Generic versions of the Allergan's top-selling Alzheimer's drug, the subject of a court battle over the company's sales tactics, are now on the market.
Allergan wanted to take its original Namenda tablets off the market so it could focus on a newer, longer-lasting version that is patent-protected until 2029. A federal court said its plans violated antitrust law. The court ordered Allergan to keep selling that form of the drug for at least a few more weeks.
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The company had not decided by Tuesday what it will do with the original version of the drug after that. Namenda is used to treat moderate and severe dementia caused by Alzheimer's disease.
The patents protecting Namenda expired Saturday. Indian drugmaker Dr. Reddy's Laboratories started selling a generic version on Sunday, and Mylan NV of the Netherlands followed suit Tuesday.
To reduce the sting of cheaper, generic competition or delay their release, drugmakers often introduce new versions of the drug, get it approved for new groups of patients, or reach legal settlements with the makers of the generic versions.
The company that originally sold Namenda, Forest Laboratories, used those methods at first. In June 2013 it started selling an extended-release version called Namenda XR that is taken once a day instead of twice. The Food and Drug Administration approved Namenda for use in pediatric patients, extending its patents by six months.
Then Forest took an unusual step, announcing it would stop selling the original Namenda in tablet form. It planned to keep selling a liquid version, but was throwing its full weight behind Namenda XR.
"Forest has made the decision to focus on once-daily Namenda XR capsules," the company said in a letter sent to health care providers. It also announced that it was pricing Namenda XR at a discount to the original.
Actavis Inc. bought Forest in July 2014. This year Actavis acquired Allergan, the maker of Botox, and it changed its name to Allergan PLC.
New York Attorney General Eric Schneiderman sued Actavis and Forest in 2014, saying their actions violated antitrust law. In December a federal appeals court ruled against Allergan and ordered it to keep selling Namenda until at least 30 days after generic versions went on sale. That ruling was upheld in May.
Allergan says Namenda XR is better than the original and that most Namenda patients are now taking the extended-release version.
Shares of Allergan PLC rose $2.27 to $320.62. The stock is trading at all-time highs and is up 44 percent over the last year.