A legal challenge to patents on Pfizer's Lipitor by a generic drug maker has some on Wall Street worried a cheaper copycat of the world's biggest-selling drug could come to market much earlier than expected. In a two-week trial that ended in December, Ranbaxy Laboratories, a small generic drug maker in India, sought to crack two patents that Pfizer says protect the cholesterol-lowering drug until 2009 and 2011. The litigation will be decided in the next six to 12 months by Judge Joseph Farnan of the U.S. District Court of Delaware. According to a Wall Street Journal article, the prevailing view on Wall Street has been that Ranbaxy, which is trying to establish itself in the U.S. wasn't likely to win the case. But testimony at the trial form both sides on how the patents should be interpreted, as well as disclosures about Pfizer's conduct in applying for the patents, have left a small but growing number of investors less certain that Pfizer will triumph. If Ranbaxy prevails, it would send enormous shockwaves throughout the pharmaceutical world. Lipitor had global sales of $9.2 billion in 2003, a big chunk of Pfizer's revenue of $45.2 billion that year.