This study will test the safety, tolerability and blood concentrations of single and multiple oral doses of PF-06751979 in health subjects and healthy elderly subjects. PF-06751979 is being developed for the treatment of Alzheimer's disease.
The purpose of this study is to evaluate the safety, tolerability and pharmacokinetics (PK) of PF-06751979 following oral doses in healthy adult and healthy elderly subjects at higher doses than previously administered. Such characteristics will enable the design of future clinical trials in patient population, in the effort to optimize the efficacy of PF-06751979, as well as to establish safety margins in humans. Inclusion of healthy elderly subjects will be optional, but can provide additional safety and tolerability information in the age range of the target population while confirming the PK of PF-06751979 in these subjects for future clinical trials in the Alzheimer's disease patient population. The Primary Objective is to evaluate the safety and tolerability of single and multiple ascending oral doses of PF-06751979 in healthy adult subjects. Secondary Objectives are to characterize the pharmacokinetics of PF-06751979 in: plasma following single and multiple ascending oral dose administration in healthy adult subjects and urine following multiple ascending oral dose administration in healthy adult subjects. An additional secondary objective is to evaluate the effect of multiple oral doses of PF 06751979 on CSF A-beta fragments in healthy adult subjects. This study is divided into three parts: Part A - Single ascending doses (SAD) healthy adult subjects (18-55 years); Part B - Multiple ascending doses (MAD) in healthy adult subjects (18-55 years); Part C - Multiple doses (MD) in healthy elderly subjects (60-85 years). Study Parts may be run in a staggered fashion; Part C of the study may commence after satisfactory review of relevant data from Parts A and B.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
46
PF-06751979 administered as a single dose suspension in cross-over fashion. Each subject may receive up to 4 study treatments (placebo and up to 3 doses of PF 06751979). The planned dose levels are 200 mg, 400 mg, 700 mg, 200 mg fed (these doses are subject to change based on emerging data).
Matched Placebo suspension administered as single dose
PF-06751979 suspension administered daily for 14 consecutive days to parallel cohorts. The planned dose levels are mg, 100 mg, 200 mg, 340 mg (these are subject to change based on emerging data).
Pfizer Clinical Research Unit
Brussels, Belgium
Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)
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 were events between first dose of study drug and up to the follow up visit (up to 36 days in Part A, 49 days in Part B and C), that were absent before treatment or that worsened relative to pretreatment state.
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Number of Participants With Abnormal Physical Examinations Findings
Full physical examination included head, ears, eyes, nose, mouth, skin, heart, lung, lymph nodes, gastrointestinal, musculoskeletal, and neurological systems. Abnormality in physical examinations was based on investigator's discretion.
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Number of Participants With Abnormal Neurological Examinations Findings
The neurological examination included the assessment of higher cortical function, the cranial nerves, motor function, deep tendon reflexes, sensory exam, and coordination and gait. Abnormality in neurological examinations was based on investigator's discretion.
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Part B and C: Number of Participants With Positive Response on the Columbia Suicide Severity Rating Scale (C-SSRS) at Baseline
C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("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 self-injurious behavior with no suicidal intent). In this outcome measure, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any non-suicidal self-injurious behavior, at baseline were reported.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Matched placebo suspension administered daily for 14 consecutive days.
PF-06751979 suspension administered daily for 14 consecutive days. The planned dose level is 340 mg (this is subject to change based on emerging data).
Multiple dose administration to Healthy Elderly Subjects (Placebo)
Time frame: Baseline
Part B and C: Number of Participants With Positive Response on the Columbia Suicide Severity Rating Scale (C-SSRS) at Day 7
C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("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 self-injurious behavior with no suicidal intent). In this outcome measure, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any non-suicidal self-injurious behavior, at Day 7 were reported.
Time frame: Day 7
Part B and C: Number of Participants With Positive Response on the Columbia Suicide Severity Rating Scale (C-SSRS) at Day 14
C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("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 self-injurious behavior with no suicidal intent). In this outcome measure, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any non-suicidal self-injurious behavior, at Day 14 were reported.
