Intramuscular Dose-Escalation Study With ETI-204 in Adult Volunteers

Inclusion Criteria

• Females or males ≥18 years of age;
• All females regardless of childbearing potential must have a negative serum beta human chorionic gonadotropin (β-hCG) pregnancy test at Screening and Day -1;
• Females of childbearing potential (i.e., not postmenopausal or surgically sterile) must agree to practice abstinence or to use a medically accepted method of contraception from the time of Screening through 30 days after the final study visit. Acceptable methods of contraception include diaphragm/cervical cap with spermicide; sponge with spermicide; condom with spermicide; or intrauterine device with condom or spermicide. The following contraceptive methods are acceptable only when used with a condom and spermicide: birth control pills, birth control patches, vaginal ring, hormone under the skin, or hormone injections;
• Postmenopausal females, defined as females who have had amenorrhea for at least 12 months either naturally or following cessation of all exogenous hormonal treatments, and have a follicle stimulating hormone level of >40 mIU/mL at Screening;
• Females who have undergone surgical sterilization, including hysterectomy, bilateral oophorectomy, bilateral salpingectomy, tubal ligation, or tubal essure;
• Males must agree to practice abstinence or use a condom with spermicide and to refrain from sperm donation from Screening during the study and for 30 days after the final study visit;
• Provide written informed consent;
• Willing to comply with study restrictions.

Exclusion Criteria

• Body weight >100 kg;
• Body mass index ≥32 kg/m2;
• Pregnant or lactating female;
• Clinically significant comorbidity that would interfere with completion of the study procedures or objectives, or compromise the subject's safety;
• Supine systolic blood pressure (BP) ≥150 mmHg or ≤90 mmHg or diastolic BP ≥95 mmHg;
• Use of H1 receptor antagonists (i.e., antihistamines) within 5 days prior to Day 1;
• Evidence of drug or alcohol abuse within 6 months of Day 1 as determined by the Investigator;
• Positive test result for drugs of abuse (with the exception of medically prescribed drugs) at Screening or on Day -1;
• Positive test for alcohol at Screening, subject to Investigator's discretion. Subjects who test positive for alcohol at Day -1 are excluded from the study;
• Treatment with an investigational agent within 30 days or 5 half-lives of the investigational agent at Day 1 (whichever is longer);
• Congenital or acquired immunodeficiency syndrome;
• Prior solid organ or bone marrow transplant;
• Positive test for Hepatitis B (surface antigen), Hepatitis C, or human immunodeficiency virus (HIV) at Screening;
• History of prior treatment for anthrax exposure or prior anthrax infection;
• Prior immunization with any approved or investigational anthrax vaccine or prior treatment with an investigational anthrax treatment (e.g., ETI-204, raxibacumab, or anthrax immune globulin);
• Military personnel deployed in 1990 or after, unless the subject can provide documentation demonstrating he or she has not previously received any approved or investigational anthrax vaccine;
• Use of systemic steroids, immunosuppressive agents, anticoagulants, or anti-arrhythmics within 1 year prior to Day 1. A single short course (i.e., less than 14 days) of systemic steroid therapy is allowed, provided it concluded more than 6 months prior to Day 1;
• Donation or loss of >500 mL of blood within 30 days or plasma within 7 days of Day 1;
• Prior stroke, epilepsy, relapsing or degenerative central nervous system disease, or relapsing or degenerative ocular disease;
• Myocardial infarction or acute coronary syndrome in the past 5 years, active angina pectoris, or heart failure (New York Heart Association scale >1);
• History of chronic liver disease;
• Calculated creatinine clearance of 1.2 X the upper limit of normal at Screening or Day -1;
• Poor muscle mass as determined by the Investigator;
• Fa