Xolair, also known as omalizumab, is a medication that is being used to treat asthma and food allergies. The drug, which is available as an injection, has various side effects, costs, and dosages, and its use is being explored for reducing severe reactions in people with multiple food allergies. Additionally, a biosimilar of Xolair has been approved by the FDA, although it is unclear if this is related to the medication's use in treating food allergies or asthma.