Nourianz Now Available in US as Add-on to Carbidopa/Levodopa to Treat Parkinson’s Off Periods

Kyowa Kirin’s Nourianz (istradefylline) tablets are now available in the United States as an add-on treatment for off periods in Parkinson’s disease patients on a carbidopa/levodopa regimen.

Off periods — when the effects of a medication wear off before a new dose can be taken — are characterized by the re-emergence of Parkinson’s motor symptoms and are typically more common as the disease progresses. Within five years of starting levodopa/carbidopa therapy, approximately 50% of patients may experience off periods.

“We are pleased to offer patients Nourianz, the first and only FDA-approved adenosine A_2Areceptor antagonist treatment for ‘off’ time associated with [Parkinson’s],” Tom Stratford, president of Kyowa Kirin USA Holdings, said in a press release. “Nourianz administered with levodopa/carbidopa therapy can help reduce ‘off’ time and increase ‘on’ time without troublesome dyskinesia.”

Nourianz blocks a receptor, known as the adenosine A_2A receptor, found at high levels in the basal ganglia, a region of the brain that controls movement. By blocking this receptor, Nourianz can alter the release of neurotransmitters — chemical substances produced in response to nerve signals that allow nerve cells to communicate — in the basal ganglia, regulating motor activity.

The U.S Food and Drug Administration (FDA) approved Nourianz in August based on the results of four randomized, placebo-controlled Phase 2 and 3 clinical trials (NCT00955526, NCT00455507, NCT01968031, and NCT00250393).

The trials assessed the safety and efficacy of two doses (20 mg and 40 mg) of Nourianz to reduce the mean total hours of awake time per day spent in the off state and also lessen motor symptoms.

A total of 1,143 Parkinson’s patients taking levodopa/carbidopa, levodopa/benserazide, or levodopa and any other dopa-decarboxylase inhibitor were recruited. Treatment with Nourianz significantly decreased daily off time, compared with patients on a placebo, and improved motor function.

The most common side effects of Nourianz included involuntary muscle movement (dyskinesia), dizziness, constipation, nausea, hallucinations, and insomnia.

“In my clinical practice, I see patients who experience the troublesome effects of Parkinson’s disease and ‘off’ episodes that interfere with activities of daily living,” said Peter A. LeWitt, MD, a professor of neurology at Wayne State University School of Medicine and director of the Parkinson’s Disease and Movement Disorders Program, Henry Ford Hospital.

“Nourianz represents an important milestone and provides U.S. patients and their caregivers with a nondopaminergic, once-a-day oral treatment option to significantly decrease the amount of ‘off’ time,” LeWitt added.

Nourianz has been marketed in Japan under the brand name Nouriast since May 2013.