Amneal to Market Generics Version of Allergan’s Alzheimer’s Drug Pending FDA Approval

Amneal Pharmaceuticals can begin marketing its generics version of Allergan’s Alzheimer’s extended-release drug Namenda XR on Jan. 31, 2020, pending FDA approval, under an agreement reached by the two firms.

The agreement settles patent infringement litigation brought by Allergan’s Forest Laboratories subsidiary and Adama Pharmaceuticals against Amneal’s ANDA for generic Namenda XR (memantine hydrochloride). Amneal is the first applicant to file an ANDA containing a Paragraph IV certification, which maintains that the proposed generic doesn’t infringe on the brandname drug’s patents or that the patents are invalid.

With the settlement, Allergan is guaranteed a little more than four years exclusivity for its extended-release version of the drug. The agreement follows the July launch of generic versions of the drugmaker’s older Namenda IR by Mylan and Dr. Reddy’s.

In May, a federal appeals court upheld a lower court’s ruling barring Allergan from pulling Namenda IR and replacing it with Namenda XR to extend exclusivity until 2026. The ruling required Allergan to keep the original version on pharmacy shelves nationwide until Aug. 11.

Allergan has pushed for physicians to prescribe Namenda XR to patients, claiming that its once-a-day formulation is superior to the twice-daily Namenda IR. In many states, pharmacists can fill Namenda IR prescriptions with generic versions, but can’t automatically switch Namenda XR to the Namenda IR generics.

Namenda had U.S. sales of about $1.4 billion for the 12 months ending in May, according to IMS Health. — John Bechtel