The market can be a fickle beast, as investors in biopharma giant Celgene (NASDAQ:CELG) found out last week. Shares have been down more than 5% since Wednesday after a perceived revenue miss in its third-quarter earnings report.

Perhaps yet another reason to ignore earnings guidance (or at least the reaction in a share price when it changes slightly), the worry about Celgene was that it reduced full-year 2007 revenue guidance from its "$1.4 billion range" of last quarter to $1.375 billion.

This is a measly $25 million revenue shortfall, for those who are stingy enough to even count the new top-line guidance as outside of its previous range. Even with the "lowered" guidance, Celgene affirmed its adjusted earnings-per-share forecast at the top of its previous range of $1.00 to $1.05.

Getting into the third quarter's results, revenue was up 43% versus last year as REVLIMID experienced 97% growth with on- and off-label sales in different blood disorders. Adjusted EPS showed the kind of scale usually only seen from tech and drug developers: up 93% versus the third quarter of last year to $0.29 a share

Another source of angst for analysts was whether REVLIMID would continue its torrid sales growth, considering it has solid market share in the treatment of myelodysplastic syndromes -- a disease of the bone marrow -- and multiple myeloma in the U.S., where it competes with Rule Breakers pick Millennium Pharmaceuticals (NASDAQ:MLNM).

Celgene countered these worries by noting that the European market for REVLIMID is only just beginning to come on line, with European revenues accounting for 11% to 19% of REVLIMID sales, and that market saturation won't start to occur until "late 2008" at the earliest. There are also the numerous label expansions into even solid tumors, which could re-energize REVLIMID sales beyond this date.

The larger point here is that slightly decreasing the full-year 2007 revenue forecast is minuscule relative to Celgene's long-term value drivers like the potential label expansions with REVLIMID and progress for its other next-generation drugs.

Revenue miss or not, shares of Celgene aren't on my biopharma buy list because there's so many other exciting drug developers out there, but some investors likely just got the unjust discount on shares of Celgene that they were waiting for.

A free trial to Rule Breakers gives you a chance to chat with other investors and our analysts about the technologies that will change our lives and help our portfolios.  

Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has not lowered guidance on its disclosure policy.