Safety, Immunogenicity, and Efficacy of INO-4800 for COVID-19 in Adults at High Risk of SARS-CoV-2 Exposure

This is a Phase 2/3, randomized, placebo-controlled, multi-center trial to evaluate the safety, immunogenicity and efficacy of INO-4800 administered by intradermal (ID) injection followed by electroporation (EP) using CELLECTRA® 2000 device to prevent coronavirus disease 2019 (COVID-19) in participants at high risk of exposure to severe acute respiratory syndrome coronavirus - 2 (SARS-CoV-2).

The Phase 2 segment will evaluate immunogenicity and safety in approximately 400 participants at two dose levels across three age groups. Safety and immunogenicity information from the Phase 2 segment will be used to determine the dose level for the Phase 3 efficacy segment of the study involving approximately 7116 participants.


Eligibility Criteria:
Key Inclusion Criteria:

* Working or residing in an environment with high risk of exposure to SARS-CoV-2 for whom exposure may be relatively prolonged or for whom personal protective equipment (PPE) may be inconsistently used, especially in confined settings.
* Phase 2 only: Screening laboratory results within normal limits for testing laboratory or are deemed not clinically significant by the Investigator.
* Be post-menopausal or be surgically sterile or have a partner who is sterile or use medically effective contraception with a failure rate of \< 1% per year when used consistently and correctly from Screening until 3 months following last dose (Phase 2) or until last dose (Phase 3).

Key Exclusion Criteria:

* Acute febrile illness with temperature higher than or equal to 100.4°F (38.0°C) or acute onset of upper or lower respiratory tract symptoms (e.g., cough, shortness of breath, sore throat).
* Positive serologic or molecular (Reverse transcription polymerase chain reaction (RT-PCR)) test for SARS-CoV-2 at Screening (this criterion applies to all Phase 2 participants and only applies after approximately 402 participants positive for SARS-CoV-2 serologic test are randomized in the Phase 3 segment of the study).
* Pregnant or breastfeeding or intending to become pregnant or intending to father children within the projected duration of the trial starting from the Screening visit until 3 months following the last dose (Phase 2) or until last dose (Phase 3).
* Known history of uncontrolled human immunodeficiency virus (HIV) based on clusters of differentiation (CD4) count less than 200 cells per cubic millimeter (/mm\^3) or a detectable viral load within the past 3 months.
* Is currently participating or has participated in a study with an investigational product within 30 days preceding Day 0.
* Previous or planned receipt of an investigational (including Emergency Use Authorization (EUA) or local equivalent authorization) or licensed vaccine for prevention or treatment of COVID-19, middle east respiratory syndrome (MERS), or severe acute respiratory syndrome (SARS) (documented receipt of placebo in previous trial would be permissible for trial eligibility).
* Respiratory diseases (e.g., asthma, chronic obstructive pulmonary disease) requiring significant changes in therapy or hospitalization for worsening disease during the 6 weeks prior to enrolment.
* Immunosuppression as a result of underlying illness or treatment.
* Lack of acceptable sites available for ID injection and EP.
* Blood donation or transfusion within 1 month prior to Day 0.
* Reported alcohol or substance abuse or dependence, or illicit drug use (excluding marijuana use).
* Any illness or condition that in the opinion of the investigator may affect the safety of the participant or the evaluation of any study endpoint.