneously Q4W is appropriate for eligible adults and adolescents with severe, uncontrolled asthma.

Interplay of cytokines in the pathophysiology of atopic dermatitis: insights from Murin models and human

The pathogenesis of atopic dermatitis (AD) is understood to be crucially influenced by three main factors: dysregulation of the immune response, barrier dysfunction, and pruritus. In the lesional skin of AD, various innate immune cells, including Th2 cells, type 2 innate lymphoid cells (ILC2s), and basophils, produce Th2 cytokines [interleukin (IL)-4, IL-5, IL-13, IL-31]. Alarmins such as TSLP, IL-25, and IL-33 are also produced by epidermal keratinocytes, amplifying type 2 inflammation. In the chronic phase, not only Th2 cells but also Th22 and Th17 cells increase in number, leading to suppression of filaggrin expression by IL-4, IL-13, and IL-22, which further deteriorates the epidermal barrier function. Dupilumab, which targets IL-4 and IL-13, has shown efficacy in treating moderate to severe AD. Nemolizumab, targeting IL-31RA, effectively reduces pruritus in AD patients. In addition, clinical trials with fezakinumab, targeting IL-22, have demonstrated promising results, particularly in severe AD cases. Conversely, in murine models of AD, several cytokines, initially regarded as promising therapeutic targets, have not demonstrated sufficient efficacy in clinical trials. IL-33 has been identified as a potent activator of immune cells, exacerbating AD in murine models and correlating with disease severity in human patients. However, treatments targeting IL-33 have not shown sufficient efficacy in clinical trials. Similarly, thymic stromal lymphopoietin (TSLP), integral to type 2 immune responses, induces dermatitis in animal models and is elevated in human AD, yet clinical treatments like tezepelumab exhibit limited efficacy. Therapies targeting IL-1α, IL-5, and IL-17 also failed to achieve sufficient efficacy in clinical trials. It has become clear that for treating AD, IL-4, IL-13, and IL-31 are relevant therapeutic targets during the acute phase, while IL-22 emerges as a target in more severe cases. This delineation underscores the necessity of considering distinct pathophysiological aspects and therapeutic targets in AD between mouse models and humans. Consequently, this review delineates the distinct roles of cytokines in the pathogenesis of AD, juxtaposing their significance in human AD from clinical trials against insights gleaned from AD mouse models. This approach will improve our understanding of interspecies variation and facilitate a deeper insight into the pathogenesis of AD in humans.

A dual computational and experimental strategy to enhance TSLP antibody affinity for improved asthma treatment

Thymic stromal lymphopoietin is a key cytokine involved in the pathogenesis of asthma and other allergic diseases. Targeting TSLP and its signaling pathways is increasingly recognized as an effective strategy for asthma treatment. This study focused on enhancing the affinity of the T6 antibody, which specifically targets TSLP, by integrating computational and experimental methods. The initial affinity of the T6 antibody for TSLP was lower than the benchmark antibody AMG157. To improve this, we utilized alanine scanning, molecular docking, and computational tools including mCSM-PPI2 and GEO-PPI to identify critical amino acid residues for site-directed mutagenesis. Subsequent mutations and experimental validations resulted in an antibody with significantly enhanced blocking capacity against TSLP. Our findings demonstrate the potential of computer-assisted techniques in expediting antibody affinity maturation, thereby reducing both the time and cost of experiments. The integration of computational methods with experimental approaches holds great promise for the development of targeted therapeutic antibodies for TSLP-related diseases.

Systemic treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials

BACKGROUND

Atopic dermatitis (AD) is an inflammatory skin condition with multiple systemic treatments and uncertainty regarding their comparative impact on AD outcomes.

OBJECTIVE

We sought to systematically synthesize the benefits and harms of AD systemic treatments.

METHODS

For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, Web of Science, and GREAT databases from inception to November 29, 2022, for randomized trials addressing systemic treatments and phototherapy for AD. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. This review is registered in the Open Science Framework (https://osf.io/e5sna).

