The Anglo-Swedish company said the latest study found that the drug was unlikely to prolong survival or to stop the progression of the disease. Expectations for the drug had been lowered after an earlier study also found no significant benefits for treating non-metastatic cancer.
AstraZeneca shares fell slightly at the opening of the London Stock Exchange on Monday but were 0.7 percent higher at 2,954 pence by late morning.
"Investors should interpret this as another blow to the zibotentan program - a sub-billion market opportunity - and a further reflection of what we view as the company's wider challenges in delivering successful innovation," said Dr. Mike Mitchell, analyst at Seymour Pierce.
AstraZeneca is continuing with studies on the use of zibotentan with standard chemotherapy for treating metastatic cancer.
The company had another disappointment last month when the U.S. Food and Drug Administration extended its review of the experimental blood thinner Brilinta, considered a potential blockbuster product.
The FDA requested a new analysis from the company's 18,000-patient study comparing its drug to Plavix, the third-best-selling drug in the United States last year. The study showed better outcomes for patients taking Brilinta overall, though U.S. patients fared worse.