AstraZeneca (LSE/STO/NYSE: AZN) reported that its drug tozorakimab reduced moderate and severe chronic obstructive pulmonary disease (COPD) exacerbations in two Phase III trials, with full results published in the New England Journal of Medicine and presented at the European Respiratory Society Congress 2026.

In the OBERON trial, tozorakimab 300mg administered once every four weeks reduced exacerbations by 29% in former smokers and 30% in the overall population of current and former smokers, compared with placebo. In the TITANIA trial, reductions were 34% in former smokers and 29% in the overall population. A total of 2,306 patients were randomized across both trials.

In a pooled analysis of both trials, patients with a baseline blood eosinophil count below 150 cells per microliter achieved a 23% reduction in exacerbations, those at or above 150 achieved a 34% reduction, and those at or above 300 achieved a 43% reduction.

A separate integrated analysis presented at the ERS Congress showed tozorakimab also reduced mucus plug scores in COPD patients. The only adverse drug reaction reported was injection-site reaction.

Tozorakimab is described as a monoclonal antibody targeting interleukin-33 (IL-33), inhibiting signaling of both the reduced and oxidized forms of the protein. The US Food and Drug Administration has accepted a Biologics License Application for tozorakimab under Priority Review as an add-on maintenance treatment for adult COPD patients. The Prescription Drug User Fee Act date is expected in the first quarter of 2027 following use of a Priority Review voucher. The drug is also under regulatory review in the EU and China, and is being studied in a Phase II trial for severe asthma and a Phase III trial for severe viral lower respiratory tract disease.