Anthrax Vaccine Clinical Trial to Assess Dose Reduction and Route Change (AVRP)

Anthrax Vaccine Adsorbed: Human Reactogenicity and Immunogenicity Trial to Address Change in Route of Administration and Dose Reduction

Anthrax Clinical Trial Objectives:

To assess whether:

• Anthrax vaccine (AVA or BioThrax, BioPort Corp. Lansing MI) administered by the intramuscular (IM) route elicits antibody responses that are not inferior (i.e., "non-inferior") to that achieved by the currently licensed schedule.
• BioThrax administered by the IM route and containing fewer numbers of doses elicits antibody responses that are not inferior (i.e., "non-inferior") to that achieved by the currently licensed schedule.
• Differences in reactogenicity exist between the IM and subcutaneous (SQ) administration of BioThrax.

Additionally for the final report we will assess whether:

• Occurrence of adverse events following AVA administration is influenced by selected risk factors.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Biological: Anthrax Vaccine Adsorbed; Biological: Saline injection

Detailed Description

This study is a 43-month prospective, randomized, double-blind, placebo-controlled comparison of immunogenicity and reactogenicity elicited by BioThrax given by different routes of administration (SQ versus IM) and dosing regimens (as many as 8 doses versus as few as 4 doses). Sterile saline is used as the placebo where doses are dropped in regimens using AVA, and in the all-placebo study group.

This study is conducted among a total of 1564 healthy adult men and women (18 to 61 years of age) at five sites in the United States. Participants were randomized into one of 6 study groups with 260 participants per group. One group receives BioThrax given as currently licensed (SQ with 6 doses followed by annual boosters); another group is given placebo IM (130 participants) or SQ (130 participants) in the currently licensed dosing regimen. The four other groups receive BioThrax IM in modified dosing regimens; placebo is given when a dose of BioThrax is omitted from the licensed dosing regimen. There are a total of 25 required visits for this study, during which all participants receive an injection of vaccine or placebo (8 injections total), have a blood sample drawn (16 or 17 total), and have an in-clinic examination for adverse events (22 total).

Immunogenicity is assessed by assaying 16 serial blood samples obtained from all participants and a 17th sample from a subset of participants before vaccination and at other specified times. Total anti-protective antigen IgG antibody (anti-PA IgG) is quantified using a standardized and validated enzyme-linked immunosorbent assay (ELISA); the primary study endpoints are 4-fold rise in antibody titer and antibody concentration relative to the pre-vaccination titers or assay reactivity threshold. A subset of serum samples is also assayed in an in vitro toxin neutralization assay (TNA) to measure the functional activity of anti-BioThrax antibodies. The kinetics of the immune response to BioThrax are examined at 3 time points in the study and blood samples from a subset of participants will be further tested in correlates of protection and immunogenetics substudies. All adverse events (AEs), including vaccine reactogenicity, are actively monitored. While all AEs will be ascertained among study participants, several endpoints will be defined based on the likelihood of their occurrence and/or their clinical importance. Of primary interest is the occurrence of local AEs such as warmth, tenderness, itching, pain, arm motion limitation, erythema, induration, nodule, and bruise. Systemic AEs such as fever, fatigue, muscle ache, headache, temperature, and painful axillary adenopathy are also evaluated.

This study is expected to provide the basis for consideration of change in route of BioThrax administration from SQ to IM and reduction in number of vaccine doses required for primary and booster immunization.

There is an interim analysis of data collected through each participant's first 7 months of this study for consideration in changing the route of BioThrax administration from SQ to IM, and elimination of the 2 week vaccine priming dose.

At the end of the study, the Sponsor will present the entire results of the trial to FDA for consideration in elimination of additional doses from the licensed BioThrax schedule. At that time, the Sponsor will also supplement these data with results from parallel non-human primate challenge studies and additional research on immunologic correlates of protection.

• Study Type: Interventional
• Enrollment (Actual): 1564
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294-2050
      • University of Alabama, Birmingham (UAB)
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory
  • Maryland
    • Silver Spring, Maryland, United States, 20910-7500
      • Walter Reed Army Institute for Research (WRAIR)
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • Texas
    • Houston, Texas, United States, 77030
      • Baylor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 61 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Read/sign Informed Consent Document; Female or male, 18 to 61 years old (up to 62nd birthday); Females must agree to exercise adequate birth control from the time of the screening procedures to one month after the last vaccination; willingness/ability to return for all follow-up visits and blood collections for the duration of the study; ability to understand/comply with planned study procedures; agree to complete the Participant Diary (Appendix G) and to report concomitant medications and AEs during the study period; thave two intact upper arms with sufficient subcutaneous and intramuscular tissue in the deltoid regions for vaccine administration.Potential participants with a history of the following conditions remain eligible for study enrollment: gestational diabetes; treated, controlled, uncomplicated hypertension; treated hypo- or hyperthyroidism; cured nonmetastatic cancer; disease-free for 5 years (excluding hematologic malignancies); localized skin cancer, resected (including squamous cell and basal cell carcinomas, participants with a history of melanoma must be disease-free for 5 years); exercise-induced bronchospasm; mild asthma: use of inhalers only for control of symptoms is acceptable (Persons who have required hospitalization for asthma within the previous 2 years or those who require chronic or frequent oral/parenteral steroids will not be eligible; use of low to medium doses of inhaled steroids; history of coronary artery disease, asymptomatic (NYHA Function Class I), on a stable medical regimen. Persons meeting these criteria must be at least 2 years post-myocardial infarction, cardiac bypass surgery, and/or percutaneous coronary intervention (e.g., angioplasty, stent placement, etc) in order to qualify. Persons with a history of cardiac disease must be under the care of a physician.

