After warning that Celgene (NASDAQ: CELG) would only achieve the low end of its previous guidance range for 2009, the stock of the company sold off significantly, noted biotech expert John McCamant.

Nevertheless, in his ‘Medical Technology Stock Letter’ he sees the selloff as any opportunity, calling the company a "great growth story."

"Celgene pre-announced 1Q 09 revenues of $600 million, which was significantly below Wall Street consensus estimates of $640-$650 million,” he said.

McCamant added that the earnings miss was completely unexpected, and has partially shaken the belief that the “Big Bios” would be able to deliver solid earnings despite the economic problems.

"Nevertheless, we remain positive on the CELG story because we continue to believe that Revlimid is emerging as a major franchise in cancer. The company has executed very well in the lab by creating Revlimid as a better drug that its parent Thalomid.”

He added, "The improved efficacy and safety profile of Revlimid positions the drug to be a leader in the treatment of both multiple myeloma (MM) and myelodysplastic syndrome (MDS).”

According to him, the drug additionally has multiple other shots to work in other cancers of the blood, with NHL representing a very nice opportunity for further revenue growth.

The non-U.S. market opportunity in multiple myeloma has been underestimated by most of Wall Street and provides a significant growth opportunity.

CELG makes more money and has better operating margins in Europe, McCamant noted.

"We also continue to believe that there is strong synergy and potential for meaningful earnings from the Pharmion acquisition through Vidaza sales,” he continued.

"It may be a bit of battle before the stock begins to work its way higher as many on Wall Street are in a wait-and-see mode. We continue to believe that CELG is a great growth story.

"In addition, we would add that one small positive from the recent decline is that CELG is now a very attractive acquisition candidate at current price levels."