Double-Patenting: Deeming older patents invalid or obvious when newer ones are filed

In a recent ruling between two large biotechnology companies, Gilead Sciences and Natco Pharma, the Federal Circuit held that it is indeed possible for a later-granted patent to invalidate an earlier-granted one for "obviousness-type double patenting" (Brinckerhoff). With regards to the case in question, the patent holder, Gilead Sciences, held two very similar patents; however, one of them was issued later and expired earlier.

This is problematic because the patent system has determined that when a patent expires, that intellectual property is no longer proprietary and can now be used by the public to create further modifications. However, in this case, Natco Pharma was still unable to use the invention outlined in Gilead's expired patent because the earlier issued patent prevented them from doing so.

"Judge Chen begins his analysis of the case at hand with this telling statement:

[I]t is a bedrock principle of our patent system that when a patent expires, the public is free to use not only the same invention claimed in the expired patent but also obvious or patentably indistinct modifications of that invention.

[...]

And that principle is violated when a patent expires and the public is nevertheless barred from practicing obvious modifications of the invention claimed in that patent because the inventor holds another later-expiring patent with claims for obvious modifications of the invention. Such is the case here.

"

It is important to note that the second patent obtained by Gilead was for what was determined to be a "obvious variation," which is why it doubly prevented Natco Pharma from using the invention.

However, this ruling has the potential to be extremely problematic. If a company slightly modifies their product and wants to get a second patent on the modification, they run the risk of invalidating their original patent, which is a terrifying prospect for any company. For this reason, Chief Judge Rader pointed out in his dissent that it is definitely important that we disallow double patenting when it comes to same-invention patenting. However, why should we disallow the patenting of an improvement that is made on the product? Furthermore, how do we determine that this obvious modification is actually obvious and that its obviousness is a reason to discount the original patent altogether? 

Source:http://www.mondaq.com/unitedstates/x/310614/Patent/Federal+Circuit+Expands+Doctrine+of+Obviousness+Type+Double+Patenting