Nouryant Again Denied Marketing Approval in Europe
A committee of the European Medicines Agency (EMA) has issued a negative opinion for Nouryant (istradefylline) — approved as Nourianz in the U.S. — as an add-on medication for treating “off” episodes in those with Parkinson’s disease in the European Union.
“We are disappointed by the CHMP opinion. We will take time to assess our plans for istradefylline in EMEA,” said Tomohiro Sudo, executive officer, head of global product strategy department, at Kyowa Kirin.
“We appreciate the collaboration we have had with all stakeholders and applaud the Parkinson’s community for their commitment to supporting people living with this chronic, debilitating condition,” he added.
The medicine, an oral tablet to be taken daily, was approved by the U.S. Food and Drug Administration in 2019 to treat “off” episodes in Parkinson’s patients who are on a carbidopa/levodopa treatment regimen.
Parkinson’s is characterized by the loss of neurons that make the neurotransmitter dopamine. Carbidopa/levodopa currently is the cornerstone of Parkinson’s disease therapies. Levodopa is transformed in the brain into dopamine and carbidopa works by inhibiting a protein that breaks down dopamine. “Off” periods arise when the effects of the medication wear off and Parkinson’s motor symptoms re-emerge.
Nouryant is thought to ease “off” episodes by blocking a receptor called the adenosine A2A receptor on brain cells located in the basal ganglia, a brain region responsible for motor control. This increases the release of gamma amino-butyric acid (GABA), a neurotransmitter involved in motor control. Neurotransmitters are substances produced in response to nerve signals that act as chemical messengers.
Kyowa Kirin’s application to the EMA included data from eight studies involving a total of 3,245 patients who were experiencing off episodes despite treatment with carbidopa/levodopa.
In all studies Nouryant was compared to a placebo and, in one, with Comtan (entacapone), another therapy for “off” episodes approved in both the U.S. and the EU. The goal was to assess Nouryant’s ability to reduce “off” periods when added to levodopa-based treatments.
In its first evaluation, the CHMP said the benefits of Nouryant may not outweigh its risks. Also, the EMA pointed out that Nouryant had an effect in “off” time in only four of the eight studies. Moreover, the reduction in “off” time did not increase with an increased dose of Nouryant.