RESULTS

The 149 included trials (28,686 patients with moderate-to-severe AD) evaluated 75 interventions. With high-certainty evidence, high-dose upadacitinib was among the most effective for 5 of 6 patient-important outcomes; high-dose abrocitinib and low-dose upadacitinib were among the most effective for 2 outcomes. These Janus kinase inhibitors were among the most harmful in increasing adverse events. With high-certainty evidence, dupilumab, lebrikizumab, and tralokinumab were of intermediate effectiveness and among the safest, modestly increasing conjunctivitis. Low-dose baricitinib was among the least effective. Efficacy and safety of azathioprine, oral corticosteroids, cyclosporine, methotrexate, mycophenolate, phototherapy, and many novel agents are less certain.

CONCLUSIONS

Among individuals with moderate-to-severe AD, high-certainty evidence demonstrates that high-dose upadacitinib is among the most effective in addressing multiple patient-important outcomes, but also is among the most harmful. High-dose abrocitinib and low-dose upadacitinib are effective, but also among the most harmful. Dupilumab, lebrikizumab, and tralokinumab are of intermediate effectiveness and have favorable safety.

Tezepelumab: an anti-thymic stromal lymphopoietin monoclonal antibody for the treatment of asthma

Asthma is a common chronic respiratory disease in which epithelial cytokines and airway inflammation play critical pathophysiological roles. Thymic stromal lymphopoietin (TSLP), an epithelial cytokine, is central in the initiation and persistence of airway inflammation in asthma. Tezepelumab is a human immunoglobulin G2λ (IgG2λ) monoclonal antibody developed for treating moderate-to-severe asthma by specifically binding to TSLP and preventing its binding to the TSLP receptor on inflammatory cells. In this narrative review, we describe the results of clinical trials that evaluated the pharmacokinetics, pharmacodynamics, efficacy and safety of tezepelumab in patients with moderate-to-severe asthma. We also introduce the ongoing clinical trials in patients with asthma as well as future trials investigating the use of tezepelumab for other indications.

Atopic dermatitis: a brief review of recent advances in its management

Atopic dermatitis (AD) is a common inflammatory skin disorder characterized by recurrent eczematous lesions and intense itching. The disorder affects people of all ages and ethnicities, has a substantial psychosocial impact on patients and relatives, and is the leading cause of the global burden of skin diseases. Atopic dermatitis is associated with an increased risk of multiple comorbidities, including food allergies, asthma, allergic rhinitis, and mental health disorders. The pathophysiology is complex and involves a strong genetic predisposition, epidermal dysfunction, and T-cell-driven inflammation. Although type-2 mechanisms are dominant, there is increasing evidence that the disorder involves multiple immune pathways. Until recently, the management of AD rested mainly on the judicious use of emollients, topical steroids, and topical calcineurin inhibitors in the majority of patients, and systemic immunosuppressants were advocated in severely diseased patients. However, in the last few years, new therapeutic strategies have been designed and developed to target the various steps in the chain of molecular events that lead to the AD phenotype. This review highlights the recent advancements in the management of AD.

Evidence-Based Approach of Biologic Therapy in Bronchial Asthma

The emergence of biologic agents in the treatment of bronchial asthma has a wide impact on improving quality of life, reducing morbidity, and overall health care utilization. These therapies usually work by targeting specific inflammatory pathways involving type 2 inflammation and are particularly effective in severe eosinophilic asthma. Various randomized controlled trials have shown their effectiveness by reducing exacerbation rates and decreasing required glucocorticoid dosages. One of the relatively newer agents, tezepelumab, targets thymic stromal lymphoprotein and has proven its efficacy in patients independent of asthma phenotype and serum biomarker levels. This article reviews the pathophysiologic mechanism behind biologic therapy and offers an evidence-based discussion related to the indication, benefits, and adverse effects of such therapies.

Monoclonal antibody and protein therapeutic formulations for subcutaneous delivery: high-concentration, low-volume vs. low-concentration, high-volume

Biologic drugs are used to treat a variety of cancers and chronic diseases. While most of these treatments are administered intravenously by trained healthcare professionals, a noticeable trend has emerged favoring subcutaneous (SC) administration. SC administration of biologics poses several challenges. Biologic drugs often require higher doses for optimal efficacy, surpassing the low volume capacity of traditional SC delivery methods like autoinjectors. Consequently, high concentrations of active ingredients are needed, creating time-consuming formulation obstacles. Alternatives to traditional SC delivery systems are therefore needed to support higher-volume biologic formulations and to reduce development time and other risks associated with high-concentration biologic formulations. Here, we outline key considerations for SC biologic drug formulations and delivery and explore a paradigm shift: the flexibility afforded by low-to-moderate-concentration drugs in high-volume formulations as an alternative to the traditionally difficult approach of high-concentration, low-volume SC formulation delivery.

