Numerous clinical trials evaluate the therapeutic efficacy, safety, and pharmacokinetics of Istradefylline across Phase 1 through Phase 4 studies. Primarily focusing on Parkinson's disease, idiopathic Parkinson's disease, and motor tremor, research also investigates indications such as cognitive impairment, drug abuse, hepatic impairment, and spinal cord injuries. Sponsored by pharmaceutical developers like Kyowa Kirin and academic institutions including Georgetown University and the University of Chicago, these protocols span various recruitment statuses from completed and active to terminated and not yet recruiting.
| NCT Number | Recruitment | Conditions | Sponsor/Collaborators | Start Date | Phases |
|---|---|---|---|---|---|
| NCT07704385 | NOT_YET_RECRUITING | Adults |
University of Florida |
2026-10-01 | PHASE1; PHASE2 |
| NCT05217498 | NOT_YET_RECRUITING | Spinal Cord Injuries; Myelopathy |
Randy Trumbower, PT, PhD |
2027-09-01 | PHASE1; PHASE2 |
| NCT05377424 | ACTIVE_NOT_RECRUITING | ALS |
University of Florida |
2022-06-21 | PHASE1; PHASE2 |
| NCT05333549 | COMPLETED | Parkinson Disease; Cognitive Impairment |
Virginia Commonwealth University |
2022-07-18 | PHASE2 |
| NCT05885360 | COMPLETED | Parkinson Disease; Tremor |
Georgetown University |
2023-01-20 | PHASE4 |
| NCT05885360 | Active not recruiting | Parkinson Disease|Tremor |
Georgetown University|Kyowa Kirin Inc. |
2023-01-20 | Phase 4 |
| NCT02610231 | COMPLETED | Idiopathic Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2015-12 | PHASE3 |
| NCT01968031 | COMPLETED | Idiopathic Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2013-10 | PHASE3 |
| NCT02609477 | COMPLETED | Drug Abuse |
Kyowa Kirin Co., Ltd. |
2016-01 | PHASE1 |
| NCT02610231 | Completed | Idiopathic Parkinson''s Disease |
Kyowa Kirin Co. Ltd.|Kyowa Hakko Kirin Pharma Inc. |
2015-12 | Phase 3 |
| NCT02256033 | COMPLETED | Hepatic Impairment |
Kyowa Kirin Co., Ltd. |
2014-08 | PHASE1 |
| NCT02256033 | Completed | Hepatic Impairment |
Kyowa Kirin Co. Ltd.|Kyowa Hakko Kirin Pharma Inc. |
2014-08 | Phase 1 |
| NCT02174250 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2014-06 | PHASE1 |
| NCT00957203 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2009-10 | PHASE3 |
| NCT00955526 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2009-07 | PHASE3 |
| NCT00199381 | TERMINATED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2005-10 | PHASE3 |
| NCT00455507 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2007-03 | PHASE2 |
| NCT00455507 | Completed | Parkinson''s Disease |
Kyowa Kirin Co. Ltd. |
2007-03 | Phase 2 |
| NCT00199368 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2004-10 | PHASE3 |
| NCT00203957 | COMPLETED | Parkinson's Disease |
University of Chicago |
2005-03 | PHASE3 |
| NCT00250393 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2005-11 | PHASE2 |
| NCT00199446 | COMPLETED | Sleep Disorder; Restless Legs Syndrome |
Kyowa Kirin, Inc. |
2005-07 | PHASE2 |
| NCT00199433 | COMPLETED | Parkinson's Disease; Movement Disorder Syndrome |
Kyowa Kirin, Inc. |
2005-05 | PHASE2 |
| NCT00199355 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2005-04 | PHASE2 |
| NCT00199407 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2004-06 | PHASE3 |
| NCT00199420 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2004-07 | PHASE3 |
| NCT00199394 | COMPLETED | Parkinson's Disease |
Kyowa Kirin Co., Ltd. |
2004-11 | PHASE3 |
| NCT00456794 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2002-03 | PHASE2 |
| NCT00955045 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2002-08 | PHASE2; PHASE3 |
| NCT00456586 | COMPLETED | Parkinson's Disease |
Kyowa Kirin, Inc. |
2002-04 | PHASE2 |
(data from https://clinicaltrials.gov, updated on 2026-07-15)
Check the
Istradefylline
product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.
Mechanism and Biochemical Profile
Appendix RUO and cGMP Quality Standards
| Quality Dimension | RUO (Research Use Only) | cGMP (Current Good Manufacturing Practice) |
|---|---|---|
| Clinical Applicability | Prohibited in human clinical trials or medical diagnostics. | Mandatory for human clinical trials (Phase I–III) and therapies. |
| Regulatory Status | Non-regulated grade; exempt from drug manufacturing laws. | Legally enforced by health authorities (e.g., FDA, EMA, NMPA). |
| Facility Environment | Unclassified analytical or research laboratories. | Validated Cleanrooms (ISO Class 5–8) with continuous monitoring. |
| Quality Control | Basic purity and activity testing. | Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma). |
| Process Validation | Basic equipment calibration; no process validation required. | Full qualification (IQ/OQ/PQ) and complete batch records. |
| Quality Assurance | Vendor self-declared without required formal QMS. | Mandatory QA/QC unit, Change Control, CAPA, and vendor audits. |
| Regulatory Impact | High risk of IND rejection if used as a critical raw material. | Required for IND/NDA filings, supported by Drug Master Files (DMF). |
Footnotes
Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).
Note: Technical data last updated: Sep 1, 2026.