Sunovion Pharma. Inc. v. Teva Pharma. USA, Inc.

Case Name: Sunovion Pharma. Inc. v. Teva Pharma. USA, Inc., Civ. No. 09-cv-01302, 2013 U.S. Dist. LEXIS 7695 (D.N.J. Jan. 17, 2013) (Cavanaugh, J.)

Drug Product and Patent(s)-in-Suit: Lunesta® (eszopiclone); U.S. Pat. No. 6,444,673 (“the ‘673 patent”)

Nature of the Case and Issue(s) Presented: Sunovion is the assignee of the ’673 patent, which covers the brand name sleep medication, Lunesta. Defendant Dr. Reddy’s sought to introduce generic eszopiclone tablets in 1 mg, 2 mg and 3 mg tablet formulations. On Dec. 15, 2008, the defendant filed an ANDA with the FDA, requesting permission to market and sell its generic version. In response, Sunovion filed suit in the District of New Jersey. The ’673 patent covering Lunesta claims a combination of two isomers, which share the same chemical formula, but differ in structure. The two isomers are known as dextrorotary (S-isomer) and levorotary (R-isomer). After a Markman hearing held on Feb. 22, 2012, the Court determined that the phrase “essentially free” of the R-isomer meant that the R-isomer was present in the claimed compound at a concentration of less than 0.25%. Dr. Reddy’s ANDA called for an R-isomer concentration in an amount between 0.3% and 1.0%. The FDA initially objected to that range, and Dr. Reddy’s submitted a revised R-isomer range of between 0.0% and 0.6%. On May 25, 2012, the Court denied Dr. Reddy’s motion for summary judgment of non-infringement without prejudice, and instructed Dr. Reddy’s that it could re-submit its summary judgment motion if it were accompanied by a declaration indicating that it would not market a generic version of its drug containing less than 0.3% of the R-isomer. Dr. Reddy’s filed a renewed motion for summary judgment with that declaration on June 8, 2012.  The Court granted Dr. Reddy’s motion.

Why Dr. Reddy’s Prevailed:  After construing the term “essentially free” as “less than 0.25% of [its/the] levorotary isomer,” the issue before the Court was whether Dr. Reddy’s generic formulation fell within the scope of the claims of the ’673 patent. During the time that the instant motion was pending, Dr. Reddy’s submitted an eszopiclone Drug Master File containing two alternate proposed specifications. Dr. Reddy’s initial specification called for a concentration range between 0.3% and 1.0%. Its alternative specification was for a concentration of not more than 1.0%. Dr. Reddy’s took the position that its generic drug did not infringe under either of the proposed specifications that it submitted to the FDA.

Dr. Reddy’s noted that although its drug would appear to infringe under the “not more than 1.0%” proposed range, the process used to manufacture the drug (known as Process I) would not result in a concentration of less than 0.25%. The Drug Master File also disclosed a process known as Process II that required additional steps that resulted in a concentration below the 0.25% threshold, but Dr. Reddy’s certified that Process II was used exclusively with a third party, and would not be used to manufacture eszopiclone tablets with an isomer concentration below 0.3%.

The court concluded that based on Dr. Reddy’s submissions to the FDA, Sunovion had not shown by a preponderance of evidence that Dr. Reddy’s would likely market an infringing product. The Court also dispensed with Sunovion’s argument that Dr. Reddy’s formulation infringed under the doctrine of equivalents. The Court noted that although Sunovion provided data suggesting that Dr. Reddy’s product would benefit the end user in a manner that is substantially similar to Sunovion’s branded drug, the data was insufficient to support a finding that Sunovion was entitled to equivalents to the “essentially free” limitation in concentrations above 0.3% of the R-isomer. Allowing Sunovion to do so would result in impermissible broadening of statements made during the course of prosecution of the ‘673 patent.