U.S. drug giant Pfizer ($PFE) is mulling an early run at an FDA approval for what is easily one of the biggest potential cancer drugs in any pharma pipeline right now. As Bloomberg reports, the company's thinking on the drug, code-named PD 0332991, comes after results of a mid-stage study last month showed that patients on the drug lived for more than two years without their breast cancers progressing. Also, the FDA has been willing to rapidly green-light new drugs that offer major benefits for life-threatening conditions, especially cancers. The drug could be a $5 billion annual product. Article