The Impact of Tezepelumab in Uncontrolled Severe Asthma: A Systematic Review of Randomized Controlled Trials

Asthma, a chronic illness, is characterized by inflammation and airway constriction. Uncontrolled severe asthma is related to poor quality of life and increased utilization of health resources. Conventional treatments are associated with a significant amount of adverse effects. Recent years have seen the identification of various molecular effectors and signaling pathways as interesting targets for the biological therapy of severe asthma that is resistant to current therapies. Because they only target some downstream components of the inflammatory response in asthma, leaving other components unaffected, current biologic treatments only lower the exacerbation rate by 50%. If we focus on the upstream mediators of the inflammatory response in asthma, it might have a greater effect and be more efficient. Tezepelumab is a human monoclonal IgG2 antibody that specifically binds to thymic stromal lymphopoietin (TSLP) at the level of its TSLPR (thymic stromal lymphopoietin receptor) binding site, inhibiting the interaction between human TSLP and TSLPR. It is being used to treat the cytokines on the respiratory epithelial layer known as "alarmins." It is the only biologic drug available for treating severe uncontrolled asthma, despite limitations in biomarker and phenotype. In light of recent developments, the lack of knowledge on tezepelumab prompts us to publish a comprehensive systematic review. We discovered that regardless of blood eosinophil level and fractional exhaled nitric oxide levels, tezepelumab dramatically lowers asthma exacerbation in patients with severe uncontrolled asthma when compared to placebo. Tezepelumab also lessens patients' demand for healthcare resources while improving clinical indicators of lung function, health-related quality of life, and asthma management in patients. Tezepelumab plays a role in enhancing pre-bronchodilator FEV1 and lowering blood eosinophil count and fractional exhaled nitric oxide in patients with or without chronic allergies (FeNO). There have been no reports of fatalities or severe adverse events connected to tezepelumab.

Tezepelumab for Patients with Severe Uncontrolled Asthma: A Systematic Review and Meta-Analysis

Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin, an epithelial-cell-derived cytokine implicated in the pathogenesis of asthma. It was approved by the United States Federal Drug Administration (US FDA) as an add-on maintenance treatment for patients with severe uncontrolled asthma in December 2021. We conducted a systematic review and meta-analysis to investigate the safety and efficacy of tezepelumab on forced expiratory volume (FEV1) (L), the rate of asthma exacerbations, health-related quality of life, fractional exhaled nitric oxide (FeNO) (ppb), and blood eosinophil count (cells/mL) in patients with severe, uncontrolled asthma. Mean changes for efficacy and proportions (safety) with their corresponding 95% confidence intervals (CIs) were used to provide pooled estimates. A total of six randomized controlled trials comprising 2667 patients were included, of whom 1610 were treated with tezepelumab and 1057 received placebo. The pooled analysis showed that tezepelumab treatment resulted in an improvement in FEV1 of 0.15 L (95% CI: 0.12 to 0.17), a reduction in the asthma exacerbation rate per year of 0.60 (95% CI: 0.51 to 0.70), and a reduction in FeNO of -12.41 ppb (95% CI: -14.28 to -10.53) when compared to placebo. Improvements in FEV1 and FeNO levels were maintained at 24 and 52 weeks. As for safety, patients did not experience a higher incidence of adverse drug reactions with tezepelumab (0.79 (95% CI: 0.55 to 1.12)) as compared to placebo. As for quality of life, different doses of the tezepelumab intervention group depicted non-significant improvement in the QoL, from 0.15 (95% CI: -0.09 to 0.38) for 70 mg, 0.18 (95% CI: -0.10 to 0.46) for 210 mg, 0.08 (95% CI: -0.16 to 0.32) for 280 mg as compared to the placebo. Tezepelumab significantly reduced exacerbation rates and improved FEV1 with an acceptable safety profile.

