Can the response to Omalizumab be influenced by treatment duration? A real-life study

Objective It is unknown whether Omalizumab effectiveness changes over the course of time. Our retrospective real-life study tried to analyze whether Omalizumab response may be influenced by treatment duration. Methods 340 severe asthmatics treated with Omalizumab for different periods of time were recruited. They were subdivided into 4 groups according to the Omalizumab treatment length: <12, between 12 and 24, between 24 and 60 and >60 months. Omalizumab treatment results (FEV1, exacerbations, ACT, SABA use, asthma control levels, medications used e and ICS doses) were compared. Results ACT, exacerbations, GINA control levels, ICS doses and SABA use were similar in all groups with different Omalizumab treatment durations. Using a linear regression model, corrected for all confounding variables, a higher significant positive increase in FEV1% in subjects treated for 12–24 (β = 9.49; p = 0.034) or 24–60 months (β = 8.56; p = 0.043) was found when compared with subjects treated for a shorter period. Treatment duration was positively associated with a step down of the other associated therapies (OR: 1.013; p = 0.019). This association was more relevant (OR: 4.167; p = 0.005) when we considered Omalizumab treatment duration >60 months compared to the shorter therapy. In particular, the percentage of subjects that were taking Montelukast, LABAs and oral corticosteroids was lower in the group treated with Omalizumab for a longer period of time. Conclusion In real-life, the positive Omalizumab response remained stable for over 60 months. Long term Omalizumab treatment may lead to a discontinuation of some associated medications and to a slowing down of FEV1decline.