An AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. 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 or incapacity, congenital anomaly. A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. AEs included both serious and non-serious adverse events.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

An AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. 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 or incapacity, congenital anomaly. A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. AEs included both serious and non-serious adverse events.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

An adverse event was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. AE was assessed according to severity; mild (does not interfere with participant's usual function), moderate (interferes to some extent with participant's usual function) and severe (interferes significantly with participant's usual function).A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. AEs included both serious and non-serious adverse events.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

An adverse event was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. AE was assessed according to severity; mild (does not interfere with participant's usual function), moderate (interferes to some extent with participant's usual function) and severe (interferes significantly with participant's usual function). A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. AEs included both serious and non-serious adverse events.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

An AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. Relatedness to PF-06412528 was assessed by the investigator.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

An AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. A treatment emergent AE was defined as an event that emerged during the treatment period that was absent before treatment, or worsened during the treatment period relative to the pretreatment state. Relatedness to PF-06412528 was assessed by the investigator.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4. Overall number of participants analyzed=0 for arm PF-06412528 >40-80 mg as no participants were evaluable for this outcome measure at Week 2.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population: all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1-4. Overall number of participants analyzed=0 for arm PF-06412528 >40-80 mg as no participants were evaluable for this outcome measure at Week 3.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population: all participants who were screened and received at least 1 dose of PF-06412528 from Week 1-4. Overall number of participants analyzed=0 for arm PF-06412528 <=20 mg and PF-06412528 >40-80 mg as no participants were evaluable for this outcome measure at Week 4.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 1 to Week 4.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population: all participants who were screened and received at least 1 dose of PF-06412528 from Week 5-10. Overall number of participants analyzed=0 for arm PF-06412528 >40-80 mg as no participants were evaluable for this outcome measure at Week 10.

COWS is a clinician-administered instrument, to assess participants' clinical opiate withdrawal level. The scale ranges from 0 (none symptoms) to 48 (severe symptoms), higher score = more severe withdrawal. Scores category: 0 to 4 = none to minimal, 5 to 12 = mild, 13 to 24 = moderate, 25 to 36 = moderately severe withdrawal and 37 to 48 = severe withdrawal. Participants experiencing a COWS score greater than equal to (>=) 13 is treated for opiate withdrawal signs and symptoms according to the investigator's medical judgment. In this outcome measure, participants as per COWS score categories are reported. Only those COWS categories are presented which had at least 1 participant for any reporting arm.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 from Week 5 to Week 10.

Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes.

Data for this outcome measure was not collected, as there were insufficient pharmacokinetic samples due to early termination of the study by the sponsor.

Css, av was defines as the average steady state concentration of a drug ("steady state" has been achieved when the rate of drug administration and the rate of drug elimination are equal).

Data for this outcome measure was not collected, as there were insufficient pharmacokinetic samples due to early termination of the study by the sponsor.

Pre-defined criteria of vital signs included supine diastolic blood pressure (DBP) change from baseline greater than or equal to (>=) 20 millimeter of mercury (mmHg): increase and decrease; supine systolic blood pressure (SBP) change from baseline >=30 mmHg: increase and decrease.

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 in the study.

Laboratory parameters included: hematology (hemoglobin: <0.8*LLN, hematocrit: <0.8*LLN, red blood cell: <0.8* LLN, platelet <0.5*LLN; >1.75*ULN and white blood cell count <0.6*LLN, neutrophils <0.8* LLN, eosinophils >1.2*ULN, monocytes >1.2*ULN, basophils >1.2*ULN and lymphocytes <0.8* LLN), chemistry (blood urea nitrogen >1.3*ULN, creatinine>1.3*ULN, sodium <0.95*LLN, potassium <0.9*LLN, >1.1*ULN, aspartate aminotransferase >3.0*ULN, alanine aminotransferase >3.0*ULN, total bilirubin >1.5*ULN, alkaline phosphatase >3.0*ULN, albumin <0.8*LLN, total protein<0.8*LLN, >1.2*ULN, Albumin <0.8*LLN, Blood Urea Nitrogen >1.3*ULN, Creatinine >1.3*ULN, HDL Cholesterol <0.8*LLN, Chloride <0.9*LLN, Phosphate <0.8*LLN, Bicarbonate <0.9*LLN, Glucose <0.6*LLN, Creatine Kinase >2.0*ULN, Urobilinogen >=1) and urinalysis (specific gravity <1.003, pH <4.5 urine glucose >=1, ketones >=1 urine protein >=1, urine bilirubin >=1, nitrite >=1, urine leukocytes >=20).

Analysis population included all participants who were screened and had received at least 1 dose of PF-06412528 in the study and evaluated for laboratory abnormalities.

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 plasma concentration of a drug. Apparent volume of distribution after oral dose (Vz/F) is influenced by the fraction absorbed.

Data for this outcome measure was not collected, as there were insufficient pharmacokinetic samples due to early termination of the study by the sponsor.

Data for this outcome measure was not collected, as there were insufficient pharmacokinetic samples due to early termination of the study by the sponsor.