Can dose reduction be made in patients with allergic bronchopulmonary aspergillosis receiving high-dose omalizumab treatment?

Summary: Background. Allergic bronchopulmonary aspergillosis (ABPA) is an endotype of severe asthma which frequently needs biologics for their steroid sparing effect. We aimed to evaluate the outcomes of reducing the omalizumab dose in patients with ABPA who were on long-term omalizumab treatment. Methods. Once asthma was controlled, two approaches were used to reduce total monthly omalizumab dose: 1) both extending dose intervals from 2 to 4 weeks and decrease omalizumab dose, 2) to reduce omalizumab dose while keeping dose intervals stable. Results. Thirteen patients with ABPA (8F/5M, mean age 53.4 ± 13.0 years) were included. Pre-omalizumab, mean numbers of attacks and hospitalizations were 2.5 ± 1.5 and 1.3 ± 0.8, mean oral corticosteroid (OCS, as methylprednisolone) dose was 12.2 ± 10.4 mg daily. First omalizumab dose reduction was made to all patients at a median time of 35 months (min 13, max 47). The 2^nd dose reduction was made in four patients at median of 23.5 months. Mean OCS decreased to 0.69 ± 0.95 mg/day (p = 0.001) in the 1st year of omalizumab, could be stopped in 11 patients in last evaluation. Attacks/hospitalizations decreased significantly to 0.31 ± 0.86 and 0, respectively, in the 1st year of omalizumab. Total omalizumab dose was reduced by median 40% (min 20, max 60) in 1st intervention and 50% (min 20, max 67) after 2nd intervention. After omalizumab dose reduction, asthma control did not deteriorate and there was no need to increase the omalizumab or OCS-dose. Conclusions. Decreasing the total omalizumab dose does not cause clinical deterioration in ABPA after the disease is controlled.