[Chinese expert consensus on the use of Omalizumab in allergic asthma (2021 version)].

As the first targeted biotherapy for asthma, Omalizumab, was officially approved in China in August 2017, and was applied in clinical practice since March, 2018. Dozens of experts in Respirology and Allergy from China fully discussed the important clinical issues on the use of Omalizumab in allergic asthma by referring to the relevant publications over the world and the first version of consensus published in March 2018. Until now, over 30, 000 allergic asthma patients have received the treatment of Omalizumab. Therefore, with the latest evidence of clinical and basic research around the world, we updated the consensus with the following issues: (1) The mechanisms and available evidence on anti-IgE treatment; (2) Selection and exclusion criteria for patients using Omalizumab; (3) Cautions on the administration of Omalizumab and highlights of the use of Omalizumab with various vaccines, including novel Coronavirus vaccines, and key points to note during a Novel Coronavirus pandemic; (4) Long-term use and safety; (5) The use of Omalizumab in specific populations; (6) Clinical applications of omalizumab with other targeted therapies and allergen-specific immunotherapy. Omalizumab, combining to the Cε3 area of IgE, reduces the free IgE level, and downregulates the expression of FcεRⅠ, which inhibits the release of inflammatory mediators of mast cell sources, and leads to reduced asthma exacerbation, decreased rate of emergency visit and hospitalization, improved symptoms and quality of life, as well as less concomitant moderate to severe asthma, poorly controlled after at least 3 months treatment of ICS/LABA, and confirmed with allergic status through skin prick test or serum total IgE or specific IgE. Conditions that exclude the use of Omalizumab include patients who are suspected to be allergic to drug ingredients. Omalizumab is administered based on dosing tables by subcutaneous injection. Omalizumab should be administered by a health care professional (doctor or nurse) in a medical institution equipped with facilities for post-injection observation and rescue treatment for anaphylactic shock. After the injection, the patient should be closely monitored whether there is an anaphylactic reaction. The duration of Omalizumab treatment should be at least 16 weeks to judge its effectiveness, after 16 weeks, Omalizumab treatment will be continued or withdrawn based on the overall asthma control evaluation. Patients should be followed every 3 months to assess the disease control and dosing adjustment. The common adverse reactions were injection sites reactions. Based on the latest evidence around the word, we focused on updating the relevant treatment course, administration method and use of specific populations, in order to guide clinicians in the use of Omalizumab. The use of Omalizumab in China still requires long-term observation and further research. With the increase of clinical evidence, this consensus will be continuously improved and supplemented.