Evaluation Of PF-00572778 And Alprazolam On Naloxone Challenge In Healthy Subjects

A Phase I, Randomized, Placebo Controlled, Parallel Group, Single Dose Study To Evaluate The Effects Of PF-00572778 And Alprazolam On A Naloxone Challenge In Healthy Adult Subjects

Status

Terminated

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00580190

Enrollment

Registered

2007-12-24

Start date

2007-09-30

Completion date

2008-02-29

Last updated

2009-09-14

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

Conditions

Healthy

Brief summary

PF-00572778, a CRH antagonist, is expected to attenuate adrenocorticotropin (ACTH) and cortisol responses to naloxone by blocking the effect of the CRH increases induced by naloxone at the postsynaptic receptors. Demonstration of a statistically significant attenuation of naloxone induced increases in cortisol and/or ACTH concentrations by PF-00572778 compared to placebo would thus constitute proof of mechanism for the compound. Therefore, this study is to evaluate pharmacodynamic effects of PF-00572778 following naloxone challenge in healthy subjects.

Interventions

DRUGalprazolam

tablet, 0.5 mg, single dose, only on Day 7 of the study

OTHERPlacebo

solution, matching placebo to 500 mg PF-00572778, single dose, Days 1 and 7 of the study

DRUGPF-00572778

solution, 500 mg, single dose, only on Day 7 of the study

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

18 Years to 65 Years

Healthy volunteers

Yes

Inclusion criteria

Healthy male and/or female subjects between the ages of 18 and 45 years; Body Mass Index (BMI) of approximately 18 to 30 kg/m2; and a total body weight \>50 kg (110 lbs).

Exclusion criteria

Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease; Family (1st degree relatives) and personal history of meeting Diagnostic and Statistical Manual -IV (DSM-IV) criteria for alcohol abuse or dependence.

Design outcomes

Primary

Measure	Time frame
Area under the cortisol concentration time curve from 0 to 3 hours ( AUC(0-3) ) following naloxone challenge	1st day on treatment

Secondary

Measure	Time frame
Time to reach the maximum observed serum concentration (Tmax)	1st day on treatment
Safety laboratory tests, vital signs, ECGs, adverse events monitoring, and physical<br>examinations	34 days (weekly)
Maximum observed serum concentration (Cmax)	1st day on treatment
Area under the concentration-time curve from time = 0 to time of the last quantifiable serum PF-00572778 concentration (AUClast)	2nd day on treatment (Days 6-7)
Area under the ACTH concentration curve from 0 to 3 hours ( AUC(0-3) ) following naloxone challenge	1st day on treatment
Peak concentrations for plasma cortisol and ACTH	1st day on treatment

Countries

United States

Outcome results

None listed

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