Time frame: Day 14
Part B and C: Number of Participants With Positive Response on the Columbia Suicide Severity Rating Scale (C-SSRS) at Day 19
C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("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 self-injurious behavior with no suicidal intent). In this outcome measure, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any non-suicidal self-injurious behavior, at Day 19 were reported.
Time frame: Day 19
Number of Participants With Abnormal Electrocardiogram (ECG) Findings
Criteria for abnormal values of ECG parameters: maximum pulse rate (PR) interval greater than or equal to (\>=)300 milliseconds (msec); maximum PR interval increase from baseline (IFB): \>=25 percent (%) when baseline was greater than (\>)200 msec; or \>=50 % when baseline was greater than (\>)200 msec, maximum QRS interval \>=140 msec and QRS interval IFB: \>=50%. QT interval using Fridericia's correction (QTcF) ranges from 450 msec to maximum less than (\<)480 msec, less than or equal to (\<=) 480 msec to maximum \<500 msec and maximum \>=500 msec, maximum QTcF interval IFB range from \<=30 to \<60 msec and maximum \>=60 msec. Only categories which included at least 1 participant with abnormality are reported in this outcome measure.
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Part A: Number of Participants With Cardiac Rhythms of Potential Clinical Concern Assessed By Telemetry
In all Periods of Part A, continuous cardiac monitoring was maintained for 8 hours (or longer if considered clinically necessary by the investigator) following dose administration on Day 1. All abnormal cardiac rhythms were recorded and reviewed by the study physician for the presence of rhythms of potential clinical concern.
Time frame: Day 1
Number of Participants With Vital Sign Abnormalities
Criteria for vital signs abnormalities: systolic blood pressure (SBP) \<90 millimeter of mercury (mmHg), diastolic blood pressure (DBP) \<50 mmHg, supine pulse rate \<40 beats per minute (bpm). Maximum IFB in Supine SBP \>=30 mmHg, Maximum decrease from baseline (DFB) in Supine SBP \>=30 mmHg, maximum DFB in Supine DBP \>=20 mmHg.
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Number of Participants With Laboratory Abnormalities
Abnormalities criteria:hematology(hemoglobin; hematocrit; RBC\<0.8\*lower limit of normal \[LLN\]; platelets\<0.5\*LLN,\>1.75\*upper limit of normal \[ULN\]; WBC\<0.6\*LLN,\>1.5\*ULN; lymphocytes; neutrophils; basophils; eosinophils; monocytes\<0.8\*LLN,\>1.2\*ULN; coagulation(prothrombin ratio\>1.1\*ULN), liver(bilirubin\>1.5\*ULN; aspartate aminotransferase; alanine aminotransferase; alkaline phosphatase; gamma GT\>0.3\*ULN; protein; albumin\<0.8\*LLN,\>1.2\*ULN); renal(blood urea nitrogen, creatinine\>1.3\*ULN; uric acid\>1.2\*ULN); electrolytes(sodium\<0.95\*LLN,\>1.05\*ULN; potassium; chloride; calcium; bicarbonate\<0.9\*LLN,\>1.1\*ULN), chemistry(glucose\<0.6\*LLN,\>1.5\* ULN); urinalysis(pH \<4.5,\>8; glucose, ketones, protein, blood, urobilinogen, nitrite, bilirubin, leukocyte, esterase\>1; WBC; bacteria\>=20, epithelial cells\>=6; granular casts, hyaline casts, red cell casts, white cell casts\>1; lipids(cholesterol\[C\], LDL-C\>1.3\*ULN; HDL-C\<0.8\*LLN, triglycerides\>1.3\*ULN); hormones(T4, T3, T4, TSH\<0.8\*LLN,\>1.2\*ULN).
Time frame: Part A: Baseline up to 36 days; Part B and C: Baseline up to 49 days
Part A: Maximum Observed Plasma Concentration (Cmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Area Under the Curve From Time Zero to Time of Last Quantifiable Concentration (AUClast) of PF-06751979
Area under the plasma concentration-time profile from time zero to the time of last measured concentration (AUClast).