Current Insights into Immunology and Novel Therapeutics of Atopic Dermatitis

Atopic dermatitis (AD) is one of the most prevalent inflammatory disease among non-fatal skin diseases, affecting up to one fifth of the population in developed countries. AD is characterized by recurrent pruritic and localized eczema with seasonal fluctuations. AD initializes the phenomenon of atopic march, during which infant AD patients are predisposed to progressive secondary allergies such as allergic rhinitis, asthma, and food allergies. The pathophysiology of AD is complex; onset of the disease is caused by several factors, including strong genetic predisposition, disrupted epidermal barrier, and immune dysregulation. AD was initially characterized by defects in the innate immune system and a vigorous skewed adaptive Th2 response to environmental agents; there are compelling evidences that the disorder involves multiple immune pathways. Symptomatic palliative treatment is the only strategy to manage the disease and restore skin integrity. Researchers are trying to more precisely define the contribution of different AD genotypes and elucidate the role of various immune axes. In this review, we have summarized the current knowledge about the roles of innate and adaptive immune responsive cells in AD. In addition, current and novel treatment strategies for the management of AD are comprehensively described, including some ongoing clinical trials and promising therapeutic agents. This information will provide an asset towards identifying personalized targets for better therapeutic outcomes.

Estimation of Clearance and Bioavailability of Therapeutic Monoclonal Antibodies from Only Subcutaneous Injection Data in Humans Based on Comprehensive Analysis of Clinical Data

Introduction

Theoretically, the separate estimation of clearance (CL) and bioavailability (F) requires both intravenous and extravascular injection data. This study investigated whether CL and subcutaneous F of therapeutic monoclonal antibodies (mAbs) in humans can be separately estimated from subcutaneous injection data only.

Methods

First, the geometric mean of linear pharmacokinetic parameters (CL, intercompartmental CL [Q], volume of distribution in the central compartment [V_c], and volume of distribution in the peripheral compartment [V_p]) after intravenous injection for mAbs in humans that have been reported in public data sources was estimated from 103 mAbs with linear pharmacokinetics and 44 mAbs with nonlinear pharmacokinetics. Next, we estimated the CL and F of 25 mAbs with linear pharmacokinetics from plasma/serum mAb concentration–time profiles after subcutaneous injection in humans by fixing the geometric mean of Q, V_c, and V_p based on the public data. Moreover, the plasma/serum concentration–time profile of 25 mAbs after intravenous injection was simulated using the estimated CL and the geometric mean of Q, V_c, and V_p.

Results

There were no significant differences in parameters among subclasses (immunoglobulin [Ig] G1, 2, and 4) or in linearity (derivation from linear and nonlinear pharmacokinetics). Using only subcutaneous injection data, we successfully estimated the CL of 23/25 mAbs (92%) and F of all 25 mAbs (100%) within 1.5-fold of the observed value. Moreover, overall, the simulated concentration–time profiles were largely consistent with observed data (90.8% within 1.5-fold of the observed values).

Conclusions

This approach does not require intravenous injection data to separately estimate CL and F after subcutaneous injection in humans and can therefore accelerate the clinical development of mAbs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-021-01023-z.

Functionality and Performance of an Accessorized Pre-Filled Syringe and an Autoinjector for At-Home Administration of Tezepelumab in Patients with Severe, Uncontrolled Asthma

BACKGROUND

Tezepelumab is an anti-thymic stromal lymphopoietin monoclonal antibody in development for the treatment of severe asthma. This study assessed the functionality and performance of an accessorized pre-filled syringe (APFS) and an autoinjector (AI) for administration of tezepelumab in the clinic and at home.

METHODS

This phase 3, multicenter, randomized, open-label, parallel-group study (PATH-HOME, ClinicalTrials.gov identifier: NCT03968978) was conducted in patients aged 12-80 years with asthma that was uncontrolled despite treatment with medium- to high-dose inhaled corticosteroids plus at least one additional controller medication. Patients received six subcutaneous doses of tezepelumab 210 mg via APFS or AI. The first dose was administered by a healthcare professional, and patients or caregivers administered subsequent doses. First, second, third and final doses were administered in the clinic; fourth and fifth doses were administered at home. The primary endpoint was the proportion of successful administrations of tezepelumab. Secondary endpoints included the functionality and performance of the devices, Asthma Control Questionnaire (ACQ)-6 score, pharmacokinetics and safety.

