Federal Circuit Endorses the Doctrine of Equivalents Once more for Lilly’s ALIMTA®:  Completely different Modification, Identical Outcome

Back in July we wrote about the doctrine of equivalence (DOE) in bio / pharmaceutical cases in general and the ongoing DOE saga in Lilly’s ALIMTA® Litigation specifically. Last week the Federal Circuit wrote a new chapter and issued a non-priority decision in the Eli Lilly and Company v Apotex, Inc. case.

Didn’t it all end last June? Not quite.

It is again about Lilly’s US Patent No. 7,772,209 (“the ‘209 patent”), which claims an “improved method” for treating patients by administering pemetrexed disodium in combination with folic acid and vitamin B12. However, as originally filed, the independent claims indicated an “antifolate” and not pemetrexed disodium (itself a type of antifolate). In order to overcome an objection to the state of the art during law enforcement, Lilly narrowed this claim down from administering an “antifoliate” to administering “pemetrexed disodium”.

The Federal Circuit in Hospira decided that this change was tangential, DOE was applied, and that the Hospira and Dr. Reddys Laboratories (“DRL”) developed alternative forms of salt were injured.

Like Hospira and DRL, Apotex developed a different salt: here pemetrexed dipotassium. And as before, Lilly filed lawsuit to claim DOE.

But here is the crease. For example, as originally filed, claim 9 cited a “method according to any one of claims 1 to 8 wherein the antifoliate is ALIMTA”. The examiner rejected claims related to “ALIMTA” as being perpetual. Later, when Lilly filed the application, which ultimately was granted as a ‘209 patent, she filed a provisional amendment that set aside the “ALIMTA” claims and only pursued the “Pemetrexed Disodium” claims. The issue here was whether the amendment replacing “ALIMTA” with “Pemetrexed Disodium” led to a congestion in criminal prosecution history and whether one of the exceptions was true.

Apotex argued that the amendment was narrower because “ALIMTA” was a broader term that referred either to pemetrexed alone or specifically to pemetrexed disodium. The District Court and the Federal Circuit disagreed, and concluded that specification and law enforcement history makes it clear that “ALIMTA” and “Pemetrexed Disodium” are synonymous and not a limiting change. Accordingly, the Federal Circuit upheld the District Court’s summary judgment.

The decision here clearly depended on the facts. However, the Federal Circuit’s willingness to use DOE in life science cases is evident. Given the apparent rise in DOE in the life sciences, this case is at least another reminder that life science patent practitioners need to keep doctrine in mind when dealing with law enforcement, due diligence, and freedom of operation analysis.

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