That could represent further problems for Eyetech (nasdaq: EYET - news - people ), which, along with Pfizer (nyse: PFE - news - people ), already sells a treatment called Macugen for the disease--age-related macular degeneration (AMD).

FORBES: More Eye-Opening Data From Genentech

Another wrinkle: Genentech (nyse: DNA - news - people ), which is Eyetech's (nasdaq: EYET - news - people ) rival in the field of vision treatments, is OSI's partner on the cancer pill Tarceva--meaning that the companies will be close allies in one area but foes in another.

FORBES: OSI Chief Explains $935 Million Eyetech Buy