Clinical Determinants of Successful Omalizumab Therapy in Severe Allergic Asthma Patients: 4-Year-Long, Real-Life Observation

Long-term safety, durability of response, cessation and switching of biologics

PURPOSE OF REVIEW

Severe asthma patients suffer from decreased quality of life, and increased asthma symptoms, exacerbations, hospitalizations, and risk of death. Biologics have revolutionized treatment for severe asthma. However, with multiple biologic agents now available, clinicians must consider initial selection the long-term effectiveness of biologics. Additionally, patients have overlapping eligibilities and clinicians may consider switching between biologics for improved response. Finally, careful assessment of biologics cessation is needed for severe asthma patients who depend on these add-on therapies for asthma control.

RECENT FINDINGS

Evidence for long-term durability and safety varies by biologic agent. In general, initial benefits noted from these agents (ex. exacerbation reduction) is, at minimum, sustained with long term use. Rates of adverse events and serious adverse events, including those requiring cessation of a biologics are low with long term use. Further studies are needed to understand the development of antidrug antibodies but currently their prevalence rates are low. Adverse events and insufficient efficacy are common reasons for biologic cessation or switching. Discontinuation maybe associated with waning of benefits but can be considered in certain situations. Biologic switching can be associated with improved asthma control.

SUMMARY

Biologics are safe and effective long-term therapies for the management of asthma. Discontinuation must be carefully considered and if possible avoided. Reasons for insufficient efficacy must be evaluated and if needed, biologic switching should be considered.

Eosinophil to lymphocyte ratio may predict OCS reduction and change in quality of life (AQLQ) resulting from asthma biological treatment

OBJECTIVES

Simple clinical parameters that could be helpful in choice of monoclonal antibodies and prediction of their effectiveness are being sought. The aim was to assess if neutrophil-to-lymphocyte, eosinophil-to-lymphocyte and platelet-to-lymphocyte ratios may predict outcomes of biologic therapy for severe asthma.

METHODS

Retrospective, single-center study including severe asthma patients treated with three different biologics. The blood ratios were assessed at initiation of treatment (point 0) and after six months (point 1). The chi-square test was used to analyze differences in nominal variables. Quantitative variables were compared by Student's t-test, Mann-Whitney U or Wilcoxon signed-rank tests.

RESULTS

53 patients with severe asthma were included, among them 21 patients (40%) treated with omalizumab and 32 patients (60%) with mepolizumab or benralizumab. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios did not change during six-month-course of biological treatment. Eosinophil-to-lymphocyte ratio was higher at the point 0 (p = 0.016) in the group treated with anti-eosinophils than in the omalizumab group and lower at the point 1 (p = 0.006). In the anti-eosinophil group this ratio decreased between points 0 and 1 (p < 0.001). In the omalizumab group there was an inverse correlation between the initial ratio and oral corticosteroid dose reduction (rs = -0,67). In the a/eos group there were significant correlations between initial ratio and age (rs = 0.36), and ACQ (rs = -0.4) and ACQ (rs = 0.41) measured at the point 1.

CONCLUSIONS

Pretreatment eosinophil-to-lymphocyte ratio may predict oral corticosteroid dose reduction resulting from omalizumab treatment and change in quality of life and asthma control resulting from anti-IL-5 and IL-5R treatment.

Biological therapy management from the initial selection of biologics to switching between biologics in severe asthma

The aim of this review is to elaborate the management of biologic therapy from initial selection to switching biologics in severe asthma. A nonsystematic review was performed for biological therapy management in severe asthma. Depending on clinical characteristics and biomarkers, selecting the preferred biologic based on super-responder criteria from previous studies may result in adequate clinical efficacy in most patients. On the other hand, no matter how carefully the choice is made, in some patients, it may be necessary to discontinue the drug due to suboptimal clinical response or even no response. This may result in the need to switch to a different biological therapy. How long the biological treatment of patients whose asthma is controlled with biologics will be continued and according to which criteria they will be terminated remains unclear. It has been shown that in patients with a long history of good response to biologics, asthma control may be impaired when biologics are discontinued, while it may persist in others. Therefore, discontinuation of biologics may be a viable strategy in a particular patient group. Clinicians should make the best use of all predictive factors to identify patients who will most benefit from each biologic. Patients who do not meet a predefined response criterion after sufficient time for response evaluation and who are eligible for one or more alternative biological agents should be offered the opportunity to switch to another biologic. There is no consensus on when the biologics used in severe asthma that produce favorable results should be discontinued. In our opinion, treatment should continue for at least five years, as premature termination may potentially deteriorate asthma control.

