Quotes of the Day

In China, where supplies of the traditional cure for erectile dysfunction—tiger penis—have shriveled, men in search of an extra boost have been snapping up doses of knockoff Viagra. Although they're illegal, the fakes are so widespread that American pharmaceutical giant Pfizer says it's having a difficult time selling the real thing. Last week Pfizer's job grew even tougher. China's State Intellectual Property Office (SIPO) overturned the company's patent rights to Viagra, potentially opening the Chinese market to a flood of cheap, locally made generic rivals.

Details of the decision have not been released, but SIPO says Pfizer's patent was rescinded on the grounds that its description of the drug was insufficient to meet the standards of Chinese law. The company claims it's being penalized for not fulfilling requirements that didn't even exist when its patent was approved in 2001, and U.S. Trade Representative spokesman Richard Mills says he will raise the issue with the Chinese government. Pat Powers, Beijing-based director of China operations for the U.S.-China Business Council, says SIPO's decision "sends a negative signal to foreign companies looking to defend their property rights." Still, it's not clear whether China's patent office did anything wrong. Other countries have thrown out Viagra patents for various reasons, and intellectual-property lawyers say that until more details come to light it's impossible to tell whether SIPO had legitimate cause or succumbed to pressure from local drug makers, as critics such as Powers contend. Pfizer says the patent will stay in effect while it appeals, but Chinese companies are already clamoring to make their own versions of the drug. Says Lu Xinyu, marketing manager of Guangzhou drug company Beautiful Pearl Group, "I can't imagine how vicious the competition will be."

• Matthew Forney | Beijing
• Erectile dysfunction is big business in China