Reslizumab
Reslizumab is a humanized IgG4-κ anti-IL-5 mAb developed by drafting technology from a rat mAb with high affinity against human IL-5152. Reslizumab binds to a small region corresponding to amino acids 89-92 of IL-5, which are critical for binding to IL-5Rα153. Reslizumab administration results in clinical improvement in asthma and an increase in FEV1 in patients with eosinophilic counts > 400 cells/µL compared to placebo153-158. Apparently contrasting results have been reported on the effects of reslizumab on the improvement of FEV1 compared to placebo. Although several studies reported that reslizumab significantly improved FEV1 compared to placebo154, 157, other investigators found that reslizumab had no improvement in FEV1 compared to those receiving placebo 154. A real-life study recently confirmed the efficacy of reslizumab treatment in reducing the number of exacerbations and increasing FEV1 6 months after the beginning of treatment159.