A Study to Evaluate the Pharmacodynamic Effects of Single Oral Doses of PF-06648671 on β-Amyloid (Aβ) Concentrations in Cerebrospinal Fluid (CSF)

• Drug: PF-06648671
  
  Experimental Pfizer compound which will be dosed as oral suspension, single dose at 300 mg and/or 1-2 lower doses
• Drug: Placebo
  
  Placebo which will be dosed as oral suspension, single doses to match PF-06648671

• Experimental: PF-06648671 High dose group
  
  subjects receive a single oral dose of PF-06648671 at 300 mg
  Intervention: Drug: PF-06648671
• Experimental: PF-06648671 Low dose group
  
  Subjects receive a single oral dose of PF-06648671 lower than 300 mg dose
  Intervention: Drug: PF-06648671
• Placebo Comparator: Placebo group
  
  Subjects receive matching placebo
  Intervention: Drug: Placebo
• Experimental: PF-06648671 Low dose group (2)
  
  Optional arm. Subjects receive a single oral dose of PF-06648671 at second lower dose if 300 mg dose is not repeated in cohort 2
  Intervention: Drug: PF-06648671

Inclusion Criteria:

• Healthy male and/or female subjects of non childbearing potential
• BMI of 17.5 to 30.5 kg/m2 and a total body weight >50 kg (110 lbs)
• Evidence of a personally signed and dated informed consent document indicating that subject has been informed of all pertinent aspects of the study.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease (including drug allergies, but excluding untreated asymptomatic, seasonal allergies at the time of dosing)
• Treatment with an investigational drug within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of study medication (whichever is longer)
• Subjects with a history of significant active bleeding, coagulation disorder or clinically significant finding on prothrombin time/ partial thromboplastin time/International Normalized Ratio (PT/PTT/INR) at Screening
• Subjects with lower spinal malformations (on physical examination), local spinal infection, or other abnormalities that would exclude puncture (LP)
• Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study