Copyright ©ERS Journals Ltd 2002 The anti-IgE antibody omalizumab improves asthma-related quality of life in patients with allergic asthma1 Pulmonary Division, University Hospital, Mainz, and 2 Allergy and Asthma Clinic, Charité Berlin, Germany. 3 Pulmonary Division, University Hospital, Basel, Switzerland. 4 Allergy, Immunology & Asthma Medical Group, Stockton, CA, and 6 Allergy & Asthma Associates, San Jose, CA, USA. 5 Novartis Pharma AG, Basel, Switzerland. 7 Novartis Horsham Research Centre, Horsham, UK CORRESPONDENCE: R. Buhl, Pulmonary Division, University Hospital, Langenbeckstrasse 1, D-55131, Mainz, Germany. Fax: 49 6131175545. E-mail: R.Buhl@3-med.klinik.uni-mainz.de Keywords: allergic asthma, anti-immunoglobulin E, omalizumab, quality of life
Received: February 25, 2002
This study was supported by Novartis Pharma AG, Basel, Switzerland and Genentech Inc., South San Francisco, CA, USA.
The aim of the present study was to determine the effect of treatment with omalizumab, an anti-immunoglobulin E antibody, on asthma-related quality of life (AQoL) in patients with moderate-to-severe allergic asthma. A total of 546 patients with allergic asthma were randomised to double-blind subcutaneous treatment with either placebo or omalizumab for 52 weeks. A constant beclomethasone dipropionate dose was maintained during the first 16 weeks (steroid-stable phase). This was followed by a 12-week steroid-reduction phase. The core study was followed by a 24-week double-blind extension phase. AQoL was evaluated at baseline and at the end of the steroid-stable (week 16), steroid-reduction (week 28) and extension phases (week 52) using the Juniper Asthma Quality of Life Questionnaire (AQLQ).
Baseline AQLQ scores were comparable for the two treatment groups. Relative to placebo, omalizumab-treated patients demonstrated statistically significant improvements from baseline across all four AQLQ domains, as well as overall AQoL score, at weeks 16 (except environmental exposure), 28 and 52. Patients on omalizumab were also more likely to achieve clinically significant improvements in AQoL during the course of the study. Overall, almost 70% of patients and investigators rated treatment with omalizumab as "excellent/good", compared with Clinical studies show that omalizumab enhances disease control whilst reducing corticosteroid consumption in patients with allergic asthma. The results of the present study show that these changes are paralleled by improvements in asthma-related quality of life that are meaningful to such patients. It is well established that asthma-related symptoms and the ever-present risk of serious exacerbations requiring emergency treatment and/or hospitalisation exert a profoundly negative effect on various aspects of quality of life (QoL) 1, 2. Many clinical trials involving patients with asthma have therefore assumed that an improvement in symptoms and other conventional clinical indices (e.g. spirometry) leads to concomitant changes in the patient's QoL. However, whilst providing valuable information about the status of the affected organ system, conventional clinical measures rarely fully capture the extent of the patient's functional impairment and decreased well-being 3, 4. Thus, in order to obtain a holistic view of the patient's health status, both conventional clinical measures and the patient's health-related QoL should be evaluated during asthma therapy. The pathophysiology of asthma is allergy related in >90% of cases 5. Central to the mechanisms of allergic inflammation is the release of a number of pro-inflammatory mediators after allergen binding to immunoglobulin (Ig)E on the surface of effector cells 610. Targeting of IgE therefore represents a promising basis for the development of new therapeutic agents for the treatment of allergic asthma. Moreover, stopping the allergic cascade at this early stage may bring about improvements in other IgE-mediated allergic (atopic) diseases, such as seasonal allergic rhinitis, which is highly prevalent in patients with allergic asthma 11. Omalizumab is the first anti-IgE agent to undergo clinical evaluation in the treatment of IgE-mediated diseases 12. A recombinant humanised monoclonal anti-IgE antibody 13, omalizumab forms complexes with circulating free IgE and prevents it binding to high- and low-affinity receptors on effector cells, thereby inhibiting allergen-induced activation 1416. Indeed, the pronounced reduction in serum-free IgE concentrations after the first injection of omalizumab in patients with allergic asthma 17 attenuates both the early and late asthmatic responses to inhaled allergen 18, 19. Recently, the authors reported that subcutaneous treatment with omalizumab improved asthma control and allowed a significant reduction in the dose of inhaled corticosteroids in a large placebo-controlled trial in patients with moderate-to-severe allergic asthma 20, 21. In the present study, the findings of the effect of omalizumab on asthma-related QoL (AQoL), which was evaluated in parallel with routine clinical indices in this clinical trial, are reported.
