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# Nourianz Regulatory Review Period
- URL: https://www.fdaweb.com/nourianz-regulatory-review-period/
- Published: 2022-11-08T12:00:00.000Z
- Updated: 2026-09-14T18:05:33.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5153153

*Federal Register* notice: FDA has determined for patent extension purposes the regulatory review period for Kyowa Kirin’s Nourianz (istradefylline), indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson’s disease experiencing “off” episodes. The regulatory review period is 7,300 days, of which 2,792 days occurred during the testing phase and 4,508 days occurred during the approval phase. To view the notice, click [here](https://www.govinfo.gov/content/pkg/FR-2022-11-07/pdf/2022-24217.pdf?ref=fdaweb.com).