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Area Under the Plasma Concentration-Time Curve From Time Zero Extrapolated to Infinite Time (AUCinf) of PF-06751979
AUCinf = Area under the plasma concentration versus time curve (AUC) from time zero (pre-dose) to extrapolated infinite time (0-inf).
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Dose Normalized Maximum Observed Plasma Concentration (Cmax[dn]) of PF-06751979
Cmax(dn) was obtained calculated by dividing Cmax by the exact dose of PF-06751979 (in milligram) administered to a participant.
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Dose Normalized Area Under the Curve From Time Zero to Last Quantifiable Concentration (AUClast[dn]) of PF-06751979
AUClast(dn) was calculated by dividing AUClast by the exact dose of PF-06751979 (in mg) administered to a participant. AUClast was area under the plasma concentration-time profile from time zero to the time of last measured concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Dose Normalized Area Under the Plasma Concentration-time Profile From Time Zero Extrapolated to Infinite Time (AUCinf [dn]) of PF-06751979
AUCinf (dn) was calculated by dividing AUCinf by the exact dose of PF-06751979 (in mg) administered to a participant. AUCinf was area under the plasma concentration-time profile from time zero extrapolated to infinite time (0-inf).
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Time to Reach Maximum Observed Plasma Concentration (Tmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Plasma Decay Half-Life (t1/2) of PF-06751979
Plasma decay half-life is the time duration for the plasma concentration of PF-06751979 to decrease by one-half of its original concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Apparent Clearance (CL/F) of PF-06751979
Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part A: Apparent Volume of Distribution (Vz/F) of PF-06751979
Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired blood concentration of a drug. Apparent volume of distribution after oral dose (Vz/F) is influenced by the fraction absorbed.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 hours post dose on Day 1
Part B: Maximum Observed Plasma Concentration (Cmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Area Under the Curve From Time Zero to End of Dosing Interval (AUCtau) of PF-06751979
Area under the plasma concentration versus time-curve from time zero to end of dosing interval (AUCtau), where dosing interval was 24 hours.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part B: Time to Reach Maximum Observed Plasma Concentration (Tmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Dose Normalized Maximum Observed Plasma Concentration (Cmax[dn]) of PF-06751979
Cmax(dn) was obtained calculated by dividing Cmax by the exact dose of PF-06751979 (in mg) administered to a participant.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Dose Normalized Area Under the Curve From Time Zero to End of Dosing Interval Tau (AUCtau[dn]) of PF-06751979
Area under the concentration curve from time zero to end of dosing interval (AUCtau), where dosing interval was 24 hours. AUCtau (dn) was calculated by dividing AUCtau by the exact dose of PF-06751979 (in mg) administered to a participant.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part B: Apparent Clearance (CL/F) of PF-06751979
Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Minimum Observed Plasma Concentration (Cmin) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Peak-to-Trough Ratio of PF-06751979
Peak-to-trough ratio was calculated by dividing Cmax with Cmin of PF-06751979. Cmax was maximum plasma concentration during the dosing interval and Cmin was minimum observed plasma concentration during the dosing interval.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Observed Accumulation Ratio (Rac) for AUCtau of PF-06751979
Rac for AUCtau for Day 7 was calculated as: AUCtau on Day 7 divided by AUCtau on Day 1. Rac for AUCtau for Day 14 was calculated as: AUCtau on Day 14 divided by AUCtau on Day 1.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part B: Observed Accumulation Ratio for Maximum Observed Plasma Concentration (Rac Cmax) of PF-06751979
Rac for Cmax on Day 7 was calculated as: Cmax on Day 7 divided by Cmax on Day 1 and Rac for Cmax on Day 14 was calculated as: Cmax on Day 14 divided by Cmax on Day 1, where Cmax was the maximum observed plasma concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 7; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Plasma Decay Half-Life (t1/2) of PF-06751979
