Allergan and its subsidiaries Forest Laboratories, LLC and Forest Laboratories Holdings, Ltd., along with Adamas Pharmaceuticals, Inc., have settled with Amneal Pharmaceuticals LLC and related companies and subsidiaries relating to patent-infringement litigation brought by Forest and Adamas in response to Amneal’s abbreviated new drug application (ANDA) seeking approval to market generic versions of Allergan’s Namenda XR (memantine hydrochloride) extended-release capsules. It is Allergan’s understanding that Amneal is the first applicant to file an ANDA containing a paragraph IV certification regarding Namenda XR.

Specifically, under the terms of the settlement agreement, and subject to review of the settlement terms by the US Federal Trade Commission, Forest, and Adamas will grant Amneal a license to market generic versions of Namenda XR beginning on January 31, 2020, following receipt by Amneal of final approval from the US Food and Drug Administration (FDA) on its ANDA for generic Namenda XR. Alternatively, under certain circumstances, Amneal has an option to launch an authorized generic version of Namenda XR beginning on January 31, 2021. Other terms of the settlement were not disclosed.

Similar patent-infringement litigation brought by Forest, Adamas and Merz Pharma GmnH & Co. KgaA, against certain other companies that have filed ANDAs seeking approval to market generic versions of Namenda XR remain pending in the US District Court for the District of Delaware.

Namenda XR (memantine HCl) is a higher dose, once-daily extended-release formulation of Namenda for treating Alzheimer’s disease. Allergan had sought to discontinue the immediate-release version of Namenda, but earlier this year, a panel of the US Court of Appeals for the Second Circuit issued a ruling upholding a December 15, 2014 preliminary injunction requiring the company to continue distribution of Namenda (memantine HCl) immediate-release tablets, which are indicated for the treatment of moderate to severe dementia of the Alzheimer’s type.

Actavis also recently launched once-daily Namzaric, a fixed-dose combination of Namenda XR and donepezil that provides another treatment option for patients with moderate to severe Alzheimer’s disease. Since the launch of Namenda XR in 2013, the two medications, Namenda XR and donepezil, have been commonly prescribed in combination with one another to treat the symptoms of moderate to severe Alzheimer’s disease. Donepezil is the active ingredient in Aricept (donepezil hydrochloride), which is indicated for the treatment of mild to severe dementia of the Alzheimer’s type. Actavis and Adamas collaborated on the development of the fixed-dose combination. Actavis has exclusive US commercialization rights while Adamas will retain exclusive commercialization rights outside of the US.

Source: Allergan