Circassia Group PLC is a biotechnology company that develops a range of therapies for asthma, chronic obstructive pulmonary disease, and allergy. The company has a single operating segment: NIOX. The NIOX segment relates to the portfolio of products used to improve asthma diagnosis and management by measuring fractional exhaled nitric oxide (FeNO). Geographically, it derives a majority of revenue from the US and also has a presence in EU, Asia Pacific and Rest of world.