Trial Outcomes & Findings for Phase 2 Open-label Study of Alum-adjuvanted Chikungunya Virus-like Particle Vaccine (PXVX0317) (NCT NCT03992872)
NCT ID: NCT03992872
Last Updated: 2024-10-16
Results Overview
Seroconversion, defined as a 4-fold or greater rise in neutralizing antibody against chikungunya virus, as determined by luciferase-based assay (NT80), induced by PXVX0317. PXVX0317 was administered to prior alphavirus vaccine recipients versus gender- and age-matched controls.
Recruitment status
COMPLETED
Study phase
PHASE2
Target enrollment
60 participants
Primary outcome timeframe
Day 22 (21 days after vaccination)
Results posted on
2024-10-16
Participant Flow
Participants were recruited from two US sites, Walter Reed Army Institute of Research (WRAIR) Clinical Trials Center (CTC) and US Army Medical Research Institute for Infectious Disease (USAMRIID) immunization clinic.
Participant milestones
| Measure |
Experimental : Prior Alpha
All study participants received the same Investigational Product according to the same schedule. Subjects were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve subjects served as controls.
|
|---|---|---|
|
Overall Study
STARTED
|
30
|
30
|
|
Overall Study
Exposed
|
30
|
30
|
|
Overall Study
Safety
|
30
|
30
|
|
Overall Study
mITT
|
30
|
30
|
|
Overall Study
Immunogenicity Evaluable
|
30
|
30
|
|
Overall Study
COMPLETED
|
30
|
30
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Phase 2 Open-label Study of Alum-adjuvanted Chikungunya Virus-like Particle Vaccine (PXVX0317)
Baseline characteristics by cohort
| Measure |
Experimental : Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Subjects were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve subjects serves as controls.
|
Total
n=60 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
30 Participants
n=99 Participants
|
30 Participants
n=107 Participants
|
60 Participants
n=206 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Sex: Female, Male
Female
|
10 Participants
n=99 Participants
|
10 Participants
n=107 Participants
|
20 Participants
n=206 Participants
|
|
Sex: Female, Male
Male
|
20 Participants
n=99 Participants
|
20 Participants
n=107 Participants
|
40 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
3 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
28 Participants
n=99 Participants
|
29 Participants
n=107 Participants
|
57 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Asian
|
1 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
4 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Black or African American
|
2 Participants
n=99 Participants
|
12 Participants
n=107 Participants
|
14 Participants
n=206 Participants
|
|
Race (NIH/OMB)
White
|
26 Participants
n=99 Participants
|
14 Participants
n=107 Participants
|
40 Participants
n=206 Participants
|
|
Race (NIH/OMB)
More than one race
|
1 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
2 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Height
|
171.12 cm
STANDARD_DEVIATION 11.37 • n=99 Participants
|
175.10 cm
STANDARD_DEVIATION 11.16 • n=107 Participants
|
173.11 cm
STANDARD_DEVIATION 11.35 • n=206 Participants
|
|
Weight
|
90.99 Kg
STANDARD_DEVIATION 19.19 • n=99 Participants
|
94.64 Kg
STANDARD_DEVIATION 18.14 • n=107 Participants
|
92.82 Kg
STANDARD_DEVIATION 18.60 • n=206 Participants
|
|
BMI
|
31.04 Kg/m^2
STANDARD_DEVIATION 6.11 • n=99 Participants
|
30.78 Kg/m^2
STANDARD_DEVIATION 4.72 • n=107 Participants
|
30.91 Kg/m^2
STANDARD_DEVIATION 5.42 • n=206 Participants
|
|
Time Since Prior Alphavirus Vaccine
|
16.2 years
STANDARD_DEVIATION 8.3 • n=99 Participants
|
NA years
STANDARD_DEVIATION NA • n=107 Participants
|
16.2 years
STANDARD_DEVIATION 8.3 • n=206 Participants
|
PRIMARY outcome
Timeframe: Day 22 (21 days after vaccination)Population: Immunogenicity evaluable population
Seroconversion, defined as a 4-fold or greater rise in neutralizing antibody against chikungunya virus, as determined by luciferase-based assay (NT80), induced by PXVX0317. PXVX0317 was administered to prior alphavirus vaccine recipients versus gender- and age-matched controls.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 88.6 to 100.0
|
SECONDARY outcome
Timeframe: Day 1, 8, 22, 29, 57, 182Population: Immunogenicity evaluable population
Evaluation of Geometric Mean Titer of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 8
|
271.88 titers
Interval 163.72 to 451.49
|
87.48 titers
Interval 52.66 to 145.3
|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 1
|
9.21 titers
Interval 7.8 to 10.87
|
7.69 titers
Not estimable due to lack of response; all baseline values in this group were \< the limit of detection (LOD) (15) and imputed as LOD/2.
