New medication, Istradefylline, gets approved for Parkinson’s disease
On August 27, 2019, pharmaceutical company Kyowa Kirin received FDA approval for Istradefylline, a new medication for Parkinson’s disease (PD) to be used as an add-on treatment to carbidopa/levodopa for those experiencing OFF episodes. (For more information on OFF periods in PD, please see this recent APDA webinar.)
The medication, which will be marketed in the US under the brand name NourianzTM, has been approved in Japan since 2013, but was not initially approved by the FDA when it was first reviewed back in 2008, due to concerns about lack of efficacy. To gain approval of the medication, Kyowa Kirin presented to the FDA the results of four successful placebo-controlled trials which tested the medication in 1,143 patients and demonstrated that the medication reduced OFF time as compared to placebo.
The medication is different than most other PD medications, in that it does not directly manipulate dopamine or the dopamine receptors. Instead, it is an adenosine inhibitor, and works to block the effects of the adenosine receptor. Like dopamine, adenosine is a neurotransmitter that works in the basal ganglia, the deep structures of the brain that are affected in PD. However, to some degree, adenosine and dopamine have opposite effects, so that inhibiting the adenosine receptor improves motor function.
Approval of NourianzTM is exciting news for the PD community as it adds a novel approach to improving PD symptoms. Here is the Kyowa Kirin’s press release announcing the approval.
NOTE: If you have questions about Istradefylline and want to know if it is an appropriate medication for you or a loved one, please consult your neurologist.