Trial Outcomes & Findings for A Study of IVX-A12 in Adults Participants (NCT NCT06481579)
NCT ID: NCT06481579
Last Updated: 2025-08-26
Results Overview
Model-adjusted GMCs and 95% CIs were derived using an ANCOVA model for log2 nAb responses at Day 29 with independent variables of study intervention, log2 baseline response, and age group. Measured values were calculated as the anti-logarithm transformation of the least square means and 95% CIs from the model.
COMPLETED
PHASE2
143 participants
At Day 29
2025-08-26
Participant Flow
Participants were recruited at 5 investigative sites in the United States.
A total 143 participants were enrolled and randomized to receive vaccinations in this study.
Participant milestones
| Measure |
IVX-A12
Participants received a single dose of 300 micrograms (mcg) IVX-A12, intramuscular (IM) injection on Day 1.
|
AREXVY
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Overall Study
STARTED
|
71
|
72
|
|
Overall Study
COMPLETED
|
66
|
71
|
|
Overall Study
NOT COMPLETED
|
5
|
1
|
Reasons for withdrawal
| Measure |
IVX-A12
Participants received a single dose of 300 micrograms (mcg) IVX-A12, intramuscular (IM) injection on Day 1.
|
AREXVY
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Overall Study
Death
|
1
|
0
|
|
Overall Study
Withdrawal by Subject
|
3
|
0
|
|
Overall Study
Other
|
1
|
1
|
Baseline Characteristics
A Study of IVX-A12 in Adults Participants
Baseline characteristics by cohort
| Measure |
IVX-A12
n=71 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
Total
n=143 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
66.8 years
STANDARD_DEVIATION 5.9 • n=5 Participants
|
66.6 years
STANDARD_DEVIATION 5.6 • n=7 Participants
|
66.7 years
STANDARD_DEVIATION 5.7 • n=5 Participants
|
|
Sex: Female, Male
Female
|
36 Participants
n=5 Participants
|
38 Participants
n=7 Participants
|
74 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
35 Participants
n=5 Participants
|
34 Participants
n=7 Participants
|
69 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
13 Participants
n=5 Participants
|
14 Participants
n=7 Participants
|
27 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
58 Participants
n=5 Participants
|
57 Participants
n=7 Participants
|
115 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
1 Participants
n=5 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Asian
|
2 Participants
n=5 Participants
|
2 Participants
n=7 Participants
|
4 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Black or African American
|
19 Participants
n=5 Participants
|
14 Participants
n=7 Participants
|
33 Participants
n=5 Participants
|
|
Race (NIH/OMB)
White
|
49 Participants
n=5 Participants
|
56 Participants
n=7 Participants
|
105 Participants
n=5 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
1 Participants
n=5 Participants
|
PRIMARY outcome
Timeframe: At Day 29Population: Immunogenicity analysis set (IAS) included all participants in the SAF who had no eligibility-related protocol deviations judged to have the potential to interfere with the generation or interpretation of an immune response. Here, "Overall Number of Participants Analyzed" signifies participants who were evaluable for this outcome measure.
Model-adjusted GMCs and 95% CIs were derived using an ANCOVA model for log2 nAb responses at Day 29 with independent variables of study intervention, log2 baseline response, and age group. Measured values were calculated as the anti-logarithm transformation of the least square means and 95% CIs from the model.
Outcome measures
| Measure |
IVX-A12
n=66 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=67 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Model-adjusted Geometric Mean Concentration (GMC) for RSV/A Neutralizing Antibodies (NAb)
|
5910.4 internation unit per milliliter (IU/mL)
Interval 4210.4 to 8296.8
|
10500.4 internation unit per milliliter (IU/mL)
Interval 7565.2 to 14574.3
|
PRIMARY outcome
Timeframe: From baseline up to Day 29Population: IAS included all participants in the SAF who had no eligibility-related protocol deviations judged to have the potential to interfere with the generation or interpretation of an immune response. Here, "Overall Number of Participants Analyzed" signifies participants who were evaluable for this outcome measure.
The GMFR was calculated as the anti-logarithm of Σ(log2 transformed (post-baseline response/baseline response)/n), where n is the number of participants with non-missing response information at baseline and at the post-baseline timepoint.
Outcome measures
| Measure |
IVX-A12
n=66 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=67 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Geometric Mean Fold Rise (GMFR) in RSV/A NAb Concentrations
|
3.4 fold rise
Interval 2.7 to 4.3
|
6.5 fold rise
Interval 5.0 to 8.5
|
PRIMARY outcome
Timeframe: Within the 30 minutes after vaccination on Day 1Population: The SAF included all randomized participants who received one dose of study intervention, irrespective of their protocol adherence and continued participation in the study.
Immediate AEs were defined as having an onset time within 30 minutes after study vaccination.
Outcome measures
| Measure |
IVX-A12
n=71 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Number of Participants With Immediate Unsolicited Adverse Events (AEs)
|
0 Participants
|
0 Participants
|
PRIMARY outcome
Timeframe: Day 1 through Day 8Population: The SAF included all randomized participants who received one dose of study intervention, irrespective of their protocol adherence and continued participation in the study.