Study design and patients The present QoL study was conducted as part of a multicentre, randomised, double-blind, placebo-controlled clinical trial with omalizumab, for which the protocol and main clinical/tolerability findings are reported in full elsewhere 20, 21. Briefly, the study enrolled patients aged 1275 yrs with a diagnosis of moderate-to-severe allergic asthma of 1 yr's duration, a total serum IgE level of 30700 International Unit (IU)·mL1 and a positive skin-prick test to at least one common allergen (Dermatophagoides farinae, D. pteronyssinus, dog or cat). All patients had stable disease and required regular treatment with inhaled corticosteroids (dose equivalent to 5001,200 µg·day1 of beclomethasone dipropionate (BDP)), but were symptomatic even with such treatment. After screening, patients entered a run-in period of 46 weeks, during which time all patients were switched to inhaled BDP and the dose was adjusted to establish the lowest dose required for control of asthma symptoms and peak expiratory flow (PEF) at levels acceptable to the patient and investigator. Patients were maintained on this dose of BDP for the final 4 weeks of run-in (baseline). Eligible patients were subsequently randomised to subcutaneous treatment with either placebo or omalizumab every 2 or 4 weeks ( 0.016 mg·kg1·IgE1 (IU·mL1) per 4 weeks) for 52 weeks. The baseline dose of concomitant BDP was maintained during the first 16 weeks of the study (steroid-stable phase). In the following 12 weeks (steroid-reduction phase), the BDP dose was reduced by 25% every 2 weeks over the first 8 weeks until total elimination, or until there was a decrease in forced expiratory volume in one second (FEV1) of 20% compared to the last measurement of the previous phase or the development of an event defining asthma worsening, as follows: 1) deterioration of symptoms requiring an urgent or unscheduled physician visit; 2) PEF of 50% of patient's personal best; 3) decrease in morning PEF of 20%, compared to the last week of the previous phase, on two or more of 3 successive days; 4) increase in rescue medication of 50%, compared to the average use for the last week of the previous phase and exceeding eight puffs of salbutamol per day, on 2 or more of 3 successive days; 5) more than 2 of 3 successive nights disrupted due to asthma symptoms requiring rescue medication.
If there was a decrease in FEV1 of The core study was followed by a 24-week double-blind extension during which patients continued on randomised treatment and the lowest effective dose of BDP (which could be adjusted accordingly). During the extension phase, the use of concomitant asthma medication was liberalised and investigators were allowed to administer additional asthma medication and/or switch patients to other asthma medications if deemed necessary. The study was conducted in accordance with the Declaration of Helsinki. All patients (or their parents or guardians, when appropriate) provided written informed consent prior to the initiation of study. Ethical approval was obtained from the relevant institutional review board of each study centre.
Measurement of asthma-related quality of life
Evaluation of treatment effectiveness
Statistical analysis
Patients A total of 546 patients from 42 centres in nine countries completed the run-in/baseline phase and were randomised to study medication: omalizumab, n=274; placebo, n=272. A total of 487 patients (89%) completed the core study: omalizumab, n=255 (93%); placebo, n=232 (85%). Most patient withdrawals in each treatment group occurred during the initial 16-week steroid-stable phase: omalizumab, n=13; placebo, n=27. Withdrawal of consent was the most common reason for discontinuation. A total of 483 patients continued into the extension phase of the study: omalizumab, n=254; placebo, n=229. Nearly three times as many patients in the placebo group (n=26 (11.4%)) as in the omalizumab group (n=10 (3.9%)) discontinued prematurely during the extension. Withdrawal of consent and loss to follow-up were the most frequent reasons for discontinuation, affecting more placebo than omalizumab patients in both cases.
