A Study To Assess the Effects Of PF-04457845 On BOLD fMRI In Subjects With Post Traumatic Stress Disorder

A Study To Assess the Effects Of PF-04457845 On BOLD fMRI In Subjects With Post Traumatic Stress Disorder

A Randomized, Double Blind, Placebo Controlled, Parallel Group Phase 2 Study To Assess Effects Of Pf 04457845 On Bold Functional Mri In Subjects With Ptsd

The study stopped based on Pfizer portfolio prioritization and not due to safety and/or efficacy concern or change in benefit:risk assessment of PF-04457845.

The purpose of the study is to evaluate proof of mechanism of PF-04457845, using a well-established neuroimaging paradigm including behavioral tasks selected to activate neuro-circuitry relevant to Post Traumatic Stress Disorder. It is hypothesized that PF-04457845 will modulate the Blood-oxygen-level dependent Functional Magnetic Resonance Imaging signal from the relevant neuro-circuits in patients with Post Traumatic Stress Disorder.

This is a Phase II, randomized, placebo-controlled, parallel group design study in male and female subjects with moderate-to-severe Post Traumatic Stress Disorder between the ages of 18 and 60 years old. During this study, a dose of 4 mg PF-04457845 will be administered in the morning on Days 1-7. On Each subject will undergo a resting state fMRI (pre and post and day 8), a fearful vs. neutral faces fMRI task and a fear extinction fMRI paradigm. The Emotional Faces Paradigm and resting state tasks will be performed on Day 1 (prior to drug or placebo) and on Day 8. Acquisition of fear conditioning will be performed during the first imaging session on Day 1. After the first imaging session on Day 1, subjects will complete behavioral rating scales and then be dosed. Approximately six hours after dosing subjects will re-enter the scanner and perform the fear extinction paradigm. On Day 2, subjects will perform the fear extinction memory retention task within the scanner. Further physiological monitoring, including skin conductance and heart rate, will take place during the fear extinction paradigm. One safety follow-up visit will occur between Days 11-18.

Change From Baseline Blood-Oxygen-Level Dependent (BOLD) Functional Magnetic Resonance Imaging fMRI) Percent Signal Change in Fearful Versus Neutral Face Contrast in Bilateral Amygdala

Baseline BOLD fMRI percent signal change measured from baseline in fearful versus neutral face contrast during the emotional face processing task in bilateral amygdala.

Change From Baseline in BOLD fMRI Percent Activation in Bilateral Ventromedial Pre-Frontal Cortex (vmPFC)

Difference measured in BOLD fMRI percent activation in the bilateral vmPFC during the fear extinction recall phase of the fear extinction paradigm.

Change From Baseline in BOLD fMRI Percent Signal Change in Fearful Versus Neutral Face Contrast in Right Amygdala

Difference measured in BOLD fMRI percent signal change in the right amygdala in fear versus neutral faces during the emotional face processing task.

Change From Baseline in BOLD fMRI Percent Signal Change in Fearful Versus Neutral Face Contrast in Left Amygdala

Difference measured in BOLD fMRI percent signal change in the left amygdala in fearful versus neutral faces during face processing task.

The full physical examination included head, ears, eyes, nose, mouth, skin, heart, and lung examinations, lymph nodes, gastrointestinal, skeletal, and neurological systems.

Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Withdrawals Due to AEs

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to 28 days after last study drug administration that were absent before treatment or that worsened relative to pretreatment state. AEs included non-serious AEs and SAEs.

Number of Participants With Clinical Laboratory Values Meeting Criteria for Potential Clinical Concern

The following laboratory parameters were analyzed: hematology (hemoglobin, hematocrit, red blood cell count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelet count, white blood cell count, total neutrophils, eosinophils, monocytes, basophils, lymphocytes; liver function (aspartate aminotransferase, alanine aminotransferase, total bilirubin, alkaline phosphatase, albumin, total protein); renal function (blood urea nitrogen, creatinine, uric acid); electrolytes (sodium, potassium, chloride, calcium, bicarbonate); chemistry (glucose); urinalysis (dipstick) (urine pH, urine glucose, urine protein, urine blood, urine ketones, urine bilirubin, urine nitrite, urine leukocyte esterase); urinalysis microscopy (urine red blood cell, urine white blood cell, urine bacteria). Only parameters with abnormal values were reported.

Vital signs assessment included pulse rate and blood pressure. Criteria for vital sign values meeting potential clinical concern included: supine pulse rate <40 or >120 beats per minute (bpm), standing pulse rate <40 or >140 bpm; systolic blood pressure (SBP) of >=30 millimeters of mercury (mmHg) change from baseline or SBP <90 mmHg; diastolic blood pressure (DBP) >=20 mmHg change from baseline or DBP <50 mmHg.

Number of Participants With Post-Baseline Electrocardiogram (ECG) Values Meeting Criteria of Potential Clinical Concern

ECG criteria of potential clinical concern were QTc absolute value >=450 milliseconds (msec) or QTc absolute change >=30 msec.

Inclusion Criteria: Men and women 18-60 years of age with a primary psychiatric diagnosis of Post Traumatic Stress Disorder Exclusion Criteria: Other psychiatric illness requiring current treatment with medication.

https://trialinfoemail.pfizer.com/pages/landing.aspx?StudyID=B0541013&StudyName=A%20Study%20To%20Assess%20Effects%20Of%20PF-04457845%20On%20Blood-Oxygen-Level%20Dependent%20Functional%20Magnetic%20Resonance%20Imaging%20In%20Subjects%20With%20Post%20Traum