Last week's setback for multiple myeloma drug Revlimid lenalidomide drove Celgene Corp. shares down $7.72 (11%) to $59.45 last Thursday. Although the shares pared some of the loss on Friday, the company still is in a position to retire even more shares under a recently authorized $2.5 billion buyback plan.

The stock fell after the company withdrew a European application to extend Revlimid's label to include maintenance treatment in newly diagnosed