523-533When Pfizer patented its new discovery of
second medical use of sildenafil globally for Viagra, it met extensive
challenges in many countries, with reasons of, among others, obviousness and
insufficient disclosure. As ruled by the courts or patent offices in several
countries, patent claims should not go beyond what the inventor disclosed to
the public, or it may violate the basic rationale of the patent system and be
challenged. The story of the Viagra patent in China was uniquely significant.
When the Patent Reexamination Board invalidated the Viagra patent, China
received unusual criticism which believably imposed influence upon the judicial
decisions. Transnational corporations and their agents were advised to respect
and not try to interfere with administrative and judicial procedures in China,
which might help establish a fair and efficient judicial system that would
benefit both domestic and international parties in a long run. The reasons leading to such extensive
failure of the Viagra patents in many countries, especially in a time of enhanced
global IP protection are explored in this paper