Biologic agents as therapeutic modalities have emerged as an important new drug treatment. This article focuses on specific groups of immune response modulators of mAbs and recombinant proteins, and their use or their potential use in asthma as an example of an inflammatory allergic process. Although some of these new biologic agents are currently used only in animal models of allergic disease or in other inflammatory or autoimmune diseases, this field is advancing so rapidly that in a few years, these new treatment modalities could be applied to allergic diseases. This article provides a brief rationale for the use of these new biologic agents in asthma. Although optimism is very high for this new class of drugs, caution is needed in extrapolating in vitro data or studies from animal models; adverse events will happen. Nevertheless, as we learn how to modify and alter the inflammatory and immune processes with these new biologic agents, clinicians will enter a new era of treatment options available for their patients with allergic disorders.