The FDA's decision to add a boxed warning to Prolia is a significant regulatory action that directly impacts Amgen Inc., as it may lead to heightened caution among prescribers and patients, potentially reducing the drug's usage and negatively affecting sales. Given that Prolia is a product of Amgen and the warning is specific to this drug, the relevance is high. The importance is significant as well, considering that changes in drug labeling can influence market perception and sales. The confidence in this analysis is high due to the direct relationship between FDA warnings and pharmaceutical sales, although the exact financial impact may vary.