Tezepelumab compared with other biologics for the treatment of severe asthma: a systematic review and indirect treatment comparison

Methods for Indirect Treatment Comparison: Results from a Systematic Literature Review

INTRODUCTION

Health technology assessment (HTA) agencies express a clear preference for randomized controlled trials when assessing the comparative efficacy of two or more treatments. However, an indirect treatment comparison (ITC) is often necessary where a direct comparison is unavailable or, in some cases, not possible. Numerous ITC techniques are described in the literature. A systematic literature review (SLR) was conducted to identify all the relevant literature on existing ITC techniques, provide a comprehensive description of each technique and evaluate their strengths and limitations from an HTA perspective in order to develop guidance on the most appropriate method to use in different scenarios.

METHODS

Electronic database searches of Embase and PubMed, as well as grey literature searches, were conducted on 15 November 2021. Eligible articles were peer-reviewed papers that specifically described the methods used for different ITC techniques and were written in English. The review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 73 articles were included in the SLR, reporting on seven different ITC techniques. All reported techniques were forms of adjusted ITC. Network meta-analysis (NMA) was the most frequently described technique (in 79.5% of the included articles), followed by matching-adjusted indirect comparison (MAIC) (30.1%), network meta-regression (24.7%), the Bucher method (23.3%), simulated treatment comparison (STC) (21.9%), propensity score matching (4.1%) and inverse probability of treatment weighting (4.1%). The appropriate choice of ITC technique is critical and should be based on the feasibility of a connected network, the evidence of heterogeneity between and within studies, the overall number of relevant studies and the availability of individual patient-level data (IPD). MAIC and STC were found to be common techniques in the case of single-arm studies, which are increasingly being conducted in oncology and rare diseases, whilst the Bucher method and NMA provide suitable options where no IPD is available.

CONCLUSION

ITCs can provide alternative evidence where direct comparative evidence may be missing. ITCs are currently considered by HTA agencies on a case-by-case basis; however, their acceptability remains low. Clearer international consensus and guidance on the methods to use for different ITC techniques is needed to improve the quality of ITCs submitted to HTA agencies. ITC techniques continue to evolve quickly, and more efficient techniques may become available in the future.

Tezepelumab in patients with allergic and eosinophilic asthma

Asthma is a heterogeneous disease commonly driven by allergic and/or eosinophilic inflammation, both of which may be present in severe disease. Most approved biologics for severe asthma are indicated for specific phenotypes and target individual downstream type 2 components of the inflammatory cascade. Tezepelumab, a human monoclonal antibody (immunoglobulin G2λ), binds specifically to thymic stromal lymphopoietin (TSLP), an epithelial cytokine that initiates and sustains allergic and eosinophilic inflammation in asthma. By blocking TSLP, tezepelumab has demonstrated efficacy across known asthma phenotypes and acts upstream of all current clinically used biomarkers. In a pooled analysis of the phase 2b PATHWAY (NCT02054130) and phase 3 NAVIGATOR (NCT03347279) studies, compared with placebo, tezepelumab reduced the annualized asthma exacerbation rate over 52 weeks by 62% (95% confidence interval [CI]: 53, 70) in patients with perennial aeroallergen sensitization (allergic asthma); by 71% (95% CI: 62, 78) in patients with a baseline blood eosinophil count ≥300 cells/μL; and by 71% (95% CI: 59, 79) in patients with allergic asthma and a baseline blood eosinophil count ≥300 cells/μL. This review examines the efficacy and mode of action of tezepelumab in patients with allergic asthma, eosinophilic asthma and coexisting allergic and eosinophilic phenotypes.

Novel Immunopharmacological Drugs for the Treatment of Allergic Diseases

The exponential rise in the prevalence of allergic diseases since the mid-twentieth century has led to a genuine public health emergency and has also fostered major progress in research on the underlying mechanisms and potential treatments. The management of allergic diseases benefits from the biological revolution, with an array of novel immunomodulatory therapeutic and investigational tools targeting players of allergic inflammation at distinct pathophysiological steps. Prominent examples include therapeutic monoclonal antibodies against cytokines, alarmins, and their receptors, as well as small-molecule modifiers of signal transduction mainly mediated by Janus kinases and Bruton's tyrosine kinases. However, the first-line therapeutic options have yet to switch from symptomatic to disease-modifying interventions. Here we present an overview of available drugs in the context of our current understanding of allergy pathophysiology, identify potential therapeutic targets, and conclude by providing a selection of candidate immunopharmacological molecules under investigation for potential future use in allergic diseases.

