Omalizumab in an allergology clinic: real life experience and future developments

The Incredible Adventure of Omalizumab

The basis of our current understanding of allergies begins with the discovery of IgE in the mid-1960s. The whole theory of the physiology and pathophysiology of allergic diseases, including rhinitis and asthma, dates from that period. Among the key regions of IgE identified were the FAB (fragment antigen binding) portion that has the ability to capture allergens, and the Cε3 domain, through which IgE binds to its membrane receptor. It was then postulated that blocking IgE at the level of the Cε3 domain would prevent it from binding to its receptor and thus set in motion the allergic cascade. This was the beginning of the development of omalizumab, a monoclonal antibody with an anti-IgE effect. In this article, we review the pathophysiology of allergic disease and trace the clinical development of omalizumab. We also review the benefits of omalizumab treatment that are apparently unrelated to allergies, such as its effect on immunity and bronchial remodeling.

Paeoniflorin inhibits IgE-mediated allergic reactions by suppressing the degranulation of mast cells though binding with FcϵRI alpha subunits

Paeoniflorin (PF), a monoterpene glycoside isolated from the aqueous extract of the Chinese herb Radix Paeoniae Alba, has been used for treating various inflammatory diseases. In this study, we aimed to investigate the anti-allergic activities of PF. The anti-anaphylactic activity of PF was investigated using mast cell (MC) degranulation assay as well as Ca²⁺ influx in vitro and skin swelling and extravasation assays in vivo. The results showed that PF inhibited MC degranulation (histamine release from 74.5 ± 4.95 ng/ml to 58.7 ± 6.06 ng/ml) and Ca²⁺ influx challenged by DNP-BSA in vitro. In addition, PF reduced the degree of swelling and Evans blue exudation in mice paws. Furthermore, PF dose-dependently reduced serum inflammatory mediator release in mice sensitized with ovalbumin for 48 h by inhibiting MC degranulation. Molecular docking study revealed that PF bound better with the α subunit of FcϵRI than with the β subunit. SPR revealed that PF had a strong affinity interaction with FcϵRI α subunit and the K_D value was (7.08 ± 0.97) e-6 M. Our findings revealed that PF inhibited anaphylactic responses in vivo and in vitro, and it can be considered a novel FcϵRI inhibitor for preventing MC-related allergic diseases.

Quality of life in asthmatic children and their caregivers after two-year treatment with omalizumab, a real-life study

Introduction

Omalizumab, a monoclonal anti-immunoglobulin E antibody, has been successfully used as a supplementary therapy to improve asthma control in children aged ≥ 6 years with severe persistent allergic asthma.

Aim

To demonstrate the quality of life in children with severe asthma and their caregivers, and changes from baseline in forced expiratory volume in 1 s (FEV₁) and daily inhaled corticosteroids (ICS) dose after 2-year treatment with omalizumab.

Material and methods

Participants were seen in the clinic at enrollment (visit 1), after 16 weeks (visit 2), after 52 weeks (visit 3) and after 104 weeks (visit 4) of treatment with omalizumab. We evaluated lung function, ICS use and the quality of life with the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and the Pediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ).

Results

Nineteen children and caregivers were enrolled. Significant improvement was observed in PAQLQ and PACQLQ scores, both in all domains and in total scores. Significant differences were found between the first and the other visits. A positive correlation between PAQLQ and PACQLQ at the first and at the second visit was found, 63.3% of patients achieved reduction in ICS doses. We did not notice any significant improvement in FEV₁.

Conclusions

The improvement in quality of life in asthmatic children and adolescents observed after omalizumab correlates with the improvement of quality of life in caregivers, reduction in ICS use but not with FEV₁.

Treating IgE-mediated diseases via targeting IgE-expressing B cells using an anti-CεmX antibody

Targeting the IgE pathway is a clinically validated strategy for treating IgE-mediated diseases. Omalizumab, an anti-IgE antibody, which binds to free IgE and prevents the binding of IgE to FcεRI on mast cells and basophils has been approved for severe persistent allergic asthma and chronic spontaneous (idiopathic) urticaria. The therapeutic efficacy of anti-IgE has also been reported in allergic rhinitis, allergic bronchopulmonary aspergillosis, latex allergy, atopic dermatitis, allergic urticaria, anaphylaxis, and others. Anti-CεmX, which binds to membrane-bound IgE (mIgE) on IgE-switched B cells, lyses mIgE-expressing B lymphoblasts and prevents the allergen-induced generation of IgE-producing plasma cells, offers an alternative mechanism of intervening with the IgE inflammatory pathway. Because anti-CεmX does not bind to free IgE, it can modulate the IgE pathway regardless of the serum IgE levels in treated patients. These unique pharmacologic mechanisms potentially enable anti-CεmX to provide different clinical utilities from anti-IgE and serve as a therapeutic and a prophylactic in some IgE-mediated diseases, which are not adequately treated with current medicine.