Biologics for severe asthma: The real-world evidence, effectiveness of switching, and prediction factors for the efficacy

Biologics have been a key component of severe asthma treatment, and there are currently biologics available that target IgE, IL-5, IL-4/IL-13, and TSLP. Randomized controlled trials have established clinical evidence, but a significant portion of patients with severe asthma in real-life settings would have been excluded from those trials. Therefore, real-world research is necessary, and there is a growing body of information about the long-term efficacy and safety of biologics. Multiple clinical phenotypes of severe asthma exist, and it is crucial to choose patients based on their phenotypes. Blood eosinophil count is an important biomarker for anti-IL-5 therapies, and FeNO and eosinophil counts serve as prediction markers for dupilumab. Reliable markers for predicting response, however, have not yet been fully established for omalizumab. Identification of clinical or biological prediction factors is crucial for the path toward clinical remission because the current treatment goal includes clinical remission, which is defined as a realistic goal for remission off treatment. Additionally, since there are now multiple biologic options and overlaps in eligibility for biologics in clinical practice, the evidence regarding the effectiveness of switching the biologics is crucial. Investigations into the clinical trajectory following the cessation of biologics are another important issue. Recent research on omalizumab, mepolizumab, benralizumab and dupilumab's real-world effectiveness, the prediction factor for the efficacy, and the impact of switching or discontinuation will be reviewed and discussed in this review.

Difficult-to-Treat Asthma Management in School-Age Children

The World Health Organization divides severe asthma into three categories: untreated severe asthma; difficult-to-treat severe asthma; and severe, therapy-resistant asthma. The apparent frequency of severe asthma in the general population of asthmatic children is probably around 5%. Upon referral of these children, it is important to evaluate the diagnosis of asthma carefully before modifying management and applying a long-term monitoring plan. Identification of pathophysiologic phenotypes using objective biomarkers is essential in our routine assessments of severe asthma. Although conventional pharmacologic approaches should be attempted first, there is growing recognition that children with difficult-to-treat asthma may have unique clinical phenotypes that may necessitate alternative treatment approaches including asthma biologics. These new medications, especially those with effects on multiple pathologic features of asthma, raise the hope that new treatment strategies could induce remission. Besides introducing new medications, the opportunity for closer monitoring is feasible with advances in digital health. Therefore, we have the opportunity to improve response to medications, individualize treatment, and monitor response along with potential steps to prevent severe asthma.

Oral Corticosteroids Dependence and Biologic Drugs in Severe Asthma: Myths or Facts? A Systematic Review of Real-World Evidence

Airway inflammation represents an important characteristic in asthma, modulating airflow limitation and symptom control, and triggering the risk of asthma exacerbation. Thus, although corticosteroids represent the cornerstone for the treatment of asthma, severe patients may be dependent on oral corticosteroids (OCSs). Fortunately, the current humanised monoclonal antibodies (mAbs) benralizumab, dupilumab, mepolizumab, omalizumab, and reslizumab have been proven to induce an OCS-sparing effect in randomized controlled trials (RCTs), thus overcoming the problem of OCS dependence in severe asthma. Nevertheless, a large discrepancy has been recognized between selected patients enrolled in RCTs and non-selected asthmatic populations in real-world settings. It is not possible to exclude that the OCS-sparing effect of mAbs resulting from the RCTs could be different than the real effect resulting in clinical practice. Therefore, we performed a systematic review and correlation analysis to assess whether mAbs are effective in eliciting an OCS-sparing effect and overcoming the OCS dependence in severe asthmatic patients in real-world settings. Overall, real-world studies support the evidence that OCS dependence is a real condition that, however, can be found only in a small number of really severe asthmatic patients. In most patients, the dependence on OCS can be related to modifying factors that, when adequately modulated, may lead to a significant reduction or suspension of OCS maintenance. Conversely, in severe asthmatics in whom OCS resistance is proved by a high daily dose intake, mAbs allow reversion of the OCS dependence, leading to the suspension of OCS therapy in most patients or >50% reduction in the daily OCS dose.