The Acceptance of Indirect Treatment Comparison Methods in Oncology by Health Technology Assessment Agencies in England, France, Germany, Italy, and Spain

INTRODUCTION

Randomized controlled trials (RCTs) are the gold standard when comparing treatment effectiveness, and Health Technology Assessment (HTA) agencies state a clear preference for such direct comparisons. When these are not available, an indirect treatment comparison (ITC) is an alternative option. The objective of this study was to assess the acceptance of ITC methods by HTA agencies across England, France, Germany, Italy, and Spain, using oncology cases for a homogeneous sample of HTA evaluations.

METHODS

The study was conducted on the PrismAccess database in May 2021 to retrieve HTA evaluation reports for oncology treatments for solid tumors, in which an ITC was presented. The analysis was restricted to HTA evaluation reports published between April 2018 and April 2021 in England, France, Germany, Italy, and Spain. Identified HTA evaluation reports were screened and reviewed by two independent reviewers. For each ITC presented, the methodology and its acceptance by the HTA agency were analyzed.

RESULTS

Five hundred and forty-three HTA evaluation reports were identified, of which 120 (22%) presented an ITC. This proportion was the highest in England (51%) and lowest in France (6%). The overall acceptance rate of ITC methods was 30%, with the highest in England (47%) and lowest in France (0%). Network meta-analysis (NMA; 23%) was the most commonly used ITC technique, with a 39% acceptance rate overall, followed by Bucher ITC (19%; 43% acceptance rate) and matching-adjusted indirect comparison (13%; 33% acceptance rate). The most common criticisms of the ITC methods from HTA agencies related to data limitations (heterogeneity and lack of data; 48% and 43%, respectively) and the statistical methods used (41%).

CONCLUSIONS

The generally low acceptance rate of ITC methods by HTA agencies in oncology suggests that, whilst in the absence of a direct comparison ITCs may provide relevant evidence, this evidence is not widely considered sufficient for the purpose of HTA evaluations. The perception of ITC methods for the purpose of HTA evaluations varies substantially between countries. There is a need for further clarity on the properties of ITC techniques and the assessment of their results as ITC methods continue to evolve quickly and further techniques may become available in the future.

Which biologic? New findings from a real-world study

See related article

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.

Effect of Tezepelumab on Lung Function in Patients With Severe, Uncontrolled Asthma in the Phase 3 NAVIGATOR Study

INTRODUCTION

Severe asthma is associated with airway inflammation and airway obstruction. In the phase 3 NAVIGATOR study, tezepelumab treatment significantly improved pre-bronchodilator forced expiratory volume in 1 s (FEV1) compared with placebo in patients with severe, uncontrolled asthma. This analysis assessed the effect of tezepelumab versus placebo on additional lung function parameters in patients from NAVIGATOR.

METHODS

NAVIGATOR was a multicenter, randomized, double-blind, placebo-controlled study. Patients (12-80 years old) receiving medium- or high-dose inhaled corticosteroids and at least one additional controller medication, with or without oral corticosteroids, were randomized 1:1 to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. Changes from baseline to week 52 in pre-bronchodilator FEV1, post-bronchodilator FEV1, forced vital capacity (FVC), pre-bronchodilator FEV1/FVC ratio, pre-bronchodilator forced expiratory flow between 25 and 75% of vital capacity (FEF25-75), and morning and evening peak expiratory flow (PEF) were assessed.

RESULTS

Tezepelumab treatment improved all evaluated lung function parameters over 52 weeks compared with placebo [least-squares mean difference (95% confidence interval): pre-bronchodilator FEV1, 0.13 (0.08, 0.18) L; post-bronchodilator FEV1, 0.12 (0.07, 0.16) L; FVC, 0.13 (0.07, 0.19) L; FEV1/FVC ratio, 2.06% (1.22%, 2.90%); FEF25-75, 0.13 (0.07, 0.19) L/s; morning PEF, 16.6 (8.1, 25.1) L/min; and evening PEF, 14.9 (6.3, 23.4) L/min]. Improvements were observed as early as weeks 1-2 and were maintained over 52 weeks. Greater improvements in lung function compared with placebo were observed in patients with a disease duration of less than 20 years, those with baseline post-bronchodilator FEV1 reversibility of at least 20%, and in patients with a baseline post-bronchodilator FEV1/FVC ratio of less than 0.7.

