LONDON — AstraZeneca announced on Thursday that a cancer drug in development had not shown as much progress as expected, a setback for the pharmaceutical company, which is grappling with weak sales and competition from manufacturers of generics.
The treatment for lung cancer had been expected to be a major driver of growth for AstraZeneca. Like many of its rivals, the company faces increased pressure from manufacturers that capitalize on the loss of patent protections on best-selling medicines.
The trial’s disappointing results sent shares in AstraZeneca plummeting nearly 16 percent, to about $56.
The company said on Thursday that the trial of the drug, known as Mystic, had not met a “primary endpoint” and would not have met a secondary target. Sean Bohen, executive vice president and chief medical officer at AstraZeneca, said in a statement that the results were “disappointing.”
AstraZeneca, a British-Swedish company, fended off a $119 billion takeover attempt from an American rival, Pfizer, in 2014, arguing that it had promising drugs in the pipeline. At the time, analysts said that the lung cancer drug could be worth as much as $6 billion in annual sales, and Pfizer had identified potential treatments for cancer as one of the assets that had attracted it to the company.