Exclusion Criteria:

Prior history of anthrax or immunization against anthrax; Known allergy to aluminum hydroxide, formaldehyde, benzethonium chloride, or latex; Pregnant/plans to become pregnant for duration of study/does not agree to use adequate birth control from the time of screening procedures to one month after last vaccination; Used cytotoxic therapy in previous 5 years; Cardiovascular disease with significant likelihood of progression over 5 years; Moderate to severe asthma, chronic obstructive pulmonary disease, other significant pulmonary disease; using high doses of inhaled steroids; Clinically recognized hepatic or renal insufficiency; Inflammatory, vasculitic, or rheumatic disease including systemic lupus erythematosis, polymyalgia rheumatica and rheumatoid arthritis, scleroderma; Known HIV, hepatitis B or hepatitis C infection; Other conditions known to produce or be associated with immune suppression; Neuropathy or other evolving neurologic condition; Unstable/moderate to severe mental illness; Ongoing drug abuse/dependence (including alcohol); Seizure disorder; Active malignancy or history of metastatic or hematologic malignancy; current diabetes; Anyone who plans to receive within 60 days of study entry: cytotoxic therapy, experimental products, a live vaccine outside this trial, immunosuppressive therapy, parenteral immunoglobulin or blood products; Anyone who plans to receive an inactivated vaccine outside this trial within 42 days after study entry;: experimental products, a live vaccine outside this trial, immunosuppressive therapy; Anyone who received an inactivated vaccine outside this trial within 14 days prior to study entry, parenteral immunoglobulin or blood products within three months of study. In addition to conditions listed above, temporary exclusion would result from moderate or severe illness and/or oral temperature >100.4˚F within 3 days of injection or chronic condition that, in opinion of investigator, would render injection unsafe or would interfere with evaluations.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Anthrax Vaccine Adsorbed 8-SQ; receive 8 injections of AVA injected SQ at the same points as the original licensure: 0m, 2weeks, 1m, 6m, 12m, 18m, and 2 boosters - 30m and 42m.	Biological: Anthrax Vaccine Adsorbed; Other Names: AVA; BioThrax
Experimental: Anthrax Vaccine Adsorbed 8-IM; receive 8 injections of AVA IM administered at 0m, 2weeks, 1m, 6m, 12m, 18m, and 2 boosters - 30m and 42m.	Biological: Anthrax Vaccine Adsorbed; Other Names: AVA; BioThrax
Experimental: Anthrax Vaccine Adsorbed 7-IM; receive 7 injections of AVA IM administered at 0m, 1m, 6m, 12m, 18m, and 2 boosters - 30m and 42m.	Biological: Anthrax Vaccine Adsorbed; Other Names: AVA; BioThrax
Experimental: Anthrax Vaccine Adsorbed 5-IM; receive 5 injections of AVA IM administered at 0m, 1m, 6m, and 2 boosters - 30m and 42m.	Biological: Anthrax Vaccine Adsorbed; Other Names: AVA; BioThrax
Experimental: Anthrax Vaccine Adsorbed 4-IM; receive 4 injections of AVA IM; months 0, 2, 6 and a booster at month 42	Biological: Anthrax Vaccine Adsorbed; Other Names: AVA; BioThrax
Placebo Comparator: Saline placebo IM or SQ; Saline injections to be administered either IM or SQ at 0m, 2weeks, 1m, 6m, 12m, 18m, and 2 boosters - 30m and 42m.	Biological: Saline injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Local AEs	warmth, tenderness, itching, pain, arm motion limitation, erythema, induration, nodule, and bruise. The number of injections analyzable varies for each event based on the presence or absence of reported data.	4 weeks after each injection
Systemic AEs	Fatigue, Muscle Ache, Headache, Fever, Tender Axillary Lymphnode The number of injections analyzable varies for each event based on the presence or absence of reported data.	4 weeks after each injection
Anti-protective Antigen IgG Geometric Mean Concentration	Geometric mean of the Anti-PA IgG Concentration measured in μg/mL. The lower limit of quantification (LLOQ) is 3.7, results below the LLOQ have been replaced by 1/2 LLOQ (1.85) before taking the geometric mean.	4 weeks after the m1, m6 and m42 injections
Anti-protective Antigen IgG Geometric Mean Titer	Geometric mean of the Dilutional Titer. The Dilutional Titer is the reciprocal of the dilution at which the anti-PA IgG response reaches a threshold. The lower limit of quantification (LLOQ) is 58, results below the LLOQ have been replaced by 1/2 LLOQ (29) before taking the geometric mean.	4 weeks after the m1, m6 and m42 injections
4-fold Rise in Anti-protective Antigen IgG Titer Response	Percent of participants who achieved a 4-fold or greater rise in anti-PA IgG Titer relative to the pre-vaccination level at month 0. The Dilutional Titer is the reciprocal of the dilution at which the anti-PA IgG response reaches a threshold. The lower limit of quantification (LLOQ) is 58, results below the LLOQ have been replaced by LLOQ (58) before calculating the fold response. Thus the lowest titer that can achieve 4-fold rise is 4*58 = 232.	4 weeks after the m1, m6 and m42 injections

