One reason might be to "to delay its introduction of a cut-price product". A second might be that "the cost and legal uncertainty associated with patent trials are simply too great." Finally, it may be that the firm may know that "its patent was mistakenly awarded, perhaps because the purported breakthrough was too minor or obvious."
David Balto, a former official at the Federal Trade Commission, is quoted as saying, "Branded pharmaceutical firms have been stretching the limits of what deserves a patent, and the courts are just catching up."
It seems they have a long way to go.
