Date Published: July 26, 2017
Publisher: BioMed Central
Author(s): S. M. Snelder, E. J. M. Weersink, G. J. Braunstahl.
Omalizumab is licensed as add-on therapy for patients with severe allergic asthma. Response is in most studies scored by the physician’s global evaluation of treatment effectiveness (GETE). A good clinical and validated parameter for treatment response is currently missing. Also, there are no established criteria for identifying patients who will respond to omalizumab based on pre-treatment characteristics. The Dutch National Omalizumab in Asthma Registry was developed in 2011 to better evaluate inclusion criteria and measure treatment response after 4 months.
This is a “real world” prospectively designed, observational data registry in which the outcomes of patients who received omalizumab between 2012 and 2015 were evaluated. Data were collected from all centers in the Netherlands comprising demographic features, criteria for starting treatment, GETE, FEV1, oral corticosteroid use and ACQ.
65.5% of the 403 patients had a good or excellent response to omalizumab after 16 weeks according to the treating physician GETE. 64.5% fulfilled all the criteria for prescribing omalizumab at baseline. The mean ACQ improved from 2.96 at baseline to 1.83 at 16 weeks (p < 0.001). 75.3% of the responders showed more than 0.5 points improvement in the ACQ. The mean FEV1 increased from 71.58 to 79.06 (p < 0.001). There was no relationship between patients with a FEV1 <80 and ≥80% at baseline and response (p = 0.981). Most of the responders had a considerable improvement of FEV1 either/or ACQ or OCS use (88.3%). While 86.7% of the responders had an improvement of either ACQ or FEV1. 75.4% of the responders had an improvement of ACQ, while 50.4% had an improvement of FEV1. Finally 11.7% of the patients with no improvement of FEV1, ACQ or OCS use were considered to have a good response. This registry of 403 inadequately controlled severe allergic asthma patients in the Netherlands showed a good or excellent response of 65.5% to omalizumab after 16 weeks, in accordance with previous studies. The assumption that careful registration would lead to higher response rates could not be supported by the data from this registry. Improvement of ACQ appears to be a useful additional assessment tool to measure response in omalizumab treated patients.
Omalizumab (Xolair®) is a subcutaneously administrated humanized anti-immunoglobulin E (IgE) monoclonal antibody that targets circulating free IgE and prevents its interaction with the high-affinity IgE receptor (FCƐR1). It is licensed in the European Union as add-on therapy for patients aged 6 years and older with either allergic asthma or chronic idiopatic urticaria [1, 2]. Since 2006, omalizumab has been prescribed for inadequately controlled severe allergic asthma in the Netherlands. Randomized studies demonstrated a significantly greater improvement in asthma control in patients treated with add-on omalizumab than patients treated with placebo [3–6].
This is a “real world” prospectively designed, observational data registry in which the outcomes of patients who received omalizumab between 2012 and 2015 were evaluated. Data were collected from all centers in the Netherlands where omalizumab was prescribed for the treatment of severe allergic asthma. The survey questionnaire was approved by the national board of Chest Physicians (NVALT) and comprised the following start criteria: severe allergic asthma, age >6 years, a positive skin test or in vitro activity to a relevant perennial aeroallergen, a FEV1 less than 80%, more than two severe exacerbations and substantial symptoms despite treatment with inhaled corticosteroids (ICS) and long-acting B2-agonists (LABAs). In addition, inhalation technique and compliance were checked and optimized, and smoking stopped (or at least tried). Patients gave informed consent to participate in the survey. The data were centrally collected and analyzed by three independent physicians.
403 patients had a full data set and could be evaluated. Baseline characteristics are shown in Table 1. The mean age was 47. 62.8% of the patients were female. The mean IgE was 619.9 with a range from 3 to 10,800. 69.2% had a FEV1 <80% of predicted. 64.5% of the patients fulfilled all of the criteria for prescribing omalizumab at baseline (Table 2).Table 1Baseline characteristicsVariableValueTotal no patients403Age Mean (SD)47 (15.6)Gender (%) Male149 (37.0) Female253 (62.8)Body weight, kg Mean (SD)78.6 (17.4)Baseline IgE level, IU/mL Mean (SD)619. 9 (1036.4) Range3–10,800Severe allergic asthma (%) Yes380 (94.3) No12 (3.0)Positive skin-prick test/RAST (%) Yes363 (90.3) No26 (6.5)FEV1 <80 (%) Yes279 (69.2) No116 (28.8)More than 2 exacerbations (%) Yes384 (95.3) No11 (2.7)Maximum dose ICS and LABAs (%) Yes394 (99) No4 (1)Smoking (%) Tried to quit smoking101 (25.1) Didn’t try to quit smoking29 (7.2)Table 2Fulfilled all the criteria for prescribing omalizumab at baseline vs responseResponseYesNoTotalCriteria fulfilled yes17387260Criteria fulfilled no9152143Total264139403p = 0.558 65.5% of the 403 patients with inadequately controlled severe allergic asthma had a good or excellent response to omalizumab after 16 weeks. 75.3% of the responders had more than 0.5 points improvement of the ACQ. Overall the ACQ improved, FEV1 increased and there was lower use of OCS at 16 weeks. 50.4% of the responders had an improvement of more than 5% of the FEV1. More patients who had a good or excellent response had an improvement of the ACQ (75.3%) than an improvement of FEV1 (50.4%) or OCS use (16.7%). This suggests that the ACQ may be the best measurement for response. This registry of 403 inadequately controlled severe allergic asthma patients in the Netherlands showed a good or excellent response of 65.5% to omalizumab after 16 weeks. Overall the ACQ improved, FEV1 increased and there was lower use of OCS at 16 weeks. This is in accordance with previous data from randomized controlled trials and real word data. 75.3% of the responders had more than 0.5 points improvement of the ACQ. There was no relationship between patients with a FEV1 <80 and ≥80% at baseline and the response. Improvement of ACQ appears to be a useful assessment tool to measure response in omalizumab treated patients. Source: http://doi.org/10.1186/s13223-017-0206-9