The purpose of this study is to determine whether HemaMax is safe and well tolerated to support efficacy under FDA's Animal Rule to reduce the morbidity and mortality associated with the hematopoietic syndrome of acute radiation syndrome.

This is a phase 2 single dose, randomized, double-blind, placebo-controlled, multi center study to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of HemaMax™ (rHuIL-12) in healthy adult male and female subjects considered representative of U.S. population.

Inclusion Criteria:

Male and Female healthy subjects who have signed the informed consent form must meet all of the following criteria

• ≥18 to ≤75 years of age
• Body mass index (BMI) ≥ 18 and ≤ 35 kg/m2
• Normal ECG, vital signs and laboratory test results
• Use of effective birth control method and abstinence from sex
• Negative pregnancy test and drug screen

Exclusion Criteria:

Subjects with any of the following characteristics will be considered ineligible:

• History of clinically significant renal, hepatic pulmonary, cardiovascular, cerebrovascular, gastrointestinal, metabolic, hematological, endocrine, urological, immunological, neurologic or psychiatric disorders or connective tissue disease
• Positive for human immunodeficiency virus (HIV), Hepatitis B, or surface antigen (HBsAg) or Hepatitis C antibody, tuberculosis (TB)
• Drug or alcohol addiction
• History of clinically significant allergy of any kind
• Prior use of IL-12 or HemaMax
• Use of any approved or investigational biologic agents or vaccinations of any kind in last 3 months