Potential Treatment Options for ACO, Including Biologics: Are There Any Roles of Biologics?

Anti-immunoglobulin E (IgE) antibody (omalizumab), anti-interleukin (IL)-5 antibodies (mepolizumab and reslizumab), anti-IL-5R antibody (benralizumab), and anti-IL-4Rα antibody (dupilumab, an IL-4 and IL-13 blocker) have been approved to treat severe asthma, targeting individuals with an allergic background or eosinophilic asthma. These biologics have been demonstrated to be selectively effective in patients with type 2 (T2)-high severe asthma; however, studies on their use in patients with chronic pulmonary obstructive disease (COPD) have reported inconsistent results. Therefore, it is important to differentiate severe asthma, especially late-onset asthma, from COPD. However, experience with the use of biologics in patients with asthma and COPD overlap (ACO) is limited. Some patients with ACO predominantly have T2-high inflammation and may respond to these biologics. In patients with severe ACO who exhibit uncontrolled symptoms despite currently available standard treatment, including inhaled triple therapy, advanced treatment with biologics may be considered. Thus, the evaluation of T2-high biomarkers, such as blood eosinophils, fractional exhaled nitric oxide, and IgE, may help select appropriate biologics for ACO. The selection of the most suitable biologics for each patient should be multifaceted, considering the eligibility criteria, clinical characteristics (phenotypes), molecular mechanisms (endotypes), comorbidities, route of administration, and dosing frequency.