Omalizumab Transitions in Severe Asthma: Factors Influencing Switching Decisions and Timing for Optimal Response

To assess the effectiveness of switching from omalizumab to another biologic therapy for patients with severe asthma and evaluate factors that influenced the decision to switch and determined the optimal time for a good biologic response.A retrospective study of severe asthma patients was conducted at Al-Rashed Allergy, a tertiary center in Kuwait. After meeting the eligibility criteria, patients were divided into two comparative groups; those continuing with omalizumab and those who started with omalizumab but switched to another biologic.One hundred sixteen patients with severe asthma were recruited, and only 33 had access to multiple biological treatments. Approximately 22.4% switched from omalizumab. Male patients with a history of ischemic heart disease, chronic rhinosinusitis, and nasal polyps were more likely to switch if they had higher levels of eosinophils in the sputum. This study showed that every 1% increase in sputum eosinophils doubled the likelihood of a switch. Patients with access to alternative biological options had a much shorter mean duration of omalizumab therapy before switching compared to those with only affordable omalizumab: 4.9±1.5 years versus 8.9±1.3 years (p<0.001). The optimal time to predict the likelihood of a good response was less than 5.5 years, with an AUC of 0.91 and p=0.003. This cutoff point provided a sensitivity and specificity of approximately 89% and 100%, respectively.An early transition to omalizumab, specifically within the first 5 years of treatment, in patients with severe asthma and higher sputum eosinophils may enhance the likelihood of a good response if other biological therapies were available.