AstraZeneca PLC (LSE:AZN, NASDAQ:AZN) shares rose 3% to 14,230p, placing the drugmaker at the top of the FTSE 100 leaderboard on a subdued Friday session, after its experimental COPD treatment tozorakimab succeeded in two late-stage clinical trials.
The results mark the first positive phase III readout from a programme of more than 20 major data releases AstraZeneca expects to deliver in 2026, each adding weight to the company's ambition to reach $80 billion in annual revenue by 2030.
Tozorakimab met its primary endpoint in both the OBERON and TITANIA trials, reducing the rate of moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease (COPD), the progressive lung condition that is the third leading cause of death worldwide, affecting nearly 400 million people.
The drug works by blocking interleukin-33 (IL-33), a protein the body releases in response to damage or irritation in the airways.
When IL-33 is activated, it triggers inflammation and contributes to the build-up of excess mucus that makes breathing progressively harder for COPD patients, setting off a damaging cycle of worsening that can lead to hospitalisation or death.
By intercepting IL-33 at source and neutralising both its active and oxidised forms, tozorakimab aims to break that cycle simultaneously at two points: cooling the inflammatory response and clearing the mucus dysfunction that standard inhaled therapies cannot adequately address.
The trials enrolled patients who were still experiencing exacerbations despite being on standard inhaled treatments, a population with significant unmet medical need.
Tozorakimab, administered as a 300mg injection every four weeks on top of existing therapy, reduced exacerbation rates in both former smokers, the primary study population, and in the broader group, including current smokers and patients across all levels of a blood marker called eosinophils, a type of white blood cell often used to categorise COPD patients for treatment.
The drug was described as generally well-tolerated with a favourable safety profile.
Frank Sciurba, professor of pulmonary and critical care medicine at the University of Pittsburgh and chief investigator of the trial programme, said the results suggested meaningful clinical benefit across a broad COPD population, regardless of smoking status or eosinophil levels.
Sharon Barr, AstraZeneca's executive vice president of biopharmaceuticals research and development, described the outcome as a major scientific advancement, noting that tozorakimab is the first IL-33-targeting biologic to demonstrate statistically significant reductions in COPD exacerbations across two replicate phase III trials.
Two further last-stage clinical evaluations of tozorakimab in COPD, PROSPERO and MIRANDA, are ongoing, alongside separate studies in severe viral lower respiratory tract disease and asthma.