CONCLUSION

These findings further support the benefits of tezepelumab treatment in improving airflow limitation in patients with severe, uncontrolled asthma.

CLINICAL TRIAL REGISTRATION

NAVIGATOR (NCT03347279).

Increasing transparency in indirect treatment comparisons: is selecting effect modifiers the missing part of the puzzle? A review of methodological approaches and critical considerations

Failure to adjust for effect modifiers (EMs) in indirect treatment comparisons (ITCs) can produce biased and uncertain effect estimates. This is particularly important for health technology assessments (HTAs), where the availability of new treatments is based on comparative effectiveness results. Much emphasis has been placed on advancing ITC methods to adjust for EMs, yet whether EMs are appropriately identified for the conduct of ITCs in the first place is unclear. To understand the extent of guidance and requirements for the selection of EMs for ITCs currently available and if and how this guidance is applied in practice, a series of pragmatic reviews of guidance documents from HTA and non-payer organizations, primary published ITC analyses, and prior HTA submissions in two indications (non-small cell lung cancer and psoriasis) was conducted. The reviews showed that current ITC guidance mainly focused on developing analytical methods to adjust for EMs. Some organizations, such as HTA bodies in the UK, France and Germany, recommended the use of literature reviews, expert opinion and statistical methods to identify EMs. No detailed guidance on the selection process or the appropriate literature review approach was found. Similar trends were identified through the database search and review of prior HTA submissions; only few published ITCs and submissions included information on the EM selection process which was either based on findings from the literature, trial subgroup analyses, or clinical input. No reference to a systematic selection approach was found. There is an urgent need to fill the guidance gap identified across the reviews by including a step in ITC guidelines on how EMs should be identified through systematic reviews, formal expert elicitation, and a quantitative assessment of the EM distribution. Researchers and manufacturers are also encouraged to improve transparent reporting and justification of their selection of EMs to allow for an independent review of the set of factors being considered for adjustment. Both will contribute toward reducing bias in the ITC results and ultimately increase confidence in decision-making.

Omalizumab Transitions in Severe Asthma: Factors Influencing Switching Decisions and Timing for Optimal Response

OBJECTIVE

The objective of this study was to assess the effectiveness of switching from omalizumab to another biologic therapy for patients with severe asthma and evaluate factors that influenced the decision to switch and determined the optimal time for a good biologic response.

SUBJECTS AND METHODS

A retrospective study of severe asthma patients was conducted at Al-Rashed Allergy Center, a tertiary center in Kuwait. After meeting the eligibility criteria, patients were divided into two comparative groups: those continuing with omalizumab and those who started with omalizumab but switched to another biologic.

RESULTS

One hundred sixteen patients with severe asthma were recruited, and only 33 had access to multiple biological treatments. Approximately 22.4% switched from omalizumab. Male patients with a history of ischemic heart disease, chronic rhinosinusitis, and nasal polyps were more likely to switch if they had higher levels of eosinophils in the sputum. This study showed that every 1% increase in sputum eosinophils doubled the likelihood of a switch. Patients with access to alternative biological options had a much shorter mean duration of omalizumab therapy before switching compared to those with only affordable omalizumab: 4.9 ± 1.5 years versus 8.9 ± 1.3 years (p < 0.001). The optimal time to predict the likelihood of a good response was less than 5.5 years, with an area under the curve of 0.91 and p = 0.003. This cutoff point provided a sensitivity and specificity of approximately 89% and 100%, respectively.

CONCLUSION

An early transition from omalizumab, specifically within the first 5 years of treatment, in patients with severe asthma and higher sputum eosinophils may enhance the likelihood of a good response if other biological therapies were available.

Effects of Tezepelumab on Quality of Life of Patients with Moderate-to-Severe, Uncontrolled Asthma: Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

To assess the effects of tezepelumab on quality of life (QoL) in patients with moderate-to-severe, uncontrolled asthma.

