A Phase 2 interventional study of AV7909 Full Dose (0.5 mL) and AV7909 Half Dose (0.25 mL) in Anthrax, sponsored by Biomedical Advanced Research and Development Authority. Completed at 7 sites in United States. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by Biomedical Advanced Research and Development Authority · Phase 2, Interventional, and Other
This randomized, phase 2, double-blinded, multicenter study is designed to assess the safety and immune response kinetics of CYFENDUS™ (henceforth AV7909) administered on 2 primary series vaccination schedules followed by 6- and 12-month boosters.
This trial is a randomized, double-blinded, multicenter study designed to evaluate safety and immune response kinetics of full and half doses of AV7909 administered on 2 primary series vaccination schedules followed by 6- and 12-month boosters. Healthy adult male and female subjects aged 18 through 65 years, inclusive, will be screened for baseline health status to ensure trial eligibility. Subjects meeting all the inclusion and none of the exclusion criteria will be randomized to receive either half or full doses of AV7909 on 1 of 2 vaccination schedules. Randomization will be stratified by sex. Subjects will be randomized 1:1:1:1 within stratum across 4 treatment groups (approximately 55 subjects per group). Subjects will receive a total of 5 intramuscular (IM) injections. Primary series investigational product (IP) doses will be administered on Days 1, 15, and 29, and booster IP doses will be administered on Days 181 and 366. On each IP administration day, each subject will receive an IM injection of full-dose AV7909 (0.5 mL), half-dose AV7909 (0.25 mL), or placebo (0.5 mL or 0.25 mL sodium chloride for injection), based on their assigned treatment group.
Update: The 2 treatment groups (Study Groups 1 and 2) in which subjects are to receive full doses of AV7909 were closed to enrollment on 13 May 2024 to preserve resources for the groups that BARDA considers the highest priority and reflects no concerns due to a safety signal or request of the Data Safety Monitoring Board (DSMB). Subjects randomized prior to this date will continue in the study in their assigned treatment group as described in the protocol. Subjects randomized on or after 13 May 2024 will be randomized 1:1 within stratum across the 2 remaining treatment groups (Study Groups 3 and 4), and on each IP administration day will receive an IM injection of half-dose AV7909 (0.25 mL) or placebo (0.25 mL sodium chloride for injection), based on their assigned treatment group. There are no other changes to the study protocol.
Safety assessments will be based on solicited adverse events (AEs; local and systemic reactogenicity symptoms) with onset within 7 days after each IP administration; unsolicited treatment-emergent adverse events (TEAEs) with onset within 30 days after each IP administration; and treatment-emergent serious adverse events (SAEs), potentially immune-mediated medical conditions (PIMMCs), and medically attended adverse events (MAAEs) occurring during study participation (ie, up to 1 year after the last IP administration). For this study, a PIMMC is considered to be unexpected and will be treated as a serious and unexpected suspected adverse reaction (SUSAR) per 21 CFR 312.32.
Immunogenicity assessments will include geometric mean titer (GMT), seroprotection rate, and seroconversion rate by toxin-neutralizing antibody (TNA) 50% neutralization factor (NF50) and enzyme-linked immunosorbent assay (ELISA) anti-protective antigen (PA) Immunoglobulin G (IgG).
75 studies on the registry are indexed under Anthrax; 12 are open to participants now.
This study's enrollment of 220 is above the median of 100 across 57 interventional studies indexed under Anthrax.
Browse Anthrax studies →Biomedical Advanced Research and Development Authority is the lead sponsor of 10 studies on the registry; none are open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 6 (86%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
If a female of who is sexually active, agrees to use an acceptable method of from Screening to Day 396 and has used a reliable birth control method for at least 2 months prior to Screening.
Exclusion Criteria:
Has an acute illness, as determined by the site investigator, within 72 hours prior to study IP administration.
Has an acute or chronic or infection, as identified through laboratory testing.
- A subject who has been effectively treated for hepatitis C, as evidenced by a negative hepatitis C ribonucleic acid (RNA) confirmation test, and who no longer requires antiviral therapy is not excluded.
Has taken as follows within 30 days prior to Screening.
Has any laboratory test result or clinical findings (including vital signs) that singly or in combination are likely to unfavorably alter the risks of subject participation or to confound study safety or immunogenicity results, in the opinion of the site investigator. Additionally, the following are exclusionary:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This study group will receive full dose AV7909 (0.5mL) at study days 1, 15, 181 and 366. A placebo full dose (0.5 mL) will be administered between the second and third dose of AV7909 at study day 29. Update: Enrollment to this treatment arm was closed on 13 May 2024.
Biological: AV7909 Full Dose (0.5 mL) · Biological: Placebo: Sodium Chloride Injection, USP 0.9% (0.5 mL)
This study group will receive of AV7909 full dose (0.5 mL) at study days 1, 29, 181 and 366. A placebo full dose (0.5 mL) will be administered between the first and second dose of AV7909 at study day 15. Update: Enrollment to this treatment arm was closed on 13 May 2024.
