The Tale of Viagra Patents: Comparative Studies of the Global Challenges in China and Other Countries

When 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.