CompletedNCT01317667Updated Jan 3, 2020Results posted

Safety and Immunogenicity Study of Recombinant Ricin Toxin A-Chain Vaccine (RVEc™)

A Phase 1 interventional study of RVEc in Ricin, sponsored by U.S. Army Medical Research and Development Command. Completed at 1 site in United States. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-01-03.

Sponsored by U.S. Army Medical Research and Development Command · Phase 1, Interventional, and Other

Phase: Phase 1
Study type: Interventional
Enrollment: 30
Allocation: Randomized
Ages: 18 Years to 50 Years
Sex: All

Study summary

This study is a Phase 1, escalating, multiple-dose, single-center study to evaluate the safety and immunogenicity of the RVEc vaccine.

The two principal hypotheses to be tested are: RVEc vaccine will display an acceptable safety profile as determined by adverse event data and RVEc vaccine will elicit ELISA immunoglobulin G (IgG) titers greater than or equal to 1:500 and toxin-neutralizing antibody (TNA) anti-ricin toxin-neutralizing antibody titers greater than or equal to 1:50 in vaccine recipients.

Conditions studied

Ricin

Keywords

Ricin
RVEc

In context

Lead sponsor

U.S. Army Medical Research and Development Command is the lead sponsor of 151 studies on the registry; 8 are open to participants now.

Of its 23 completed or terminated interventional studies of FDA-regulated products, 16 (70%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years to 50 Years
Sexes eligible: All
Accepts healthy volunteers: Yes

Inclusion criteria

Study subjects must be 18-50 years old.
Subjects must weigh at least 110 pounds.
Subjects must be in good health as judged from medical history, physical examination, EKG and chest x-ray, complete blood count (CBC) with differential, clinical chemistries, urinalysis, hepatitis serology, and HIV antibody test, and be medically cleared for participation by an investigator. If any HIV or hepatitis testing is positive, the individual will be provided with counseling and referral for health care.
Females of childbearing potential must have a negative pregnancy test on vaccination day before each dose and agree to not become pregnant or breastfeed for 3 months after the last dose of the vaccine and be willing to use a reliable form of contraception during the study.
Study subjects must read and sign an approved informed consent.
Study subjects must be willing to complete a subject diary card after each vaccination.
Study subjects must be willing to return for all follow-up visits.
Study subjects must agree to report any adverse event (AE) that may or may not be associated with administration of the investigational product through the 9-month follow-up visit. Study subjects will report all serious adverse events for the duration of the study.

Exclusion criteria

Exclusion Criteria:

Body weight less than 110 pounds.
Acute or chronic medical conditions or immunodeficiency from a medical condition or medical treatment, medications, or dietary supplements that, in the investigator's opinion, would impair the subject's ability to respond to vaccination.
Severe hypersensitivity to any vaccine (anaphylaxis, angioedema, bronchospasm, or laryngospasm).
History of asthma, chronic obstructive pulmonary disease, or other current/residual disease of the lungs.
Clinically significant abnormal laboratory tests.
Current smoker.
Any known allergies to sodium succinate, Tween-20 (a detergent), aluminum hydroxide, or kanamycin.
Previously received ricin toxin vaccine or has antibodies to ricin toxin proteins.
Receipt of licensed vaccines within 30 days prior to the start of the study or plans to receive other vaccines during the initial 9 months of the study (the only exceptions are the inactivated influenza vaccine that can be received at least 30 days after RVEc Dose 3).
Receipt of investigational drug/test product within 30 days prior to entry or within the initial 9 months of the study.
Females: Pregnant or breastfeeding.
Enrolled in another greater than minimal risk study.

Study design

Phase: Phase 1
Primary purpose: Other
Allocation: Randomized
Intervention model: Parallel assignment
Masking: None (open label)
Enrollment: 30 participants (actual)

Study arms

Experimental
Group 1
RVEc vaccine 20 μg/dose x 3 doses
Biological: RVEc
Experimental
Group 2
RVEc vaccine 50 μg/dose x 3 doses
Biological: RVEc
Experimental
Group 3
RVEc vaccine 100 μg/dose x 1 dose
Biological: RVEc

Interventions

BiologicalRVEc
Also known as: Recombinant Ricin Toxin A-Chain 1-33/44-198 (rRTA 1-33/44-198) Vaccine

What researchers measure

Primary outcomes

Number of Vaccinated Subjects Any Averse Events and by Location and Severity
Time frame: Days 1, 3, 7, 14, and 28 after each vaccination and at 6 and 9 months

Secondary outcomes

Over Response Rates and Comparisons for ELISA and TNA Titers
Overall response is defined as a subject having a response at any time after vaccination. A response is defined as subjects who developed total ELISA IgG titers (≥ 1:500) and TNA anti-ricin toxin-neutralizing antibody titers (≥ 1:50) at each scheduled time point for which blood samples were taken for each group and over the entire study period to study completion.
Time frame: Day 7, 14, 28, 35, 42, 56, 63, 70, 84, month 6, 9, and 12

