Objectives: 1. Determine if mRNA expression could be use as a biomarker to predict and
monitor the response to omalizumab in patients with difficult control asthma 2. Identify
which genes are switched on and which are switched off by using Omalizumab.
Methods: This study is an open label clinical trial, with six patients. The patients will
receive Omalizumab according to their age and weight (maximum dose: 375 mg every 15 days) for
4 months. There will be a run-in period of one month, when allergic asthma diagnosis will be
confirmed and treatment will be optimized. Patients will be evaluated and will have blood
sample collected on 3 occasions: in the beginning, 2 months after baseline and at the end of
the study. Blood samples will always be collected one week after the last omalizumab dose.
Primary outcome will be RNA expression of 20 genes measured by real time-PCR (high-affinity
IgE receptor, IL-4, IL-5, IL-13, gama-IFN, quimokines, Fc epsilon, between others). Secondary
outcomes will be ACT, ACQ and spirometry.