Amgen (Nasdaq: AMGN) has lost the double-digit growth of yesteryear. Oh, how investors could use the near-30% annualized revenue growth seen from 2000 to 2005; revenue in the third quarter was flat year over year.

But it gets worse. The drugs that used to be the big growers are actually dragging down sales.


Year Approved in U.S.

Change in Sales, YOY

Epogen 1989 (2%)
Neupogen 1991 0%
Enbrel 1998 (1%)
Aranesp 2001 (9%)
Neulasta 2002 5%
Sensipar 2004 6%
Vectibix 2006 21%
Nplate 2008 94%

Source: Company release. YOY = year over year.

If you add in Prolia, which launched in the past year, drugs that have launched in the last six years are up a solid 24% compared to the year-ago quarter. Unfortunately, sales are still low, so the older drugs drown out that stellar growth.

Prolia, for instance, managed just $10 million in sales during the quarter; that's less than 0.3% of sales. The slow start is to be expected, as osteoporosis is a tough market with lots of competitors: GlaxoSmithKline (NYSE: GSK) and Roche's Boniva, Warner Chilcott (Nasdaq: WCRX) and sanofi-aventis' (NYSE: SNY) Actonel, Eli Lilly's (NYSE: LLY) Forteo and Evista, generic drugs such as copy-cat versions of Merck's (NYSE: MRK) Fosamax, and that's not even all of them.

The active ingredient in Prolia, denosumab, is up for review as a treatment to prevent bone breaks in patients with tumors that have metastasized to the bone. Considering denosumab beat its closest competitor, Novartis' (NYSE: NVS) Zometa, in a couple of trials, I'll be surprised if it doesn't get approved. Investors should be cautious about the timing though. The Food and Drug Administration has set a Nov. 18 PDUFA date because it was a priority review, but the six-month review period could get pushed back by a few weeks or months, especially considering how many reviews the agency had due in October.

The prevention of breaks in cancer patients should boost sales substantially, but the mother lode would be in the prevention of bone metastasis in the first place. Data from a study in prostate cancer patients are expected before the end of the year.

Amgen is no longer a development-stage drugmaker, but that doesn't mean its pipeline isn't important. Considering the state of its established drugs, the new drugs may be more important than they were back when Amgen was just a youngster.

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GlaxoSmithKline and Novartis are Motley Fool Global Gains choices. The Fool owns shares of GlaxoSmithKline. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

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