Plasma decay half-life is the time duration for the plasma concentration of PF-06751979 to decrease by one-half of its original concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Apparent Volume of Distribution (Vz/F) of PF-06751979
Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired blood concentration of a drug. Apparent volume of distribution after oral dose (Vz/F) is influenced by the fraction absorbed.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Maximum Observed Plasma Concentration (Cmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Area Under the Curve From Time Zero to End of Dosing Interval (AUCtau) of PF-06751979
Area under the plasma concentration versus time-curve from time zero to end of dosing interval (AUCtau), where dosing interval was 24 hours.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part C: Time to Reach Maximum Observed Plasma Concentration (Tmax) of PF-06751979
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Dose Normalized Maximum Observed Plasma Concentration (Cmax[dn]) of PF-06751979
Cmax(dn) was obtained calculated by dividing Cmax by the exact dose of PF-06751979 (in mg) administered to a participant.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Dose Normalized Area Under the Curve From Time Zero to End of Dosing Interval Tau (AUCtau[dn]) of PF-06751979
Area under the concentration curve from time zero to end of dosing interval (AUCtau), where dosing interval was 24 hours. AUCtau (dn) was calculated by dividing AUCtau by the exact dose of PF-06751979 (in mg) administered to a participant.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part C: Apparent Oral Clearance (CL/F)
Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Minimum Observed Plasma Concentration (Cmin) of PF-06751979
Minimum observed concentration during the dosing interval.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Peak-to-Trough Ratio of PF-06751979
Peak-to-trough ratio was calculated by dividing Cmax with Cmin of PF-06751979. Cmax was maximum plasma concentration during the dosing interval and Cmin was minimum observed plasma concentration during the dosing interval.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Observed Accumulation Ratio (Rac) for AUCtau of PF-06751979
Rac for AUCtau at Day 14 was calculated as: AUCtau on Day 14 divided by AUCtau on Day 1.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 14
Part C: Observed Accumulation Ratio for Maximum Observed Plasma Concentration (Rac Cmax) of PF-06751979
Rac for Cmax on Day 14 was calculated as: Cmax on Day 14 divided by Cmax on Day 1, where Cmax was the maximum observed plasma concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12 and 24 hours post dose on Day 1; pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Plasma Decay Half-Life (t1/2) of PF-06751979
Plasma decay half-life was the time duration for the plasma concentration to decrease by one-half of its original concentration.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part C: Apparent Volume of Distribution (Vz/F) of PF-06751979
Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired blood concentration of a drug. Apparent volume of distribution after oral dose (Vz/F) is influenced by the fraction absorbed.
Time frame: pre-dose, 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 72, 96 and 120 hours post dose on Day 14
Part B: Amount of PF-06751979 Excreted Unchanged in Urine Over the Dosing Interval Tau (Aetau)
Aetau was the amount of drug excreted unchanged in urine during the dosing interval tau, where tau was 24 hours.
Time frame: 0-24 hours on Day 14
Part B: Percentage of Dose of PF-06751979 Excreted Unchanged in the Urine Over the Dosing Interval Tau (Aetau%)
Aetau% was calculated as: 100\*Aetau/dose. Aetau was the amount of drug excreted unchanged in urine during the dosing interval tau, where tau was 24 hours.
Time frame: 0-24 hours on Day 14
Part B: Renal Clearance of PF-06751979
Renal clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated in urine. It was calculated as amount of drug excreted unchanged in urine during the dosing interval tau (Aetau) divided by area under the plasma concentration time-curve from time zero to end of dosing interval (AUCtau), where dosing interval was 24 hours.
Time frame: 0-24 hours on Day 14
Part B: Percent Change From Baseline in Cerebrospinal Spinal Fluid (CSF) Amyloid Beta (ABeta) Fragments
ABeta is the peptide fragment of the amyloid precursor protein. Percent change from baseline in CSF concentration of ABeta fragments (ABeta 1-38, ABeta 1-40, ABeta 1-42, ABeta total, ABeta x-38, ABeta x-40, ABeta x-42, soluble amyloid precursor protein alpha (sAPP-alpha), soluble amyloid precursor protein beta (sAPP-beta) at Day 14 was reported in this outcome measure.
Time frame: Baseline, Day 14