Wall Street apparently decided to ignore the big picture on Friday as investors bid up shares of Transkaryotic Therapies Inc. on news that a federal judge has reduced the number of patents involved in Amgen Inc.'s erythropoietin (EPO) infringement case against TKTX.

U.S. District Court Judge William Young decided that TKTX does not infringe AMGN's U.S. Patent No. 5,618,698, thus relieving TKTX from defending that charge. But the ruling does not affect central questions pertaining to four remaining patents.