Treating Asthma with Omalizumab

treating asthma

Researchers studied whether treating asthma with omalizumab reduced the frequency and severity of rhinovirus (RV) illnesses in asthmatic children.

Past studies have alluded to the association between allergic sensitization and the increased prevalence of viral respiratory illnesses, in particular, those caused by rhinoviruses (RV). These viral infections can lead to asthma-related exacerbations. Since IgE antibodies are mainly responsible for producing this allergic response, researchers explored the effects of treating asthma with omalizumab, which works by reducing IgE.

Does Omalizumab Reduce Rhinovirus?

In a study published in the American Journal of Respiratory and Critical Care Medicine, researchers in the United States conducted an interventional study to test whether treating asthma with omalizumab reduced the frequency and severity of rhinovirus illnesses. The study included children between the ages 6-17 years with allergic asthma from low-income census tracts in eight different U.S. cities. The participants were randomly allocated to treatment with guidelines-based asthma care or add-on omalizumab.

The study took place over a 90-day period in the fall season of 2012 or 2013, where weekly respiratory symptom scores and nasal samples tested for RVs were collected. A rhinovirus infection was defined as the detection of the virus, and duration of infection was determined based on a number of consecutive samples detected with the same virus. An exacerbation was defined as the need for systemic steroids for treating asthma, and a viral exacerbation was defined as detection of rhinovirus within seven days before or after an acute asthma exacerbation.

A total of 478 participants were included in the final analysis. Rhinovirus was detected in 57% of the exacerbation samples compared with 36% of non-exacerbation samples. The study found that infections, particularly with RV-A and RV-C strains, were most strongly linked to exacerbations and to a lesser extent with RV-B strains.

Omalizumab Reduces Rates of Rhinovirus

They also saw that treating asthma with omalizumab significantly reduced the weekly rates of detecting rhinovirus and the average duration of infection with any rhinovirus. Not only did omalizumab shorten the duration of viral shedding, the peak viral shedding was also reduced in the omalizumab treatment group. Lastly, the study found that omalizumab treatment significantly decreased the frequency of rhinovirus illness though it didn’t have an effect on the duration of respiratory symptoms.

The study’s findings with omalizumab treatment support the hypothesis that the mechanisms that act against IgE can interfere with rhinovirus replication to, therefore, reduce the frequency and severity of associated respiratory infection and illness. The study observed clinically significant effects of omalizumab to reduce rhinovirus infection frequency, severity, and duration of viral shedding. The study’s design with a large sample size, weekly monitoring and targeted IgE reduction intervention are strengths to the study. Since rhinovirus prevalence can differ by geographic location, it was another study strength that the researchers included children from eight different U.S. cities.

With that said, the study’s focus was the detection of rhinovirus, however, other respiratory viruses may also contribute to exacerbations and illness, which weren’t accounted for in the study. Overall, the study’s findings provide evidence that treatment focused against IgE can decrease rhinovirus infections and illness and viral asthma exacerbations.

Written by Maggie Leung, PharmD

Reference: Esquivel, A., Busse, W. W., Calatroni, A., Togias, A. G., Grindle, K. G., Bochkov, Y. A., . . . Gern, J. E. (2017). Effects of Omalizumab on Rhinovirus Infections, Illnesses, and Exacerbations of Asthma. American Journal of Respiratory and Critical Care Medicine, 196(8), 985-992. doi:10.1164/rccm.201701-0120oc