AstraZeneca COPD drug trials succeed as shares fall to six-week low
First-in-class IL-33 inhibitor Tozorakimab meets Phase III targets in two confirmatory studies, challenging Regeneron-Sanofi rival
AstraZeneca shares fell to a six-week low on Friday despite the pharmaceutical giant reporting successful Phase III trials for its experimental COPD treatment, in a sign that investors may be tempering expectations amid intensifying competition in respiratory medicine.
The company announced that tozorakimab, a first-in-class monoclonal antibody targeting interleukin-33 (IL-33), met its primary endpoint in both the OBERON and TITANIA trials, significantly reducing the annualized rate of moderate-to-severe COPD exacerbations compared with placebo. The drug demonstrated efficacy across both former smokers—the primary study population—and the overall population, which included current smokers and patients across varying lung function severity stages.
The trial results represent a significant scientific advance, marking the first two confirmatory studies for an IL-33 biologic in COPD treatment. Tozorakimab is designed to reduce inflammation and disrupt the cycle of mucus dysfunction that drives disease progression in patients with chronic obstructive pulmonary disease.
Yet AstraZeneca's American depositary receipts declined 2% to $183.40, while its London-listed shares slipped to 13,532 pence, the lowest level in six weeks. The stock is now trading below its 50-day moving average of $193.92 and remains well off its 52-week high of $210.50 reached last November.
The muted market reaction appears to reflect growing competition in the COPD treatment space. Regeneron and Sanofi, which are co-developing itepekimab—a rival IL-33 inhibitor—reported mixed Phase III results last May. Their AERIFY-1 trial met its primary endpoint with a 27% reduction in moderate or severe acute exacerbations, but the AERIFY-2 study failed to achieve statistical significance.
Meanwhile, GlaxoSmithKline's Nucala, an IL-5 inhibitor, secured FDA approval for COPD in May 2025 specifically for patients with inadequately controlled disease and high eosinophil levels. GSK is also advancing its own anti-IL-33 antibody, GSK3862995, currently in Phase 1 clinical testing.
Regeneron and Sanofi's Dupixent, which targets IL-4 and IL-13, received regulatory approval for COPD in September 2024, establishing an early beachhead in the biologics segment for respiratory disease.
The commercial stakes are substantial. COPD is the third leading cause of death worldwide, affecting nearly 400 million people globally, with more than half experiencing exacerbations even while receiving standard care. The global COPD therapeutics market is projected to reach $27.2 billion this year and expand to $43.2 billion by 2033, according to market research.
Biologics are expected to be the fastest-growing segment of the COPD market, driven by precision medicine trends and increasing clinical adoption. The competition among pharmaceutical companies is intensifying, with strategies focusing on robust product pipelines, extensive geographic reach, and established brand trust.
Analysts maintain a largely positive outlook on AstraZeneca despite the recent share price weakness. Wall Street has assigned the stock a "moderate buy" rating, with an average 12-month price target of $208.43—representing potential upside of approximately 13.7% from current levels. Eight analysts rate the shares as buy or strong buy, compared with just one sell rating.
TD Cowen reaffirmed a buy rating on March 18, while Wall Street Zen upgraded the stock from hold to buy on March 20. Deutsche Bank maintains a sell rating, highlighting divergent views on the company's near-term prospects.
The Phase III success removes a key binary risk from AstraZeneca's respiratory pipeline, positioning the company for regulatory filings in the coming months. However, investors appear to be awaiting more detailed data, including the magnitude of clinical benefit, safety profile specifics, and commercial differentiation potential versus competing biologics already approved or in late-stage development.
AstraZeneca, with a market capitalization of $290 billion, has been expanding its respiratory franchise as part of its broader oncology-focused growth strategy. The company reported trailing twelve-month revenue of $58.7 billion and earnings per share of $6.53, with a price-to-earnings ratio of 28.66 based on recent results.
The company's next major catalyst will likely come when it presents detailed tozorakimab trial data at an upcoming medical conference, potentially providing investors with clearer visibility on the drug's commercial opportunity and competitive positioning in the rapidly evolving COPD treatment landscape.