RECENT FINDINGS

Tezepelumab improves pulmonary function tests (PFTs) and reduces the annualized asthma exacerbation rate (AAER) in patients with moderate-to-severe, uncontrolled asthma. We searched MEDLINE, Embase, and Cochrane Library from inception to September 2022. We included randomized controlled trials comparing tezepelumab versus placebo in patients aged ≥ 12 years with asthma on medium- or high-dose inhaled corticosteroids with ≥ 1 additional controller medication for ≥ 6 months and who had ≥ 1 asthma exacerbation in the 12 months before enrollment. We estimated effects measures with a random-effects model. Of 239 records identified, three studies were included, with a total of 1,484 patients. Tezepelumab significantly decreased biomarkers of T helper 2-driven inflammation, including blood eosinophil count (MD -135.8 [95% CI -164.37, -107.23]) and fractional exhaled nitric oxide (MD -9.64 [95% CI -13.75, -5.53]); improved PFTs, including pre-bronchodilator forced expiratory volume in 1 s (MD 0.18 [95% CI 0.08-0.27]); reduced the AAER (MD 0.47 [95% CI 0.39-0.56]); improved asthma-specific health-related QoL in the Asthma Control Questionnaire-6 (MD -0.33 [95% CI -0.34, -0.32]), Asthma Quality of Life Questionnaire for 12 Years and Older (MD 0.34 [95% CI 0.33, -0.35]), Asthma Symptom Diary (MD -0.11 [95% CI -0.18, -0.04]), and European Quality of Life 5 Dimensions 5 Levels Questionnaire (SMD 3.29 [95% CI 2.03, 4.55]) scores, although not clinically important; and did not change key safety outcomes, including any adverse event (OR 0.78 [95% CI 0.56-1.09]).

Comparative efficacy of tezepelumab to mepolizumab, benralizumab, and dupilumab in eosinophilic asthma: A Bayesian network meta-analysis

BACKGROUND

It is unclear how the efficacy of tezepelumab, approved for the treatment of type 2 high and low asthma, compares to the efficacy of other biologics for type 2-high asthma.

OBJECTIVES

We sought to conduct an indirect comparison of tezepelumab to dupilumab, benralizumab, and mepolizumab in the treatment of eosinophilic asthma.

METHODS

The investigators conducted a systematic review and Bayesian network meta-analyses. They identified randomized controlled trials indexed in PubMed, Embase, or Cochrane Central Register of Controlled Trials (CENTRAL) between January 1, 2000, and August 12, 2022. Outcomes included exacerbation rates, prebronchodilator FEV1, and the Asthma Control Questionnaire.

RESULTS

Ten randomized controlled trials (n = 9201) met eligibility. Tezepelumab (relative risk: 0.63; 95% credible interval [CI]: 0.46-0.86) was associated with significantly lower exacerbation rates than benralizumab and larger improvements in FEV1 compared to mepolizumab (mean difference [MD]: 66; 95% CI: -33 to 170) and benralizumab (MD: 62; 95% CI: -22 to 150), though the 95% CI crossed the null value of 0. Mepolizumab improved the Asthma Control Questionnaire score the most, but this improvement was not significantly different from that of tezepelumab (tezepelumab vs mepolizumab; MD: 0.14; 95% CI: -0.10 to 0.38). For efficacy by clinically important thresholds, tezepelumab, mepolizumab, and dupilumab achieved a >99% probability of reducing exacerbation rates by ≥50% compared to placebo, but benralizumab had only a 66% probability of doing so. Tezepelumab and dupilumab had a probability of 1.00 of improving prebronchodilator FEV1 by ≥100 mL above placebo. Compared to mepolizumab, dupilumab had >90% chance for improving FEV1 by ≥50 mL, but none of the differences between biologics exceeded 100 mL.

CONCLUSIONS

In individuals with eosinophilic asthma, tezepelumab and dupilumab were associated with greater improvements (although below clinical thresholds) in exacerbation rates and lung function than benralizumab or mepolizumab.

A comparison of the effectiveness of biologic therapies for asthma: A systematic review and network meta-analysis

BACKGROUND

Trials have not directly compared biologics for the treatment of asthma.

OBJECTIVE

To compare the relative efficacy of biologics in asthma.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov from inception to May 31, 2022 for randomized trials addressing biologic therapies for asthma. Reviewers worked independently and in duplicate to screen references, extract data, and assess risk of bias. We performed a frequentist network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations approach. We present dichotomous outcomes as absolute risk differences per 1000 patients and relative risk with 95% confidence intervals (95% CI) and continuous outcomes as mean difference (MD) and 95% CI.

