An experimental treatment designed to block a major inflammatory signal reduced serious chronic obstructive pulmonary disease flare-ups by approximately 30% in two late-stage clinical trials.
The drug, tozorakimab, is a monoclonal antibody developed by AstraZeneca. Researchers presented the findings at the European Respiratory Society Congress in Barcelona, and the data were also reported as published in the New England Journal of Medicine.
The two yearlong studies included approximately 1,750 current or former smokers with COPD and a history of flare-ups. Participants continued receiving standard therapy and were assigned either tozorakimab or a placebo.
In the trials’ primary populations of former smokers, the experimental treatment reduced the annual rate of moderate-to-severe exacerbations by between 29% and 34%. Reported rates were approximately 1.41 and 1.44 flare-ups per year for patients receiving the drug, compared with 2.00 and 2.03 among placebo recipients.
COPD is a progressive group of lung conditions that includes emphysema and chronic bronchitis. It restricts airflow and can cause coughing, wheezing, excess mucus and shortness of breath. The Centers for Disease Control and Prevention says nearly 16 million American adults have been diagnosed with COPD, while many others may not know they have it.
Exacerbations are periods when symptoms suddenly become worse. Severe episodes can require emergency treatment or hospitalization, making prevention an important goal even when a treatment cannot reverse existing lung damage.
Tozorakimab targets interleukin-33, commonly called IL-33, a signaling protein associated with several inflammatory pathways. The antibody was administered by injection every four weeks.
Researchers reported broadly similar benefits across smoking history, disease severity and blood-eosinophil groups. Safety results were generally comparable with placebo during the trials.
Those findings are encouraging, but they do not establish that the medicine is appropriate for every person with COPD. Late-stage trial success must still be evaluated by regulators, and longer-term safety, pricing and real-world effectiveness remain important questions.
The treatment is under consideration by the U.S. Food and Drug Administration. It is not yet an approved COPD therapy, and patients should not alter existing medication based on preliminary news coverage.
Current COPD care may include inhaled medicines, pulmonary rehabilitation, vaccinations, smoking cessation and other treatment selected by a clinician. Anyone experiencing new or worsening breathing problems should seek appropriate medical care rather than attempting to diagnose themselves.
The trials represent a meaningful step because they suggest that targeting IL-33 could help patients whose symptoms remain difficult to control with existing inhalers.
For patients and families, the result offers cautious hope—not a cure and not an immediate replacement for established care, but evidence that another treatment option may be moving closer.
