Model-based comparisons of post-treatment free IgE and FEV1 between omalizumab asthma dosing tables in the United States and European Union.

AIMS: Omalizumab is an anti-immunoglobulin E (IgE) monoclonal antibody that was first approved by the United States (US) Food and Drug Administration (FDA) for the treatment of allergic asthma in 2003. The pivotal trials supporting the initial approval of omalizumab used dosing determined by patient's baseline IgE and body weight, with the goal of reducing the mean free IgE level to approximately 25 ng/mL or less. While the underlying parameters supporting the dosing table remained the same, subsequent studies and analyses have resulted in approved alternative versions of the dosing table, including the European Union (EU) asthma dosing table, which differs in weight bands and maximum allowable baseline IgE and omalizumab dose. In this study, we leveraged modelling and simulation approaches to predict and compare the free IgE reduction and forced expiratory volume in 1 second (FEV1) improvement with omalizumab dosing based on the US and EU asthma dosing tables. METHODS: Previously established population pharmacokinetic-IgE and IgE-FEV1 models were used to predict and compare post-treatment free IgE and FEV1 based on the US and EU dosing tables. Clinical trial simulations (with virtual asthma populations) and Monte Carlo simulations were performed to provide both breadth and depth in the comparisons. RESULTS: The US and EU asthma dosing tables were predicted to result in generally comparable free IgE suppression and FEV1 improvement. CONCLUSIONS: Despite the similar free IgE and FEV1 outcomes from simulations, this has not been clinically validated with respect to the registrational endpoint of reduction in annualized asthma exacerbations.

Pharmacokinetics and exposure-efficacy relationships of omalizumab in patients with nasal polyps.

The anti-immunoglobulin E (IgE) antibody, omalizumab (Xolair), is approved in the United States for the treatment of allergic asthma and chronic spontaneous urticaria, and has recently been studied for the treatment of nasal polyposis following completion of the two replicate phase 3 studies (POLYP 1 and POLYP 2). The dosing of omalizumab used in the phase 3 studies is based on a combination of patients' pre-treatment IgE level and body weight, similar to the approach used in allergic asthma. The objectives of the current analyses were to evaluate whether the pharmacokinetics (PK) of omalizumab and its pharmacodynamic (PD) effect on free and total IgE level in chronic rhinosinusitis with nasal polyps (CRSwNP) are consistent with those in allergic asthma via population PK/PD modeling and simulation, and to graphically explore exposure-response relationships and free IgE-response relationships in CRSwNP. Omalizumab PK and PD effect of total and free IgE in CRSwNP are generally consistent with those in asthma. Observed post-treatment free IgE suppressions were generally within the target range of the baseline IgE- and body weight-based omalizumab dosing table, with 74.2% and 93.0% of patients achieving a serum free IgE level below 25 ng/mL and 50 ng/mL, respectively at Week 24. Exposure-response analyses indicated that there was no clear correlation between omalizumab or free IgE concentration and key efficacy endpoints within the POLYP studies. Overall, these results indicate that the body weight and IgE-based dosing regimen of omalizumab was appropriate for use in CRSwNP patients.

Utility of serum periostin and free IgE levels in evaluating responsiveness to omalizumab in patients with severe asthma.

BACKGROUND: Omalizumab, a humanized anti-IgE monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum IgE levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. METHODS: In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum IgE levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. RESULTS: We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum IgE levels after 16 or 32 weeks of treatment. Reduced free serum IgE levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum IgE levels. CONCLUSION: Baseline serum periostin levels and serum free IgE levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment.

The ratio of total IgE level at week 16 to baseline significantly correlated with the clinical response to omalizumab in moderate to severe allergic rhinitis patients.

OBJECTIVE: To analyze whether the ratio of total IgE level at week 16 to baseline could be used as an indicator to evaluate clinical efficacy of patients treated with omalizumab. METHODS: We retrospectively analyzed the clinical characteristics of 62 patients with moderate-to-severe allergic rhinitis treated with omalizumab, and compared the pre-and post-treatment nasal visual analog scale (n-VAS) scores, the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Rhinitis Control Assessment Test (RCAT), improvement in nasal congestion, number of acute episodes of rhinitis, and total IgE levels in serum. The relationship between the efficacy of treatment with omalizumab and the change in total IgE levels before and after treatment was further analyzed. RESULTS: This study included 62 patients with moderate-to-severe allergic rhinitis, of which 48 demonstrated significant improvement after 16 weeks of omalizumab therapy; the results of 16 weeks' omalizumab treatment in 14 patients did not show significant improvements in allergic rhinitis symptoms based on RACT scores. After 16 weeks of omalizumab treatment, the RQLQ score decreased from (36.6 ± 13.7) at baseline level to (9.1 ± 12.6) after 16 weeks treatment.The ratio of total IgE at week 16 to total IgE levels at baseline was (2.9 ± 1.4) KU/L in 62 patients. And the ratio of total IgE levels at week 16 to total IgE levels at baseline was (3.3 ± 1.4) KU/L for responders and (1.6 ± 0.5) KU/L for non-responders. CONCLUSION: The ratio of total IgE level at week 16 to baseline significantly correlated with the clinical response to omalizumab in moderate to severe allergic rhinitis patients, when the ratio of total IgE level at week 16 to baseline was ≥2.0. Omalizumab effectively treated patients with moderate-to-severe allergic rhinitis, and improved their quality of life.

Omalizumab and IgE in the Control of Severe Allergic Asthma.

Omalizumab, a human immunoglobulin (Ig)G1 antibody against IgE, is a therapeutic agent for bronchial asthma. The Global Initiative for Asthma guidelines indicate that the use of omalizumab should be considered as an option in step 5 of treatment for patients with the most severe type of bronchial asthma. In patients with atopic asthma who are at a high risk of exacerbation, and in whom symptoms are poorly controlled despite treatment with inhaled corticosteroids, omalizumab is one of the few drugs that improves symptoms, reduces the risk of exacerbation, and improves the quality of life while offering a high level of safety. On the other hand, the associated treatment costs are high, and there are no clear methods to identify responders. A recent study suggested that evaluating the therapeutic effects and monitoring the pharmacokinetics of omalizumab could improve the success of omalizumab therapy. This review outlines the relationship between IgE-targeted therapy and the serum level of IgE to enhance the current understanding of the mechanism of omalizumab therapy. It also describes the clinical significance of measuring serum free IgE levels and monitoring omalizumab therapy.

Management of patients with cystic fibrosis and allergic bronchopulmonary aspergillosis using anti-immunoglobulin e therapy (omalizumab).

Omalizumab is a recombinant DNA-derived humanized immunoglobulin G (IgG) anti-IgE monoclonal antibody approved for use in patients with allergic asthma. However, it is not approved for allergic bronchopulmonary aspergillosis (ABPA). Conflicting reports exist about the effects of omalizumab on ABPA in patients with cystic fibrosis (CF). We report 2 patients with CF treated with omalizumab, in whom frequency of ABPA exacerbations was markedly reduced with treatment. Additionally, hospitalizations were reduced from 5 per year to once in 18 months in the first patient and from twice to once per year in the second patient. Free IgE decreased by 87.9% after 6 months of therapy in the first patient and by 95.6% after 7 months of therapy in the second patient. Neither of the two patients had evidence of asthma. Omalizumab may be useful in treating ABPA in patients with CF, and including free IgE in monitoring the response to therapy will be helpful.