The settlement relates to a 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 NAMZARIC (memantine and donepezil hydrochlorides) extended-release, a once-daily, fixed-dose combination of memantine hydrochloride (a NMDA receptor antagonist) and donepezil hydrochloride (an acetylcholinesterase inhibitor, AChEI).
It is Allergan's understanding that Amneal is the first applicant to file an ANDA containing a paragraph IV certification regarding NAMZARIC.
This settlement provides additional clarity for the patent-protected life of NAMZARIC.
Under the terms of the settlement agreement, and subject to review of the settlement terms by the U.S. Federal Trade Commission, Forest and Adamas will grant Amneal a license to market generic versions of NAMZARIC beginning on January 1, 2025, following receipt by Amneal of final approval from the U.S. Food and Drug Administration (FDA) on its ANDA for generic NAMZARIC.
Alternatively, under certain circumstances, Amneal has an option to launch an authorized generic version of NAMZARIC beginning on January 1, 2026. Other terms of the settlement were not disclosed.
Similar patent infringement litigation brought by Allergan, Forest and Adamas against Amerigen Pharmaceuticals, Inc. and Amerigen Pharmaceuticals Ltd., which have filed an ANDA seeking approval to market generic versions of NAMZARIC remains pending in the U.S. District Court for the District of Delaware.
Allergan chief commercial officer Bill Meury said: "Allergan is proud of its commitment to providing therapies and advancing the development of new treatments that can help the millions of patients and their caregivers living with Alzheimer's disease.
"Our recently announced expanded label for NAMZARIC allows patients with moderate-to-severe Alzheimer's disease, who are currently stabilized on Aricept, to start combination therapy directly with NAMZARIC. Approximately 75 percent of patients diagnosed with Alzheimer's disease are in the moderate-to-severe stage of the disease and yet only about one-third of these patients are currently treated with combination therapy."
Allergan is also focused on developing a number of new compounds for the treatment of Alzheimer's disease, including first-in-class selective small molecule agonists targeting muscarinic M1 and M4 receptors in the brain.
About NAMZARIC
NAMZARIC is a once-daily, fixed-dose combination of memantine hydrochloride, a NMDA receptor antagonist, and donepezil hydrochloride, an acetylcholinesterase inhibitor indicated for the treatment of moderate to severe dementia of the Alzheimer's type in patients stabilized on 10 mg of donepezil HCl once daily.
Memantine hydrochloride extended-release is the active ingredient in the currently marketed NAMENDA XR, which is indicated for the treatment of moderate to severe dementia of the Alzheimer's type.
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. Allergan and Adamas collaborated on the development of the fixed-dose combination and Allergan owns the exclusive U.S. commercialization rights, while Adamas will retain exclusive commercialization rights outside of the U.S.