Reslizumab
Reslizumab binds to IL-5, hindering it from stimulating the activation of eosinophils. Reslizumab, at present, is approved by FDA and EMA as add-on maintenance therapy of severe asthma only in adults with the eosinophilic phenotype (blood eosinophil count of 400/microL) and at least three severe exacerbations in the last year, despite the standard treatment. The administration is intravenous (3 mg/kg) every four weeks, placed in a prepared setting for anaphylaxis (rate 0,3%). Reslizumab leads to better control of asthma symptoms and improvement in lung function. According to two multicenter trials of Castro et al. on 953 adolescents and adults with uncontrolled asthma, the reslizumab group experiences a significant reduction in exacerbations and a persistent improvement of FEV1 through 52 weeks.7 In contrast, other analyses in adolescents show a paradoxical increase in asthma exacerbations. To the present, reslizumab is not approved for children and adolescents.
Reslizumab is also evaluated as a treatment of eosinophilic esophagitis. In a randomized controlled trial involving 226 children and adolescents, the reslizumab group obtains a significant reduction in eosinophil counts compared with placebo. However, improvements in symptoms are observed in all treatment groups and are not associated with changes in oesophageal eosinophil counts.8 Opposite results are shown in smaller trials: long-term treatment with intravenous reslizumab exhibits no relapse or disease progression. Since its role is still uncertain, FDA does not approve reslizumab in children.