It could have been worse. In fact, this morning, it was.

Amgen (NASDAQ:AMGN) is down about 1% as I write, having been down about 3% earlier. The stock's saving grace? Amgen's announcement of a Food and Drug Administration delay for its long-awaited osteoporosis drug, Prolia (its treatment for postmenopausal osteoporosis), contained this statement: "This letter does not require additional pre-marketing clinical trials to complete the review of the treatment indication."

The agency does want a new trial before it'll approve Prolia for the prevention of osteoporosis, but that's to be expected, given the results of the FDA advisory panel meeting.

To be approved to treat osteoporosis, Amgen needs to give the FDA some additional information, including more details on how it plans to monitor side effects after the drug is approved. Just by the FDA's request for that information, you can tell that Amgen is on the home stretch.

The company didn't say how long it'll take to turn in the requested information and get a response back from the FDA. I'd guess a few months, at a minimum. This is welcome news for other drugmakers of osteoporosis treatments, like GlaxoSmithKline's (NYSE:GSK) and Roche's Boniva, Procter & Gamble's (NYSE:PG) and sanofi-aventis' (NYSE:SNY) Actonel, and even generic-drug makers that sell versions of Merck's (NYSE:MRK) Fosamax.

The FDA's focus on safety with Prolia, including requiring Amgen to have a Risk Evaluation and Mitigation Strategy (REMS), could also be seen as a good sign for competitors. The osteoporosis market is extremely competitive, and a newcomer with a less-established side effect profile could be at a disadvantage.

On the other hand, Prolia is likely to excel in treating cancer patients whose tumors have spread to their bones. That indication is a little farther behind in development, but the data looks good so far, with Prolia beating Novartis' (NYSE:NVS) Zometa in one trial. With less competition in this indication, Prolia will likely have an easier time marketing the drug.

And so it's back to waiting for Amgen's investors. Tick-tock. Tick-tock.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool owns shares of Procter & Gamble and has a disclosure policy.