Adamas Aquires Global Rights to Osmolex ER for Motor Symptoms

Adamas Pharmaceuticals has acquired global rights to the Parkinson’s disease medication Osmolex ER (amantadine hydrochloride), used to treat motor symptoms, including those caused by other therapies.

The purchase, worth $7.5 million, was part of a settlement agreement with the medicine’s developer, Osmotica Pharmaceutical US, according to a press release. The two companies had been involved in ongoing patent litigation over the therapy.

“We are pleased to begin 2021 by adding Osmolex ER to our portfolio, broadening our presence in neurology and our ability to serve more patients,” Neil F. McFarlane, Adamas’ CEO, said in his company’s press release announcing the settlement.

Amantadine, the active ingredient in Osmolex, works to lessen the severity of movement and muscle control problems — also known as extrapyramidal reactions — that accompany long-term use of Parkinson’s medications that affect dopamine receptors.

The most common first-line treatment prescribed to Parkinson’s patients is levodopa, used to manage such symptoms such as tremors, stiffness, and slowness of movement. Other medications include the antipsychotics Risperdal (risperidone) and dronabinol (brand names Marinol and Syndros), which are sometimes prescribed to Parkinson’s patients. All, after longtime use, can spark problems with muscle and motor control.

The U.S. Food and Drug Administration has approved Osmolex ER for the treatment of Parkinson’s disease and drug-induced extrapyramidal reactions in adults.

Amantadine was originally developed as an antiviral medication to stop the spread of Influenza A through the body. Exactly how it counteracts movement problems remains unknown, although it is thought to work by increasing the amount of dopamine in certain parts of the body.

As an extended-release (ER) tablet, Osmolex ER provides a steady supply of medication over a long period of time. This allows patients to take just one tablet per day, rather than adhering to a more complicated medication routine.

The medication had been tested in two international Phase 3 clinical trials, called ALLAY-LID I (NCT02153645) and ALLAY-LID II (NCT02153632), both of which were terminated in 2019.

The most common side effects associated with the therapy — reported in at least 5% of patients — are nausea, dizziness or lightheadedness, and difficulty sleeping.

Adamas bought the rights to Osmolex ER as a way of settling a lawsuit over competing patent claims with Osmotica.

In addition to Osmolex ER, Adamas owns Gocovri (amantadine) extended-release capsules. Similar to Osmolex ER, Gocovri eases the severity of involuntary movements known as dyskinesia. It also reduces the number and duration of off episodes, periods in which levodopa-based treatments lose their effectiveness and motor symptoms return.

Gocovri may be taken by Parkinson’s patients using levodopa with or without other dopaminergic medications.

Neither Osmolex ER nor Gocovri is interchangeable with other amantadine-based immediate- or extended-release medications.