Discontinuation rates of omalizumab treatment in a cohort of severe asthmatics in Bulgaria

Abstract

Background: Since 2009 omalizumab has been reimbursed for severe asthma by the Bulgarian Health Insurance Fund following strict criteria for eligibility of the patients. The objective of our retrospective analysis was to identify the subjects who discontinued treatment within a cohort we followed up till present and to get an insight about the reasons for this.

Methods: We reviewed the records of 76 patients (age range 40 – 70, median 56 years, 51 women) with onset of treatment as early as 2009. We had on file the monthly dose of omalizumab and whether it was administered every 2 or 4 weeks and the reasons for discontinuation. We performed descriptive analysis (frequencies, cross-tables) and calculated odds ratios for the variables with possible influence on discontinuation as dependent variable.

Results: Out of the 76 patients, 27 (35.5%) discontinued omalizumab at different time points: 13 patients (17.1%) for lack of sufficient clinical effect as judged by the doctor or patients; 10 patients (13.2%) had decided that they were well enough and/or were apprehensive of possible adverse events; 3 (3.9%) subjects left the country and 1 (1.3%) person died from a malignant tumor. The regression analysis determined age and duration of treatment as significantly related to discontinuation of therapy (P=0.015 and P<0.001 respectively). Age was inversely related to the prospects of staying on omalizumab treatment - odds ratio 0.903 [95% confidence interval 0.838-0.938], P=0.012.

Conclusions: In our cohort of patients omalizumab was discontinued for lack of clinical effect in a percentage similar to the generally accepted non-responder rates or for personal reasons on the part of the patients.