A Study to Evaluate the Effect of Itraconazole on the Pharmacokinetics of PF-04958242 in Healthy Subjects

Collected at Day 3 for PF-04958242 0.025 mg Arm and Day 17 for PF-04958242 0.025 mg + itraconazole 200 mg Arm.

Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Clearance obtained after oral dose (apparent oral clearance) is influenced by the fraction of the dose absorbed. Clearance was estimated from population PK modeling. Drug clearance is a quantitative measure of the rate at which a drug substance is removed from the blood. Collected at Day 3 for PF-04958242 0.025 mg Arm and Day 17 for PF-04958242 0.025 mg + itraconazole 200 mg Arm.

The following laboratory parameters were analyzed: hematology (hemoglobin, hematocrit, red blood cell [RBC] count, mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC], platelet count, white blood cell [WBC] count, total neutrophils, eosinophils, monocytes, basophils, lymphocytes); blood chemistry (blood urea nitrogen [BUN], creatinine, glucose, calcium, sodium, potassium, chloride, total bicarbonate, aspartate aminotransferase [AST], alanine aminotransferase [ALT], total bilirubin, alkaline phosphatase, uric acid, albumin, and total protein; urinalysis (pH, glucose, protein, blood, ketones, nitrites, leukocyte esterase, urobilinogen, urine bilirubin and microscopy [if urine dipstick was positive for blood, protein, nitrites or leukocyte esterase]); others (follicle stimulating hormone [FSH], urine cotinine, and urine drug screening).

Vital signs assessment included pulse rate and blood pressure. Criteria for vital sign values meeting potential clinical concern included: supine/sitting pulse rate more than (<)40 or less than (>)120 beats per minute (bpm); systolic blood pressure (SBP) more than or equal to (>=)30 millimeters of mercury (mm Hg) change from baseline in same posture or SBP <90 mm Hg, diastolic blood pressure (DBP) >=20 mm Hg change from baseline in same posture or DBP <50 mm Hg. IFB = increase from baseline; DFB = decrease from baseline.

Electrocardiogram (ECG) parameters included time from ECG Q wave to the end of the T wave corresponding to electrical systole (QT) interval, beginning of the P wave until the beginning of the QRS complex (PR) interval, time from ECG Q wave to the end of the S wave corresponding to ventricle depolarization (QRS) interval, QT interval corrected for heart rate (QTc) interval, and corrected QT interval using Fridericia's formula (QTcF). Criteria for ECG changes meeting potential clinical concern included: PR interval >=300 milliseconds (msec) or >=25% increase when baseline is >200 msec and >=50% increase when baseline is less than or equal to (=<)200 msec; QRS interval >=140 msec or >=50% increase from baseline; and QTcF >=450 to <480, 480 to <500 and >=500 msec or >=30 to 60 msec increase and also >=60 msec increase. The number of participants with potentially clinically significant ECG findings at any visit were reported.

The extended neurological examination, performed by a board certified neurologist, included observations for cerebellar (intention) tremor and for non-cerebellar tremors (eg, resting or positional), finger, nose, heel, shin, Romberg, tandem walking, positional and gaze evoked nystagmus, reflexes, muscle strength, cranial nerves, sensory function of upper and lower extremities. The brief neurological examination included an assessment of motor and sensory function, cranial nerves, reflexes, non-cerebellar tremor (eg, resting or positional) and cerebellar function. The assessment of cerebellar function were complemented by the Scale for Assessment and Rating of Ataxia (SARA).

A full physical examination included head, ears, eyes, nose, mouth, skin, heart and lung examinations, lymph nodes, gastrointestinal, musculoskeletal, and neurological systems. The brief physical examination focused on general appearance, the respiratory and cardiovascular systems, as well as towards participant reported symptoms.

An AE was any untoward medical occurrence in a participant who received study drug. 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 dose that were absent before treatment or that worsened relative to pre-treatment state.

The C-SSRS (mapped to Columbia Classification Algorithm of Suicide Assessment [C-CASA]) is an interview-based rating scale to systematically assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced the following: completed suicide (1), suicide attempt (2) (response of "Yes" on "actual attempt"), preparatory acts toward imminent suicidal behavior (3)("Yes" on "preparatory acts or behavior"), suicidal ideation (4) ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent), any suicidal behavior or ideation, self-injurious behavior (7)("Yes" on "Has participant engaged in non-suicidal self-injurious behavior").