INO-4201 as Booster in Healthy VSV-ZEBOV Vaccinees

This randomized placebo-controlled phase 1b trial will evaluate the safety, tolerability and immunogenicity of the DNA-based vaccine candidate INO-4201 in healthy adult volunteers who previously received a single injection of VSV-ZEBOV. These participants will be randomized to either INO-4201 or placebo, injected once intradermally (ID) followed by electroporation (EP) with the CELLECTRA2000 device. Volunteers will be observed for 1 hour after vaccination and will attend follow-up visits at the Clinical Trials Unit in the 24 weeks after injection (8 visits in all).

Primary outcome parameters are (i) the incidence of adverse events in relationship with INO-4201 from day 0 to 14, and (ii) geometric mean titers (GMT) of EBOV-GP-binding IgG antibodies at 4 weeks post-injection.

Inclusion criteria

• Has provided written informed consent prior to screening
• Males and females ≥ 18 years old
• Previously vaccinated with a single dose of VSV-ZEBOV at any dose between 10^5 and 10^8 pfu more than 6 months prior to inclusion
• Free of clinically significant health problems, as determined by pertinent medical history and clinical examination at study screening
• Has an acceptable site for ID electroporation considering the deltoid and anterolateral quadriceps muscles
• Is post-menopausal, or surgically sterile, or has a partner who is sterile, or uses a medically effective contraception with a failure rate of <1% per year when used consistently and correctly from screening until 6 months following last dose.

Exclusion criteria

• Female volunteers who are pregnant or breastfeeding at screening or prior to dosing
• Administration of an investigational compound either currently or within 30 days of Day 0
• Prisoner or volunteers who are compulsorily detained (involuntary incarceration) for treatment of either a physical or psychiatric illness
• Active drug or alcohol or substance abuse or dependence
• Planned administration of another Ebola vaccine (including rVSV-ZEBOV and Ad26/MVA-BN-Filo vaccines) during the study period
• Administration of a live vaccine in the 21 days or an inactivated vaccine in the 14 days before planned injection
• Current or anticipated concomitant immunosuppressive therapy (excluding inhaled, topical skin and/or eye drop-containing corticosteroids, or low-dose methotrexate). Systemic corticosteroids must be discontinued at least 4 weeks prior to first dose.

Temporary exclusion criteria:

• Acute disease at the time of randomization
• Active skin lesions at the potential injection site
• Temperature ≥38.0°C at the time of randomization
• Recent receipt of a SARS-CoV-2 vaccine with final dose <4 weeks prior