Long-term effectiveness of omalizumab treatment in Thai severe asthmatic patients: a real-life experience.

BACKGROUND To evaluate long-term effectiveness of omalizumab in 'real-life' setting of Thai asthmatic patients. METHODS We conducted multi-center, observational study in severe asthma patients who received omalizumab in Thailand. Outcomes were asthma exacerbation (hospitalization and ER visit), asthma control test (ACT), and daily ICS dose. Data were evaluated at baseline, 16 Week, and 52 Week. RESULTS A total of 78 patients received omalizumab treatment (average duration 16.9 months with range 16 weeks-2 years). The mean annualized rate of exacerbations was reduced from baseline (3.79) at Week 16 (3.54) and Week 52 (1.16), (p<0.05), respectively. The mean hospitalization rate was reduced from 0.49 in previous year to 0.15 at Week 16 and 0.19 at Week 52. A reduction in ER visit rates was observed at Week 16 (0.15) and Week 52 (0.97) respectively from baseline (1.44) (p<0.05). The ACT score increased from 15.4 at baseline to 20.6 at Week 16 (p<0.001) and increased to 21.5 at Week 52 (p<0.001). The number of patients with controlled asthma (ACT≥20) increased from 16 of 51 at baseline to 32 of 45 at Week 16 and 25 of 32 at week 52, respectively. The median daily dose of ICS equivalent to fluticasone was reduced from baseline 680 mcg to 500 mcg at Week 52. In all, 22 patients discontinued omalizumab after 1 year. Six patients who discontinued omalizumab were restarted due to relapse of symptoms. CONCLUSIONS These data confirms the effectiveness of one-year duration of omalizumab treatment in Thai severe asthmatic patients. Furthermore, 27% of patients who discontinued treatment required restarting due to relapse of symptoms.