|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 22
|
2032.45 titers
Interval 1412.95 to 2923.56
|
2299.18 titers
Interval 1598.09 to 3307.84
|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 29
|
1555.60 titers
Interval 1081.46 to 2237.61
|
1772.54 titers
Interval 1118.75 to 2808.39
|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 57
|
727.91 titers
Interval 540.94 to 979.52
|
814.64 titers
Interval 567.46 to 1169.49
|
|
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Day 182
|
294.35 titers
Interval 207.45 to 417.66
|
328.89 titers
Interval 231.75 to 466.74
|
SECONDARY outcome
Timeframe: Day 8, 29, 57, 182Population: Immunogenicity evaluable population. 11 alphavirus naïve subjects were unable to attend their scheduled visit at Day 29; 10 of those subjects also missed their Day 57 visit.
Evaluation of seroconversion rate of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Day 8
|
93.3 percentage of participants
Interval 78.7 to 98.2
|
66.7 percentage of participants
Interval 48.8 to 80.8
|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Day 29
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.2 to 100.0
|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Day 57
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.9 to 100.0
|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Day 182
|
86.7 percentage of participants
Interval 70.3 to 94.7
|
100 percentage of participants
Interval 88.6 to 100.0
|
SECONDARY outcome
Timeframe: Day 1, 8, 22, 29, 57, 182Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29; 10 of those participants also missed their Day 57 visit.
Evaluation of Anti-CHIKV neutralizing antibody response, as determined by luciferase-based assay (NT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 8, 22, 29, 57 and 182.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 1 (Titer >=40)
|
3.3 percentage of participants
Interval 0.6 to 16.7
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 1 (Titer >=160)
|
3.3 percentage of participants
Interval 0.6 to 16.7
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 22 (Titer >=40)
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 88.6 to 100.0
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 22 (Titer >=160)
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 88.6 to 100.0
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 57 (Titer >=160)
|
90.0 percentage of participants
Interval 74.4 to 96.5
|
95 percentage of participants
Interval 76.4 to 99.1
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 182 (Titer >=160)
|
76.7 percentage of participants
Interval 59.1 to 88.2
|
76.7 percentage of participants
Interval 59.1 to 88.2
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 182 (Titer >=640)
|
20.0 percentage of participants
Interval 9.5 to 37.3
|
30.0 percentage of participants
Interval 16.7 to 47.9
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 1 (Titer >=640)
|
0 percentage of participants
Interval 0.0 to 11.4
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 8 (Titer >=40)
|
96.7 percentage of participants
Interval 83.3 to 99.4
|
73.3 percentage of participants
Interval 55.6 to 85.8
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 8 (Titer >=160)
|
70.0 percentage of participants
Interval 52.1 to 83.3
|
40 percentage of participants
Interval 24.6 to 57.7
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 8 (Titer >=640)
|
26.7 percentage of participants
Interval 14.2 to 44.4
|
10.0 percentage of participants
Interval 3.5 to 25.6
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 22 (Titer >=640)
|
73.3 percentage of participants
Interval 55.6 to 85.8
|
93.3 percentage of participants
Interval 78.7 to 98.2
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 29 (Titer >=40)
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.2 to 100.0
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 29 (Titer >=160)
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.2 to 100.0
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 29 (Titer >=640)
|
76.7 percentage of participants
Interval 59.1 to 88.2
|
94.7 percentage of participants
Interval 75.4 to 99.1
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 57 (Titer >=40)
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.9 to 100.0
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 57 (Titer >=640)
|
63.3 percentage of participants
Interval 45.5 to 78.1
|
75 percentage of participants
Interval 53.1 to 88.8
|
|
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Day 182 (Titer >=40)
|
93.3 percentage of participants
Interval 78.7 to 98.2
|
100 percentage of participants
Interval 88.6 to 100.0
|
SECONDARY outcome
Timeframe: Day 1, 22, 29Population: Immunogenicity evaluable population
Evaluation of Geometric Mean Titer of Anti-CHIKV total antibodies, determined by immunoassay (ELISA), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Geometric Mean Titer of Anti-CHIKV Total Antibody Response
Day 1
|
39.03 titers
Interval 29.85 to 51.03
|
25.77 titers