RESULTS

Overall, 216 patients were randomized (APFS, n=111; AI, n=105). Tezepelumab was successfully administered via APFS by 91.7% of the participants (100/109) and via AI by 92.4% (97/105). Overall, 95.4-97.1% of at-home administrations were successful across device groups. Malfunction occurred in 6 of 655 dispensed APFSs and 5 of 624 dispensed AIs. Clinically meaningful improvements in ACQ-6 score were observed after 24 weeks in 81.1% and 76.2% of the patients in the APFS and AI groups, respectively. Tezepelumab pharmacokinetics were consistent between device groups and with previous studies. The most common adverse event was nasopharyngitis (9.3%). Injection-site reactions occurred in 5.7% and 0% of the patients in the AI and APFS groups, respectively.

CONCLUSION

This study demonstrated that the APFS and AI were functional and reliable, and performed equally well at home and in the clinic.

Machine Learning Attempts for Predicting Human Subcutaneous Bioavailability of Monoclonal Antibodies

PURPOSE

One knowledge gap related to subcutaneous (SC) delivery is unpredictable and variable bioavailability. This study was aimed to develop machine learning methods to predict whether mAb's bioavailability was ≥70% or below, without completely knowing the mechanism and causality between inputs and outputs.

METHODS

A database of mAb SC products was built. The model training and validation were accomplished based on this database and a set of the inputs (product properties) were mapped to the output (bioavailability) using different machine learning algorithms. Dimensionality reduction was undertaken using principal component analysis (PCA).

RESULTS

The bioavailability of the mAb products being investigated varied from 35% to 90%. The tree-based methods, including random forest (RF), Adaptive Boost (AdaBoost), and decision tree (DT) presented the best predictability and generalization power on bioavailability classification. The models based on Multi-layer perceptron (MLP), Gaussian Naïve Bayes (GaussianNB), and k nearest neighbor (kNN) algorithms also provided acceptable prediction accuracy.

CONCLUSION

Machine learning could be a potential tool to predict mAb's bioavailability. Since all input features were acquired using theoretical calculations and predictions rather than experiments, the models may be particularly applicable to some early-stage research activities such as mAb molecule triage, design/optimization, mutant screening, molecule selection, and formulation design.

Immunogenicity Challenges Associated with Subcutaneous Delivery of Therapeutic Proteins

The subcutaneous route of administration has provided convenient and non-inferior delivery of therapeutic proteins compared to intravenous infusion, but there is potential for enhanced immunogenicity toward subcutaneously administered proteins in a subset of patients. Unwanted anti-drug antibody response toward proteins or monoclonal antibodies upon repeated administration is shown to impact the pharmacokinetics and efficacy of multiple biologics. Unique immunogenicity challenges of the subcutaneous route have been realized through various preclinical and clinical examples, although subcutaneous delivery has often demonstrated comparable immunogenicity to intravenous administration. Beyond route of administration as a treatment-related factor of immunogenicity, certain product-related risk factors are particularly relevant to subcutaneously administered proteins. This review attempts to provide an overview of the mechanism of immune response toward proteins administered subcutaneously (subcutaneous proteins) and comments on product-related risk factors related to protein structure and stability, dosage form, and aggregation. A two-wave mechanism of antigen presentation in the immune response toward subcutaneous proteins is described, and interaction with dynamic antigen-presenting cells possessing high antigen processing efficiency and migratory activity may drive immunogenicity. Mitigation strategies for immunogenicity are discussed, including those in general use clinically and those currently in development. Mechanistic insights along with consideration of risk factors involved inspire theoretical strategies to provide antigen-specific, long-lasting effects for maintaining the safety and efficacy of therapeutic proteins.

Pharmacokinetic and Pharmacodynamic Modeling of Tezepelumab to Guide Phase 3 Dose Selection for Patients With Severe Asthma

Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin, an epithelial cytokine involved in asthma pathogenesis. In the phase 2b PATHWAY study (ClinicalTrials.gov identifier: NCT02054130), tezepelumab significantly reduced exacerbations in adults with severe, uncontrolled asthma. We used pharmacokinetic (PK) and pharmacodynamic (PD) modeling to guide tezepelumab dose selection for phase 3 trials in patients with severe asthma. PK data from 7 clinical studies were used to develop a population PK model. Population PK-PD models were developed to characterize the relationship between tezepelumab PK and asthma exacerbation rate (AER) and fractional exhaled nitric oxide (FeNO) levels (using phase 2b PD data only). Tezepelumab PK were well described by a 2-compartment model with first-order absorption; PK parameter estimates were consistent with those of other immunoglobulin G2 antibodies. PK-PD models predicted that subcutaneous dosing at 210 mg every 4 weeks was associated with ≈90% of the maximum drug effect of tezepelumab on AER and FeNO; further dose increases were not expected to result in additional, clinically meaningful treatment benefit. No clinically significant covariates of treatment effects on AER and FeNO were identified. Population PK simulations, exposure-response relationships and safety profiles of tezepelumab at doses up to 280 mg every 2 weeks suggested that no dose adjustment based on body weight or for adolescents was required. These results support the selection of 210 mg every 4 weeks subcutaneously as the dose for phase 3 studies of tezepelumab in adults and adolescents with severe asthma.

Tezepelumab Pharmacokinetics, Safety, and Tolerability After Administration via Vial-and-syringe, Accessorized Prefilled Syringe, or Autoinjector: A Randomized Trial in Healthy Volunteers

PURPOSE

Tezepelumab is an anti-thymic stromal lymphopoietin monoclonal antibody therapeutic in development for patients with severe, uncontrolled asthma. In ongoing Phase III studies, tezepelumab is administered via subcutaneous (SC) injections using a vial-and-syringe (V-S). This study compared the pharmacokinetic (PK) parameters, safety, and tolerability of tezepelumab administered subcutaneously via V-S versus via an accessorized prefilled syringe (APFS) or autoinjector (AI).

METHODS

This single-center, randomized, open-label, parallel-group study was conducted in healthy volunteers aged 18-65 years. Participants, stratified according to weight (50 to <70 kg, 70 to <80 kg, or 80-90 kg), were randomized evenly to 9 groups representing injections to the abdomen, thigh, or upper arm via V-S, APFS, or AI. Tezepelumab PK parameters over 113 days were evaluated after a single 210-mg SC dose. The primary end points were comparison of C_max and AUC_0-∞ between device groups. Further PK parameters, immunogenicity, safety (including injection site reactions [ISRs] and injection site pain [visual analog scale]) were also assessed.

FINDINGS

A total of 315 adults were randomized to treatment. Geometric mean ratios for comparisons between device groups of C_max, AUC_0-∞, and AUC_0-last were close to 1, with 90% CIs all within the range of 0.8-1.25, meeting bioequivalence criteria. PK variables were also similar between devices across injection sites and weight categories. Across devices, thigh injection resulted in slightly higher exposure than upper arm injection, and abdomen injection resulted in exposure similar to or slightly lower than thigh injection; however, these differences were not clinically meaningful. Treatment-emergent anti-tezepelumab antibodies were present in 3 (2.9%), 1 (1.0%), and 0 participants in the V-S, APFS, and AI groups, respectively. Treatment-related adverse events were reported in 15.0% of participants overall (V-S, 10.7%; APFS, 18.1%; AI, 16.0%), including ISRs in 1 (1.0%), 3 (2.9%), and 3 (2.8%) participants in the V-S, APFS, and AI groups. Median visual analog scale pain score (0-100 mm scale) was 2 mm immediately after injection and was 0 mm at 30 min for all groups.

IMPLICATIONS

Tezepelumab PK parameters after a single 210-mg SC dose were comparable when administered via V-S, APFS, or AI. In all groups, immunogenicity rate and injection site pain were low, and ISRs were uncommon. These findings support administration of tezepelumab via APFS or AI, in addition to V-S, providing patients and physicians with greater choice and the potential convenience of at-home use. ClinicalTrials.gov identifier: NCT03989544.

