Moderna study. Of phase 1 published

Interim analysis of original cohorts of Phase 1 study evaluated two-dose vaccination schedule of mRNA-1273 across three dose levels (25, 100, 250 µg) in 45 healthy adults ages 18-55 years; results reaffirm and expand upon positive interim data announced on May 18

Neutralizing antibody titers were observed in 100% of evaluated participants; at the 100 µg dose level selected for Phase 3, the geometric mean titers were above those seen in convalescent sera

Vaccination with mRNA-1273 elicited Th1-biased CD4 T cell responses

mRNA-1273 was generally safe and well-tolerated

Data support 30,000 participant Phase 3 study expected to begin on July 27

Conference call to be held on Wednesday, July 15 at 8:00 a.m. ET

Experimental: mRNA-1273

1. Number of Participants with a First Occurrence of COVID-19 Starting 14 days after Second Dose of mRNA-1273 or Placebo regardless of evidence of prior SARS-CoV-2 Infection [ Time Frame: Day 29 (second dose) up to Day 759 (2 years after second dose) ]
   Clinical signs indicative of COVID-19 and SARS-CoV-2 infection as predefined for the study.

nclusion Criteria:

• Participants who are at high risk of SARS-CoV-2 infection, defined as adults whose locations or circumstances put them at appreciable risk of exposure to SARS-CoV-2 and COVID-19.
• Understands and agrees to comply with the study procedures and provides written informed consent.
• Able to comply with study procedures based on the assessment of the Investigator.
• Female participants of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as surgically sterile (history of bilateral tubal ligation, bilateral oophorectomy, hysterectomy) or postmenopausal (defined as amenorrhea for =12 consecutive months prior to Screening without an alternative medical cause). A follicle-stimulating hormone (FSH) level may be measured at the discretion of the Investigator to confirm postmenopausal status.

• Female participants of childbearing potential may be enrolled in the study if the participant fulfills all the following criteria:

Exclusion Criteria:

• Is acutely ill or febrile 72 hours prior to or at Screening. Fever is defined as a body temperature =38.0°C/100.4°F. Participants meeting this criterion may be rescheduled within the relevant window periods. Afebrile participants with minor illnesses can be enrolled at the discretion of the Investigator.
• Is pregnant or breastfeeding.
• Known history of SARS-CoV-2 infection.
• Prior administration of an investigational coronavirus (SARS-CoV, Middle East Respiratory Syndrome [MERS]-CoV) vaccine or current/planned simultaneous participation in another interventional study to prevent or treat COVID-19.
• Demonstrated inability to comply with the study procedures.
• An immediate family member or household member of this study's personnel.
• History of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a vaccine.
• Bleeding disorder considered a contraindication to intramuscular injection or phlebotomy.
• Has received or plans to receive a vaccine within 28 days prior to the first dose (Day 1) or plans to receive a non-study vaccine within 28 days prior to or after any dose of investigational product (except for seasonal influenza vaccine).
• Has participated in an interventional clinical study within 28 days prior to the day of enrollment.
• Immunosuppressive or immunodeficient state, including human immunodeficiency virus (HIV) infection, asplenia, and recurrent severe infections.
• Has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to Screening (for corticosteroids =20 milligram (mg)/day of prednisone equivalent). Topical tacrolimus is allowed if not used within 14 days prior to Screening.
• Has received systemic immunoglobulins or blood products within 3 months prior to the day of Screening.
• Has donated =450 milliliters (mL) of blood products within 28 days prior to Screening.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04470427