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 (beta= 9.49; p = 0.034) or 24-60 months (beta = 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 FEV1 decline.