TSLP Inhibitors for Asthma: Current Status and Future Prospects

Thymic stromal lymphopoietin (TSLP) is an allarmin cytokine whose importance in human asthma has been repeatedly documented. Accordingly, targeting of TSLP and TSLP-mediated signalling is considered as an attractive therapeutic strategy to asthma. Tezepelumab, which is the first-in-class anti-TSLP monoclonal antibodies (mAb), is a fully human IgG2λ mAb that binds human TSLP, prevents interaction with its receptor and, consequently, inhibits multiple downstream inflammatory pathways. Because of the excellent results of Phase II trials, the Food and Drug Administration granted tezepelumab as a 'breakthrough' biological drug for the treatment of severe asthma. Several studies with this mAb are ongoing. CSJ117 is an Ab fragment that binds to TSLP and is delivered by inhalation but there is no published information on this biologic agent. Since new information suggests that targeting TSLP may be more likely to improve day-to-day asthma symptoms, in contrast to targeting mediators of the adaptive immune system, approaches that primarily act to ameliorate asthma exacerbations, novel approaches capable of blocking TSLP (for example, fully human single-chain fragment variables against TSLP, bifunctional drugs such as the one that combines an anti-IL-13 mAb with an anti-TSLP mAb, a fusion protein consisting of the ectodomains of TSLPR and IL-7Ra that extend into the extracellular space, also known as a TSLP-trap, fragments capable of disrupting the TSLP:TSLPR complex) are under preclinical investigation. However, some critical aspects remain to be clarified before being able to define this approach as the one that will probably better help patients suffering from severe asthma because of its holistic effects.

NAVIGATOR: a phase 3 multicentre, randomized, double-blind, placebo-controlled, parallel-group trial to evaluate the efficacy and safety of tezepelumab in adults and adolescents with severe, uncontrolled asthma

BACKGROUND

Patients with severe, uncontrolled asthma have a significant unmet need for new treatments that have broader effects on airway inflammation, and that provide greater improvements in asthma outcomes than currently approved biologics and standard-of-care therapies. Tezepelumab is a human monoclonal antibody that blocks the activity of the epithelial cytokine thymic stromal lymphopoietin. In the PATHWAY phase 2b study (NCT02054130), tezepelumab significantly reduced exacerbations by up to 71% in adults with severe, uncontrolled asthma, irrespective of baseline disease phenotype. This article reports the design and objectives of the pivotal phase 3 NAVIGATOR study.

METHODS

NAVIGATOR (NCT03347279) is an ongoing randomized, double-blind, placebo-controlled trial in adults (18-80 years old) and adolescents (12-17 years old) with severe, uncontrolled asthma, who are receiving treatment with medium- or high-dose inhaled corticosteroids plus at least one additional controller medication with or without oral corticosteroids (N = 1061). The study population includes approximately equal proportions of patients with high (≥ 300 cells/μL) and low (< 300 cells/μL) blood eosinophil counts. The study comprises a 5-6-week screening period, a 52-week treatment period and a 12-week post-treatment follow-up period. All patients will receive their prescribed controller medications without change throughout the study. The primary efficacy endpoint is the annualized asthma exacerbation rate during the 52-week treatment period. Key secondary endpoints include the effect of tezepelumab on lung function, asthma control and health-related quality of life.

DISCUSSION

NAVIGATOR is evaluating the effect of tezepelumab in patients with a broad range of severe asthma phenotypes at baseline, including those with low blood eosinophil counts. The target sample size for NAVIGATOR (N = 1060) was achieved, and it is the largest clinical study of tezepelumab in severe, uncontrolled asthma to date. NAVIGATOR aims to further investigate the effect of tezepelumab on exacerbations and build on observations from the phase 2b PATHWAY study, and to demonstrate further the potential of tezepelumab to provide patients with severe, uncontrolled asthma with improvements in lung function, asthma control and health-related quality of life.

TRIAL REGISTRATION

NCT03347279 (ClinicalTrials.gov). Registered 20 November 2017.

A Phase 1, Randomized, Placebo-Controlled Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Immunogenicity of Subcutaneous Tezepelumab in Healthy Japanese Men

Tezepelumab, a human immunoglobulin G2 monoclonal antibody against thymic stromal lymphopoietin, is currently under clinical development for the treatment of severe, uncontrolled asthma. This phase 1, randomized, placebo-controlled, single-ascending-dose study assessed the safety, tolerability, pharmacokinetics, and immunogenicity of subcutaneous tezepelumab in healthy Japanese men. Participants were assigned to 1 of 3 tezepelumab dose cohorts (35, 105, or 280 mg; n = 8 per cohort) and randomized (6:2) to receive a single subcutaneous dose of tezepelumab or placebo, with a follow-up period of 84 to 112 days. The overall incidences and severities of treatment-emergent adverse events were similar across tezepelumab doses and between the tezepelumab and placebo groups. Tezepelumab was absorbed slowly, reaching a maximum serum concentration (mean, 5.2-39.7 µg/mL) after 7 to 10 days. Area under the concentration-time curve (mean, 207.2-1612.0 µg · day /mL) increased in an approximate dose-proportional manner. Tezepelumab had a long terminal serum half-life (mean, 23.9-26.3 days) and a small apparent distribution volume, suggesting limited distribution into peripheral tissues. No participants developed anti-tezepelumab antibodies. Single-dose, subcutaneous administration of tezepelumab 35 to 280 mg resulted in an acceptable safety profile with linear pharmacokinetics in healthy Japanese men. No clear differences in tezepelumab safety and pharmacokinetics between Japanese and non-Japanese populations were identified.