Biological: AV7909 Full Dose (0.5 mL) · Biological: Placebo: Sodium Chloride Injection, USP 0.9% (0.5 mL)
This study group will receive of AV7909 half dose (0.25 mL) at study days 1, 15, 181 and 366. A placebo half dose (0.25 mL) will be administered between the second and third dose of AV7909 at study day 29.
Biological: AV7909 Half Dose (0.25 mL) · Biological: Placebo: Sodium Chloride Injection, USP 0.9% (0.25 mL)
This study group will receive of AV7909 half dose (0.25 mL) at study days 1, 29, 181 and 366. A placebo full dose (0.25 mL) will be administered between the first and second dose of AV7909 at study day 15.
Biological: AV7909 Half Dose (0.25 mL) · Biological: Placebo: Sodium Chloride Injection, USP 0.9% (0.25 mL)
AV7909 Anthrax Vaccine is being developed by Emergent Product Development Gaithersburg Inc. (Emergent) for post-exposure prophylaxis (PEP) of disease in persons 18 through 65 years of age following suspected or confirmed B. anthracis exposure when administered in conjunction with the recommended antibacterial regimen. AV7909 is a combination product containing BioThrax and CPG 7909, a synthetic immunostimulatory oligodeoxynucleotide that has been shown to be a potent vaccine adjuvant. CPG 7909 is a Toll-like receptor 9 agonist designed to induce both an enhanced antigen-specific antibody response and a natural killer T-cell immune response when used in combination with prophylactic (preventative) or therapeutic vaccines.
AV7909 Anthrax Vaccine is being developed by Emergent Product Development Gaithersburg Inc. (Emergent) for PEP of disease in persons 18 through 65 years of age following suspected or confirmed B. anthracis exposure when administered in conjunction with the recommended antibacterial regimen. AV7909 is a combination product containing BioThrax and CPG 7909, a synthetic immunostimulatory oligodeoxynucleotide that has been shown to be a potent vaccine adjuvant. CPG 7909 is a Toll-like receptor 9 agonist designed to induce both an enhanced antigen-specific antibody response and a natural killer T-cell immune response when used in combination with prophylactic (preventative) or therapeutic vaccines.
Sodium chloride 9 mg water for injection Quantum satis (q.s.). It contains no bacteriostat, antimicrobial agent, or added buffer. The solution may contain hydrochloric acid and/or sodium hydroxide for pH adjustment (pH 4.5-7.0).
Sodium chloride 9 mg water for injection Quantum satis (q.s.). It contains no bacteriostat, antimicrobial agent, or added buffer. The solution may contain hydrochloric acid and/or sodium hydroxide for pH adjustment (pH 4.5-7.0).
All solicited local and systemic reactogenicity symptoms with onset within 7 days after each investigational product (IP) administration day.
Time frame: Within 7 days after each IP administration.
Geometric mean titer (GMT) as measured by toxin-neutralizing antibody (TNA) 50% neutralization
Time frame: Day 64
Unsolicited treatment-emergent adverse events (TEAEs) with onset within 30 days after each IP administration day.
Time frame: Within 30 days after each IP administration.
Treatment-emergent serious adverse events (SAEs) up to 1 year after the last IP administration day.
Time frame: Within 1 year after the last IP administration.
Treatment-emergent potentially immune-mediated medical conditions (PIMMCs) up to 1 year after the last IP administration day.
Time frame: Within 1 year after the last IP administration.
Treatment-emergent medically attended adverse events (MAAEs) up to 1 year after the last IP administration day.
Time frame: Within 1 year after the last IP administration.
Geometric mean titer (GMT) as measured by toxin-neutralizing antibody (TNA) 50% neutralization factor (NF50) at Day 15, Day 29, Day 36, Day 43, Day 50, Day 85, Day 181, Day 211, Day 366, Day 396, Day 546, and Day 731.
Time frame: Day 15 through 731.
Seroprotection rate as measured by toxin-neutralizing antibody (TNA) 50% neutralization factor (NF50) at Day 15, Day 29, Day 36, Day 43, Day 50, Day 64, Day 85, Day 181, Day 211, Day 366, Day 396, Day 546, and Day 731.
Time frame: Day 15 through 731.
Geometric mean titer (GMT) as measured by enzyme-linked immunosorbent assay (ELISA) anti-protective antigen (PA) Immunoglobulin G (IgG) at Day 15, Day 29, Day 36, Day 43, Day 50, Day 64, Day 85, Day 181, Day 211, Day 366, Day 396, Day 546, and Day 731.
Time frame: Day 15 through 731.
PDFs hosted by the registry, ClinicalTrials.gov.
Ran from Dec 2023 to primary completion in Aug 2025, 20 months.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: AV7909
Biomedical Advanced Research and Development Authority