A Phase 2 Safety and Immunogenicity Study for an Anthrax Vaccine Using 3 Schedules and Two Dose Levels

The safety and immunogenicity of AV7909 for post-exposure prophylaxis of anthrax will be
evaluated using a randomized, parallel-group, active-controlled, double-blind design with
three immunization schedules and two dose levels in healthy adult volunteers. Safety will
be assessed by clinical laboratory tests (hematology, serum chemistry, and urinalysis),
monitoring of adverse events, vital signs, and physical examinations. Reactogenicity
(systemic and injection site reactions) will be assessed by the subjects using subject
e-diaries for 7 days after each immunization and by the investigator at in-clinic visits 7
and 14 days after each immunization, and at other visits, if applicable. Immunogenicity
will be measured as toxin neutralizing antibody (TNA) response and seroconversion rates.

Inclusion Criteria:

- Be 18-50 years old

- Be in good health

- Have access to a computer and the internet so you can complete a diary

- Agree to abstain from sex the first 84 days of the study or practice birth control if
you are a woman who is able to get pregnant

- Have not donated blood for the previous 8 weeks

Exclusion Criteria:

- A known anaphylactic response, severe systemic response, or serious hypersensitivity
reaction to a prior immunization.

- A history of latex allergy.

- Have received a shot (vaccine), including flu shots, in the past 6 weeks or plan to
get a shot for 4 weeks after the last study shot is given.

- Have previously served in the military any time after 1990 or plan to enlist in the
military from Screening through Day 84.

- Prior immunization with anthrax vaccine, recombinant protective antigen (rPA)
vaccine, or known exposure to anthrax organisms.

- Have participated in anthrax therapeutic or vaccine studies (monoclonal anti-PA or
anthrax immune globulins or anthrax vaccines).

- Participation in any investigational study involving use of a pharmacological
intervention within 30 days before the Screening visit or planning to participate in
a study requiring dosing through the 12-month safety follow-up telephone call.

- Have a known diagnosis of any immunodeficiency disease including but not limited to:
acquired immune deficiency syndrome (AIDS), common variable immunodeficiency disease,
immunoglobulin A (IgA) deficiency, or hypogammaglobulinemia.

- Past history of significant autoimmune disease such as rheumatoid arthritis, lupus
erythematous, psoriasis in the area of vaccinations, or requires immunotherapy,
glomerulonephritis, or autoimmune thyroiditis.

- Have received immunosuppressive therapy with cytotoxic drugs or Rituximab within the
past 2 years.

- A history of cytotoxic chemotherapy or radiation therapy.

- Chronic (>10 days) daily oral or parenteral corticosteroid therapy in the past 12
months.

- Any lung disease, including reactive airway disease, which requires the daily use of
medications.

- A female currently breastfeeding or with a positive pregnancy test.

- A history of drug or alcohol abuse within 12 months prior to Screening, or a positive
result on a urine drug screen for cocaine, marijuana, opiates, methamphetamines,
benzodiazepines, or oxycodone.

- Any tattoo or other skin condition in the deltoid region on either arm that may
obscure the assessment of the injection sites.

- A medical condition that, in the opinion of the PI or designee, could adversely
impact the subject's participation or safety or the conduct of the study.

- Any planned elective in-patient surgery during the study period.