Modulation of Signaling Mediated by TSLP and IL-7 in Inflammation, Autoimmune Diseases, and Cancer

Thymic Stromal Lymphopoietin (TSLP) and Interleukin-7 (IL-7) are widely studied cytokines within distinct branches of immunology. On one hand, TSLP is crucially important for mediating type 2 immunity at barrier surfaces and has been linked to widespread allergic and inflammatory diseases of the airways, skin, and gut. On the other hand, IL-7 operates at the foundations of T-cell and innate lymphoid cell (ILC) development and homeostasis and has been associated with cancer. Yet, TSLP and IL-7 are united by key commonalities in their structure and the structural basis of the receptor assemblies they mediate to initiate cellular signaling, in particular their cross-utilization of IL-7Rα. As therapeutic targeting of TSLP and IL-7 via diverse approaches is reaching advanced stages and in light of the plethora of mechanistic and structural data on receptor signaling mediated by the two cytokines, the time is ripe to provide integrated views of such knowledge. Here, we first discuss the major pathophysiological roles of TSLP and IL-7 in autoimmune diseases, inflammation and cancer. Subsequently, we curate structural and mechanistic knowledge about receptor assemblies mediated by the two cytokines. Finally, we review therapeutic avenues targeting TSLP and IL-7 signaling. We envision that such integrated view of the mechanism, structure, and modulation of signaling assemblies mediated by TSLP and IL-7 will enhance and fine-tune the development of more effective and selective approaches to further interrogate the role of TSLP and IL-7 in physiology and disease.

An overview of drug discovery efforts for eczema: why is this itch so difficult to scratch?

Introduction: Atopic dermatitis (AD) is a type of allergic/inflammatory dermatitis characterized by itch and an impairment in quality of life.Areas covered: Herein, the authors review drug discovery efforts for AD, highlighting the clinical efficacy of novel drugs, with a particular focus on the relief of pruritus. Topical agents include emollients, topical antihistamines, corticosteroids, calcineurin inhibitors and herbs. Recently, topical phosphodiesterase E4 (PDE4) inhibitors like crisaborole have become available and are efficacious for mild to moderate AD with few side effects. For more severe AD, monoclonal antibodies like dupilumab are considered as efficacious subcutaneous treatment options. In severe and recalcitrant AD, systemic treatment can ameliorate AD symptoms.Expert opinion: Many topical and systemic medications have demonstrated therapeutic benefits for AD. Indeed, randomized trials have shown that topical PDE4 inhibitors and subcutaneous dupilumab are safe and efficacious. Objective tools to evaluate itch and gauge treatment efficacy is important, but current methodology relies primarily on clinical scores. AD is a systemic atopic disease with a lot of complicated psychosocial issues. Suboptimal efficacy is often due to poor compliance and unrealistic expectation of curative treatment, rendering treatment difficult despite the existence of effective medications.

Pruritus in allergy and immunology

Although evolutionarily conserved to expel ectoparasites and aid in the clearance of toxins and noxious environmental stimuli from the host, the type 2 immune response can become pathologic in the setting of a variety of allergic disorders. Itch can be a behavioral extension of type 2 immunity by evoking scratching and, in the setting of disease, can become chronic and thus highly pathologic as well. Classically, our understanding of itch mechanisms has centered around the canonical IgE-mast cell-histamine axis. However, therapies aimed at blocking the histaminergic itch pathway have been largely ineffective, suggesting the existence of nonhistaminergic itch pathways. Indeed, recent advances in itch biology have provided critical new insight into a variety of novel therapeutic avenues for chronic itch in the setting of a number of allergic disorders. Here we highlight how these new developments will likely inform the problem of pruritus in a variety of well-established and emerging conditions in the field of allergy.