Trial Evaluating the Immunogenicity and Safety of an Adjuvanted Epstein-Barr Virus (EBV) Glycoprotein 350 Vaccine in EBV-seronegative Persons

Study Description:

This is a multisite randomized, double-blinded phase 1/2 study to evaluate the immunogenicity and safety of a 3-dose regimen of an adjuvanted EBV glycoprotein (gp) 350-Ferritin nanoparticle vaccine in EBV-seronegative persons. We hypothesize that the vaccine will be safe and induce a potent EBV gp350-specific immune response. Sixty EBV-seronegative participants will be randomized; 30 will receive the EBV gp350-Ferritin vaccine and 30 will receive the placebo at Days 0, 30, and between 60 and 90. Participants will be followed for 1 year after the third dose with an option to follow for a second year.

Primary Objective:

To evaluate the safety and immunogenicity of an adjuvanted EBV gp350-Ferritin vaccine administered to healthy EBV-seronegative adults.

Secondary Objectives:

• To evaluate the safety of the adjuvanted EBV gp350-Ferritin vaccine administered to EBV-seronegative adults up to 30 days after the third dose of study vaccine.
• To preliminarily evaluate the efficacy of the adjuvanted EBV gp350-Ferritin vaccine administered to EBV-seronegative adults.

Exploratory Objectives:

• To compare safety and immunogenicity of an accelerated 3-dose vaccination schedule (Days 0, 30, and 60 to 90) with the traditional

vaccination schedule evaluated in NCT04645147.

• To further evaluate the immunogenicity of the EBV gp350-Ferritin vaccine.

Primary Endpoint:

Change in mean EBV neutralizing antibody from Day 0 to 30 days after the third dose of study vaccine in EBV gp350-Ferritin vaccine recipients as compared with placebo.

Secondary Endpoints:

• Safety through 30 days after the third dose of the study vaccine:

• Solicited local and systemic reactions within 7 days after study vaccine administration.
• Unsolicited adverse events (AEs) through 30 days after the third dose of the study vaccine.
• Serious adverse events (SAEs) through 30 days after the third dose of the study vaccine.
• Reduction of viremia measured by quantitative polymerase chain reaction (qPCR) in EBV gp350-Ferritin vaccine recipients as compared with placebo in participants who become infected with EBV.
• Reduction of EBV infection as measured by new anti-EBV viral capsid antigen (VCA)-specific immunoglobulin (Ig) G or IgM or new EBV viremia for up to 2 years post-vaccination as compared with placebo.
• Reduction of EBV-related infectious mononucleosis as defined by signs and symptoms consistent with infectious mononucleosis with laboratory evidence for new EBV infection for up to 2 years post-vaccination as compared with placebo.
• Time to EBV infection as measured by new anti EBV VCA IgG or IgM or new EBV viremia.
• Time to infectious mononucleosis as defined by signs and symptoms consistent with infectious mononucleosis with laboratory evidence for new EBV infection.

Exploratory Endpoints:

• Change in mean EBV neutralizing antibody from Day 0 to 30 days after the third dose of vaccine in EBV-seronegative vaccine recipients in the standard dosing regimen (Days 0, 30, and 180) vs accelerated (Days 0, 30, and 60 to 90).
• Safety through 30 days after the third dose of study vaccine in the standard dosing regimen (Days 0, 30, and 180) vs accelerated (Days 0, 30, and 60 to 90).

• Solicited local and systemic reactions within 7 days after vaccination.
• Unsolicited AEs through 30 days after the third dose of study vaccine.
• SAEs through 30 days after the third dose of study vaccine.
• Increase in EBV gp350 IgG antibody in blood and/or EBV gp350 IgA antibody in saliva in vaccine recipients as compared with placebo.
• Increase in CD4+ T-cell response in study vaccine recipients from baseline (pre-vaccine) to 30 days after the third dose of vaccine as

compared with placebo in participants who become infected with EBV.