The injection site solicited ARs included predefined injection site pain, injection site erythema/redness, and injection site swelling. The systemic solicited ARs included predefined fever, chills, headache, myalgia (muscle aches and pains), and fatigue (physical or mental tiredness).
Outcome measures
| Measure |
IVX-A12
n=71 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Number of Participants With Injection Site and Systemic Solicited Adverse Reactions (ARs)
Solicited injection site AR
|
14 Participants
|
31 Participants
|
|
Number of Participants With Injection Site and Systemic Solicited Adverse Reactions (ARs)
Solicited systemic AR
|
19 Participants
|
17 Participants
|
PRIMARY outcome
Timeframe: Day 1 through Day 29Population: The SAF included all randomized participants who received one dose of study intervention, irrespective of their protocol adherence and continued participation in the study.
The unsolicited AEs were any AE other than predefined solicited AEs.
Outcome measures
| Measure |
IVX-A12
n=71 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Number of Participants With Unsolicited Adverse Events (AEs)
|
5 Participants
|
11 Participants
|
PRIMARY outcome
Timeframe: Day 1 through Day 29Population: The SAF included all randomized participants who received one dose of study intervention, irrespective of their protocol adherence and continued participation in the study.
A SAE defined as an AE that occurred during any phase of study and met one or more of following criteria: resulted in death; was immediately life-threatening; required in-patient hospitalization or led to prolongation of existing hospitalization; resulted in persistent or significant disability or incapacity; was a congenital anomaly or birth defect; or was considered an important medical event that might have jeopardized the participant or required medical intervention to prevent one of aforementioned outcomes. MAAEs defined as AEs leading to medically-attended visits that were not routine visits for physical examination or vaccination, such as an emergency room visit, or an otherwise unscheduled visit to or from medical personnel (medical doctor) for any reason. An AESI was an event of scientific and medical interest, specific to further understanding of safety profile of investigational vaccine and required close monitoring and rapid communication by Investigators to the Sponsor.
Outcome measures
| Measure |
IVX-A12
n=71 Participants
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 Participants
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Number of Participants With Serious Adverse Events (SAEs), Medically-attended Adverse Events (MAAEs), and Adverse Events of Special Interests (AESIs)
SAEs
|
2 Participants
|
1 Participants
|
|
Number of Participants With Serious Adverse Events (SAEs), Medically-attended Adverse Events (MAAEs), and Adverse Events of Special Interests (AESIs)
MAAEs
|
1 Participants
|
9 Participants
|
|
Number of Participants With Serious Adverse Events (SAEs), Medically-attended Adverse Events (MAAEs), and Adverse Events of Special Interests (AESIs)
AESIs
|
0 Participants
|
0 Participants
|
Adverse Events
IVX-A12
AREXVY
Serious adverse events
| Measure |
IVX-A12
n=71 participants at risk
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 participants at risk
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Breast cancer
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Cardiac disorders
Cardiac disorder
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
0.00%
0/72 • Day 1 through Day 181
|
|
Gastrointestinal disorders
Small intestinal obstruction
|
1.4%
1/71 • Number of events 3 • Day 1 through Day 181
|
0.00%
0/72 • Day 1 through Day 181
|
Other adverse events
| Measure |
IVX-A12
n=71 participants at risk
Participants received a single dose of 300 mcg IVX-A12, IM injection on Day 1.
|
AREXVY
n=72 participants at risk
Participants received a single dose of 120 mcg AREXVY, IM injection on Day 1.
|
|---|---|---|
|
Infections and infestations
COVID-19
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Infections and infestations
Upper respiratory tract infection
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
4.2%
3/72 • Number of events 3 • Day 1 through Day 181
|
|
Metabolism and nutrition disorders
Type 2 diabetes mellitus
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Respiratory, thoracic and mediastinal disorders
Cough
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Respiratory, thoracic and mediastinal disorders
Rhinorrhoea
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Gastrointestinal disorders
Abdominal wall haematoma
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
0.00%
0/72 • Day 1 through Day 181
|
|
Gastrointestinal disorders
Diarrhoea
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Skin and subcutaneous tissue disorders
Dermal cyst
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Skin and subcutaneous tissue disorders
Rash
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
0.00%
0/72 • Day 1 through Day 181
|
|
Musculoskeletal and connective tissue disorders
Arthralgia
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Musculoskeletal and connective tissue disorders
Pain in extremity
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
General disorders
Injection site bruising
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
General disorders
Injection site pruritus
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
General disorders
Peripheral swelling
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 2 • Day 1 through Day 181
|
|
General disorders
Pyrexia
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Injury, poisoning and procedural complications
Arthropod bite
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
|
Injury, poisoning and procedural complications
Incisional hernia
|
1.4%
1/71 • Number of events 1 • Day 1 through Day 181
|
0.00%
0/72 • Day 1 through Day 181
|
|
Injury, poisoning and procedural complications
Ligament sprain
|
0.00%
0/71 • Day 1 through Day 181
|
1.4%
1/72 • Number of events 1 • Day 1 through Day 181
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place