Evaluation Of The Efficacy And Safety Of Single Doses Of PF-05089771 In Patients With Primary (Inherited) Erythromelalgia

• Drug: PF-05089771
  
  A single oral dose of PF-05089771 1600 mg solution to be administered on Day 1 of each treatment session. There are 2 treatment sessions, therefore 2 single oral doses of PF-05089771 will be adminstered.
• Drug: Placebo
  
  Placebo for PF-05089771 1600 mg solution administered in each treatment session. There are 2 treatment sessions, therefore 2 single oral doses of placebo will be administered.

• Experimental: PF-05089771 1600 mg
  
  Intervention: Drug: PF-05089771
• Placebo Comparator: Placebo comparator: matching placebo
  
  Single oral dose of placebo for PF-05089771 1600 mg
  Intervention: Drug: Placebo

Inclusion Criteria:

• Male and or female subjects between the ages of 18-78 years
• Subject has clinical signs of IEM
• Minimum BMI 17.5kg/m2 and total body weight >50kg

Exclusion Criteria:

• Other severe pain conditions, e.g. rheumatologic, that may impair subject's self-assessment of pain due to IEM.
• Evidence of clinically significant hypertension, clinically significant hematological, dermatological, renal, endocrine (except diabetes mellitus), pulmonary, gastrointestinal, cardiovascular, hepatic, neurological (other than IEM), or allergic disease (including drug allergies but excluding untreated asymptomatic seasonal allergies).
• Subjects with severe obesity.