Effectiveness of the Polish program for the treatment of severe allergic asthma with omalizumab: a single-center experience

BACKGROUND

A national program for the treatment of severe allergic (IgE-dependent) asthma with omalizumab (OMA) was implemented in Poland in 2013. This observational study evaluated the effectiveness of the Polish OMA program and monitored asthma control after treatment discontinuation.

METHODS

In the first year of the program, 53 patients (23 new/30 continuing treatment) received OMA in the Barlicki Hospital, Poland. Patients were evaluated at baseline and after 16 weeks of OMA treatment by spirometry, mean dose of inhaled corticosteroids (ICS) and oral corticosteroids (OCS), number of asthma exacerbations, the Asthma Control Questionnaire (ACQ), and the Asthma Quality of Life Questionnaire (AQLQ). OMA treatment responses were determined using the global effectiveness of treatment evaluation scale. Fourteen patients ceased OMA treatment following ≥36 months of therapy and entered follow up.

RESULTS

All patients treated with OMA de novo for at least 16 weeks had a decrease in asthma exacerbations and showed a good (15/16, 94 %) or an excellent (1/16, 6 %) response to treatment. We observed a reduction in OCS dose (≥5 mg/day) in 14/16 (88 %) patients. ACQ and AQLQ scores improved by ≥0.5 points in 15/16 (94 %) and 14/16 (88 %) patients, respectively. After OMA cessation, 11/14 (79 %) patients showed worsening of asthma control and severe exacerbations.

CONCLUSIONS

Patients in the OMA program show significant benefits, including reduced use of OCS, improved asthma control and quality of life. After OMA discontinuation, frequent severe exacerbations were observed primarily in patients whose asthma was previously uncontrolled by high OCS doses.

Omalizumab in the prevention of anaphylaxis during immunotherapy: a case report

Omalizumab is approved for the treatment of chronic severe persistent asthma. As a trigger for anaphylaxis, the frequency of subcutaneous specific immunotherapy (SCIT) is high. We report the case of a 11-year-old boy with severe allergic asthma. During the initial phase of immunotherapy he experienced anaphylaxis and SCIT was discontinued. Because of uncontrolled asthma, despite the inhaled steroids and β-agonists were taken into consideration, omalizumab 300 mg once every 4 weeks was initiated. Currently, the maintenance dose has been reached and SCIT is continued without any side effects. The clinical implication of the above case report is that children with severe allergic asthma who are pre-treated with omalizumab might also benefit in the future from SIT as a causal treatment option.

Omalizumab in pregnant women treated due to severe asthma: two case reports of good outcomes of pregnancies

The article presents case reports of 2 women who became pregnant during therapy with omalizumab. Both subjects suffered from very severe asthma and were treated chronically with all available medications including systemic steroids (first - 20 mg prednisolone/day, second - 40 mg prednisolone/day). Both were enrolled into treatment with omalizumab and started regular therapy in 2007. The course of asthma significantly improved in both cases (withdrawal of oral steroids or significant reduction of their dose, better asthma control). The first woman, 32-year-old, became pregnant in 2010 and gave birth in Oct 2010 - it was her 3(rd) pregnancy, and 3(rd) labor. The second woman, 31-year-old, also became pregnant in 2010 and gave birth in Jan 2011 - it was her 5(th) pregnancy and 2(nd) labor. Both had severe asthma exacerbations during previous pregnancies and labors, and decided to continue therapy with omalizumab. The first woman, besides omalizumab, was treated with high doses of inhaled corticosteroids (ICS) and long-acting β agonists (LABA) while the second one was treated with high doses of ICS, LABA and 2.5 mg to 5 mg prednisone/day. The pregnancies proceeded without asthma exacerbations. The first woman delivered a healthy girl (Apgar 9, weight 3200 g, length 56 cm) in the 40(th) week of pregnancy by caesarean section due to the narrow pelvis. The second one delivered a healthy boy (Apgar 9, weight 3800 g, length 56 cm) in week 40 by caesarean section due to the aggravating obstetrical history. In both cases, treatment with omalizumab did not affect pregnancies and newborns.