AstraZeneca's Ultomiris fails late-stage trial, adding to 2026 setbacks

AstraZeneca's Ultomiris failed a late-stage trial in stem cell transplant patients, the drugmaker's third pipeline setback in 2026.

The drug did not achieve statistical significance for event-free survival at 26 weeks in patients with hematopoietic stem cell transplant-associated thrombotic microangiopathy, though it showed a trend toward benefit, AstraZeneca said Monday. The company is in ongoing discussions with global health authorities over potential next steps for the adult indication.

In a separate pediatric trial, Ultomiris showed an overall survival rate of 87.2% at 26 weeks and 73.4% at 52 weeks. AstraZeneca said it will advance regulatory filings for use in children.

The failed readout follows a disappointing heart-disease trial earlier this month that cast doubt on the drugmaker's trial design, and a May rejection of its breast cancer drug camizestrant by a U.S. regulatory panel on trial design grounds. The accumulating setbacks have fueled concerns about AstraZeneca's pipeline, though the company topped second-quarter profit expectations on strong demand for its cancer and rare disease therapies.

Ultomiris, known chemically as ravulizumab, is already approved in the United States, the European Union and Japan for treating certain rare blood disorders and neurological conditions. AstraZeneca is counting on up to 20 new drug launches to help generate $80 billion in annual revenue by 2030.

In brighter news, AstraZeneca's experimental gastric cancer drug sonesitatug vedotin met a key goal, showing a statistically significant and clinically meaningful improvement in overall survival in advanced gastric cancer patients.

The string of trial failures raises questions about AstraZeneca's clinical development strategy and could invite greater scrutiny from regulators and investors on upcoming data readouts. The company's next major pipeline catalyst will be closely watched as it works to rebuild confidence in its late-stage portfolio.

This article is for informational purposes only and does not constitute investment advice.