April 26, 2017

Case Name: Acorda Therapeutics Inc. v. Roxane Labs., Inc., 14-882-LPS, 2016 U.S. Dist. LEXIS 48479 (D. Del. Mar. 31, 2017) (Stark, J.)

Drug Product and Patent(s)-in-Suit: Ampyra® (dalfampridine extended-release tablets); U.S. Patents Nos. 5,540,938 (“the ’938 patent”), 8,007,826 (“the ’826 patent”), 8,663,685 (“the ’685 patent”), 8,354,437 (“the ’437 patent”), and 8,440,703 (“the ’703 patent”)

Nature of the Case and Issue(s) Presented: The patents-in-suit related to the use of dalfampridine (also known as 4-AP) to treat neurological diseases such as multiple sclerosis (“MS”) and, specifically, extended release 4-AP tablets improve MS patients’ ability to walk. Acorda marketed its drug Ampyra® for this purpose. The ’938 patent taught the use of 4-AP to treat neurological disorders such as MS and was the first patent to issue. Elan licensed the ’938 patent to Acorda in 1997. Acorda then applied for and obtained the remaining patents-in-suit, which described a method of using specific, twice daily dosing of 4-AP tablets to improve walking in MS patients. Notably, the ’938 patent was prior art to the other patents-in-suit.

The lawsuit arose when defendants filed a series of ANDAs, seeking to market generic 4-AP tablets. Each defendant stipulated to infringement if the patents-in-suit were found to be valid and enforceable. After a bench trial, the court concluded that the ’938 patent was valid, but that the other patents-in-suit were invalid as obvious in light of the prior art.

Why Acorda Prevailed: In order to invalidate the ’938 patent, defendants presented multiple prior-art references indicating that a person of ordinary skill would have reasonably expected that 4-AP formulations could successfully treat MS. The prior art did not show, however, that a person of ordinary skill would have a reasonable expectation of creating a sustained-release formulation of 4-AP. Because there was no well-characterized relationship between 4-AP and its therapeutic effects at the time of patenting, one of ordinary skill would not know how to formulate a safe and effective sustained-release 4-AP tablet. Accordingly, defendants failed to meet their obviousness burden as to the ’938 patent.

But the court determined that the prior art, including the ’938 patent, taught the additional limitations set forth in the claims of the remaining patents-in-suit. Prior art studies suggested that 4-AP could increase the walking ability of an MS patient and further suggested possible dosage ranges encompassing the claims of the patents-in-suit. The court found credible expert testimony that a person of ordinary skill would be motivated to create stable doses of the sustained-release tablets that the patent could take on a regular basis. Accordingly, here defendants did meet their burden of proof that the claims were obvious and thus invalid in light of the prior art.