Amgen Inc. said Monday that the Food and Drug Administration wants more information about its osteoporosis treatment Prolia before granting marketing approval. It delays a drug seen as a potential blockbuster for the company.
In a letter, the FDA said it wants to know how Amgen will monitor patients who use Prolia and wants the company to develop a strategy to evaluate the risks of the drug, Amgen said.
Amgen shares fell $1.08 to $60.24.
The Thousand Oaks company wants to market Prolia for the prevention and treatment of postmenopausal osteoporosis. The FDA said Amgen needs to run more clinical tests of Prolia as a preventive therapy, but Amgen will not have to perform further testing of Prolia as a treatment for the illness.
Prolia, which is also called denosumab, works by targeting cells that break down bone.
Amgen said it was reviewing the FDA's message, called a complete response letter, and planned to respond soon.