Overall, the two treatment groups were well balanced in terms of demographics and baseline clinical characteristics, including mean AQLQ domain and overall scores (table 1
Asthma-related quality of life Relative to placebo, mean AQLQ domain and overall scores showed a progressive increase throughout 52-weeks' treatment with omalizumab, consistent with an improvement in AQoL (fig. 1
Compared with placebo, a greater proportion of patients on omalizumab achieved a clinically significant improvement in AQoL during each phase of the study (fig. 3 1.5 points 24, is shown in figure 3
Treatment effectiveness The improvement in asthma control 20, 21 and AQoL with omalizumab therapy was paralleled by patient and investigator opinions of treatment effectiveness at the end of the core study, which showed significant superiority for omalizumab relative to placebo (both p<0.001). Almost 70% of patients and investigators rated treatment with omalizumab as "excellent/good", compared with 40% of those on placebo (fig. 4
It is becoming increasingly recognised amongst healthcare providers that asthma causes significant impairment of physical and psychosocial well-being in the affected individual. Consequently, improving the health-related QoL of patients should be one of the primary goals in asthma treatment. This is particularly important because traditional clinical parameters, such as lung function, have, at best, only weak associations with QoL 4, 25, an understanding that has led to a more holistic approach to management in recent years. Assessment of health-related QoL, in addition to standard clinical indices of airways status, has therefore become an integral part of the determination of treatment response in asthma patients. Omalizumab, a recombinant humanised monoclonal anti-IgE antibody, is the first anti-IgE agent to undergo clinical evaluation in the treatment of allergic asthma. The current authors have previously reported that the addition of this agent to the therapeutic regimen of patients with allergic asthma simultaneously reduces both asthma exacerbations and inhaled corticosteroid requirement, whilst improving other parameters of disease control 20, 21. The findings of the present QoL study, performed in parallel with the clinical evaluations in this clinical trial, show that such changes are clinically significant to patients, with marked improvement in all aspects of their AQoL.
The authors utilised the AQLQ in the present study, a rigorous questionnaire that was specifically designed to be sensitive to small, within-subject changes in AQoL over time. With this questionnaire, an increase in domain or overall score of As observed for the clinical indices of treatment efficacy 20, 21, notable improvements in AQoL occurred among some patients on placebo. Such findings have been observed in previous placebo-controlled AQoL studies in asthma patients 28, although a marked placebo-effect response is not unique to the treatment of this disease 29. One possible explanation for the high placebo response in the present study is improved compliance with BDP treatment. Unfortunately, it is impossible to avoid the improved compliance trap unless clinical trials are preceded by a very long (months) run-in period during which compliance is carefully monitored and a significant percentage of patients can be lost due to the very improvements seen in the present study. Indeed, close monitoring by the investigator, with repeated encouragement to adhere to therapeutic regimens combined with perfect and immediate treatment of any complaint of the patient (be it related to asthma or not), undoubtedly contributed towards the significant placebo response. Against this background, adding omalizumab was still able to significantly improve both disease control and AQoL. The optimal utility of this agent may therefore be apparent in patients who are poorly controlled despite optimal therapy and good compliance.
During the extension phase it was apparent that, while the improvement in AQLQ domain and overall scores versus baseline was still significantly higher for those receiving active treatment (see fig. 2 The present study enrolled adolescent (>12 yrs old) and adult patients with allergic asthma. In order to avoid the methodological problem of using two different questionnaires in the same trial, the adult version of the AQLQ was used exclusively in the present trial. Only 35 patients aged 1217 yrs were enrolled and were evenly distributed between the two groups. An analysis including and excluding these subjects showed that they did not influence the results of the present study. As previously mentioned, improved patient compliance with prescribed medication may partly explain an improvement in disease management and hence AQoL. Indeed, existing treatment with inhaled corticosteroids and bronchodilators may be complicated by the use of multiple inhalers with different administration schedules that can give rise to poor patient compliance. With convenient subcutaneous administration every 2 or 4 weeks by their attending physician, treatment with omalizumab may overcome the potential for poor compliance with anti-asthma therapy. Whilst the main tolerability findings of this study are reported in full elsewhere 20, 21, it is important to re-consider the side-effects of omalizumab in relation to any possible impact they may have on QoL. Overall, the side-effects of omalizumab and placebo were similar with no clinically relevant differences. As such, the tolerability profile of omalizumab is unlikely to have had a negative effect on the QoL findings of the present study. In conclusion, the results of the present study show that omalizumab therapy is associated with clinically significant improvement in all aspects of asthma-related quality of life in patients with moderate-to-severe allergic asthma. The improvement in patient functioning and well-being paralleled earlier findings of enhanced disease control, even though there was a significant reduction in inhaled corticosteroid consumption, during omalizumab therapy in this patient population 20, 21. Taken together, these findings indicate that omalizumab is a promising new agent for the treatment of allergic asthma.
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