Interval 19.71 to 33.7
|
|
Geometric Mean Titer of Anti-CHIKV Total Antibody Response
Day 22
|
2451.60 titers
Interval 1770.49 to 3394.72
|
1338.90 titers
Interval 966.77 to 1854.27
|
|
Geometric Mean Titer of Anti-CHIKV Total Antibody Response
Day 29
|
2010.72 titers
Interval 1444.72 to 2798.46
|
1194.75 titers
Interval 786.21 to 1815.57
|
SECONDARY outcome
Timeframe: Day 22, 29Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
Evaluation of seroconversion rate of Anti-CHIKV total antibodies, determined by immunoassay, on Days 22 and 29, where seroconversion was a 4-fold rise in titer over baseline.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response
Day 22
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 86.6 to 100.0
|
|
Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response
Day 29
|
100 percentage of participants
Interval 88.6 to 100.0
|
100 percentage of participants
Interval 83.2 to 100.0
|
SECONDARY outcome
Timeframe: Day 1, 22, 29Population: Immunogenicity evaluable population
Evaluation of Geometric Mean Titer of Anti-VEEV neutralizing antibodies, determined by Plaque-Reduction Neutralization Test (PRNT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response
Day 1
|
449.82 titers
Interval 262.84 to 769.8
|
9.96 titers
Not estimable due to lack of response
|
|
Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response
Day 22
|
467.95 titers
Interval 278.47 to 786.34
|
9.89 titers
Not estimable due to lack of response
|
|
Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response
Day 29
|
538.63 titers
Interval 291.97 to 993.67
|
9.66 titers
Not estimable due to lack of response
|
SECONDARY outcome
Timeframe: Days 1, 22, and 29Population: Immunogenicity evaluable population. 11 alphavirus naive participants were unable to attend their scheduled visit at Day 29.
Evaluation of Anti-CHIKV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22, and 29.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=640
|
0 Participants
|
0 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=40
|
15 Participants
|
4 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=160
|
4 Participants
|
1 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=40
|
30 Participants
|
30 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=160
|
30 Participants
|
30 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=640
|
30 Participants
|
26 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=40
|
30 Participants
|
19 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=160
|
30 Participants
|
19 Participants
|
|
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=640
|
30 Participants
|
17 Participants
|
SECONDARY outcome
Timeframe: Day 22 and 29Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
Evaluation of seroconversion rate of anti-VEEV neutralizing antibodies on Days 22 and 29 as determined by Plaque-Reduction Neutralization Test (PRNT80), where seroconversion is a 4-fold rise in titer over baseline.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response
Day 22
|
0 percentage of participants
Interval 0.0 to 11.4
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response
Day 29
|
0 percentage of participants
Interval 0.0 to 11.4
|
0 percentage of participants
Interval 0.0 to 16.8
|
SECONDARY outcome
Timeframe: Day 1, 22, 29Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
Evaluation of Anti-VEEV neutralizing antibody response, as determined by Plaque-Reduction Neutralization Test (PRNT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22 and 29.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 1 (Titer >=40)
|
90.0 percentage of participants
Interval 74.4 to 96.5
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 22 (Titer >=40)
|
90.0 percentage of participants
Interval 74.4 to 96.5
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 22 (Titer >=160)
|
80.0 percentage of participants
Interval 62.7 to 90.5
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 29 (Titer >=160)
|
83.3 percentage of participants
Interval 66.4 to 92.7
|
0 percentage of participants
Interval 0.0 to 16.8
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 29 (Titer >=640)
|
60.0 percentage of participants
Interval 42.3 to 75.4
|
0 percentage of participants
Interval 0.0 to 16.8
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 1 (Titer >=160)
|
76.7 percentage of participants
Interval 59.1 to 88.2
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 1 (Titer >=640)
|
53.3 percentage of participants
Interval 36.1 to 69.8
|
0.0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 22 (Titer >=640)
|
56.7 percentage of participants
Interval 39.2 to 72.6
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Day 29 (Titer >=40)
|
90.0 percentage of participants
Interval 74.4 to 96.5
|
0 percentage of participants
Interval 0.0 to 16.8
|
SECONDARY outcome
Timeframe: Day 1, 22, 29Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