• INCLUSION CRITERIA:

To be eligible to participate in this study, an individual must meet all the following criteria:

• Aged 18 to 25 years.
• Able to provide informed consent.
• Willing to allow samples and data to be stored for future secondary research.
• Stated willingness to comply with all study procedures and availability for the duration of the active phase of the study (approximately 18 months).
• In good general health as evidenced by medical history, physical examination, and laboratory screening results.
• Willing to forgo receipt of a licensed, live vaccine in the 30 days before and 30 days after each dose of the study vaccine. Any FDA-approved or authorized inactivated and/or protein subunit, RNA, or DNA vaccine can be used >=14 days before or >=14 days after administration of the study vaccine.
• Hemoglobin within institutional normal limits, or if not, then assessed and deemed not clinically significant by PI or designee.
• White blood cell count and differential within institutional normal reference range, or if not, then deemed not clinically significant by PI or designee.
• Total lymphocyte count (lymphocyte absolute) >800 cells/microliters.
• Platelet count of 125,000 to 500,000/microliters.
• Alanine aminotransferase <1.25 x upper limit of normal.
• Participants who can get pregnant must agree to abstain from sexual activities that can result in pregnancy or use one of the following effective methods of contraception, starting 30 days before the first dose of study vaccine through 60 days after the third dose:

• Intrauterine device (IUD) or equivalent.
• Hormonal contraceptive (eg, consistent, timely, and continuous use of contraceptive pill, patch, ring, implant, or injection that has reached full efficacy before the first dose of study agent). If the participant uses a contraceptive pill, patch, or ring, then a barrier method (eg, internal/external condom, cervical cap, or diaphragm plus spermicide) must also be used at the time of potentially reproductive sexual activity.
• A hysterectomy and/or a bilateral tubal ligation or bilateral oophorectomy.
• Barrier method (eg, internal/external condom, cervical cap, or diaphragm) plus spermicide used correctly during sexual intercourse.
• A vasectomy in their monogamous sexual partner completed at least 6 months before the first dose of study vaccine.
• Continuous abstinence.

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this study:

• Pregnant or breastfeeding, or planning to become pregnant while participating through 60 days after the third dose of study vaccine.
• Has received any of the following:

• More than 10 days of systemic glucocorticoids (>=10 mg of prednisone or equivalent) within the 30 days prior to first dose of study agent.
• More than 10 days of systemic immunosuppressive medications, cytotoxic medications, or immunomodulating therapy within 180 days prior to first dose of study agent.
• Blood products, including immunoglobulins, within 120 days prior to first dose of study agent.
• Any live attenuated vaccination within 30 days prior to first dose of study agent.
• Investigational research agents within 30 days prior to first dose or planning to receive investigational products while on study.
• Allergy treatment with antigen injections, unless on a maintenance schedule of shots no more frequently than once per month.
• Has any of the following:

• Febrile illness within 14 days of the first dose of study agent.
• Body habitus such that identification of the deltoid muscle and/or administration of vaccine into the deltoid would be compromised or if body habitus would make study inclusion not in the best interest of the participant.
• History of serious reactions to vaccines.
• Hereditary, acquired, or idiopathic forms of angioedema.
• Idiopathic urticaria within the past year.
• Asthma that is not well-controlled or that required emergency care, urgent care, hospitalization, or intubation during the past 2 years, or that requires the use of oral or intravenous steroids.
• Diabetes mellitus type 1 or type 2, excluding a history of gestational diabetes.
• Clinically significant autoimmune disease or immunodeficiency.
• Bleeding disorder diagnosed by doctor (eg, factor deficiency, coagulopathy, or platelet disorder requiring special precautions).
• Significant bruising or bleeding difficulties with intramuscular injections or blood draws.
• Malignancy that is active or treated malignancy for which there is no reasonable assurance of sustained cure or malignancy that is likely to recur during the study period.
• Seizure disorder other than a history of 1) febrile seizures, 2) seizures secondary to alcohol withdrawal more than 3 years ago, or 3) seizures that have not required treatment within the past 3 years.
• Asplenia, functional asplenia, or any condition resulting in absence or removal of the spleen.
• History of Guillain-Barre Syndrome.
• Alcohol or drug abuse or addiction.
• HIV infection.
• Active hepatitis B or C infection.
• Documented EBV infection.
• Prior enrollment in an EBV vaccine clinical trial.
• Any medical, psychiatric, or social condition that, in the judgement of the investigator, is a contraindication to protocol participation or impairs the participant s ability to give informed consent.

Co-enrollment guidelines:

Co-enrollment in other studies is restricted, other than enrollment on observational studies. Consideration for co-enrollment in trials evaluating the use of a licensed medication will require the approval of the PI or sponsor medical monitor (SMM). Study staff should be notified of co-enrollment on any other protocol as it may require the approval of the PI or SMM.