The U.S. Food and Drug Administration has halted Amgen Inc.'s pediatric clinical trials of the kidney drug Sensipar (cinacalcet hydrochloride) after a 14-year-old patient died. Sensipar is used as a hyperparathyroidism treatment for adults with chronic kidney disease on dialysis. The drug was being tested in children younger than 18 years old. The FDA said it has not yet concluded whether or not Sensipar had a role in the patient's death.

(The outlook for Amgen)

"Amgen is working as rapidly as possible to understand the circumstances of what happened," Ashleigh Koss, a spokeswoman for the Amgen told Bloomberg. "This analysis is ongoing and will be concluded as quickly as possible."