Evaluation of Geometric Mean Titer of Anti-VEEV total antibody as determined by an immunoassay (ELISA) in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Geometric Mean Titer of Anti-VEEV Total Antibody Response
Day 1
|
324.36 titers
Interval 195.37 to 538.52
|
14.03 titers
Interval 8.45 to 23.3
|
|
Geometric Mean Titer of Anti-VEEV Total Antibody Response
Day 22
|
2574.16 titers
Interval 1812.27 to 3656.35
|
14.92 titers
Interval 10.5 to 21.2
|
|
Geometric Mean Titer of Anti-VEEV Total Antibody Response
Day 29
|
2006.14 titers
Interval 1320.28 to 3048.31
|
16.94 titers
Interval 9.97 to 28.76
|
SECONDARY outcome
Timeframe: Day 22, 29Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
Evaluation of seroconversion rate of Anti-VEEV total antibody, as determined by immunoassay (ELISA), on Days 22 and 29, where seroconversion is a 4-fold rise in titer over baseline.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV
Day 22
|
86.7 percentage of participants
Interval 70.3 to 94.7
|
0 percentage of participants
Interval 0.0 to 11.4
|
|
Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV
Day 29
|
80.0 percentage of participants
Interval 62.7 to 90.5
|
0 percentage of participants
Interval 0.0 to 16.8
|
SECONDARY outcome
Timeframe: Days 1, 22, and 29Population: Immunogenicity evaluable population. 11 alphavirus naive participants were unable to attend their scheduled visit at Day 29.
Evaluation of Anti-VEEV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160, or 640 on Days 1, 22, and 29.
Outcome measures
| Measure |
Experimental: Prior Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 Participants
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants serve as controls.
|
|---|---|---|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=160
|
25 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=640
|
18 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=40
|
27 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=160
|
23 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 1 Titers >=640
|
16 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=40
|
27 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=160
|
24 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 22 Titers >=640
|
17 Participants
|
0 Participants
|
|
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Day 29 Titers >=40
|
27 Participants
|
0 Participants
|
Adverse Events
Experimental : Prior Alpha
Serious events: 0 serious events
Other events: 17 other events
Deaths: 0 deaths
Control: Naive Alpha
Serious events: 1 serious events
Other events: 17 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Experimental : Prior Alpha
n=30 participants at risk
All study participants received the same Investigational Product according to the same schedule. Subjects were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 participants at risk
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve subjects serves as controls.
|
|---|---|---|
|
Musculoskeletal and connective tissue disorders
Pain in extremity
|
0.00%
0/30 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
3.3%
1/30 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
Other adverse events
| Measure |
Experimental : Prior Alpha
n=30 participants at risk
All study participants received the same Investigational Product according to the same schedule. Subjects were prior recipients of experimental alphavirus vaccines.
|
Control: Naive Alpha
n=30 participants at risk
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve subjects serves as controls.
|
|---|---|---|
|
General disorders
Injection site pain
|
43.3%
13/30 • Number of events 13 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
30.0%
9/30 • Number of events 9 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
|
General disorders
Fatigue
|
10.0%
3/30 • Number of events 3 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
10.0%
3/30 • Number of events 3 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
|
General disorders
Malaise
|
10.0%
3/30 • Number of events 3 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
3.3%
1/30 • Number of events 1 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
|
Musculoskeletal and connective tissue disorders
Myalgia
|
13.3%
4/30 • Number of events 4 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
23.3%
7/30 • Number of events 7 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
|
Musculoskeletal and connective tissue disorders
Arthralgia
|
10.0%
3/30 • Number of events 3 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
10.0%
3/30 • Number of events 3 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
|
Nervous system disorders
Headache
|
23.3%
7/30 • Number of events 7 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
13.3%
4/30 • Number of events 4 • Local and systemic post-injection solicited events were collected through Day 8. Unsolicited adverse events were collected through Day 29. Serious adverse events and adverse events leading to withdrawal were collected through Day 183 end of study visit.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place