In the last decades, several key mechanisms driving asthma pathophysiooogy have been discovered. These include the role of IgE in allergic disease, and the role of IL-5 in eosinophilic inflammation. In the last few years, tools to block each of these have been developed. At this time, early clinical studies with neutralizing antibodies against both IgE and IL-5 have been performed in asthma patients, with promising results, and larger studies are underway. The mechanisms of, and possible role of, both anti-IgE and anti-IL-5 treatment in asthma are discussed in this review article.