Amgen's bone drug gets delayed by the FDA, and Wall Street isn't surprised

Drugmaker Amgen (AMGN) did not win the Food & Drug Administration's approval on Monday for its experimental osteoporosis treatment denosumab. Amgen, based in Thousand Oaks, Calif., had been banking on the drug's approval for company growth, but the FDA asked for more information before making a decision. Although the news was unsurprising, clearly, the road ahead for the drug is far bumpier than initially Amgen, analysts and investors had envisioned.

It's unclear how much time Amgen will need to meet the FDA's requests. Amgen applied in February for approval of denosumab -- or Prolia, by its trade name -- which it's studying in a range of bone-loss conditions, including rheumatoid arthritis and bone loss from treatment for breast and prostate cancer, and for its potential to delay bone cancer metastases and to inhibit and treat bone destruction across many stages of cancer.