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      IPCRG background paper: need for research into severe and difficult (poorly controlled) asthma

Introduction
Asthma affects an estimated 300 million people worldwide and 30 million in Europe.1 Although inhaled corticosteroids and long-acting ß2 agonists are effective at controlling symptoms and preventing exacerbations in most patients with mild-to-moderate asthma,2 approximately 18% of Europeans with asthma have severe persistent disease,3 of whom 20% are uncontrolled.4 Given that 50% of these patients have allergic asthma,5 an estimated 2% of all asthma patients have uncontrolled severe persistent allergic disease.

Consequences of uncontrolled severe asthma
Inadequate control of severe persistent asthma causes a large burden of morbidity and mortality. Patients with severe asthma often have severely impaired quality of life (QoL), are frequently absent from school or work, have decreased productivity and are at an increased risk of hospital admission and death. Asthma caused 12,000 deaths in Western Europe in 2002, or 0.3% of all deaths,6 and an estimated 7% of Western Europeans with asthma are admitted to hospital due to asthma every year.4 Efforts to reduce mortality and morbidity due to asthma should focus on poorly controlled severe disease, as 80-85% of asthma deaths occur in this group7 and there is a strong association between increased recurrences of hospitalisation and asthma severity.8

Treatment options for uncontrolled severe asthma
Previously, treatment options to improve asthma control in patients with uncontrolled severe persistent asthma were limited. However, the advent of anti-immunoglobulin E (IgE) therapy with omalizumab, which targets a root cause of allergic asthma, may help to address the needs of patients with inadequately controlled severe persistent allergic asthma. Clinical studies with this anti-IgE antibody have shown a significant reduction in the rate of asthma exacerbations, emergency visits and hospitalizations while improving lung function and QoL in this difficult-to-treat population. In a pooled analysis of data from seven clinical trials in 4308 patients with allergic asthma (93% had severe disease), addition of omalizumab to best available therapy reduced the rate of asthma exacerbations by 38%, total emergency visits by 47% and hospital admissions by 52%.9

Conclusions
Anti-IgE therapy has been recommended in the recent 2004 guidelines of the Global Initiative for Asthma (GINA) as an add-on therapy for patients with asthma who are inadequately controlled despite treatment with high-dose inhaled corticosteroids and long-acting ß2-agonists, with or without additional controller medications.2 In the USA, where omalizumab was launched in June 2003, more than 20,000 patients with inadequately controlled moderate-to-severe asthma have received treatment with this anti-IgE agent. There remains a significant need for additional treatment options for European patients with inadequately controlled severe asthma. Approval of anti-IgE therapy in Europe might help to meet this need.

References
  1. Masoli M, Fabian, D, Holt, S, Beasley, R. Global burden of asthma. Global Initiative for Asthma. 2004.
  2. Global Initiative for Asthma. Global strategy for asthma management and prevention. NIH Publication No 02-3659 (updated 2004). 2004. National Institutes Of Health/National Heart, Lung, And Blood Institute.
  3. Rabe KF, Vermeire PA, Soriano JB, Maier WC. Clinical management of asthma in 1999: the Asthma Insights and Reality in Europe (AIRE) study. Eur Respir J 2000;16:802-807.
  4. Rabe KF, Adachi M, Lai CK, Soriano JB, Vermeire PA, Weiss KB, et al. Worldwide severity and control of asthma in children and adults: the global asthma insights and reality surveys. J Allergy Clin Immunol 2004;114:40-47.
  5. ENFUMOSA. The ENFUMOSA cross-sectional European multicentre study of the clinical phenotype of chronic severe asthma. Eur Respir J 2003;22:470-477.
  6. World Health Organization. The World Health Report 2003. 2004.
  7. Papiris S, Kotanidou A, Malagari K, Roussos C. Clinical review: severe asthma. Crit Care 2002;6:30-44.
  8. Hartert TV, Speroff T, Togias A, Mitchel EF, Jr., Snowden MS, Dittus RS, et al. Risk factors for recurrent asthma hospital visits and death among a population of indigent older adults with asthma. Ann Allergy Asthma Immunol 2002;89:467-473.
  9. Bousquet J, Cabrera P, Berkman N, Buhl R, Holgate S, Wenzel S, et al. The effect of treatment with omalizumab, an anti-IgE antibody, on asthma exacerbations and emergency medical visits in patients with severe persistent asthma. Allergy 2005;60:302-308.
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