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

Following completion of a Screening visit subjects will arrive at the clinic on Day -1. On Day 1, subjects will be randomized in a 3:1 ratio to receive an IM dose of either ETI-204 or matching placebo, respectively: Cohort 1: 4 subjects randomized to 4 mg/kg ETI-204 or matching placebo Cohort 2: 8 subjects randomized to 8 mg/kg ETI-204 or matching placebo Cohort 3: 8 subjects randomized to 16 mg/kg ETI-204 or matching placebo Cohort 4: 8 subjects randomized to 20 mg/kg ETI-204 or matching placebo Cohort 5: 8 subjects randomized to 24 mg/kg ETI-204 or matching placebo Study drug will be injected bilaterally into the vastus lateralis muscles, with the subject in a supine position. A separate syringe with a 21-gauge,1.5-inch needle will be used for each injection. The number of injections and injection volume will increase with increasing dose allowing for an assessment of increasing IM ETI-204 doses and the tolerability of a larger number of injections and larger injection volume. Subjects will be pretreated with 50 mg oral diphenhydramine approximately 30 minutes prior to administration of study drug. Subjects will be discharged from the study facility on Day 4 following completion of study assessments and will return to the study facility for additional visits on Days 7, 10, 15 (±3 days), 29 (±3 days), 43 (±3 days), and 71 (±4 days). Decisions to dose-escalate will be made by the investigator(s) in conjunction with the sponsor and will be based solely on the available safety and local tolerability data up to and including Day 4.