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A Study to Evaluate Abuse Potential of Istradefylline

A Double-Blind, Randomized, Placebo- and Active-Controlled Crossover Study to Evaluate the Abuse Potential of Istradefylline in Recreational Drug Users

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02609477
Enrollment
42
Registered
2015-11-20
Start date
2016-01-31
Completion date
2016-07-31
Last updated
2024-04-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Drug Abuse

Keywords

Recreational stimulant users, Recreational Drug Users

Brief summary

This study is to evaluate the abuse potential of single-doses of istradefylline compared to placebo and phentermine in recreational stimulant users. Subjects will participate in an outpatient medical Screening visit, a 5-day Qualification (Drug Discrimination) Phase, a 6-period Treatment Phase, and an outpatient safety Follow-Up visit. Study will be approximately 25 weeks total. Within 28 days of the Screening visit, eligible subjects will be admitted to the CRU (Day -1) for the Qualification Phase. During the Qualification Phase, subjects will receive single oral doses of phentermine 60 mg and matching placebo in a randomized, double blind, crossover manner, with each drug administration separated by approximately 48 hours (Day 1 and Day 3), to ensure that they can discriminate and show positive subjective effects of the active controls. Following evaluation of eligibility, subjects may be discharged (those who fail Qualification criteria) or remain in the CRU (those who pass criteria and are eligible) and then proceed directly to the Treatment Phase. The washout interval between last drug administration in the Qualification Phase and first drug administration in the Treatment Phase will be at least 96 hours (4 days). Following confirmation of eligibility from the Qualification Phase, subjects will be randomized to one of 6 treatment sequences according to a 6x6 Williams square. Subjects will receive single oral doses of each of the 6 treatments in a randomized, double-blind, crossover manner, Istradefylline 40 mg, Istradefylline 80 mg, Istradefylline 160 mg, Phentermine 45 mg, Phentermine 90 mg, Placebo. Each drug administration will be separated by at least 21 days. Serial pharmacodynamic evaluations will be conducted up to 24 hours after each study drug administration to confirm exposure to istradefylline.

Interventions

Istradefylline 40, 80, 160 mg

DRUGPhentermine 45 mg

Phentermine 45 or 90 mg

OTHERPlacebo

Placebo

Sponsors

Kyowa Hakko Kirin Pharma, Inc.
CollaboratorINDUSTRY
Kyowa Kirin Co., Ltd.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

* Subjects who will provide written informed consent * Healthy volunteer, male and female between 18 and 55 years of age, inclusive * Subjects with a body mass index (BMI) within 18.0 to 33.0 kg/m2, inclusive * Subjects who are recreational drug user

Exclusion criteria

* Subjects who have an alcohol or substance dependence within the 12 months * Subjects who have ever been in treatment for substance use disorder * Subjects who consume on average more than 5 servings of caffeinated beverages per day * Subjects with a history of or presence of any clinically significant cardiovascular disease * Subject with hyperthyroidism or glaucoma.

Design outcomes

Primary

MeasureTime frameDescription
Drug Liking VAS24 hoursTo evaluate the abuse potential of istradefylline compared to phentermine and placebo.

Secondary

MeasureTime frameDescription
C-SSRS (Columbia Suicide Severity Rating Scale)24 hoursTo evaluate the safety and tolerability of istradefylline.
Alerness/Drowsiness, Agitation/Relaxation VAS24 hoursTo evaluate the safety and tolerability of istradefylline.
Caffine Withdrawal/Symptom Questionnaire24 hoursTo evaluate the safety and tolerability of istradefylline.
Overall Drug Liking, Take Drug Again VAS24 hoursTo evaluate the safety and tolerability of istradefylline.
Drug Similarity VAS24 hoursTo evaluate the safety and tolerability of istradefylline.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026