RESULTS

We identified 64 trials, including 26,630 patients. For patients with eosinophilic asthma, tezepelumab (329 fewer exacerbations per 1000 [95% CI, 272.6-366.6 fewer]) and dupilumab (319.6 fewer exacerbations per 1000 [95% CI, 272.6-357.2 fewer]) reduce exacerbations compared with placebo (high certainty). Tezepelumab (MD, 0.24 L [95% CI, 0.16-0.32]) and dupilumab (0.25 L [95% CI, 0.21-0.29]) improve lung function compared with placebo (high certainty). Both tezepelumab (110.97 fewer hospital admissions per 1000 [95% CI, 94.53-120.56 fewer]) and dupilumab (97.27 fewer hospitalizations [4.11-124.67 fewer]) probably reduce hospital admissions compared with placebo (moderate certainty). For patients with low eosinophils, biologics probably do not improve asthma outcomes. For these patients, tezepelumab (MD, 0.1 L [95% CI, 0-0.19]) and dupilumab (MD, 0.1 L [95% CI, 0-0.20]) may improve lung function (low certainty).

CONCLUSION

Tezepelumab and dupilumab are effective at reducing exacerbations. For patients with low eosinophils, however, clinicians should probably be more judicious in using biologics, including tezepelumab, because they probably do not confer substantial benefit.

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.

Hydrolyzable Tannins in the Management of Th1, Th2 and Th17 Inflammatory-Related Diseases

Plants rich in hydrolyzable tannins were traditionally used all over the world for a variety of chronic inflammatory disorders, including arthritis, colitis, and dermatitis. However, the knowledge of their immunological targets is still limited though fundamental for their rational use in phytotherapy. The recent advances regarding the pathogenesis of inflammatory-based diseases represent an opportunity to elucidate the pharmacological mechanism of plant-derived metabolites with immunomodulatory activity. This review collects recent articles regarding the role of hydrolyzable tannins and their gut metabolites in Th1, Th2, and Th17 inflammatory responses. In line with the traditional use, rheumatoid arthritis (RA), inflammatory bowel diseases (IBDs), psoriasis, atopic dermatitis (AD), and asthma were the most investigated diseases. A substantial body of in vivo studies suggests that, beside innate response, hydrolyzable tannins may reduce the levels of Th-derived cytokines, including IFN-γ, IL-17, and IL-4, following oral administration. The mode of action is multitarget and may involve the impairment of inflammatory transcription factors (NF-κB, NFAT, STAT), enzymes (MAPKs, COX-2, iNOS), and ion channels. However, their potential impact on pathways with renewed interest for inflammation, such as JAK/STAT, or the modulation of the gut microbiota demands dedicate studies.

Monoclonal antibodies targeting small airways: a new perspective for biological therapies in severe asthma

Small airway dysfunction (SAD) in asthma is characterized by the inflammation and narrowing of airways with less of 2 mm in diameter between generations 8 and 23 of the bronchial tree. It is now widely accepted that small airways are involved in the pathogenesis of asthma and are a major determinant of airflow obstruction in this disease. 

In recent years, specialized tests have been developed, such as Impulse Oscillometry (IOS) and Multiple Breath Nitrogen Washout (MBNW) tests, which have been deemed more accurate in detecting SAD than conventional spirometry. Clinical studies show that SAD is associated with more severe bronchial hyperresponsiveness, worse asthma control, and a higher risk of exacerbations. Recent data from a large cohort study showed that the prevalence of SAD in asthma patients increases with asthma severity. Overall, SAD seems to represent a treatable trait, which makes it appealing for asthma control optimization and exacerbation rate reduction, especially in moderate-to-severe asthma.

Biologic agents are now available for the treatment of different severe asthma phenotypes and endotypes. However, the effect of these therapies on SAD remains poorly characterized. Literature showing that biologic agents can also favorably improve small airway function is accumulating. In particular, anti-IL5 agents (mepolizumab and benralizumab) seems to have a greater impact on SAD as compared to other biological agents, but direct comparisons in prospective randomized controlled trials are lacking.

In this mini-review article, we address the latest evidence on the effect of biological therapies on SAD in patients with severe asthma.