A Study of IVX-A12 in Adults Participants

Phase 2

Completed

• Conditions: Healthy Participants
• Interventions: Biological: IVX-A12; Biological: Licensed RSV Vaccine

• Registration Number: NCT06481579
• Lead Sponsor: Icosavax, Inc.

Brief Summary

The primary purpose of this study is to assess the immunogenicity and safety of IVX-A12 in adults 60 years of age and older.

Detailed Description

This is a randomized, modified double-blind, active controlled study to characterize the immunogenicity and safety of IVX-A12.

Approximately 140 participants will be randomized in a 1:1 ratio to receive IVX-A12 (approximately 70) or licensed respiratory syncytial virus (RSV) vaccine (approximately 70).

The study is planned to be conducted at approximately 5 sites in the United States. The duration of each participant's involvement in the study will be approximately 6 months following administration of study vaccination.

Study Timeline

• Study Start: 2024-06-10
• Study First Submitted: 2024-06-25
• Study First Submitted QC: 2024-06-25
• Study First Posted: 2024-07-01
• Primary Completion: 2024-07-17
• Study Completion: 2024-12-19
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-25
• Last Update Posted: 2025-04-27

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 143

Inclusion Criteria

1. Adults >=60 years of age at the time of signing informed consent.
2. Participants who are medically stable according to the judgment of the Investigator.
3. Able to understand and comply with study requirements/procedures based on the assessment of the Investigator.
4. Capable of giving signed informed consent.

Exclusion Criteria

1. Acute (time-limited) or febrile (temperature >=38.0 °C [100.4 ºF]) illness/infection within 3 days of planned dosing.
2. History of a clinically significant bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venipuncture.
3. History of hypersensitivity to any component of the study vaccination.
4. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (e.g., anaphylaxis).
5. Known or suspected congenital or acquired immunodeficiency.
6. Known or suspected autoimmune condition as determined by history and/or physical examination.
7. History of Guillain-Barré syndrome or any other demyelinating condition.
8. History of malignancy other than treated non-melanoma skin cancers or locally-treated cervical cancer in previous 5 years.
9. Any condition that may significantly increase the risk to the participant because of participation in the study, impact the participant's ability to participate in the study, or impair the interpretation of the study data.
10. Receipt of any licensed or investigational RSV and/or Human metapneumovirus (hMPV) vaccine any time prior to administration of study intervention.
11. Receipt of any licensed vaccine (other than licensed influenza or COVID-19 vaccines) within 28 days prior to or expected receipt within 28 days after administration of study intervention. Licensed influenza or COVID-19 vaccines are permitted beginning greater than (>)14 days prior to and >14 days after administration of study intervention.
12. Receipt of immunoglobulin or blood products within 3 months prior to administration of study intervention or expected receipt during the study.
13. Receipt of immune-modifying drugs or immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy within 6 months prior to enrollment (or expected receipt during study), or long-term systemic corticosteroid therapy (prednisolone or equivalent at a dose of >=20 mg daily or every other day for more than 2 consecutive weeks) within 6 months prior to study intervention or anticipated receipt during study.
14. Participation in another study or receiving interventional study investigational medicinal product (IMP), in the preceding 28 days or expected receipt of another study intervention (or participation in another study) during the period of study follow-up.
15. Employees of the Sponsor involved in planning, executing, supervising, or reviewing the IVX-A12 program, clinical study site staff, or any other individuals involved with the conduct of the study, or immediate family members of such individuals.
16. Alcohol or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion.
17. Deprived of freedom by an administrative or court order, or in emergency setting, or hospitalized involuntarily.
18. Judgment by the Investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions, and requirements.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
IVX-A12 Vaccine	IVX-A12	Participants will receive a single dose of IVX-A12, 300 micrograms (mcg), intramuscular (IM) injection on Day 1.
Licensed RSV Vaccine	Licensed RSV Vaccine	Participants will receive a single dose of licensed RSV vaccine IM injection on Day 1.

Primary Outcome Measures

Name	Time	Method
Number of Participants With Unsolicited Adverse Events (AEs)	Day 1 through 28 post-vaccination
Number of Participants With Serious Adverse Events (SAEs), Medically-attended Adverse Events (MAAEs), and Adverse Events of Special Interests (AESIs)	Through 6 months post-vaccination
Geometric Mean Fold Rise (GMFR) in RSV/A NAb Titers	From Day 0 (pre-vaccination) up to Day 29 post-vaccination	GMFR is defined as the geometric mean of the ratio of concentration of antibodies at specified timepoints after vaccination divided by concentration at baseline (Day 1).
Number of Participants With Immediate Unsolicited Adverse Events (AEs)	Day 1 within 30 minutes post-vaccination
Geometric Mean Titers (GMT) for RSV/A Neutralizing Antibodies (NAb)	Day 29	Geometric mean titer (GMT) is calculated as the anti-logarithm of sum of (log2 transformed titer)/n.
Number of Participants With Injection Site and Systemic Solicited Adverse reactions (ARs)	Day 1 through 7 post-vaccination

Trial Locations

Locations (5)

Icosavax Investigational Site US011; 🇺🇸 Lenexa, Kansas, United States

Icosavax Investigational Site US022; 🇺🇸 Anaheim, California, United States

Icosavax Investigational Site US021; 🇺🇸 Rolling Hills Estates, California, United States

Icosavax Investigational Site US002; 🇺🇸 Hollywood, Florida, United States

Icosavax Investigational Site US016; 🇺🇸 North Charleston, South Carolina, United States