The China State
Intellectual Property Office's (SIPO's) Patent Reexamination
Board has declared invalid the patent for Viagra, the US
pharmaceutical company Pfizer's treatment for erectile dysfunction.
The board said the related documentation fails to conform to
Article 26 of the Patent Law.
Sources at SIPO declined to provide further comment.
The law requires companies to provide a description of the drug
"... in a manner sufficiently clear and complete so as to enable a
person skilled in the relevant field to understand the drug. The
abstract shall state the main technical points of the invention or
utility model."
Pfizer said it will appeal the decision.
The active ingredient in Viagra is sildenafil, and the decision
by SIPO's Patent Reexamination Board overturns the sildenafil-use
patent issued in China in September 2001, the company said.
Pfizer said the patent remains in effect until a court resolves
the issue, but Article 47 of the Patent Law states that any patent
right that has been declared invalid is treated as
non-existent.
Pfizer has three months in which to file its case
in the people's court.
Viagra entered the Chinese market in July 2000. Many domestic
companies opposed the patent because drugs produced by some Chinese
companies were already using sildenafil in their products,
Sina.com.cn news reported.
Granting the patent to Pfizer meant that until 2014, any
domestic company using sildenafil citrate to produce drugs for the
treatment of erectile dysfunction would be regarded as patent
violators. In October 2001, 12 domestic pharmaceutical companies
requested SIPO to cancel the patent rights.
(China Daily July 9, 2004)