Exela ANDA Infringes Allergan’s Patents

Posted on | December 15, 2009 | No Comments

2010-1102 Allergan v. Exela PharmSci
In re Brimonidine Patent Litigation
D/DE 07-md-1866
Judge Gregory Sleet

Defendant Exela appeals from the judgment following a bench trial that its ANDA for a brimonidine solution for glaucoma treatment infringed several patents of Allergan.  Allergan markets its product as ALPHAGAN P.  The court also rejected a myriad of invalidity arguments.

Invalidity focused on the pH of Exela's proposed product.  The claims generally covered a solution buffered to a pH of 6.8 to 8.0, and Exela argued that its product would be in 6.5 to 6.7 range.

The court however sided with Allergan and its expert, who testified that the product would have to be produced and initially fall in the range of 7.0 or higher in order to account for pH drift–the tendency of the pH to fall while sitting on the shelf.  The court also found Exela's argument not credible because it had initially proposed a lower pH range (down to 5.5), but had amended it upward after the FDA questioned the equivalency of the lower pH.  Thus, in order to maintain the required pH for the entire shelf-life of the product, the court found that it would have to fall initially within the claimed pH range.

The court also addressed and rejected a number of defenses, including obviousness (Opinion, pp. 16-28), non-enablement (id. at 28-30), written description (id. at 30-32), best mode (id. at 32-34), indefiniteness (id. at 34-35), utility and operability (id. at 35-36), inventorship (id. at 36-38), and uneneforceability (id. at 38-40).
2010-1102 Opinion

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