edible hepatitis b vaccine therapy in healthy participants who have undergone previous vaccination

Conditions: Healthy, no Evidence of Disease

Summary: rationale: hepatitis b antigen peptide (hbsag) vaccine may help the body build an immune response and help prevent hepatitis b. purpose: this clinical trial studies edible hbsag vaccine therapy in healthy participants who have undergone previous vaccination.

objectives: i. to evaluate the safety, tolerability, and immunogenicity of orally delivered hbsag that is formulated as an expressed protein in transgenic potato tubers (hbv-epv) at different doses and schedules. outline: patients are randomized to 1 of 4 treatment arms. arm i: participants consume placebo hbv-epv on days 0, 14, 28, and 56. arm ii: participants consume hbv-epv expressing hbsag on days 0 and 28 and placebo hbv-epv on days 14 and 56. arm iii: participants consume hbv-epv expressing hbsag on days 0, 28, and 56 and placebo hbv-epv on day 14. arm iv: participants consume hbv-epv expressing hbsag on days 0, 14, 28, and 56. after completion of study treatment, patients are followed up at days 70, 84, 98, and 114.

Eligibility criteria:
inclusion criteria: * all roswell park cancer institute (rpci) staff, faculty, and students, who are in good health * participants confirmation of history of primary immunization series with recombinant hepatitis b (hb) vaccine (last dose at least one year prior to screening anti-hbs level assessment) * current anti-hbs levels less than or equal to 115 miu/ml * major organ functions within acceptable medical limits as determined in routine clinical laboratory screening tests * expected availability for the duration of the study period * if female, then documentation that the subject is not pregnant by an acceptable laboratory test and that the subject is using an adequate birth control method to prevent pregnancy for at least 3 months following the last immunization in the study * human immunodeficiency virus (hiv) antibody negative * ability to provide written informed consent * supervisor approval exclusion criteria: * known history of allergy or hypersensitivity to potato, potato components or potato products * known history of allergy to hepatitis b vaccine in any form or to components of hepatitis b vaccine * pregnancy or breast feeding * current anti-hbs levels greater than 115 miu/ml * known immunodeficiency, cancer, or use of immunosuppressive medication including cancer chemotherapy and systemic steroids (excluding intermittent use of topical steroids) * participation in another investigational study within 30 days of enrollment in this study * known and currently active gastrointestinal disease including any of the following: peptic ulcer disease, gastroesophageal reflux, inflammatory bowel disease, diverticulitis, or pancreatitis * use of prescription medication or over the counter h2 blockers or proton pump inhibitors (ppis) for any of the above diseases regularly and within 1 month of enrollment * diagnosis of insulin-dependent diabetes or multiple sclerosis * significant laboratory abnormality which suggests dysfunction of hematological, renal, or hepatic systems * known history of hepatitis b infection in the past * temporary exclusion for mild upper respiratory illness, gastrointestinal illness, or other febrile episode that is expected and documented to resolve