VELOCITY: An Anthrax Vaccine Clinical Study

This is a Phase 3, multicenter, randomized, double-blind, parallel-group trial designed to evaluate the lot consistency (using three consecutively manufactured lots), immunogenicity, and safety of AV7909 administered in healthy adults for an indication of postexposure prophylaxis (PEP) of anthrax. Healthy adults between 18 and 65 years of age (inclusive) will sign and date an informed consent form and then be screened for eligibility for participation in the study 2 to 28 days prior to randomization. Participants meeting the entry criteria will be randomized 2:2:2:1 to one of four study groups on Day 1. Randomization will be stratified by site. Participants will be evaluated for safety through Day 64 \[or the early withdrawal visit (EWV)\], as assessed by clinical laboratory tests (hematology, serum chemistry, and urinalysis), monitoring of Adverse Events (AE) including Serious Adverse Events (SAE) and Adverse Events of Special Interest (AESI), vital signs, and physical examinations. Adverse Events of Special Interest are adverse events associated with autoimmune disease as defined by the Center for Biologics Evaluation and Research, and might represent a safety signal for vaccine-associated autoimmunity. Reactogenicity (solicited systemic and injection site reactions) will be assessed daily by the participants using electronic diaries (e-diaries) after each vaccination. Information on the use of medications will be collected at each study visit. In addition, blood samples for auto-antibody assessment will be taken at Day 1 predose and Day 64 (or Early Withdrawal Visit). Participants who receive at least one dose of vaccine but who for any reason discontinue vaccinations prematurely will be asked to participate in the further planned study visits up to Day 64 for safety assessment only. Participants who receive at least one dose of vaccine will also be asked to participate in safety follow-up phone calls occurring on Day 43, Month 4, Month 7, Month 10, and Month 13 (nominally 0.5, 3, 6, 9, and 12 months after the last vaccination) to collect information on AEs, SAEs and any potential AESIs. Based on responses at these phone contacts, participants may be asked to return to the clinic for an unscheduled visit to provide blood samples for auto-antibody testing to investigate reports of potential AESIs. Independent safety oversight will be provided by a Data Safety Monitoring Board, which will be notified of significant AEs as determined by the Medical Monitor on an ongoing basis.