Allergan plc, a global pharmaceutical company, announced that its subsidiaries Forest Laboratories, LLC and Forest Laboratories Holdings, Ltd., along with Adamas Pharmaceuticals, Inc., have entered into a settlement agreement with Amneal Pharmaceuticals LLC and related companies and subsidiaries.

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 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 authorised generic version of Namenda XR beginning on January 31, 2021. Other terms of the settlement were not disclosed.

Similar patent infringement litigations 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.

Allergan is committed to Alzheimer's patients and caregivers through the company's continued support of Namenda XR, as well as the recent introduction of a new innovative treatment option, Namzaric (memantine hydrochloride extended-release and donepezil hydrochloride).

Namzaric is the first and only treatment that combines two proven medicines - Namenda XR (memantine HCI) and donepezil HCl - in a single, once-daily capsule, working together to treat the symptoms of moderate to severe Alzheimer's disease. Clinical data demonstrate that combination therapy with Namenda XR and donepezil results in greater improvements in cognition and function than either Namenda XR or donepezil alone.

Namzaric (memantine hydrochloride extended-release and donepezil hydrochloride) is indicated for the treatment of moderate to severe dementia of the Alzheimer's type in patients stabilized on memantine hydrochloride (10 mg twice daily or 28 mg extended-release once daily) and donepezil hydrochloride 10 mg,  memantine hydrochloride (5 mg twice daily or 14 mg extended-release once daily) and donepezil hydrochloride 10 mg in patients with severe renal impairment.

There is no evidence that Namzaric prevents or slows neurodegeneration in patients with Alzheimer's disease.

The most common adverse reactions, occurring at a frequency of at least 5per cent in patients taking memantine hydrochloride extended-release 28 mg/day, and greater than placebo, were headache (6 per cent vs 5 per cent), diarrhea (5 per cent vs 4 per cent), and dizziness (5 per cent vs 1 per cent).

The most common adverse reactions, occurring at a frequency of at least 5per cent in patients taking donepezil, and at twice or more the rate of placebo, were diarrhea (10 per cent vs 4 per cent), anorexia (8 per cent vs 4 per cent), vomiting (8 per cent vs 4 per cent), nausea (6 per cent vs 2 per cent), and ecchymosis (5 per cent vs 2 per cent).