Results

Posted Feb 11, 2015

Participant flow

Participant flow — Overall Study
Milestone	Group 1	Group 2	Group 3
Started	10	10	10
Completed	10	10	10
Not completed	0	0	0

Outcome measures

PrimaryNumber of Vaccinated Subjects Any Averse Events and by Location and Severity

Time frame:: Days 1, 3, 7, 14, and 28 after each vaccination and at 6 and 9 months
Reported as:: Number · participants

Number of Vaccinated Subjects Any Averse Events and by Location and Severity
participants	Group 1	Group 2	Group 3
Any adverse events	10	10	9
Local life-threatening	0	0	0
Local severe	1	0	0
Local moderate	1	0	0
Local mild	7	8	2
Systemic life-threatening	0	0	2
Systemic severe	3	2	2
Systemic moderate	7	8	5
Systemic mild	10	10	8

SecondaryOver Response Rates and Comparisons for ELISA and TNA Titers

Overall response is defined as a subject having a response at any time after vaccination. A response is defined as subjects who developed total ELISA IgG titers (≥ 1:500) and TNA anti-ricin toxin-neutralizing antibody titers (≥ 1:50) at each scheduled time point for which blood samples were taken for each group and over the entire study period to study completion.

Time frame:: Day 7, 14, 28, 35, 42, 56, 63, 70, 84, month 6, 9, and 12
Reported as:: Number · participants

Over Response Rates and Comparisons for ELISA and TNA Titers
participants	Group 1	Group 2	Group 3
ELISA	10	6	6
TNA	5	0	1

Adverse events

Collected over 9 months. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Group 1	—	1/10 (10%)	10/10 (100%)
Group 2	—	0/10 (0%)	10/10 (100%)
Group 3	—	1/10 (10%)	9/10 (90%)

Most frequent serious events

Most frequent serious events
Event	Group 1	Group 2	Group 3
ArthralgiaMusculoskeletal and connective tissue disorders	1/10	0/10	0/10
RhabdomyolysisMusculoskeletal and connective tissue disorders	0/10	0/10	1/10

Most frequent other events

Showing 10 of 79

Most frequent other events
Event	Group 1	Group 2	Group 3
Injection site painGeneral disorders	7/10	8/10	1/10
HypernatraemiaMetabolism and nutrition disorders	2/10	3/10	6/10
HeadacheNervous system disorders	5/10	5/10	1/10
Urine leukocyte esteraseInvestigations	0/10	4/10	0/10
Blood creatine phosphokinase increasedInvestigations	0/10	4/10	3/10
HyperkalaemiaMetabolism and nutrition disorders	1/10	1/10	3/10
HypophosphataemiaMetabolism and nutrition disorders	1/10	3/10	0/10
Blood urea increasedInvestigations	3/10	2/10	0/10
Upper respiratory tract infectionInfections and infestations	1/10	3/10	1/10
LymphadenopathyBlood and lymphatic system disorders	3/10	1/10	0/10

Baseline characteristics

Age, Continuous
Age, Continuous(years)	Group 1	Group 2	Group 3	Total
Mean	35.6 ± 8.19	35.0 ± 7.62	32.2 ± 8.13	34.3 ± 7.85

Sex: Female, Male
Sex: Female, Male(Participants)	Group 1	Group 2	Group 3	Total
Female	3	4	3	10
Male	7	6	7	20

Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)	Group 1	Group 2	Group 3	Total
Hispanic or Latino	1	1	0	2
Not Hispanic or Latino	9	9	10	28
Unknown or Not Reported	0	0	0	0

Race (NIH/OMB)
Race (NIH/OMB)(Participants)	Group 1	Group 2	Group 3	Total
American Indian or Alaska Native	0	0	0	0
Asian	0	0	0	0
Native Hawaiian or Other Pacific Islander	0	0	0	0
Black or African American	0	0	1	1
White	10	10	9	29
More than one race	0	0	0	0
Unknown or Not Reported	0	0	0	0

Study locations

1 site

Department of Clinical Research, U.S. Army Medical Research Institute of Infectious Diseases
Fort Deterick, Maryland 21702, United States

References and documents

Publications

Pittman PR, Reisler RB, Lindsey CY, Guerena F, Rivard R, Clizbe DP, Chambers M, Norris S, Smith LA. Safety and immunogenicity of ricin vaccine, RVEc, in a Phase 1 clinical trial. Vaccine. 2015 Dec 16;33(51):7299-7306. doi: 10.1016/j.vaccine.2015.10.094. Epub 2015 Nov 3. PubMed 26546259 ↗

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Jan 3, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT01317667
Lead sponsor: U.S. Army Medical Research and Development Command
Collaborators: US Army Medical Research Institute of Infectious Diseases
Responsible party: Sponsor
First posted: Mar 17, 2011
Start date: Mar 2011
Primary completion: Nov 2012
Completion: Dec 2014
Results posted: Feb 11, 2015
Last update: Jan 3, 2020

Study contacts

Phillip R Pittman, MD, MPH

principal investigator · US Army Medical Research Institute of Infectious Diseases

Oversight

Data monitoring committee: No

View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Dec 2019. You cannot join it, but the record below documents what was studied.

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