In Eli Lilly and Co. v. Teva Parenteral Medicines Inc., the
Federal Circuit affirmed the U.S. District Court for the District
of Delaware's decision that Eli Lilly's patent to
pemetrexed is not invalid for obviousness-type double patenting.
The Federal Circuit's decision provides important guidance on
one of the most complex areas of U.S. patent jurisprudence and
explains how information in the specification can be used in a
double patenting analysis, discusses when obviousness-type double
patenting may arise between product and method claims and notes
that unexpected results may be relevant to obviousness-type double
patenting.
The Patent at Issue
The patent at issue, U.S. Patent 5,344,932 , relates to Eli
Lilly's Alimta (pemetrexed) product, which is used in the
treatment of advanced nonsquamous nonsmall cell lung cancer. Claims
1, 2 and 7 recite Markush groups that encompass a number of
structurally related antifolate compounds, including pemetrexed.
Claim 3 is
