A Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1647 Cytomegalovirus (CMV) Vaccine in Healthy Participants 16 to 40 Years of Age

JRCT ID: jRCT2031220459

Registered date:25/11/2022

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Prevention of primary CMV infection
• Date of first enrollment: 07/01/2023
• Target sample size: 400
• Countries of recruitment: Australia,Japan,Belgium,Japan,Canada,Japan,Estonia,Japan,Finland,Japan,France,Japan,Germany,Japan,Israel,Japan,Spain,Japan,United Kingdom,Japan,United States,Japan
• Study type: Interventional
• Intervention(s): Participants will be randomly assigned to receive a single injection of either mRNA-1647 vaccine at the selected dose or placebo in a 1:1 randomization ratio. Investigational product will be administered as a single IM injection into the muscle on Day 1. The injection will have a volume of 0.5 mL and contains mRNA-1647 or saline placebo.

Outcome(s)

Primary Outcome

Seroconversion From a Negative to a Positive Result for Serum Immunoglobulin G (IgG) Against Antigens not Encoded by mRNA-1647 [Time Frame: Day 197 (28 days after the third injection) up to Day 887 (24 months after the third injection)]

Number of Participants With Solicited Adverse Reactions (ARs) [Time Frame: Up to 176 days (7 days after each injection)]

Number of Participants With Unsolicited Adverse Events (AEs) [Time Frame: Up to 197 days (28 days after each injection)]

Number of Participants With Medically-Attended Adverse Events (MAAEs) [Time Frame: Day 1 through 6 months after the last injection (up to 347 days)]

Number of Participants With Adverse Event of Special Interests (AESIs) and Serious Adverse Events (SAEs) [Time Frame: Day 1 through end of study (up to Day 887)]

Key inclusion & exclusion criteria

• Age minimum: >= 16age old
• Age maximum: <= 40age old
• Gender: Female

Include criteria

Participants aged 20 years or over, has or anticipates having direct exposure within 7 months after the planned first dose (in the home, socially, or occupationally) to at least 1 child 5 years or under of age. Direct exposure is defined as either participant is the parent, or participant has close contact (feeding, diaper changes, childcare/supervision) for at least 8 hours per week.

CMV-seronegative Cohort is CMV-seronegative based on CMV testing at Screening.

CMV-seropositive Cohort is CMV-seropositive based on CMV testing at Screening.

Investigator assessment confirms that the participant (including in the case of an emancipated minor), or parent(s)/legally acceptable representative (LAR)(s), as applicable, understand and are willing and physically able to comply with protocol-mandated follow-up including all study visits and procedures anticipated during the 30 month study period.

Female participants: Urine pregnancy test is negative at Screening and negative on the day of the first injection (Day 1). If the participant is sexually active, has practiced adequate contraception for at least 28 days prior to the first injection (Day 1) and agrees to continue adequate contraception through 3 months following the third study injection (Month 9/Day 257).

Exclude criteria

History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures.

Received or plans to receive any nonstudy vaccine less than 28 days prior to and after any study injection; in addition, the following criteria for COVID-19 and influenza vaccines apply:

Any Coronavirus disease 2019 (COVID-19) vaccination series must have been completed a minimum 28 days prior to receiving any dose of the study injection.

COVID-19 vaccines (regardless of manufacturer) must be administered at least 28 days prior to or after any study injection.

Influenza vaccines may be administered more than 14 days prior to or after any study injection.

Received systemic immunosuppressants or immune-modifying drugs for more than 14 days in total within 6 months prior to the day of first injection (Day 1) (for corticosteroids, 5 milligrams (mg)/day or over of prednisone equivalent) or plans to do so during the course of the study. Inhaled, nasal, and topical steroids are allowed. Stable immunomodulator regimens used for managing environmental allergies are allowed.

Receipt of an antiviral with activity against CMV (ganciclovir, valganciclovir, foscarnet, cidofovir, letermovir, acyclovir, valacyclovir) less than 2 weeks prior to the day of first injection or plans to do so during the course of the study.

Previous receipt of an investigational CMV vaccine.

Receipt of systemic immunoglobulins or blood products less than 3 months prior to the day of first injection.

Participated in an interventional clinical study less than 28 days prior to the day of first injection (Day 1) or plans to do so while enrolled in this study.

Participant has donated 450 milliliters (mL) or over of blood products less than 28 days prior to Screening.

Participant is a member of study team or is an immediate family member or household member of study personnel.

Related Information

• Primary Sponsor: Tsutsui Toshio
• Secondary ID(s): NCT05085366,2020-006051-17