Official Title: “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”

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.

Study Type: Interventional

Study Design: Treatment, Randomized, Single Blind (Subject), Parallel Assignment, Pharmacodynamics Study

Intervention(s) in this Clinical Trial

• Drug: alprazolam
  • tablet, 0.5 mg, single dose, only on Day 7 of the study
• Other: Placebo
  • solution, matching placebo to 500 mg PF-00572778, single dose, Days 1 and 7 of the study
• Drug: PF-00572778
  • solution, 500 mg, single dose, only on Day 7 of the study

Arms, Groups and Cohorts in this Clinical Trial

• Active Comparator: 1
• Placebo Comparator: 2
• Experimental: 3

Primary Measures

• Area under the cortisol concentration time curve from 0 to 3 hours ( AUC(0-3) ) following naloxone challenge
  • Time Frame: 1st day on treatment
    Safety Issue?: No

Secondary Measures

• Maximum observed serum concentration (Cmax)
  • Time Frame: 1st day on treatment
    Safety Issue?: No
• Time to reach the maximum observed serum concentration (Tmax)
  • Time Frame: 1st day on treatment
    Safety Issue?: No
• Safety laboratory tests, vital signs, ECGs, adverse events monitoring, and physical examinations
  • Time Frame: 34 days (weekly)
    Safety Issue?: Yes
• Peak concentrations for plasma cortisol and ACTH
  • Time Frame: 1st day on treatment
    Safety Issue?: No
• Area under the concentration-time curve from time = 0 to time of the last quantifiable serum PF-00572778 concentration (AUClast)
  • Time Frame: 2nd day on treatment (Days 6-7)
    Safety Issue?: No
• Area under the ACTH concentration curve from 0 to 3 hours ( AUC(0-3) ) following naloxone challenge
  • Time Frame: 1st day on treatment
    Safety Issue?: No

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.

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 65 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: Accepts Healthy Volunteers

Lead Sponsor: Pfizer

Overall Clinical Trial Officials and Contacts

Pfizer CT.gov Call Center Study Director Pfizer  

Information obtained from ClinicalTrials.gov on September 05, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00580190

Study ID Number: A8821006

ClinicalTrials.gov Identifier: NCT00580190

Health Authority: United States: Food and Drug Administration

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