We would like to thank Dr Panasoff1 for his comment on our report2 of the EXACT trial (NCT00096954) of omalizumab, which studied patients with atopic asthma with preserved pulmonary function who remained symptomatic on inhaled corticosteroids with or without other controller medications. To clarify, this study was done as a postmarketing commitment from the US Food and Drug Administration in which we were to evaluate patients with atopic asthma and normal lung function. Atopic asthma was not determined solely based on serum IgE levels; patients also had to have positive skin test responses or in vitro (RAST or ImmunoCAP) test responses to 1 relevant perennial aeroallergen, such as cat or house dust mite. The exclusion of prior use of systemic corticosteroids (oral or intravenous) was only if it had been in close proximity to the screening visit because this would indicate that the patient had a recent asthma exacerbation that could affect his or her lung function. The time restriction would also allow systemic steroids to have cleared from the patients' bodies so there would be no effect on baseline scores. Dr Panasoff was correct in noting that despite its proved efficacy in patients with allergic asthma, the study did not show a significant difference for omalizumab versus placebo in rate of exacerbations and that this might have been in part due to the patient population enrolled in the study. Reasons for poorly controlled asthma in the studied population might include poor compliance with therapy, improper use of inhaled medication, or chronic exposure to a potent antigen or the patients might be smokers. Omalizumab, by virtue of being administered every 2 or 4 weeks in the physician's office, might improve compliance. However, we believe that given the highly limiting patient eligibility for enrollment, the study was underpowered to demonstrate a statistically significant treatment effect in the primary end point. Because all patients in the study had positive results to allergen, we have not addressed Dr Panasoff's request to plot eosinophil levels against allergen-positive/allergen-negative status. We do appreciate his thorough review and the opportunity to provide a more in-depth explanation of the eligibility criteria and their effect on study outcome.
展开▼
