Allergan plc, a leading global pharmaceutical company, and Adamas Pharmaceuticals, Inc. announced that all four dosage strengths of Namzaric (memantine and donepezil hydrochlorides) extended-release capsules that allow patients on donepezil 10 mg to start directly on Namzaric are now available by prescription in pharmacies throughout the US.

Namzaric is a once-daily, fixed-dose combination of memantine hydrochloride (a NMDA receptor antagonist) and donepezil hydrochloride (an acetylcholinesterase inhibitor, AChEI) for the treatment of moderate to severe Alzheimer's disease in patients stabilized on 10 mg of donepezil hydrochloride once daily. Namzaric's new indication and dosage strengths were approved by the US Food and Drug Administration (FDA) in July 2016.

Approximately 75 per cent 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 treated with combination therapy. Clinical studies have shown that combination therapy with Namenda XR and an AChEI such as Aricept demonstrated significantly superior improvement in cognition and global function verses an AChEI alone.

"We are excited that with the new available dosage strengths patients with moderate to severe Alzheimer's disease, who are currently stabilized on Aricept, donepezil hydrochloride (10 mg) can now start combination therapy directly with Namzaric. Namzaric offers these patients the benefits of combining two products that each work differently to treat moderate to severe Alzheimer's disease, without increasing the number of pills a patient and their caregiver need to administer each day," said Gavin Corcoran, M.D., chief medical officer at Allergan. "This launch reinforces Allergan's commitment to development of treatments for Alzheimer's Disease and other neurological disorders."

Namzaric will be commercially available in 30 count bottles in 7 mg/10 mg, 14 mg/10 mg, 21 mg/10 mg and 28 mg/10 mg. Namzaric is covered broadly by Medicare Part D prescription plans.

The efficacy and safety of the coadministration of memantine HCl extended release and acetylcholinesterase inhibitors (AChEIs), including donepezil HCl, was based on the results of a randomized, double-blind, placebo-controlled trial of 677 patients with moderate to severe Alzheimer's disease on a stable dose of AChEIs. The clinical study was not conducted with Namzaric; however, bioequivalence of Namzaric with coadministered memantine HCl extended release and donepezil HCl was demonstrated. Approximately 68 per cent of the patients randomized to receive either memantine HCl extended release 28 mg or placebo were taking donepezil as the AChEI at Baseline and throughout the study. The results of this study, demonstrated statistically significant improvement in cognition and global function for patients treated with Namenda XR (memantine HCl extended release) 28 mg plus an AChEI compared to placebo plus an AChEI at 24 weeks.

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 US commercialization rights, while Adamas will retain exclusive commercialization rights outside of the US. Adamas is eligible to receive royalties from Allergan on the US sales of Namzaric beginning in May of 2020.