Pfizer sued Guangzhou Welman for alleged copyright infringement of Viagra reports Forbes.
I wonder why Pfizer's allegations focused on copyright infringement instead of patent infringement, or both. Or is copyright used mistakingly as the prototype of an intellectual property? Read more here
In 2001 Pfizer obtained a Chinese patent license for Viagra
July 2004 SIPO's Patent Review Board revoked its license after complaints by 12 Chinese pharmaceutical companies: Pfizer failed to accurately explain the uses of the pill's key ingredient, sildenafil citrate.
June 2, 2006 the Beijing No. 1 Intermediate People's Court reversed the review board's verdict and upheld Pfizer's patent. Read more here.
12 Chinese pharmaceutical firms have launched an appeal against this ruling. Read more here.