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
TNA ED50 Titer	Geometric mean of the ED50. The ED50 is the reciprocal of the dilution at which patient serum neutralizes 50% of a dose of anthrax lethal toxin (ED50). The lower limit of quantification (LLOQ) for this assay is 36, results below the LLOQ have been replaced with 1/2 LLOQ (18) before taking the geometric mean. Note that this secondary endpoint was only performed on ~47% of the participants.	4 weeks after the m1, m6 and m42 injections

Collaborators and Investigators

• Sponsor: Centers for Disease Control and Prevention
• Collaborators: Mayo Clinic; Baylor College of Medicine; University of Alabama at Birmingham; Emory University; Walter Reed Army Institute of Research (WRAIR)
• Investigators: Principal Investigator: Jennifer Wright, DVM, Centers for Disease Control and Prevention

Publications and helpful links

General Publications

• Quinn CP, Sabourin CL, Schiffer JM, Niemuth NA, Semenova VA, Li H, Rudge TL, Brys AM, Mittler RS, Ibegbu CC, Wrammert J, Ahmed R, Parker SD, Babcock J, Keitel W, Poland GA, Keyserling HL, El Sahly H, Jacobson RM, Marano N, Plikaytis BD, Wright JG. Humoral and Cell-Mediated Immune Responses to Alternate Booster Schedules of Anthrax Vaccine Adsorbed in Humans. Clin Vaccine Immunol. 2016 Apr 4;23(4):326-38. doi: 10.1128/CVI.00696-15. Print 2016 Apr.
• Falola MI, Wiener HW, Wineinger NE, Cutter GR, Kimberly RP, Edberg JC, Arnett DK, Kaslow RA, Tang J, Shrestha S. Genomic copy number variants: evidence for association with antibody response to anthrax vaccine adsorbed. PLoS One. 2013 May 31;8(5):e64813. doi: 10.1371/journal.pone.0064813. Print 2013.
• Pajewski NM, Parker SD, Poland GA, Ovsyannikova IG, Song W, Zhang K, McKinney BA, Pankratz VS, Edberg JC, Kimberly RP, Jacobson RM, Tang J, Kaslow RA. The role of HLA-DR-DQ haplotypes in variable antibody responses to anthrax vaccine adsorbed. Genes Immun. 2011 Sep;12(6):457-65. doi: 10.1038/gene.2011.15. Epub 2011 Mar 3.
• Marano N, Plikaytis BD, Martin SW, Rose C, Semenova VA, Martin SK, Freeman AE, Li H, Mulligan MJ, Parker SD, Babcock J, Keitel W, El Sahly H, Poland GA, Jacobson RM, Keyserling HL, Soroka SD, Fox SP, Stamper JL, McNeil MM, Perkins BA, Messonnier N, Quinn CP; Anthrax Vaccine Research Program Working Group. Effects of a reduced dose schedule and intramuscular administration of anthrax vaccine adsorbed on immunogenicity and safety at 7 months: a randomized trial. JAMA. 2008 Oct 1;300(13):1532-43. doi: 10.1001/jama.300.13.1532. Erratum In: JAMA. 2008 Nov 19;300(19):2252.
• Wright JG, Plikaytis BD, Rose CE, Parker SD, Babcock J, Keitel W, El Sahly H, Poland GA, Jacobson RM, Keyserling HL, Semenova VA, Li H, Schiffer J, Dababneh H, Martin SK, Martin SW, Marano N, Messonnier NE, Quinn CP. Effect of reduced dose schedules and intramuscular injection of anthrax vaccine adsorbed on immunological response and safety profile: a randomized trial. Vaccine. 2014 Feb 12;32(8):1019-28. doi: 10.1016/j.vaccine.2013.10.039. Epub 2013 Dec 25.

Study record dates

Study Major Dates

• Study Start: May 1, 2002
• Primary Completion (Actual): February 1, 2010
• Study Completion (Actual): February 1, 2010

Study Registration Dates

• First Submitted: July 6, 2005
• First Submitted That Met QC Criteria: July 11, 2005
• First Posted (Estimated): July 13, 2005

Study Record Updates

• Last Update Posted (Actual): May 29, 2024
• Last Update Submitted That Met QC Criteria: May 1, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: Vaccine; Immunogenicity; Reactogenicity; Anthrax
• Additional Relevant MeSH Terms: Infections; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Positive Bacterial Infections; Bacillaceae Infections; Anthrax
• Other Study ID Numbers: CDC-NCID-3344

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO