Background and Importance Severe uncontrolled asthma (SUA) is a chronic pathology that requires close monitoring of the effectiveness of biological drugs and an assessment of the safety and economic implications to individualise therapeutic goals.

Aim and Objectives Evaluate the effectiveness and safety of omalizumab, propose a switch to biologic treatment to optimise therapy and evaluate the economic impact after intervention.

Material and Methods Prospective study from January 2021 to April 2023. All patients on treatment with omalizumab for SUA were included. Patients with allergic asthma phenotype were excluded. Candidates for optimisation were patients well-controlled or those who had exacerbations in the last 12 months, Asthma Control Test (ACT) score < 20, forced expiratory volume in 1 second (FEV1) <80%, need for oral corticosteroids and the pharmacy dispensing record. To assess the effectiveness of the intervention, data were collected on biological treatment, FEV1, ACT, IgE and eosinophil values before and after the treatment switch or discontinuation. The exacerbations or treatment with oral corticosteroids were also recorded. Clinical variables were obtained using electronic medical records.

Results Sixty-one patients with mixed or eosinophilic phenotype SUA on treatment with omalizumab. Of these, 30 patients met criteria for well-controlled disease and 31 (50.8%) were candidates for optimisation of therapy. 55.5% women with a median age of 51 years (IQR 66 – 42). The median pre-test IgE value was 459 UI/mL (734.7–239.1), eosinophils 300/μL (445–140), ACT 17 (23–12) and FEV1 78% (100–65). Eight patients switched to benralizumab, seven to mepolizumab and six to dupilumab. Seven patients were discontinued due to well-controlled SUA, two patients were expected to switch due to the need for previous complementary tests, one patient died of another cause. After optimisation the eosinophil value at week 16 and 32 dropped to 80 and 50 respectively. Median ACT 18 (20–16) and FEV1 83.5 (98.5–59.5). Five patients had exacerbations and six patients required oral corticosteroids. Two of the patients with mepolizumab returned to omalizumab. Optimisation of therapy for SUA resulted in a 38.2% cost saving.

Conclusion and Relevance Optimisation of pharmacotherapy allows for individualisation of treatment and dosage, which has an impact on effectiveness and safety while minimising costs in the health system.

Conflict of Interest No conflict of interest.