Reslizumab in the management of poorly controlled asthma: the data so far.

Interleukin-5, an important cytokine in the pathophysiology of asthma, participates in terminal maturation and increases chemotaxis, endothelial adhesion, and activation of eosinophils. Blockade of interleukin-5 activity with monoclonal antibodies have been successful in decreasing eosinophil counts. Reslizumab, a monoclonal antibody that targets interleukin-5, has been studied for the treatment of severe asthma. Several studies have shown that reslizumab can effectively treat severe asthma with an eosinophilic phenotype. Compared to placebo, patients treated with reslizumab had a reduction in the rates of asthma exacerbations and experienced improvement in FEV1 and asthma control questionnaires scores as early as 4 weeks after the therapy was initiated. Reslizumab was not effective in various asthma outcomes in patients without eosinophilia. The adverse events reported were similar in both treatment and placebo groups. Patients should be observed immediately after treatment because anaphylaxis may occur rarely (0.3%) after exposure to reslizumab. Future surveillance studies are still needed to establish the risks of malignancy and safety during pregnancy.