Omalizumab for Asthma with Non-detectable Sensitization to an Aeroallergen

Omalizumab is a humanized monoclonal anti-IgE antibody used to treat severe
allergic asthma. In allergic asthma omalizumab alleviates symptoms by capturing
free (total including allergen-specific) IgE molecules and preventing them from
binding to IgE receptors on effector cells which would otherwise cause
allergen-dependent cell activation and histamine release. Recent studies have
shown omalizumab to be clinically effective in treating patients with severe
asthma without detectable allergic asthma, however, the mechanism behind the
efficacy of this drug in these patients is not clear.

To assess the immunological efficacy of four-month treatment of omalizumab in
patients with non-atopic asthma compared to patients with allergic asthma

single center, observational study

Patients will be treated with Omalizumab initiated by the department of
pulmonology at the LUMC. During the first visit information regarding medical
history and demography will be obtained. Nasal flush samples (5ml) and blood
samples (70 ml) will be collected at entry and after the four-month treatment
period. Patients will undergo pulmonary function tests and will be required to
complete the Asthma Control Questionnaire (ACQ) and before and after the
treatment period. The physician will perform a Global Evaluation of Treatment
Efficacy (GETE). The nasal flush sample collection is specific to this study
and is not part of the patient*s standard care. All other parameters including
venepuncture will be performed regardless of participation in this trial. The
burden experienced by the patient consists of additional tubes of blood being
collected during the routine venepuncture and the time required to perform the
nasal flush (15-20 minutes). There is minimal risk associated with this
procedure. Although the patients involved in this study will not benefit
directly, the outcome may facilitate improvement of healthcare for asthma
patients in the future.