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.